Census Techniques in Ecology

Transcription

Census Techniques in Ecology
Methoden in der Ökologie
LV# 444-561
Protocol
Soil Fauna
Soil Field Techniques
Stream Ecology - I
Stream Ecology - II
(Census of Flora)
Census of Fauna
Microclimate
Bioindicators
Teilprotokolle
1/8
2/8
3/8
4/8
5/8
6/8
7/8
8/8
(Erfassung der Bodenfauna))
(Bodenkundliche Felmethoden)
(Fliessgewässeruntersuchung -I)
(Fliessgewässeruntersuchung - II)
Erfassung der Pflanzenwelt
(Erfassung der Tierwelt)
Kleinklimamessung
(Bioindikatoren)
October 6th 1997
till
October 13th 1997
Handed in by:
Pierre Madl (Mat-#: 9521584)
and
Maricela Yip (Mat-#: 9424495)
Salzburg, 31st October 1997
biophysics.sbg.ac.at/home.htm
References:
Protocol
Title of References
1/8
• F. Schinner / R. Öhlinger / Ekandeler / R. Margesin Methods in Soil Biology Springer Verlag
- 1995 - FRG
• W. J. Sutherland Ecological Census techniques Cambridge University Press 1996 - New York
2/8
• W. J. Sutherland Ecological Census techniques Cambridge University Press New York 1996 USA
• E. Schlichting, H.P Blume, K. Stahr Bodenkundliches Praktikum Blackwell Science Berlin
1995 - FRG
• N.D. Gordon, T.A. McMahon, B.L. Finlayson Stream Hydrology John Wiley & Sons Melbourne 1992 - AUS
• J.D. Allan Stream Ecology Chapman & Hall - Michigan 1995 - USA
• D. Meyer Makroskopisch-bioligische Feldmethoden ALG Hannover 1990 - FRG
• Wetzel Robert G., Likens Gene E. Limnological Analyses, 2nd Edition, Springer-Verlag 1991
• H.B.N. Hynes The Ecology of Running Waters Liverpool Univ. Press 1970 - UK
• N.D. Gordon, T.A. McMahon, B.L. Finlayson Stream Ecology John Wiley & Sons Melbourne 1992 - AUS
• J.D. Allan Stream Ecology Chapman & Hall - Michigan 1995 - USA
• W. J. Sutherland Ecological Census techniques Cambridge University Press New York 1996 USA
• W. J. Sutherland Ecological Census techniques Cambridge University Press 1996 New York USA
• H. Janetschek Ökologische Feldmethoden Verlag Eugen Ulmer Stuttgart 1982 – FRG
• M. Mühlbenberg Freilandökologie Quelle und Meyer Verlag Heidelberg 1989 - FRG
• F. Schinner / R. Öhlinger / Ekandeler / R. Margesin Methods in Soil Biology Springer Verlag
- 1995 - FRG
• H. Janetschek Ökologische Feldmethoden Verlag Eugen Ulmer Stuttgart 1982 - FRG
• W. J. Sutherland Ecological Census techniques Cambridge University Press 1996 - New York
• H. Janetschek Ökologische Feldmethoden Verlag Eugen Ulmer Stuttgart 1982 – FRG
• H.H. Kreeb Pflanzenökologie und Bioindikation Gustav Fischer Verlag Stuttgart 1990 - FRG
• Schubert Bioindikatoren
• H.J. Jäger, L. Steubing Monitoring of air pollutants by plants Junk Publishers The Hague
1982 - NL
• I.F. Spellerberg Monitoring Ecological Change Cambridge University Press 1991 – UK
• D.W. Jeffrey, B. Madden Bioindicators and Environmental Management Academic Press
London 1991 - UK
• S.Ellisa, A. Mellor Soils and Environment Routiedge Publ. London 1995 - UK
3/8
4/8
5/8
6/8
7/8
8/8
Methods in Ecology
Sub-Protocol 1/8
1
Methods in Ecology
(Methoden in der Ökologie)
Soil Fauna
(Erfassung der Bodenfauna)
Protocol - 1/8
October 6th 1997
Instructors: Dr. W. Foissner
Mag. A. Leitner
Handed in by:
Salzburg, in the month of October 1997
Soil Fauna
Methods in Ecology
Sub-Protocol 1/8
2
Soil Fauna
Introduction: The biosphere represents the fauna and flora which live above, at and below the Earth’s surface,
along with organic material which is no longer alive.
Because soil contains rock material, water, air and biota, it is the interface at which all the environmental
components interact and is the most complex medium within environmental systems, both influencing and
responding to their operation. The geosphere determines the parent material from which a soil develops, the
hydrosphere determines the presence of water which is vital for the operation of many of the processes of soil
formation. The atmosphere determines the climatic conditions which influence their rate of operation, and the
biosphere determines which fauna and flora are available for participation in these processes.
The use of soil provides information about past environmental conditions has been developed in more recent
decades through a number of disciplines.
The soil contains a rich variety of animals of very different sizes and life forms. The most abundant groups are
the Protozoa, Nematoda, Annelida, and Arthropoda.
These microorganisms are involved in the shredding and decomposition of organic compounds to make
them available for reabsorbtion of sessile organisms like plants. Digging and burrowing animals help to
increase the pore volume and improve aeration as well as mixing of the soil.
Grouped on a nutritional bases, animals are collectively categorized as
• phytotrophic (feeding on living plants),
• zootrophic (feeding on animal matter),
• microtrophic (living on microroganisms), and
• saprotrophic (utilizing dead organic matter).
Since soil zoological investigations require adequate methods, the precise identification of the animals
collected is of essential importance.
Based on the size of the organism, this soil organisms are grouped into micro-, meso-, and macrofauna.
• The microfauna utilizes pores with a diameter of less than 100[µm];
It consists of microscopically small eukaryotic, single-celled protozoans (amoebae, ciliates and
flagellates) and multicellular organism (rotifers, tardigrades, nematodes): together these phyla of
animals consume considerable amounts of bacteria, fungi, and debris. Protozoans and Nematodas
alone require approx. 103 to 105 bacteria each per cell division to maintain their daily metabolism.
Therefore, being in direct contact to the surrounding environment due to their delicate external
membranes these organisms can adapt quickly to changes in environmental patterns. Consequently,
members of the microfauna are a really cosmopolitan group of organisms.
• The mesofauna (Acari, Collembola, Enchytraeidae) occurs predominantly in the larger pore space,
i.e.: macropores of <2[mm]. Most member of these phyla (mites, springtails, potworms) feed on
substrate like plant litter, fungi, mineral particles, or feces from other soil animas. As with the
organisms of the microfauna, the member of this category are highly adaptable as well; they are found
in moist mineral soils to deciduous litter; i.e.: approx.: 105 [individuals/m2].
• The macrofauna (Oligochates, Chilopoda, Diplopoda, Diptera, Coleoptera) utilize existing cracks and
root canals, as well as, dig and burrow actively; they contribute considerably to the loosening and
aeration of the soil. The distribution of earthworms, for instance, is strongly dependent on their
surroundings like water content, soil type, vegetation and pH. In addition, their respective digging
habits splits them into litter dwellers, horizontal burrowers, and deep (vertical) burrowers. Due to their
size, earthworms contribute a large fraction of the biomass in loamy meadows.
Predators like centipedes depend highly on atmospheric humidity, therefore, they vary in numbers
depending upon the soil structure; e.g.: as many as 300 [individuals/m2] can be found in leaf litter of
deciduous forests. Millipedes support the activity of earthworms and are found in almost all types of
soil (excluding very acidic sites). They are primary decomposers of great soil-biological importance.
Flies contribute heavily to the turnover in the soil. They are not only decomposers, but they are also
great predators and can reach up to 2000 [individuals/m2]. Beetles occur in all strata and trophic
levels. The smaller forms occur in the upper soil layers; among them are found fungivores, omnivores
and predators alike.
The microflora (prokaryota, autotrophic flagellates, diatoms, etc.) and macroflora (plants and fungi in
general) are not treated in this protocol.
The following pages list some simple procedures used during the course.
Methods in Ecology
Sub-Protocol 1/8
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Soil Fauna
Sampling Organisms of the Macrofauna (Earthworms): The estimation of earthworm abundance is difficult
due to the heterogeneous moisture distribution of the soil and their special lifestyle. To obtain a
representative result, at least a couple of probes should be taken with either method.
• A simple but not very reliable way to extract and count
earthworms is the electrical method. A weak voltage (12V) Materials used:
procedure not executed
is applied on a chosen area. The electrodes, arranged in a
circle force the earthworms to abandon their dark
environment and to emerge the surface. The effectiveness
of this procedure is highly dependent upon soil water content.
• Handsorting is the most efficient procedure. A given area of
0.25 [m2] is sorted out by extracting a layer, approx. 20
[cm] deep. The top grass layer should be carefully
separated to avoid further damage; crumble the soil,
remove the earthworms found into a container, rinse, count,
weigh, and return them back to the soil. Close the
excavation site, and try to put the soil layers back as they
were previously.
Materials used:
i) frame covering 0.25
[m2]
i) spade
i) digital balance
• The chemical extraction by using a diluted formalin solution is easier, Although both horizontal and
vertical burrowing earthworms are affected, only the
vertical burrowers will be counted. This technique gives an Materials used:
i) frame covering ¼ [m2]
estimate of the individuals living underneath. Formalin used
i) formalin bottle
in such diluted quantities will not kill the earthworms, but
200 [mL] volumetric flask
will make the soil unpleasant for their normal activities.
i) bucket of water 5[L]
Deep dwelling borrowers, avoiding such a disturbance, will
i) digital balance
emerge to the surface. Depending on the water content of
the soil, about 5 to 10 [l] of a 0.2 to 0.4 [%] formalin
solution is used. Pour 1/3 of the solution onto the sampling area of about 0.25 [m2] in repeated
intervals of 10 [min].
Remarks: Because of the toxicity of formalin, protection gloves and glasses should be used when
handling this solution in concentrated form.
Results of Formalin and Handsorting techniques (¼ m2 for each group):
Lawn
Meadow
Group Formalin-Solution
Handsorting
Formalin-Solution
Handsorting
#
Total mass [g]
#
Total mass [g]
#
Total mass [g]
#
Total mass [g]
I
II
III
IV
Comments:
Methods in Ecology
Sub-Protocol 1/8
4
Soil Fauna
Sampling Organisms of the Mesofauna:
Separation of invertebrates from soil, litter, and other debris can be achieved with a Tullgren funnel.
The soil sample s filled into the funnel; the tungsten lamp
Materials used:
creates a warm, dry, and well illuminated condition at the top
i) funnel
of the funnel, which encourages cool-, shaded-, and moisturei) gaze-filter
loving invertebrates to move down the funnel through a filter,
i) beaker
into a collecting bottle. If live specimens are required then a
i) formalin flask
lightly moistened piece of filter paper should be placed in the
i) bucket
collecting container. Funnels are usually left in operation for a
i) spade or shovel
week or so, and if life specimens are being collected, they
i) lighting source or other
should be checked daily.
The Berlese funnel is a slightly altered apparatus, in which hot
water is passed through an outer extra cage instead of a electrical light source, causing the same effect
described above.
Remarks: The use of desiccation funnels is not labor-intensive, since sorting can be left unattended. But
small and inconspicuous invertebrates are likely to be missed during sieving. Larger funnels tend
to extract relatively more larger invertebrates than smaller ones, since smaller invertebrates may
become desiccated within the larger funnel before they reach the collecting tube.
A Tullgren funnel for separating small invertebrates from soil, litter, etc.,
Methods in Ecology
Sub-Protocol 2/8
1
Methods in Ecology
(Bodenkundliche Feldmethoden)
Protocol - 2/8
13th of October 1997
Instructor: Dr. T. Peer
Handed in by:
Methods in Ecology
Sub-Protocol 2/8
2
Introduction
The soil is weathered mineral material at the Earth’s surface, which may or may not contain organic matter, and often
also contains air and water. It may range in thickness from a few millimeters to many meters, and it is present over most
of the Earth’s land surface.
Soils are complex, multivariate medium which plays an important role in all environmental disciplines. As a result, it is
necessary to understand the way in which they vary spatially and how their characteristics are suited to various forms of
environmental investigation and utilization. Soils have been recognized since history through its influence on
agriculture, drainage and human settlement.
Materials used:
Before we do any soil survey:
soil corer,
• It is necessary to know the purpose of the survey.
spade
• Required permission of authorities.
saw
• What information will be recorded and needed.
hatchet
• How much detail is required.
bucket
yardstick (metric gauge)
• What scale will the survey operate.
plastic bags
• How much time and what resources are available for the survey.
cold box
• Finally, all the information gathered from the soil must be related to
geological-, vegetation-,
the purpose of the survey.
aerial-, topographical map
flask of 0.01 [M] HCl,
Soil Sampling
mobile pH-meter,
A homogeneous representative number soil samples are taken from the
area under investigation and combined to a bulk sample, the
characteristics require are: soil texture, topography, soil depth, soil
heaviness, presence of rocks/stones, moisture conditions.
Orientation of the site of interest should be well illuminated (sunny side) and easily accessible.
Best time to do sample is in spring before the beginning of the vegetation period, fertilization and plant growth do not
have much influence at this time.
Soil horizons
Soils often comprise a series of layers aligned
roughly parallel with the surface, and the combined,
vertical sequence of horizons are known as a
profile. The number of horizons vary between
profiles, they mostly have three basic horizons
(A,B,C). different horizon combinations giving rise
to different soil types. Profiles of the other soil
types are usually a few centimeters or meters deep.
• The uppermost layer (A) contains organic
matter, mixed with mineral material.
• The underlying (B) is usually a more mineral
rich zone, into which material is often moved,
vertically or laterally, from elsewhere in the soil.
Combination of (A-B) is a solum.
• The deeper layer (C) represents the little
altered form of the material from which the soil
derives, known as the parent material.
• The underlying bedrock (D or R) are the soils
that may occur as a geologically recent,
superficial deposit, having been laid down by a
river, a glacier, the wind, or the sea.
A soil profile and pedon, showing soil horizons;
The profile is a 2-D unit, while the pedon shows characteristics in 3D
When doing the excavation, separate the various layers into piles. To minimize disturbance after the survey, return the
layers in the way they were previously.
Methods in Ecology
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Soil formation
The process by which soils form can be divided into four groups:
• Addition of material, both organic and inorganic, to the soil.
• Transformation of this material via organic matter decomposition, weathering and clay mineral formations.
• They are transfer within the soil by water or by mechanical means,
• and it is loss from the soil via either the surface or subsurface.
Phases
The soil is composed of three phases:
• Solid phase, both mineral and organic material; the liquid and gas phases are in-between pores or voids.
• Liquid component is the soil water, derived from precipitation, and ground water sources.
• Gaseous component is the soil atmosphere or soil air, consist of a mixture of gases derived from the above-ground
atmosphere and from the respiration of soil organisms.
The major soil-forming processes
Methods in Ecology
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Soil constituents
Mineral: The mineral fraction of soils is derived largely from weathering of the underlying parent material, which my
consist of consolidated bedrock (igneous-from molted magma, sedimentary-from erosion and weathering cycles or
metamorphic-from alterations due temperature/pressure) or unconsolidated superficial deposits (a variable of solid
bedrock materials and are often classified as depositional environment).
Organic components: Soil organic matter is derived from different sources such as plant litter: which consists of plant
debris, leaves, stems, flowers, twigs, bark, branches of trees, etc.
Other organic components are plant roots, root exudates, soil organisms, fecal remains, metabolites, etc. which are
washed into the soil.
Soil organisms can be producers (plants), consumers (animals), decomposers (returning material to the soil), autotrophs
and heterotrophs.
They can be also classified according to their size: microorganisms (<200 micrometer)-fauna and flora, mesofauna (2001000 micrometer) and macrofauna (>1000 micrometer)
Water: Soil water is derived from two principal sources-precipitation and ground water.
Precipitation: rain, snow, hail fog, and mist. The proportion of precipitation that reaches the ground surface depends
largely on the nature and density of vegetation cover. On surfaces devoid of vegetation, precipitation reaches the soil
directly. On reaching the surface, water can either infiltrate the soil or, run off over the surface, and evaporate.
The composition of soil water is a particularly dynamic characteristic, varying over periods of time. This behavior arises
from the intimate association between the water, small mineral and organic particles (clay and humus) and plant roots,
which can involve the exchange of ions between these components. Soil water contains a number of dissolved solid and
gaseous constituents, many of which exists in mobile ionic form, and a variety of suspended solid components. Basic
cations (Ca2+, Mg2+, K+, Na+, NH4+) may be derived from a number of sources.
Color: There other dissolved components in the soil usually minor and local in their occurrence. These include organic
material and silica, together with a number of pollutants such as heavy metals (lead, zinc, cadmium) and radionuclides
(cesium).
Soil water contains not only dissolved solids but also a number of suspended constituents. These include small particles
of mineral and organic material, which often results in discoloration and increased turbidity of soil water. Similarly,
precipitates may accumulate in soil water, as a result of chemical changes as the water migrates through the soil.
Air: Water has a reciprocal arrangement in terms of
their occupancy of soil pore space, in saturated
soils, air content is low, whereas in dry soils the
pore spaces are largely air-filled. Changes in water
and air content are particularly dynamic because
much of the water present in a saturated soil drains
away rapidly, while heavy rainfall can quickly bring
the soil back to saturation. The gaseous constituents
of soil air are derived largely from the atmosphere,
the respiration and metabolism of soil organisms,
and from the evaporation of soil moisture. Soil air
is continuos with the atmosphere provided that the
soil surface is not sealed due to compacting or
crusting, and such continuity ensures the free
movement and exchange of gases. In addition to
CO2, organisms release other gases into the soil,
including (CH4, H2) as a result of organic matter
decomposition.
Composition by volume of a typical topsoil
Methods in Ecology
Sub-Protocol 2/8
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Soil physical properties
Mineral particles
The principal properties of soil mineral particles in an environmental context are their size, shape, nature of surface,
orientation and mineralogy. The mineration fractions consists of particles of different sizes such as larger ones, cobbles
and pebbles, sand, silt and clay (2mm in diameter). Most studies of soil is concerned with the (<2 mm) range and is
called fine earth. It is the proportion by weight of the size categories within the fine fraction which defines the particle
size distribution or texture of a soil. Most soils comprise a continuos spectrum of particle sizes, and the width of this
spectrum is defined by the degree of sorting.
Texture
Can be estimated in the field simply by rubbing the soil between thumb and forefinger. Sand grains are easily
distinguished by their coarseness, while silt has a distinctive soapy feel and clay is characteristically plastic and
moldable when moist. In order to analyze the soil in more detail, it is required laboratory analyzes such as the a Coulter
Counter or laser diffractometer, a scanning electron microscope, which allows the particle sizes to be viewed in 3dimentions. Minerals differ markedly in their composition such as physical and chemical characteristics: texture, acidity,
and nutrient status.
Aggregates
Aggregation in soils is promoted by a number of physical, chemical and biotic forces. Physical forces: expansion,
shrinkage associated with wetting and drying, compaction by raindrop impact, animal trampling and agricultural
machinery. Chemical forces: electrostatic, presence of adsorbed cations in association with the negative surface charge
of colloidal particles such as clay and humus. Aggregates or peds, which persists during wetting/drying and
freezing/thawing cycles form the basis of soil structure.
Pore space
Vary in shape from spherical voids to tortuous, interconnecting cracks and channels. They also vary in size from large
macropores to fine micropores (<1 [µm]). Pore space will influence both the bulk density and the porosity of a soil.
Porosity is a measure of the percentage volume of the pore space, and can be determined indirectly from particle and
bulk density. Porosity and pore size distribution are influenced by a number of soil characteristics: texture, degree of
aggregation, bulk density, presence of swelling clays and organic content.
Moisture
Soil water possesses free energy which is a measure of its potential for movement and change in the soil. In soils with a
high moisture content, forces attracting the water to solid particles are weak and its free energy is high.
Moisture is affected by: adsorption, water is attracted to the surfaces of colloids by electrostatic forces. Capillarity,
water is held in soil pores by adsorptive forces at the water surface. Matric suction, combination of capillarity and
adsorption. Osmosis, occur between solutions of different ionic concentrations.
Several methods are available to measure soil moisture: it can be determined gravimetrically using bulk samples which
requires weighing, field-moist, oven-drying, etc. the weight differences representing the moisture content, expressed as a
percentage of either filed-moist or oven-dried soil.
Temperature
Soil temperature is a dynamic property because it varies between day and night, seasonally, it can be rapid and extreme.
It is also influence by: texture, moisture and organic content.
Mechanics
Soil mechanics properties are strength/stability: derived from interparticle and interped forces responsible for the
development of soil structure. For stability: survival during wetting, breakdown or slaking, resistance to compression,
and shear-indication for cohesion; for strength: related to soil properties, texture, organic content bulk density and
moisture content. and consistence of the soil.
Color
Is determined in the field, and provides useful information regarding the presence or absence of soil constituents. For
example: dark colors are usually indicative of high organic, manganese, moisture content, while red colors is for soil
rich in iron oxides, blue-gray colors indicate the presence of iron in its reduced form.
The Munsell color notation has three components:
• Hue-indicates major color present.
• Value-measures the degree of darkness or lightness of the color.
• Chroma-measure of color intensity.
Methods in Ecology
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Interrelationship between selected soil properties
Soil Chemical Properties
Elements and compounds in a soil occur in two principal forms – as the chemicals that make up the structure of the basic
soil constituents, and as individual components which are held in the soil by interparticle attraction.
The chemical that make up the structure of mineral material are determined by total chemical analysis, i.e. by atomic
absorption spectrometry following dissolution of the material in strong acids. Or by the more rapid method of X-ray
fluorescence spectrometry.
Ion exchange: Is the most important soil property in that it plays a key role in plant nutrition, and in a broader context,
in the development of many chemical characteristics of soils. Central to ion exchange is the way in which ions are held
on the surfaces of colloidal particles.
Acidity and pH: Acids in aqueous solutions undergo dissociation to release their constituent ions, namely (H+). Acidity
is measured in terms of (H+) ion concentration using the pH scale.
Soil water in equilibrium with atmospheric CO2 (dissolved in precipitation)and from the soil air where it is a product of
soil organisms respiration and decay, pH can sink below 5.0 because CO2 levels in soil air are greater than in the
atmosphere: CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3H+ is also released by plants in exchange for nutrient base cations, and part of nitrification in which NH4+ is converted to
NH3. The measurement of soil pH is usually made in a standard suspension of 1:2.5 weight to volume (e.g. 110 g of soil
in 25 ml distilled water). Distilled water is often used to make up the suspension, a suspension made with a dilute
solution of calcium chloride (0.01M) in order to provide a more realistic value of H+ concentration minimizes Ca release
from the soil exchange complex. For this reason pH levels measured in CaCl suspension are generally lower than those
recorded in a suspension made up with distilled water. Soil acidity promotes the development of further acidity through
aluminum hydrolysis, and this becomes an important source of H+ ions when soils become acidic. pH < 5.5, Al3+ ions
begin to occupy exchange sites.
Unpolluted rain water in equilibrium with atmospheric CO2 has a pH = 5.6
Aeration
Soil aeration relates to the amount of oxygen present in the soil atmosphere. A particularly useful indicator of degree of
soil aeration is the redox potential (Eh) or oxidation-reduction status, a chemical species undergoes oxidation or
reduction through the transfer of electrons (e-).
Methods in Ecology
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Methods in Ecology
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8
No.:
Date:
Investigator:
NOTE SHEET
for the Soil-Field-Research
Location:
Altitude [m]:
Landscape, landsurface:
Geology (parent material):
Vegetation:
Climate / weather:
Soil hydrology:
Human or animal influence:
Disturbances:
Soil type:
Horizon-sequence
Tickness [cm]
Boundaries
Moisture
Color
Organic matter
Texture
Structure
Porosity
Consistence
Larger separates
Coatings
Spots / patches
Root development
Carbonates
pH-Value
Biology:
Development:
Risks:
Soil-stability:
Protection:
Other remarks:
Exposition:
Inclination:
Methods in Ecology
Sub-Protocol 3/8
1
Methods in Ecology
Stream Ecology I
(Fliessgewässeruntersuchung - I)
Protocol - 3/8
6th of October 1997
Instructors: Dr. W. Foissner
Mag. A. Leitner
Handed in by:
Stream Ecology - I
Methods in Ecology
Sub-Protocol 3/8
2
Stream Ecology - I
Introduction: Since soil contains rock material, water, air and biota, it is the interface at which all the
environmental components interact and is the most complex medium within environmental systems, both
influencing and responding to their operation. The geosphere determines the parent material from which a soil
develops, the hydrosphere determines the presence of water which is vital for the operation of many of the
processes of soil formation. The atmosphere determines the climatic conditions which influence their rate of
operation, and the biosphere determines which fauna and flora are available for participation in these processes.
The hydrosphere (mainly hydrogen and Oxygen) are the many forms in which water can occur at and below the
Earth’s surface as seen with lakes, rivers, oceans, ground water, etc.
Substrate is a complex aspect of the hydrosphere. Current, together with available parent material, determines a
mineral substrate composition of a fresh water system. Organic detritus is found in conjunction with mineral
material, and can strongly influence the organism’s response to substrate. This includes everything on the bottom
or sides of streams or projecting out into the stream, not excluding a variety of human artifacts and debris, on
which organisms reside, it is very heterogeneous.
Slower currents, imply finer substrate particle size often correlated with lower oxygen content. The size and
amount of organic matter, which affects algae and microbial growth, vary with the substrate. Substrate itself is
highly variable from place to place, exhibiting small-scale patchiness both vertical and horizontally within the
stream bed, and changing over time in response to fluctuations in flow.
Inorganic substrate includes bed materials of many streams ranging from clays and silts to boulders and bedrock.
Organic substrate in general consist of very small organic particles (<1 mm) and usually serve as food rather than
as substrate to which other organisms attach, except perhaps for the smallest invertebrates and microorganisms.
Larger ones range from mosses, plant stems to submerged logs, generally functions as substrate rather than food.
In autumn-shed-leaves on the stream bed are a substrate to insects that graze algae from their surfaces, and food
to insects that eat the leaves themselves. More commonly, are large organic substrates that serve as perches from
which to capture food items transported in the water column, as sites where fine detrital material accumulates,
and as surfaces for algae growth.
Autumn-shed-leaves are a significant feature of woodland streams during at least part of the year. Aggregations
of leaves on the stream bottom usually support the greatest diversity and abundance of invertebrates. Mosses and
some other plants that are macroscopic but relatively small maintain very high local densities of animals without
themselves serving of food. Plants serve as a refuge, and a trap for silt and organic matter, but provide little or
not direct nourishment. Submerged wood is yet another category of organic substrate,
Clearly these are not amenable to the statistical averaging one does with mineral substrates.
Benthic Organisms of the substrate
The great majority of steam-dwelling macroinvertebrates live in close association with the substrate, and so they
have been the main focus of organisms-substrate studies. Many taxa show some degree of substrate
specialization. When one examines preferences among stones of various sizes, substrate specialization. Some
stream-dwelling organisms are quite restricted in the conditions they occupy, and biologists have a number of
terms to describe these substrate specialists.
Lithophilous taxa are those found in association with stony substrates. Streambeds of gravel, cobble and
boulders occur in a great many areas around the world, harboring a diverse fauna. Many specialists are
equally common on stones of all sizes, some are demonstrably more likely to be found with a particularly
size class.
Larvae of the water penny (Psephenidae) occur mainly on the undersides of rocks, and often under boulders in
torrential flow.
Pyralid moth larvae live underneath silken shelters constructed within depressions on rock surfaces. Attached
and encrusting growth forms require a substrate that is not easily overturned by current.
Diatom populations are greatly reduced by storms that scour and flip substrate.
Mosses, bryozoans and sponges are found mainly on larger stones or in locations where scouring is infrequent.
An other way to categorize benthic organisms can be done with the following scheme:
Microbenthos / Microphyta: . Protoista, single- and multicellular organism of auto- and heterotrophic origin.
Macrobenthos: Animals of various taxa, e.g.: Plecoptera, Ephemoptera, Trichoptera, Turbellaria, Hirudinea,
Gastropoda, Bivalvia, Anphipoda, Isopoda, Diptera and Oligochaeta.
Macrophyta: Macroscopic water plants, like Chlorophyta, and larger aquatic plants.
Methods in Ecology
Sub-Protocol 3/8
3
Stream Ecology - I
Methods in catching benthic dwellers: On estuaries and sandy or muddy shores, large, low-density
invertebrates such as various polychaete and oligochaete worms, can be surveyed and monitored by digging
substrate samples. Invertebrates can then be extracted by wet sieving. Large polychaete worms rapidly retreat
deep into the substrate when sensing disturbance. If surveying larger molluscs or worms, the substrate can simply
be sorted by hand. Smaller invertebrates and those occurring at a higher densities are best sampled by taking
smaller substrate cores. The benthos must be carefully handled, taking care not to damage the delicate
invertebrates within it. The lower, unwanted portion can be discarded.
There are many methods, but we only one to handle easy and practical ones discussed in class.
Sampling of Microbenthos: Brushing off encrustations the lower
Useful tools:
side (bedrock-side) of larger stones present in the streambed, a
i) water-resistant boots
representative aggregation of microscopic organisms can be
i) latex gloves
obtained.
i) pocket-lens
Sampling of Macrobenthos: Observation of the underside of lager
i) brush
bedrocks (up to 20 or more) is an easy an fast method to detect
i) pipette
the most common species present in a stream system.
i) tea-spoon
Pond nets: Ponds can be used as a quick methods of catching large
i) various sizes of glass
numbers of aquatic invertebrates. There is a variety of
bottles
techniques: moving the net in a figure of eight, above the
i) sieve
bottom of the water, so that invertebrates on the substrate are
i) flat trays
stirred up and caught as they swim away, pressing the net rim
i) various 1 [l] plastic
against mossy stones to catch highly clinging nimphs ,and
bottles
moving the net at different speeds and depths through open
i) conservation liquid
water and patches of aquatic vegetation. After taking the net
i) soft tweezers
out of the water, it should be allowed to drain the net contents
i) towels
should be emptied onto a white tray, sorted out and taking care
i) procedure not executed
of the specimens.
Wet sieving: Benthic invertebrates are best extracted by wet sieving,
using, sieves of 2.0 mm, 1.0 mm, and 0.5 mm mesh size. Sorting may be made quicker and more efficient
by adding a 1% solution of rose bengal dye, which stains translucent invertebrate pink.
Bucket sampling: With the help of bucket, collect a group of invertebrates, together with other fragments and
water, in the bucket, bring it to the surface, and examine the bucket.
Kick sampling: The majority of invertebrates in fast and slow-moving streams are found amongst stones and
gravel on the stream bed. Kick sampling involves dislodging invertebrates in the stream bed by kicking
and disturbing the substrate and catching the dislodged invertebrates in a net held a short distance
downstream. This technique is widely used to obtain macroinvertebrates for use in water quality
assessment. Then sorted out in a white or black tray. It is a quick method to estimate relative population
densities, but tends to under-record invertebrates firmly attached to stones such as stone-cased caddis fly
larvae.
Surber sampler: Is a refined method of kick sample which involves a frame glass bucket with an attachment net.
The area to be sampled being defined by the frame resting on the substrate, Then observe the samples,
select the ones of interest, push them inside the net with the help of a stick, rinse the net with the stream
water, and pull the whole sample to the surface with the help of a staff member.
Frame placed on stream-bed
Methods in Ecology
Sub-Protocol 3/8
4
Stream Ecology - I
Water Quality: Although technical means should be used to judge water quality, observation of water
transparency is an easy way to indicate levels of pollution. Sedimental flow patterns (organic sediments
does not settle down as fast as mineral sediments) enrich the first hand judgments.
Water quality data may include electrical conductivity, pH, concentration of heavy metals and other ions
(ammoniom, chloride, sulfate), organic such as pesticides, dissolved oxygen, biological oxygen demand
(BOD), turbidity, salinity and temperature.
In order to monitor waters, samples must be collected manually at fixed intervals of time. The aim is to
determine seasonal variability. Data should be reviewed to see if the range of discharges is adequately
sampled. For further information on this subject, see sub-protocol 4/8, Stream Ecology-II.
Water quality Index - WQI (after D. Meyer)
Level of
Saprobic Index
organic strain
(WQI)
insignificant
1.0 - <1.5
I
(very clean)
low
1.5 - <1.8
I-II
(clean)
medium
1.8 - <2.3
II
(fairly clean)
intermediate
12.3 - <2.7
II-III
(f.c. - doubtful)
heavy
2.7 - <3.2
III
(doubtful)
very heavy
3.2 - <3.5
IIIIV (doubtful - bad)
excessively
3.5 - <4.0
IV
(bad)
NH4-N
[mg/l]
<0.1
stream: <0.2
river: <0.3
stream: <0.3
river: <0.5
<1.0
1.0 - <5.0
5.0 - 10.0
>10.0
O2 Saturation [%]
max. saturation
[%]
95 - 100
100 - 103
85 - 95
103 - 110
70 - 85
110 - 125
50 - 70
125 - 150
30 - 50
150 - 200
20 - 30
200
< 20
BOD5
[mg/l]
Chloride Cl[mg/l]
<1
<100
1-2
100 - 250
2-5
250 - 500
5 - 7.5
>500 - 1500
7.5 - 11
>1500 - 2500
11 - 15
>2500 - 3500
>15
>3500
Methods in Ecology
Sub-Protocol 4/8
1
Methods in Ecology
Stream Ecology - II
(Fliessgewässeruntersuchung - II)
Protocol - 4/8
October 6th 1997
Part: Dr. R. Patzner
Handed in by:
and
Salzburg, 31st of October 1997
Stream Ecology - II
Methods in Ecology
Sub-Protocol 4/8
2
Stream Ecology - II
Introduction:
Stream waters contains a variety of dissolved and suspended constituents, often muddy with sediments, and
drainage in limestone-rich regions are fertile while those containing only granite rocks are not. Many factors
influence the composition of river water, causing variations from place to place. Rain is one source of chemical
inputs to rivers, and a stream flowing through a region of relatively insoluble rocks can be chemically very
similar to rain-water in its composition. But this varies with geology, and with the magnitude of inputs via other
pathways including volcanic activity and pollution. Materials are concentrated by evaporation and altered by
chemical and biological interactions within the stream.
Water Quality: Although technical means should be used to judge water quality, observation of water
transparency is an easy way to indicate levels of pollution. Sedimental flow patterns (organic sediments do
not settle down as fast as mineral sediments) enrich the first hand judgments.
Water quality data may include electrical conductivity, pH, concentration of heavy metals and other ions
(ammonium, chloride, sulfate), organic such as pesticides, dissolved oxygen, biological oxygen demand
(BOD), turbidity, salinity and temperature.
In order to monitor waters, samples must be collected manually at fixed intervals of time. The aim is to
determine seasonal variability. Data should be reviewed to see if the range of discharges is adequately
sampled.
Water quality Index - WQI (after D. Meyer)
Level of
Saprobic Index
organic strain
(WQI)
insignificant
1.0 - <1.5
I
(very clean)
low
1.5 - <1.8
I-II
(clean)
medium
1.8 - <2.3
II
(fairly clean)
intermediate
12.3 - <2.7
II-III
(f.c. - doubtful)
heavy
2.7 - <3.2
III
(doubtful)
very heavy
3.2 - <3.5
IIIIV (doubtful - bad)
excessively
3.5 - <4.0
IV
(bad)
NH4-N
[mg/l]
<0.1
stream: <0.2
river: <0.3
stream: <0.3
river: <0.5
<1.0
1.0 - <5.0
5.0 - 10.0
>10.0
O2 Saturation [%]
max. saturation
[%]
95 - 100
100 - 103
85 - 95
103 - 110
70 - 85
110 - 125
50 - 70
125 - 150
30 - 50
150 - 200
20 - 30
200
< 20
BOD5
[mg/l]
Chloride Cl[mg/l]
<1
<100
1-2
100 - 250
2-5
250 - 500
5 - 7.5
>500 - 1500
7.5 - 11
>1500 - 2500
11 - 15
>2500 - 3500
>15
>3500
Saprobic index: Biotic scores are based on the presence or absence of certain taxa. The score is weighted
according to the known tolerance of those taxa to pollution (levels of certain physical and chemical
variables).
Unpolluted running water sites are based on macro-invertebrate fauna. A comparison of observed and
predicted families is then used as a bases for assessment of environmental stress affecting river
communities.
1. Executed Techniques:
2. Datasheet of Experiments
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
Determining the content of Dissolved Oxygen
Biochemical Oxygen Demand
Determining Conductivity
Determining pH
Hardness of Water
Spectrochemical Analysis in the case of Nitrate NO3
Taking a water sample with a Winkler flask
Evaluating Soil Texture
Determining Flow Velocity
Measuring Profile of River Bed - Determining Flow Capacity
Census of Fish population - Electrofishing - DeLury Method
Methods in Ecology
1.1
Sub-Protocol 4/8
3
Stream Ecology - II
Dissolved Oxygen in Water [mg/L]:
Materials used:
Both O2 and CO2 gas occur in the atmosphere and
i) 1 beaker
dissolve into water according to partial pressure and
i) aqua destillata
temperature. Air is nearly 21% O2 by volume and
i) Oximeter (Fa.WTW)
just 0.03% CO2, but the latter is more soluble in
water. Although saturated freshwater has higher
concentrations of O2 than CO2, the difference is not so great.
CO2 tends to deviate from atmospheric equilibrium in highly productive lowland streams where luxuriant
growths of macrophytes and microbenthic algae can result in dealing with shifts in dissolved CO2.
The impact of high oxygen demand due to pollution can be exacerbated by high summer temperatures,
i.e.: pollution reduces the solubility of O2 in water, and by ice cover in winter, which minimizes diffusion.
It is a critical factor in aquatic ecology. Its concentration is affected by temperature, salinity, plant
respiration, organic material, organic pollution, and eutrophication.
Two major techniques to measure O2 in water:
The Winkler titration (requires many chemicals, therefore not executed) or by the O2-electrode.
The O2-electrode is a very convenient, time saving method and has the potential for continous
measurament in remote areas.
It consists of a multipurpose meter and a sensor, the probe provides direct monitoring.
Remarks: When taking readings with an O2-meter, a water flow must be present (or by slightly stirring
probe) since it abstracts O2 from the water. Rinse electrode with distilled water after use.
Electrodes must be kept clean and moist.
Hypothetical effect of
organic pollution
in a river:
a & b, physical and
chemical changes;
c, changes in microorganisms;
d, changes in larger
organisms
Methods in Ecology
Sub-Protocol 4/8
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Stream Ecology - II
1.2 Biochemical Oxygen Demand - BOD [mg/L]:
The biochemical oxygen demand is one common
Materials used:
standard applied to monitoring and surveillance of
i) 2 glass bottles with stopper
fresh water. It is considered to be an aspect of
i) distilled water
chemical monitoring.
i) Oximeter (Fa.WTW)
The BOD is the ability of a given volume of water to
i) magnetic stirrer
used up oxygen over a period of five days at a
temperature of 18 [°C]. A second bottle of the same
water body is kept for two days under the same
conditions as a reference.
Organic matter in the sample of water decomposes and the amount of oxygen consumed is then calculated.
See WQI -table heading this protocol.
Remarks: BSB2 and BSB5 - bottles have to be filled completely; make sure no that no air-bubbles are left
in the flask after placing the stoppers. Place bottles in a dark place at 18 [°C].
Before determining O2 content, pop the magnetic topping onto electrode.
Rinse electrode with distilled water after uses.
Methods in Ecology
Sub-Protocol 4/8
5
Stream Ecology - II
1.3 Conductivity of Water [S/m]:
The total dissolved solids (TDS) content of fresh
Materials used:
water is the sum of the concentrations of the
i) 1 beaker
dissolved major ions. The world average is about
i) aqua destillata
100 mg/l. Both the total and the concentration of
i) conductivity-meter (Fa.WTW)
the constituents vary considerably from place to
place, due to variability in natural and
anthropogenic inputs. However, the vast majority
of the world’s rivers have TDS of more than 50% HCO3- and 10-30% (CL- , SO42-). This reflects the
dominance of sedimentary rock weathering, and especially of carbonate minerals. Salinity is sometimes
used with TDS. The ionic concentration of rain-water is more diluted: Na+, K+, Ca2+, Mg2+, and Clderived also from particles of the air. Year to year variation in stream flow influences the amount of
dissolved material exported from a watershed because the concentration of most ions in stream water is
relatively constant, the amount exported is determined largely by stream flow.
Fresh water has a lower conductivity than sea water, because sea water has a higher ionic concentration.
There are many laboratory conductivity meters. Meters that measure over a single wide range tend to be
inaccurate, especially at the fresh water end of the scale. A better way is to use meters that focuses on
whichever part of the scale is relevant. The conductivity reading is in [mS/cm] and provides an estimate of
salinity.
Furthermore, water conductivity in fresh water systems gives an estimate of water polluting levels:
Water body
aqua distillata
clean water current (free of carbonates)
clean water current (containing carbonates)
polluted water system (containing carbonates)
sea water
conductivity [µS/cm]
<10
approx. 100
approx. 350
approx. 500
approx. 55000
Remarks: Dip electrode into the water and slightly stirring it; rinse electrode with distilled water after use.
Methods in Ecology
Sub-Protocol 4/8
6
Stream Ecology - II
1.4 Determining pH of Water[-]
Most natural waters contain various bicarbonate
Materials used:
and carbonate compounds, originating from
i) 1 beaker
dissolution of sedimentary rocks. The calcium
i) aqua destillata
bicarbonate content of freshwater determines the
i) pH-meter (Fa.WTW)
pH or acidity/alkalinity balance. When CO2
dissolves in pure water, a small fraction is
hydrated to form carbonic acid. Stream waters
usually contains bicarbonates and carbonates , and
H2CO3 readily dissolves calcium carbonate rocks,
neutralizing the soil and river water, and forming calcium bicarbonate. Freshwater can vary widely in
acidity and alkalinity due to natural causes as well as anthropogenic inputs. Extreme pH values, generally
those much below 5 or above 9, are harmful to most organisms, and so the buffering capacity of water is
critical to the maintenance of life. The CO2, HCO3-, CO32- equilibrium serves as the major buffering
mechanisms.
The pH is a measurement of hydrogen- (H+) or hydroxyl- (OH-) ion activity. For fast and accurate
determination we used an portable electronic device, which is a pH-meter and an electrode. The electrode
is immersed in the solution (or directly into the water body) and the meter reads the pH.
Indication values (pH)
• pH-levels around 7 indicate natural water.
• pH-levels below 7 indicate acidic reactions
• pH above 7 alkaline reaction.
Remarks: Adjust pH-meter before use; rinse electrode with distilled water after use.
Methods in Ecology
Sub-Protocol 4/8
7
Stream Ecology - II
1.5 Hardness of Water [dH]:
The hardness of water is caused by its
concentration of polyvalent cations, principally
Materials used:
calcium and magnesium, which tend to precipitate
i) 1 beaker
soap. It is measured and adjusted by water
i) aqua destillata
treatment operators, it is expressed in terms of mg
i) Merck Test Kit
CaCO3. It can be computed from known
concentrations of calcium and magnesium. When
other hardness-producing cations are present in
significant amounts, their concentrations must be
measured and included in the computations. The
concentration [mg/l] of each hardness-producing cations is multiplied by the appropriate factor to obtain
equivalent calcium carbonate concentrations:
Hardness CaCO3 equivalent [mg/l] = cation [mg/l] x factor
These equivalents are then summed to obtain the total hardness.
Using the test kit provided by Merck:
• Rinse test-tube several times with sampling water.
• Fill test-tube with 5 [ml] of water sample.
• Add 3 drops of test-chemical (A); the water sample should change to a reddish hue (shake if
necessary).
• Fill syringe with titrant solution to the maximum (0-mark).
• Slowly dribble titrant into the test-tube containing the (now) reddish sample.
Stop adding titrant as soon as the hue shifts towards green.
• The position of the piston (syringe) directly indicates the hardness of the water sample.
Methods in Ecology
Sub-Protocol 4/8
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Stream Ecology - II
1.6 Spectrochemical Analysis (nitrate NO3 [mg/L]):
Nitrogen is often determined in water because it is
Materials used:
important for plant growth, and maybe a limiting
i) 1 beaker
nutrient in water. If excessive quantities are
i) aqua destillata
present, eutrophication may result. Nitrogen exists
i) diluted sulfuric acid
in gaseous state in water and soluble in organic
i) microspatula
form. Soluble N exists in many forms and
i) spectrophotometer
constantly fluctuates between oxidized and
i) 1 test tube
reduced forms.
i) electrical shaker
Nitrate is determined by reducing all of the nitrate
to nitrite and then determining this nitrite
concentration spectrometrically. Similarly this
procedure can be used to trace chloride, phosphorous, nitrite, or ammonium.
Ammonium ion ↔
NH4+
↔
ammonia ↔ nitrite
NH3
↔ NO2
↔
↔
nitrate
NO3-
Using the test kits provided by Merck:
• Use micro-spoon provided to put a scoop of reagent (NO3-1A) into the test-tube.
• Add 5 [ml] of 96% sulfuric acid (H2SO4) to the sample (NO3-2A).
• Pop the test-tube with a stopper and vigorously mix it with the shaker.
• Slowly add 1.5 [ml] of water sample to the mixture (exergonic - beware of heat formation).
• Let it rest for 10 [min].
• Place test-tube into the measurement-cage and attend a few seconds before value is displayed.
Remarks: Use protection gloves and glasses when handling sulfuric acid!
Methods in Ecology
Sub-Protocol 4/8
9
Stream Ecology - II
1.7 Water Temperature [°C]:
Water temperature increases in downstream
Materials used:
direction, to a point where the water reaches an
i) 1 beaker
equilibrium with air temperatures. Water
i) aqua destillata
temperature changes both seasonally and daily, but
i) digital thermometer (Fa.WTW)
to a lesser degree than air temperature does.
i) mercury thermometer
Local variations in shade, wind, stream depth,
i) alcohol thermometer
water sources and the presence of inpoundments
will alter the general trends caused by
geographical position. Many organisms take
advantage of these local variations. When water cools, it becomes more dense and sinks. The temperature
of a stream is critical to aquatic organisms through its effects on their metabolic rates and thus growth and
development times. It is an important factor in regulating the occurrence and distribution of vegetation,
fish, invertebrates, and other organisms. It affects other properties of water such as viscosity as well.
Taking a water sample with a Winkler flask
This flask is used to obtain samples of water from different depths. The flask is dropped to the required
depth and then the rope is jerked. This causes the elastic cord to stretch, pulling out the stopper and
permitting water to flow through the tube and into the bottle; then the rope is pulled quickly to close the
inlets by sealing the flask. Then bring the sampled water to the surface.
Determining the Temperature: Measure both the surface- and deep water (1 meter) temperature with three
different meters.
Remarks: When using the analog meters, make sure that they are exposed long enough in the water.
Do not conduct measurements under direct exposure from the sun, since solar radiation will
slightly alter the readings.
Displacement sampler for water oxygen samples.
Methods in Ecology
Sub-Protocol 4/8
10
Stream Ecology - II
1.8 Evaluating Soil Texture of Stream bed:
In a stream, substrate usually refers to the
Materials used:
particles on the stream bed, both organic and
i) set of different sizes of sieves
inorganic. Studies of substrate composition
i) digital balance
should consider the average and range of particle
i) transparent plastic bags
sizes, the degree of packing or imbeddedness,
and the irregularity or roundness of individual
particles.
Substrate is a major factor controlling the occurrence of benthic (bottom) animals. A sharp distinction
exists between the types of fauna found on hard stream beds such as bedrock or large stones and soft ones
composed of shifting sands. The greatest number of species are usually associated with complex substrates
of stone, gravels and sand. The composition of stream can be altered by sediment influxes from upland
erosion and by channel modification. Excessive siltation of gravel and cobble beds can lead to
suffocation of fish eggs and aquatic insect larvae and can affect aquatic plant densities. This in turn, can
result in changes mollusk, crustacean and fish populations. Generally, these changes tend to cause a shift
towards downstream conditions (unstable beds of fine materials), effectively extending lowland river
ecosystems further upstream.
When sampling streams for suspended sediment it is important to obtain a sample which accurately
reflects the stream’s sediment load. There are several technical to trap large and small particles called bed
load samplers, pit-type, basket-type, pan-type, etc.
Physical analyses include soil particles parameters like: size, shape, mineralogical composition, surface
texture, orientation in space; bulk includes: color, average density, porosity, permeability.
For this practical exercise, we only concentrate to determine the particle size.
Particle size analyses can be applied to any mixture of sediments which include: width , diameter,
settling velocity, length [mm].
Some of the techniques are:
• Visual analyses (done by eye) classification: boulders, cobbles, gravel, sand and silt or clay.
• Hand texturing: the soil composition is estimated from the feel and malleability of a wetted sample
(bolus), by working the bolus between the thump band forefinger.
• Direct measurement: Individual boulders, cobbles and large gravel’s can be measured directly in the
field.
• Dry sieving: is the most common used method for the analysis of sand sized particles. First separate,
pick and weigh all of the larger-sized rocks, Further subdividing may be desirable to prevent
overloading the sieves when working down to sieve sizes of 2 mm and finer. A set of sieves of
required sizes is stacked together, decreasing in aperture size downwards.
• Wet sieving: is a good methods for sizing coarse particles and sand-sized particles when aggregation
problems are encountered.
Class
Stone
Gravel
Coarse sand
Medium sand
Fine sand
Very fine sand
Silt
Size [mm]
> 63
20 - 63
6.3 - 20
2.0 - 6.3
0.6 - 2.0
0.2 - 0.6
0.06 - 0.2
Examples of commonly used soil textural
classification systems
Methods in Ecology
Sub-Protocol 4/8
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1.9 Waterflow [m/s]:
Current is the most significant characteristic of
Materials used:
running water, and it is in their adaptations to
i) chronometer
constantly flowing water that many stream
i) floating object
animals differ from their still-water relatives.
i) yardstick (metric)
Some species have an innate demand for high
water velocities, relying on them to provide a
continual replenishment of nutrients and oxygen,
to carry away waste products and to assist in the dispersal of the species. At a given temperature, the
metabolic rates of plants and animals are generally higher in running water than in still waters. However,
it takes a great deal of energy to maintain position in swift waters, and most inhabitants of these zones
have special mechanisms for avoiding or withstanding the current.
Current velocity can be measured by placing a float in the water and measuring the time taken to travel a
predetermined distance.
Methods in Ecology
Sub-Protocol 4/8
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Stream Ecology - II
1.10 Profile of Riverbed
To describe the physical characteristics of a
Materials used:
stretch, a basic survey should include a
i) yardstick (metric)
measurement of the channel slope, several crossi) cord (at least 10 [m] in length)
section profiles representative of the stream, a
i) level
description of bed materials and a sketch of the
i) water-resistant boots
stream itself.
i) clinimeter (not executed)
Sites can be located at random, spaced uniformly
or selected as representative of a smaller area of
the stretch.
• A cross-sectional profile of a small stream can be obtained with a measuring tape and a meter rule a
and survey staff. If the stream has water in it, the water surface provides a horizontal surface from
which to take vertical measurements at several points along the horizontal line. The horizontal
distance to the measurement points and the vertical distance to the stream bed and water depth are
recorded. Measurement should be taken at each break in slope along the bed. The depth of water at
each edge should also be recorded.
• The bank slope is best measured using a staff and clinometer, it is held against the staff which is set
against the bank, and the angle is read directly from the clinometer.
• The bank overhang is measured with a staff or meter rule from the farthest point of undercut to the
most distant point of overhang.
• The bankfull width and depth provide a more standardized description of channel dimensions, the
bankfull elevation is identified by scour lines, vegetation limits, changes between bed and bank
materials, the presence of flood deposited slit or abrupt changes in slope. Training and experience will
lead to consistent interpretations.
Field measurement of a stream cross-section.
Profiling river-bed
Methods in Ecology
Sub-Protocol 4/8
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Stream Ecology - II
Flow Capacity [m3/s]:
Channel cross-section showing vegetation zones, reflecting actual situation of the measured riverbed
section, where flow capacity has been determined.
Methods in Ecology
Sub-Protocol 4/8
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Stream Ecology - II
1.11 Census of Fish population:
Fish capturing methods are of two categories:
Materials used:
passive methods (rely on the fish swimming into
i) bucket
a net or a trap), and active methods in which the
i) electrofishing unit
fish is pursued (electrofishing, SCUBA, etc.).
i) fish net
The selection of the technique will depend on
i) rubber fishing boots
the habitat to be sampled, Factors such as depth,
i) safety rubber gloves
clarity, presence of vegetation or speed of the
i) measuring tubes (metric)
current will need to be considered. A
i) MS-222 as anesthetic
hydrographical survey prior to sampling may be
necessary
The mark-recapture technique is based on the recognizable (marked) organisms relapsed to the population
will be recaught in numbers proportional to their abundance in that population. The size of the natural
population can be estimated from the proportion of marked to unmarked organisms in random samples
obtained form the entire population. By using the DeLury procedure, the data obtained give an estimate
(approximation) of how many individuals there are present in the surveyed area.
.Assumptions for mark-recapture technique:
• There can be no difference in mortality or emigration between marked and unmarked organisms.
• Tags or other marks must remain recognizable and must not be lost. All marks on recaptures must be
reported.
• There must not be a difference in catchability between marked and unmarked organisms.
• Marked organisms must be mixed randomly within the entire population.
• There can be no unknown recruitment or immigration to the population.
Handling of capture fish:
• All the catched fish should be placed in a bucket of water (for narcotization use MS-222).
• Weigh, measure (length) and/or mark one fish at a time, making sure that they do not escape from the
hands.
• Return the fish to the bucket for recovery.
• Proceed to return all the fish into the water.
Electrofishing:
It involves passing an electric current through water via electrodes which stuns nearby fish, leading to the
disorientation and easy capture. Power is supplied by an electrical generator (or batteries for backpack
units) and is converted to the required form via an electrofishing unit or box. The circuit is completed by
on/off switches on the anode. Several currents are used, producing different effects o the fish. The most
common is direct current (DC), because it attracts fish to the anode and causes fewer harmful effects to the
fish than alternating current (AC).
During electrofishing, anodes are often hand-held, while the cathode trails behind the boat or operator.
The charge is usually kept on during fishing. The key is to be always close enough to the target fish to
induce a response and to explore all available habitats with the anode. The operator should always work in
a upstream direction, as disturbed sediments flow away from the sampling area and the stunned fish drift
towards the operator. In streams and rivers, fish are captured efficiently and absolute measures of
abundance may be generated. Overexposition of stunned fish to the anode may lead to death. Large and
thinner fish are easier to stun than smaller and thicker ones.
Remarks: Water and electricity are dangerous, people have been killed while electrofishing, therefore only
licensed operators may electrofish. Wearing rubber gloves and boots at all times avoiding
immersion of any unprotected parts into the water. Equipment should have automatic dead-man
switches on the anodes. Emergency stop buttons (in case the operator falls in the water). High
number of personnel are required (minimum of three).
Methods in Ecology
Sub-Protocol 4/8
15
DeLury Method:
A section of a stream, 2 to 3 [m] wide x 100 [m] in length has been surveyed.
The fish census technique resulted in a catch of:
1st catch: 9 individuals
2nd catch: 5 individuals
3rd catch: 2 individuals
estimated number:
NE = (xn+xn+1) / 2
Stream Ecology - II
Methods in Ecology
Sub-Protocol 4/8
16
Stream Ecology - II
2. Datasheet:
1. Dissolved O2
Uniteich
[mg/L]
7.9
2. Biochem. O2 Demand
BOD2
BOD5
[mg/L]
9.8
6.8
3. Conductivity
Pongau
Uniteich
[µS/cm]
116
636
4. pH
Uniteich (ausfluss)
[-]
8.01
5. Hardness
[dH]
4
6. Spectrochemical NO3
Uniteich
Pongau
7. Temperature
digital
analogue (Hg)
analogue
(Probemeter)
[%]
96
[mg/L]
0.9-1.0
3.9
[°C] at 1[m]
15.6
15.1
15.6
8. Soil Texture (woo?)
Stone (> 63)
Gravel (20 - 63)
Coarse sand (6.3 - 20)
Med. Sand (2.0 - 6.3)
Fine sand (0.6 - 2.0)
Very fine (0.2 - 0.6)
Silt(0.06 - 0.2)
[g]
268
461
925
198
46
-
9. Flow Velocity
Hellbrunnerbach v1
Hellbrunnerbach v2
Hellbrunnerbach v3
averaged
[m/s]
0.19
0.20
0.2
0.2
[°C] at 0
17.2
17.0
17.5
10. Fish
Census
# 1
# 2
# 3
# 4
# 5
# 6
# 7
# 8
# 9
#10
#11
#12
#13
#14
#15
#16
[g]
20
21
21
23
28
31
31
39
81
134
135
144
149
150
175
290
Std [cm] Tot [cm]
10
10
10
10
10
11
11
12
17
20
20
20
21
21
22
25
12
12
12
12
12
13
13
14
20
23
23
23
24
24
25
28
K-Factor
167
175
175
192
233
239
239
279
405
583
587
626
621
625
700
1036
Teilprotokoll 5/8
1
Erfassung des Pflanzenbestandes
(Methods in Ecology)
(Census of Flora)
Protokoll - 5/8
7ten Oktober 1997
Betreut durch: Dr. W. Strobl
Mag. B. Hummer
Eingereicht von:
Cäcilia Aigner (Mat-#: 9620537)
Anita Rötzer (Mat-#: 9472202)
Salzburg, im Oktober 1997
Teilprotokoll 5/8
2
Einleitung:
Die Methoden der Vegetationsbescheibung und deren Aufnahme werden vom Zweck der Untersuchung
bestimmt. Derzeit kommt die floristische Methode nach Braun-Blanquet am häufigsten zum Einsatz.
Als Aufnahme bezeichnet man die listenmässigeErfassung sämtlicher vorkommender Pflanzen und ihrer
Mengenanteile. Voraussetzung ist die Kenntnis der Flora. Nicht sofort bestimmbare Pflanzen müssen gesammelt
werden. An den Kopf der Liste kommen allgemeine Angaben wie Datum, Ortsbezeichnung, Meereshöhe,
Hangneigung, Exposition, , Grösse der Probefläche, Entwicklungszustand der Vegetation, Schätzung der
Gesamtdeckung (nach Schichten getrennt). Dazu Angaben über den Standort (v.a. Boden).
Auswahl und Abgrenzung der Probefläche:
Sorgfältige Auswahl ist für den Erfolg späterer statistischer Auswertungen ausschlaggebend. Für einen
allgemeinen Eindruck muss das Untersuchungsgebiet zuerst begangen werden.
Weit verbreitete Vegetationstypen müssen in Optimum ihres Entfaltungsraumes studiert werden, bevor
verarmte Randgebiete bearbeitet werden. Die Form der Probefläche ist unwesentlich , die Verteilung der
Probefläche im Gesamtareal erfolgt an besten zufällig.
Die Probefläche soll homogen sein, d.h. Pflanzenbestand und Standortbedingungen sollen keine grösseren
Schwankungen aufweisen. Die Probefläche muss gross genug sein, um alle Arten zu erfassen, aber nicht
grösser als unbedingt nötig.
Zufallsverteilung:
Unter sehr gleichmässigen Bedingungen sollten die verschiedene Pflanzen einer Pflanzengemeinschaft
zufällig über die Fläche verteilt sein (nicht willkürlich!). Die Verteilung der Pflanzen im Gelände kann
gemessen und kartiert werden; die einzelnen Arten können taxonomisch bestimmt oder nach Lebensform
beschrieben und ihre Mengenanteile festgestellt werden. Die möglichst umfassende Beschreibung der
Vegetation ist auf jeden Fall nützlich.
Beispielhaft sei hier der tropische Regenwald genannt, der mit seiner komplexen Raumstruktur und der
Vielzahl ökologischer Nischen. Ähnlich homogen, wenn auch weit weniger komplex sind die artenreichen
sommergrünen Wälder des nördlichen Hemisfäre.
Eine wirkliche zufällige Verteilung der Pflanzen im strengeren Sinn gibt es nicht. Selbst bei der
Erstbesiedelung von Ödland (Sukzession) führen morfologische Merkmale zu einer Musterbildung.
Antropogener Einfluss:
In Mitteleuropa gibt es kaum mehr natürliche Vegetaton; seit mehr als 1000 Jahren ha der Mensch seine
Spuren hinterlassen. Wälder und Wiesen werden bewirtschaftet; durch Düngung, Unkraut- und
Schädlingsbekämpfung hat sich der Artenbestand verändert. Noch am ehesten naturbelassen sind die
Hochregionen des Gebirges, in denen aber auch bis vor wenigen Jahren intensive Weidenutzung betrieben
wurde.
Teilprotokoll 5/8
3
1. Vegetationsaufnahme - Artenspektrum:
Eine einmalige Vegetationsaufnahme gibt nur einen einzigen
Aspekt wieder. Der jahreszeitliche Dominanzwechsel ist aber
eine wesentliche Eigenschaft der Vegetation; daher müssen
Aufnahmen aller charakteristischer Fasen gemacht werden.
Material:
Bestimmungsbuch aus
Botanik
In diesem Protokoll wurde nur eine einmalige
Vegetationsaufnahme durchgeführt.
Ort:
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Spezie
Hypericum tetrapterum L. (Johanniskraut)
Eurynchium striatum (Schönschnabel)
Galium aparine L. (Klebkraut)
Urtic dioica L. (Grosse Brennessel)
Calystegia sepium L. (gem. Zaunwinde)
Filipendula ulmaria L. Maxim (Ectes Mädesüss)
Rubus caesius L. (Kratzbeere)
Lythrum salicaria L. (Blutwegerich)
Galium aparine L. (Klebkraut)
Poa trivialis L. (gem. Rispengras)
Plantago lanceolata L. (Spitzwegerich)
Vicia gracca L. (Vogelwicke)
Lathyrus pratensis L. (Wiesen Platterbse)
Sorbus aucuparial L. (Eberesche)
Mentha logifolia L. (Rossminze)
Acer pseudoplatanus L. (Bergahorn)
Spirea mecensis L. (Spierstrauch)
Phragmites australis (CAV.) (Schilfrohr)
Valeriana officinalis L. (Baldrian)
Dactylis glomerata L. (Wiesen Knäuelgrass)
Heracleum sphonedylium L. (Wiesen Bärenblau)
Phalaris phragmitis L. (Glanzgras)
Lolium perenne L. (engl. Raygras)
Taraxacum officinale (gem. Löwenzahn)
Galium molugo L. (Wiesenlabkraut)
Fraxinus excelsior L. (gem. Esche)
Teilprotokoll 5/8
4
2. Mengenschätzung, Frequenz: [%]
Mit dieser Methode wird innerhalb der Probefläche (zufällig
Material:
verteilt oder nach einem bestimmten Muster) eine grössere
i) Frequenzrahmen 0.5 x
Zahl von flächengleichen Kleinquadraten abgesteckt. Die
0.5 [m] in 10 [cm2]
Flächengrösse dieser Quadrate kann frei gewählt werden (im
geteilte Quadrate
Grünland am besten zwischen 25 und 1200 [cm2]. Nun wird
für jedes Kleinquadrat eine Artenliste erstellt, die bei
geringen Flächengrösse selbstverständlich immer nur wenige Namen umfasst.
Die Frequenz einer Art ergibt sich dann durch die Auszählung der Kleinflächen, in denen die zu
untersuchende Art vorkommt. Sie wird in der Regel auf die Gesamtzahl der Kleinflächen bezogen und als
Frequenzprozent angegeben.
Anmerkungen: Das Verfahren ist sehr zeitaufwendig und durch zahlreiche Keimlinge und kleine Rosetten
(die einwandfrei zugeordnet werden müssen) meist sehr mühsam. Ein besonderer Nachteil liegt
darin, dass die Ergebnisse der Frequenzbestimmung in gewissem Umfang von der gewählten
Grösse der Kleinquadrate abhängt. Demgegenüber steht der Vorteil dass bei korrekter Anwendung
das Ergebnis nicht von der subjektiven Beurteilung des Beobachters abhängt.
Die Grösse der Kleinflächen
beeinflusst das Ergebnis der
Frequenmzbestimmung, aber
auch die Aussage über den
Bindungstrend (Musterbildung)
zwischen den Arten A, B, C.
Bei gleicher Individuenzahl
beeinflusst auch die
Pflanzengrösse das Ergebnis der
Freqwuenzbestimmung
Die Raumverteilung
(Dispresion) ist ebenfalls von
grossem Einfluss auf die
Frequenz
Eigenaufnahme
Mithilfe der Frequenzbestimmung:
Teilprotokoll 5/8
5
3. Transekt Methode: [%]
Eine Frequenzbestimmung entlang eines ökologischen
Material:
Gradienten ergibt ein Transekt.
i) Massstab (mind. 25 [m]
Solche Profile sind überall dort empfehlenswert und
lang
aufschlussreich, wo sich die Vegetation in klarer
Abhängigkeit von einem oder wenigen Standortfaktoren
ändert und zunächst keine floristisch einheitliche Fläche erkennbar ist. Ein Transekt liefert unter anderem
Antwort auf die Frage, ob es sich tatsächlich um einen kontinuierlichen Übergang handelt oder ob
floristisch homogene Teilbereiche abgrenzbar sind.
Dazu wird entlang einer parallel zum standörtlichen Gradienten verlaufenden Markierungslinie ein
Streifen bestimmter Breite abgesteckt. Anschliessend werden innerhalb dieses Streifens in regelmässigen
Abständen Frequenzbestimmungen durchgeführt. Die Breite des Streifens und der Minimalabstand der
Frequenzerhebungen muss nach standortlichen Situationen festgelegt werden.
Anmerkungen: Transekte sind sehr zeitaufwendig. Eine wesentliche Zeitersparnis lässt sich erreichen,
wenn auf Frequenzbestimmung verzichtet wird und statt dessen auf etwas vergrösserten
Kleinflächen (30 x 30 [m] bis 50 x 50 [m]) sie Deckung der einzelnen Arten entsprechend der
Braun Planquet Skala abgeschätzt wird.
Teilprotokoll 5/8
6
4. Vegetationsaufnahme nach Braun-Blanquet Methode: [%]
Sie besteht im wesentlichen aus einer kompletten Artenliste
Material:
und der nach einer bestimmten Klassifizierung geschätzten
Häufigkeit.
lang
Mit einiger Übung und Erfahrung liefert dieses Verfahren bei
mässigem Zeitaufwand Resultate ausreichender Genauigkeit.
Ein schwieriges Problem ist die richtige Wahl der Probenfläche. Sie sollte einheitlich sein (keine
Störstellen, Randstrukturen, oder standörtlich abweichende Kleinflächen enthalten) und eine mehr oder
minder gleichmässige Verteilung der beteiligten Pflanzenarten aufweisen.
Die Grösse der Aufnahmefläche sollte so gewählt werden, dass möglichst alle Arten der beteiligten
Pflanzengemeinschaft enthalten sind, andererseits nicht zu gross da man sonst mit der Homogenität der
Pflanzenverteilung in Konflikt geraten könnte.
Die ökologische Aussage, die das Vorhandensein oder Fehlen einer Pflanze liefert, lässt sich durch
Angaben zur Menge der einzelnen Arten weiter präzisieren. Nach Braun-Blanquet geschieht das mit einer
Skala, die sowohl die Individuenanzahl (Abundanz) als auch die Deckung der einzelnen Arten
(Dominanz) auf der Probefläche berücksichtigt.
Beide Grössen werden in einer 7-stüfigen Klasseneinteilung vereinigt, deren Klassenkennzeichnung als
Artmächtigkeit bezeichnet wird.
Folgende Artenmächtigkeitsskala wird verwendet:
R (1)
+ (2)
1 (3)
2 (4)
3 (5)
4 (6)
5 (7)
selten (meist nur ein Exemplar)s
2-5 Individuen, spärlich, nur wenig Fläche deckend
6-50 Individuen, Deckung unter 5%
über 50 Individuen, Deckung 5-25%
Individuenzahl beliebig, Deckung 25 - 50%
Anmerkungen: Grössere Genauigkeiten wären nur durch erheblich aufwendigere Verfahren erreichbar; der
dafür erforderliche Zeitaufwand ist entsprechend gross.
Häufig wird diese Klassifizierung durch den Geselligkeitsgrad (sociability) erweitert (es lässt sich
nicht erkennen, ob es sich um eine grosse Zahl kleinwüchsiger Pflanzen oder wenige grosse
Rosetten handelt).
Auch die Vitalität (performance) als Ausdruck der Üppigkeit, Kümmerlichkeit die übers normale
Mass hinausgeht kann vermerkt werden – beides wurde in diesem Protokoll nicht berücksichtigt.
Entwicklungsfasen eines Waldes, Optimal-, Terminal-, Zerfallsfase; die Schichtung verliert sich,
gruppenweise Verjüngung setzt ein
Teilprotokoll 5/8
7
Aufnahmeblatt:
Aufnahme Nummer:
Region
Datum:
Ort:
Kartenblatt (Koordinaten):
Meereshöhe:
Geländemorfologie:
Exposition:
Inklination:
Höhen-, Vegetationsstufe:
Gesteinsunterlage:
Boden:
Bewirtschaftung:
Mikroklima:
Aspekt:
Grösse:
Vegetation der Aufnahmefläche:
Höhe
BS.1
BS.2
Bemerkgn.
Deckung Alter
Sonstiges
Höhe
SS.1
SS.2
KS
MS
Deckung:
Deckung Alter
Sonstiges
Methods in Ecology
Sub-Protocol 6/8
1
Methods in Ecology
Census of Fauna
(Erfassung der Tierwelt)
Protocol - 6/8
October 8th 1997
Instructors: Dr. J. R. Haslett
E. Traugott
Handed in by:
Field Studies - Invertebrates
Methods in Ecology
Sub-Protocol 6/8
2
Introduction: A number of techniques can be used for ecological field studies. The choice in using a particular
method is primarily based on the purpose the study is aiming at. To determine the importance of a site, the
population size of the species, the habitat requirements of a species, the reasons for the species decline, etc. it
is important to plan the work carefully. The data must be stored in a way that it can be retrieved and
understood by others in the future, such as data sheets, in files or computer records, properly labeled
specimen, etc. It is useful to determine the exact locations where species of particular interests were found.
Designing and Planing ecological field Studies:
• Purpose of the study,
• What information will be needed, and what is worth to be recorded,
• How much detail is required,
• On what scale will the survey be operating,
• How much time and what resources (funds, time, etc.) are available to conduct the survey.
Selection of suitable study sites: The activity of most invertebrates, is often influenced by weather conditions and
time of the day. The level of activity may determine in which micro- or habitat a particular individual is at
any one time, how easy the individual is to locate and to catch, and how likely it is to enter a trap.
• Accessibility of is the site (especially if heavy equipment is needed),
• What are the necessary materials needed to conduct the investigation,
• Availability of the organism to be studied at a particular site,
• Required permission of authorities (parks, conservation zones, etc.)
Designing the sampling program: The difficulty of identifying many invertebrate species, together with the need
to prevent invertebrates once caught in traps from devouring each other or dying and decaying, often
requires them to be killed and preserved. Catches of individuals within the trap therefore will reflect both
the abundance and activity of the species, together with the species susceptibility to be caught in the
particular trap.
• How many samples are needed (excessive sampling is time consuming, could alter population density,
and will result in intense evaluation work after the survey). Any trapping program should take into
account the likely effect that such removal of invertebrates may have on local population. This
particularly important in the case of trapping large sexually mature invertebrates such as dragonflies,
butterflies, and crickets, where the colony may only include a small number of adults.
• Which sampling pattern to use (random, periodic, limiting area, etc.),
• Time of sampling (periodically, seasonal or daily, at what times are organisms active, etc.).
Sampling Populations of Organisms:
Invertebrates are able to exploit very small and specific areas within the environment (microhabitats). A
number of these individuals spend their larval stage in different habitats than as adult organisms.
Changes over time: It may be necessary to sample on a number of occasions throughout the year, in order to
obtain a representative selection of species present. The importance and value of biological monitoring is the
interest in the changes in populations of plants, animals, loss of habitat, disturbance, changes in land use,
decline or rise in population, etc. which can be directly related to antropogenic influences, successional
changes, or other impacts.
Spatial variations: When surveying invertebrates at a particular site, it will be necessary to sample a wide
range of different microhabitats e.g. within a woodland (dead wood of different tree species at different stages
of decay and moisture content, the leaves of a variety of different three and shrub species, wet and dry leaf
litter, soil, bare ground, etc.) and macrohabitats, e.g.: cross-section of an alpine valley or other larger spatial
gradients.
Community structure: Species that occur together in space and time gives an estimate of the diversity and
relative abundance present. The higher the probe, the better the interpretability of its structure.
Methods in Ecology
Sub-Protocol 6/8
3
Two Major Categories of Sampling Methods:
Relative Methods provide information on relative frequencies of occurrence. The fact that more individuals
present at one site or time, and fewer at an other site or time allow comparisons to be made. Relative Methods
are less disturbing compared to absolute sampling methods.
• Counting numbers per unit effort (CPUE): Timed searches are useful to make quick assessments of the
invertebrate. Such method is to search each small (<1 hectare) for a total of three minutes. Searching each
habitat within a period of time in proportion to its area. In terrestrial habitats the number of individuals
counted in a set period of time has been used to obtain relative estimates of conspicuous taxa such as
butterflies at different heights; e.g.: sweep netting, etc.
• Trapping: The action of the organism itself determines the outcome of the catch, weather lured or
accidentally caught; e.g.: pitfall traps, flight intersection traps, water traps, catch-recatch method, etc. All
trapping methods rely on invertebrates actively entering the trap. Catches of individuals within the trap
will reflect both the abundance and activity of the species, together with the species’ susceptibility to
being caught in the particular trap.
Absolute Methods provide an absolute measure of population density at the time and place of sampling - the
number of individuals present per unit area or volume of habitat; e.g. D-Vac, handsorting method, etc.
Absolute methods do have quite a disturbing effect and will alter the sampled area to a certain degree
(physically or chemically).
Transect Methods: These methods are used to survey changes in vegetation along an environmental gradient
or through different habitats. This can be done by using line-, belt transects or gradsects (for larger areas).
Estimating of cover within a transect requires is mainly used for flora field studies and requires quite some
experience. Transect methods can be considered as intermediates, they are either absolute or relative - just a
matter of size and effort.
Marking / Following Individual Organisms:
Mark - Recapture is a suitable method for estimating populations, for physiological and behavioral studies,
reveals habitat preferences, migration patterns etc. Invertebrate taxa with hard exosceleton are the most
widely used. The exosceleton is marked (avoiding joints or sensory organs) using an oil-based enamel paint.
Other methods include marking the wings of butterflies and moths with felt tip pen after first rubbing a small
patch of scales off, and gluing on individually numbered tags (carapace of crabs).
This method can also be used with modular organisms (have intermediate iteration of the repeated parts or
units of structure), such as plants. However, marking, locating and identifying individuals can be very time
consuming and detailed work in a dense population especially when plants are small.
Permanent quadrants, or markers will move over time due to soil movements and intentional or accidental
interference of animals. Certain types of markers can be lost through vandalism. If an individual is only
mapped or if the marker is not fixed to the plant, then if the plant dies and a new plant grows in the same
place, this individual might be mistaken by the old one.
New individual may grow through the wired ring to create the same problem.
Killing & preserving insects
All insects and hard-bodied invertebrates can be killed and preserved by dropping them into 70% alcohol
solution. Although most other invertebrate groups can be adequately preserved in alcohol, many are better
fixed beforehand. Fixation is the process of stabilizing protein constituents in body tissue to help maintain
them in a similar condition to that when the animal was still alive.
When using alcohol solution to store invertebrates for up to a year or longer, containers should be thoroughly
sealed (since alcohol quickly evaporates) in addition to 5% glycerol to prevent specimen from becoming
brittle, or from completely drying out, should all the alcohol evaporate. Lepidoptera (Butterflies and moths)
should be pinned to prevent damage to the scales on their wings.
Labeling should be done immediately after classification by placing the card along with the specimen into the
jar containing the solution. Since labels attached to the outside invariably fall off eventually.
Some simple methods for catching insects. These are easy to use and quite efficient.
•
•
•
•
•
Pitfall Traps
Suction Sampling
Flight Intersection Trap
Sweep Netting
Water Traps
Methods in Ecology
Sub-Protocol 6/8
4
Pitfall Traps: Animals active on the soil surface are caught in containers that are burrowed at ground level.
Crawling insects are trapped, killed, and preserved in a
formalin solution. The content of the pitfall trap is sorted
Materials used:
according to animal groups. The animals are then preserved
i) 200 [mL] jars
in ethanol, then calculate the activity and abundance.
i) coverage plate on tiny
The buried jars should be filled with formalin solution (about
piles
an inch high). The protection plate should be positioned
i) formalin flask
slightly above ground over the jar to keep rainwater from
i) spatula or shovel
filling it.
After traps have been emptied, it is worth wiping their inside
surfaces with a cloth, to keep them clean and smooth (particularly if slugs and snails have entered and left
behind a mucus trail). In most cases it is sensible to make the position of traps with a small post, or flag, since
they can be surprisingly difficult to relocate, especially if left for long periods during the growing season.
The number of jars is dependent on the site structure, For uniform habitats, 8-10 traps per site are usually
enough. For sites with more complex structures, consider the different subunits within the habitat by using
about 5 jars per subunit. Depending upon species abundance, check traps periodically.
Catches in pitfall traps are a product of both invertebrate density and activity.
Remarks: Marking traps are conspicuous to passers-by and grazing stock, which may damage them. Some
species of ground beetle, once caught, emit pheromones that attract other individuals to the trap,
slightly altering the actual distribution. Catch rates vary with the nature of the surrounding vegetation.
Tend to catch larger invertebrates (<3mm long). Despite these facts, it is one of the most common
method because it is cheap and easy for catching very large numbers of invertebrates. Requires
minimum effort.
A pitfall trap for catching invertebrates moving on the surface of the ground or amongst low vegetation
Methods in Ecology
Sub-Protocol 6/8
5
Suction Sampling: It involves the sucking up of invertebrates from a
Materials used:
known area of vegetation into a net with a motor driven
i) D-Vac device
apparatus (D-Vac). The animals will reach the suction
container alive. It is necessary to keep the sampler running
between individual sucks to prevent collected specimens from escaping. Remove the filter inset including its
contents, close it, and transport if into the laboratory for further investigation.
Remarks: Can be heavy and tiring to carry long distances. Require refilling with a petrol/oil mix at frequent
intervals. Prone to breaking down. Refills need filter. Expensive. It is influenced by the weather
conditions such as rain, wind, grass too wet, etc. Collects fewer invertebrates per unit time spend in the
field. Suction sampling under-records large invertebrates (>3[mm]) that can take shelter or are firmly
attached to the vegetation, as well as those organisms that can sense the approaching vibrations, and
noise and take evasive action. Suction sampling is only effective in vegetation less than 15 [cm] high.
The sorting of the material can be made easier by cooling the samples (freezer, freezing sprays) and
yields the number of individuals per square meter.
This suction sampler can be used to suck up invertebrates from low vegetation and bare ground.
Methods in Ecology
Sub-Protocol 6/8
6
Flight Intersection Trap: It is a device suitable to collect flying insects: it works by blocking flying insects with a
screen of fine black netting. Blocked insects then drop down
into collecting trays or are guided upwards into a collecting
Materials used:
bottle (Malaise trap).
i) Malaise Trap (Townes)
It basically resembling a sac, supported by lateral as well as a
i) formalin flask
roof-like framework. The entire tent-like structure is fenced off
with a mosquito net in a way that two main entrance areas are
left open. The central chamber is divided by a white net in a way that approaching insects can’t proceed with
their intended flight-path. Insects obstructed by this net tend to redirect their route upwards to overcome the
obstacle where the funnel-like roof-construction force them to fly directly into the sealed containers partially
filled with formalin or other narcotizing substances. A battery operated lights can be useful to attract
nocturnally active organisms.
The catch will reflect both the abundance and activity of particular species..
Remarks: Expensive structure. Subject to vandalism by passers-by. Area of research requires approved
permission. Flight interception traps are rarely used to compare numbers of insects between sites or at
the same site overtime. The rate of collection is highly dependent upon the location, wind, position of
the sun. It is pretty effective at catching smaller, more agile flying insects (Hymenoptera).
Malaise Trap after Townes
Methods in Ecology
Sub-Protocol 6/8
7
Sweep Netting: The method involves passing a sweep net (Kescher net - similar like a butterfly catcher) through the
vegetation using alternate backhand and forehand strokes. Nets need to have a reinforced rim. An easy way to
standardize the method is, for each sample to consist of a series of net sweeps of approximately 1m in length
taken every other pace while walking at a steady speed through
the vegetation. After a series of sweeps, invertebrates caught in Materials used:
the net can be easily collected.
i) Kescher net
Remarks: Sweep netting cannot be carried out if the
vegetation is damp and does not work well in vegetation less than 15 [cm] high. The catch obtained
will also be influenced by the speed, depth, and angle at which the net is pulled through the vegetation.
This method is well suited for surveying purposes.
A sweep-net used for catching invertebrates in low vegetation
Methods in Ecology
Sub-Protocol 6/8
8
Water Traps: Many flying insects are attracted to certain colors and can be attracted to and caught in colored waterfilled bowels. Yellow bowel are the best for catching both flies
Materials used:
and Hymenoptera. White bowel also attracts flies, but has a
i) bowels of various
strong repellent effect of Hymenoptera. Neutral colored
colors
bowels, such as brown, gray, or blue are used, these will have
i) bucket of water
the least attractant/repellent effect on insects, and so reduce the
selectivity of the sampling. The species composition of water
trap catches varies with the height of the trap. Therefore, if
being used to survey an area, a number of trapped should be set
at different heights to catch a wide range of species. Conversely, if being used to compare catches between
sites, or at the same over time, the height that the trap is set about should be kept unchanged.. To keep leaves
from falling into the bowels, a wide-mesh gauze can be fixed above it. Traps should be emptied at least once
a week.
Remarks: Variable rippling of water, caused by wind will also affect the trap. Insects captured in that way
are sometimes eaten by birds - once learned about this source, they will visit regularly. Water traps
should also be kept out of reach from grazing stock, since they use them as drinking troughs. Traps
have to be emptied at frequent intervals, otherwise, contents will decay unless a preservative is used
(preservatives will effect the attractiveness of the trap) or flushed out after heavy rain. Likely to be
disturbed by passers-by.
They can be used in all habitats. Insects caught in the taps will depend on their activity and their
attraction to the color as well as their abundance.
A water trap for attracting and catching small flying insects.
Teilprotokoll 7/8
1
Methoden der Kleinklimamessung
(Microclimate)
Teilprotokoll - 7/8
9ten Oktober 1997
Betreut durch: Dr. P. Heiselmayer
Mag. Eichberger
Eingereicht durch:
Bernhard Schmall (Mat-#: 9620737)
Salzburg, im Oktober 1997
Teilprotokoll 7/8
2
Einleitung: Die auf Lebewesen in ihrem natürlichen (Biotop) einwirkenden Faktoren können in klimatische,
biotische und orografische (den Boden betreffend) Einflüsse eingeteilt werden.
Die elementarsten dieser Faktoren sind hinsichtlich klimatischer Einflüsse sind Sonneneinstrahlung, Temperatur,
Luftfeuchtigkeit, Niederschlag, Wind, CO2-Konzentration und Bewölkung.
Aus klimatischer Sicht unterscheidet man Witterung und Klima folgendermassen:
Als Witterung bezeichnet man den Zustand der Atmosfäre im gegebenen Augenblick und wird durch das
Zusammenwirken der einzelnen klimatischen Faktoren bestimmt.
Unter Klima versteht man den mittleren Zustand und den gewöhnlichen Verlauf der Witterung an einem
bestimmten Ort.
In meteorologischen Stationen werden die einzelnen Messpunkte so gewählt, dass die gewonnen Daten möglichst
wenig durch örtliche Gegebenheiten beeinflusst werden (Bodenbedeckung, Hangneigung, Bauwerke, etc.) d.h.:
bodenfern und freistehend. Die Datenreihe, repräsentativ für eine um die Station liegende Gegend, erfasst somit
das Makroklima.
Je näher man sich der Bodenoberfläche nähert, desto grösser werden räumliche und zeitliche Unterschiede
individueller Umweltfaktoren die Messdaten beeinflussen. Das Klima der bodennahen Luftschicht wird als
Mikroklima bezeichnet.
Die im Verlauf der Übung gesammelten Daten und deren Bestimmung beziehen sich ausschliesslich auf die
Erfassung mikroklimatischer Schwankungen die direkt oder indirekt durch die Sonneneinstrahlung gesteuert
werden.
Strahlung: Sonneneinstrahlung ist als elektromagnetische Strahlung (EMR) durch ihre Wellenlänge “λ“ [nm]
und ihre Intensität “I“ [W/m2] gekennzeichnet. Im gesamten Strahlungsbereich weist die EMR kalorische
Wirkung auf, i.e.: der strahlungsabsorbierende Körper wird erwärmt. Kürzere Wellenlängen (<1200[nm]) rufen
ausserdem chemische Veränderungen hervor (E = h⋅f).
Unter Strahlungswärme versteht man die gesamte während einer Zeiteinheit absorbierten Strahlung [J/m2].
Dabei werden aus der Vielzahl der Erfassungsmethoden drei elementare Verfahren herangezogen die direkt bzw.
indirekt die zu erfassenden Grössen beeinflussen:
Eine weitere wichtige daraus resultierende Grösse ist der Wind. Er ist einer der wichtigsten mikroklimatischen
Umweltfaktoren, der vor allem die Temperatur, Niederschlags- und Verdunstungsverhältnisse beeinflusst.
Windgeschwindigkeit und Windrichtung steuern aber auch den Austausch von Wärme, Luftfeuchtigkeit, O2 und
CO2, zwischen Lebewesen und ihrer Umgebung zu bestimmen so massgeblich die Lebensbedingungen für
Pflanzen und Tiere.
Protokollübersicht:
1. Folgende Messgrössen und deren Erfassung wurden während der Übung besprochen:
1.1 Fotosynthetisch aktive Strahlung
1.2 Bodenoberflächen Temperatur mittels Thermoelement
1.3 Relativen Luftfeuchtigkeit mit dem Aspirationspsychrometer nach Assmann
1.4 Windstärkemessung anhand eines thermischen Anemometers
1.5 Potentielle Evaporation
1.6 Bodentemperatur
2. Praktische Ausführung
2.1 Allgemeines zum Standort, Geologie, Klima und Vegetation des Messplatzes
2.2 Diskussion
2.3 Tabellarische Übersicht der gewonnen Daten
2.4 Grafische Darstellung der Tabelllenwerte
Teilprotokoll 7/8
3
1.1 Bestimmung der fotosynthetisch aktiven Strahlung (PhAR) - [µmol Photonen /(s⋅m2)]
Der Wellenlängenbereich für fotosynthetisch wirksame
Strahlung liegt zwischen 380 und 749[nm] und wird
Material:
übereinkommensgemäss auf den Bereich 400-700[nm]
i) PhAR-Meter (mit
festgelegt. Für die Berechnung von Energiegeladenen Akuusatz)
ausnützungskoeffizienten der pflanzlichen Stoffproduktion ist
i) Masstab (mind. 2 [m]
die Erfassung der auf den Pflanzenbestand einfallenden,
lang)
reflektierten und von Blättern absorbierten PhAR notwendig.
Einfallswinkel (Sonnenstand) und Beschattung (Wolken,
Vegetation, etc), fliessen in die Messwerterfassung mit ein.
Anmerkung: Messfühler besitzt eine Abschirmkappe (rot) welche bei direkter Sonneneinstrahlung über
den Sensor gestopselt wird - kam aufgrund der Schattenlage des Messplatzes nicht zum Einsatz.
Weiters sollte Messfühler nicht durch Anwesenheit von Zweit-/Dritt-Personen zusätzlich
Beschattet werden.
Messfühlerposition und Datenerfassung: 5 Mess-Durchgänge in 30-minütigem Abstand
à 4 Positionen (5/10/50/200 [cm] Höhe)
Teilprotokoll 7/8
4
1.2 Bestimmung der Bodenoberflächen-Temperatur mittels Thermoelement [°C]:
Elektrische Thermometer sind sehr klein gebaut und
Material:
ermöglichen Fernmessungen. Durch eine nachfolgende
i) Thermoelement
elektrische Verstärkung kann eine sehr hohe Messgenauigkeit
gestützes
erzielt werden. Der eigentliche Messfühler (Thermoelement)
Temperaturmeter (mit
besteht aus zwei Kontaktstelle zweier an ihren Enden
geladenen Akkusatz)
miteinander verdrillter und verlöteter Drähte aus
verschiedenen Metallen, meist Kupfer und Constatan (für
höhere Temperaturen: Pt - Pt-Rhodium oder Th-Mb Elemente). Eines der Thermopaare wird dabei einer
konstanten Temperatureinwirkung ausgesetzt (Referenz) . Lediglich das zweite Paar wird als
Relativmessfühler zur Temperaturbestimmung eingesetzt. Bei Erwärmung, Abkühlung entsteht aufgrund
des Prinzips der elektrochemischen Spannungsreihe eine elektromotorische Kraft (EMK), welche der
zweitenj (Referenzfühler) entgegenwirkt. Eine nachgeschaltete Verstärkerstufe ermöglicht die Erfassung
der gesamt EMK (ist proportional der Temperatur) mit einer digitalen oder analogen Anzeige.
Anmerkung: Vor Beginn der Messung sollte Messfühler kalibriert werden - Justage per KalibrierungsPotentiometer und Nullwertschalter auf die “0“-Marke des Zeigerinstrumentes.
Thermosensor nicht mit den Händen auf den Boden drücken - es genügt die oberste Bodenlage zu
vermessen (Körperwärme)
Messfühlerposition und Datenerfassung: 5 Messdurchgänge in 30-minütigem Abstand
à 5 Positionen
Thermoelemente zur Temperaturmessung:
A; Temperaturdifferenzmessung
B, Absolutmessung, wobei die Vergleichslötstelle in Eiswasser getaucht wird (4°C-Referenz)
C, Thermosäule, in Serie geschaltene Thermoelemente, zur Bodentemperatur-Differenz-Messung
D, Parallelschaltung, Mittelwertbildung der drei frei stehenden Thermoelemente, wobei viertes Element
als Referenzelement zu betrachten ist (analog B)
Teilprotokoll 7/8
5
1.3 Erfassung der relativen Luftfeuchtigkeit mit dem Aspirationspsychrometer nach Assmann [%]
Das Gerät, als Aspirationsthermometer mit zwei
Material:
Thermometern und einem nachgeschalteten Lüfter
i) Aspirationsmeter (mit
ausgeführt, erfasst Lufttemperatur und Verdunstungskälte.
federgetriebenen Gebläse)
Durch einen mit destilliertem Wasser getränkten
i) destilliertes Wasser
Textilstrumpf wird eines der Thermometer durch den vom
Gebläse verursachten Luftzug abgekühlt. Je trockener die
lang)
aspirierte Luft, desto grösser die Verdunstungskälte. Die
dadurch entstehende Temperaturdifferenz ist der relativen
Luftfeuchte proportional.
Das Gerät ist in ein doppeltes Gehäuse eingebaut um die Temperaturerfassung durch
Sekundärwärmeemitenten (Hand- Körperwärme) nicht zu verfälschen.
Anmerkungen: Gebläseöffnungen während der Messung nicht mit den Händen abdecken; sicherstellen,
dass Textilstrumpf vor jeder Messung mit destilliertem Wasser befeuchtet wurde.
Aspirations-Psychrometer nach Assmann
Teilprotokoll 7/8
6
1.4 Thermischer Windmesser (Hitzdraht Anemometer) [m/s]:
Heizt man einen Körper (Heizdraht) elektrisch mit konstanter
Leistung, so hängt die Differenz zwischen Körpertemperatur
und Lufttemperatur von der Windgeschwindigkeit ab. Diese
Technik eignet sich daher bestens zur Bestimmung kleiner
Windgeschwindigkeiten wie sie vor allem im Inneren von
geschlossenen Pflanzenbeständen auftreten.
Material:
i) Hitzdraht-Anemometer
(mit geladenen Akkusatz)
lang)
Anmerkungen: Vor Inbetriebnahme kalibirert sich das Messgerät automatisch - dabei sollte jedoch der
Messfühler von der Schutzlamelle (Schieberegler am Messfühlergriff) noch geschlossen sein.
Während der Messung nicht unnötig zum Messfühler blasen, husten, etc.
Hitzdraht-Anemometer
1)
2)
3)
4)
5)
6)
7)
Manganin φ 1mm
2) Manganin φ 0.2mm
Konstantan φ 0.3mm
Heizdraht aus NiCr φ 0.08mm
Bakelit
Cu-Rohr φ 5mm
Cu-Kugeln φ 6mm
Teilprotokoll 7/8
7
1.5 Potentielle Evaporation (Piche Evaporimeter) [ml/min] bzw. [m3/h]:
Die Wasserabgabe von einem Blatt und einer freien
Material:
Wasseroberfläche ist unterschiedlich. Im letzeren Fall erfolgt
i) Bürettenrohr
eine nahezu ungehinderte Änderung des Aggregatzustandes,
i) Massstab
da gasförmiges und flüssiges Wasser unmittelbar
i) Filterpapierscheiben
aneinandergrenzen.
(mit 3 [cm] Durchmesser)
Im Blatt einer Pflanze ergeben sich aufgrund des Zellgerüstes
i) Klemmfedern
komplizierte Grenzverhältnisse aufgrund der vorhandenen
i) Befestigungsklammern
Matrix. Um das jeweilige Verdunstungspotential der
i) Befestigungsstützen
Atmosfäre objektiv erfassen zu können, ist ein geeignetes
(mind. 1[m] lang)
Messverfahren notwendig.
Das Piche Evaporimeter erfüllt diese Bedingungen.
Dazu benutzt man ein Bürettenrohr und füllt es zu ¾ mit destilliertem Wasser auf. Mittels eine
Klemmfeder wird am offenen Ende eine Filterpapier-Scheibe eingespannt. Aufgestellt wird das
Evaporimeter mit der Filterscheibe nach unten in der zu untersuchenden Verdunstungshöhe (hier 5, 10, 50
[cm] Distanz zu Bodenniveau).
Durch das Umdrehen saugt sich die Papierscheibe mit Wasser an und befeuchtet sich. Sie wird durch den
dabei entstehenden geringen Unterdruck, zusätzlich zur Kraft der Feder an die Burettenöffnung
angedrückt. Weiters verhindert das Filterpapier ein auslaufen der Flüssigkeit.
Anmerkungen: Verdunstungsplättchen sollten über den gesamtem Messerfassungs-Zeitraum ungestört
bleiben (während Ablesung ist Annäherung unumgänglich). Morgendliche Messungen verlaufen
fehlerhaft, da bei
Sonneneinstrahlung
(Wasser und
Lufterwärmung) die
Flüssigkeit aus dem
Gefäss gepresst wird.
Ablesungen sind nur so
lange zulässig, als sich
kein flüssiges Wasser
auf der Papierscheibe
ansammelt (tritt bei
Regen auf). In solchen
Fällen muss der
Wasserüberschuss
abgesaugt werden.
Das Bürettenrohr ist mit
der aufgedruckten Skala
in 1/100 [ml] eingeteilt.
Dadurch ist es möglich
Ablesungen schon nach
5 [min] vorzunehmen.
Messfühlerposition und
Datenerfassung: 5
Messdurchgänge in 30minütigem Abstand
à 3 Positionen (5/10/50
[cm] Höhe)
Teilprotokoll 7/8
8
1.6 Bodentemperatur (Stechthermometer) [°C]:
Bodentemperatur kennzeichnet den Energieumsatz im Boden
und steht in enger Beziehung zum Wasser-Luft Haushalt; sie
beeinflusst ausserdem die Stoffwechseltätigkeit der
Vegetationsglieder eines Standortes, vor allem der
Mikroorganismen.
Material:
i) Stechthermometer (mit
geladenen Akkusdatz)
i) Massstab
Anmerkungen: Messfühler in das Erdreich treiben und
abwarten bis Handwärme durch Bodenwärme ersetzt wurde (zeitverzögert). Sicherstellen das
Zeigerausschlag in der Testposition den “0“-Wert erreicht.
à 3 Positionen (2/5/10/ [cm] Tiefe)
Thermoelemente zur Temperaturmessung:
A; Temperaturdifferenzmessung
B, Absolutmessung, wobei die Vergleichslötstelle in Eiswasser getaucht wird (4°C-Referenz)
C, Thermosäule, in Serie geschaltene Thermoelemente, zur Bodentemperatur-Differenz-Messung
D, Parallelschaltung, Mittelwertbildung der drei frei stehenden Thermoelemente, wobei viertes Element
als Referenzelement zu betrachten ist (analog B)
2.
Teilprotokoll 7/8
9
Praktische Ausführung:
2.1 Allgemeine Angaben zum Standort der Datenerfassung:
Standort: Salzburg - Freisaal, 100 [m] westlich der NAWI (hinter dem UNI-Teich) unter der Eiche;
Meereshöhe: 422 [m]
Terrain: eben
Geologie: Nördliche Kalkalpen (grossgeologisch) Moräne und Alluvium (abgelagertes Gesteinsmaterial
der Gletscherformation während der letzen Eiszeiten sowie Ablagerungen von Schwemmaterial des
nahegelegenen Flusses, Salzach).
Klima: Gemässigtes, feuchtes Klima (im Nordstau der Alpen);
durchschnittliche Niederschlagsmenge pro Jahr: 1300 [mm]
Jahresdurchschnittliche Temperatur: 9°[C]
Dominante Windrichtung: West
Vegetation: Mehrmahdige Wiese, mit gepflanzten Kulturbäumen und -sträuchern; nahegelegener Bach
(Hellbrunnerbach) und künstlich angelegter Teich (UNI-Gewässer); sowohl Boden als auch Gewässer
stark eutrofiert (Hinterlassenschaft von 4-Beinern).
Witterung: Leicht bis stark bewölkt - herbstlich warm
2.2 Diskussion:
Die hier kurz angerissene Gegenüberstellung beruht auf den Vergleich der hier gewonnenen Daten mit
jenen Werten der Gruppe “Wiese“ (Zocher, Machart, Hager):
Strahlungswerte der 1445er Serie sind folge einer kurzzeitigen starken Sonneneinstrahlung (gesamtes
Spektrum); im Vergleich dazu fallen die Werte “Baum“ (trotz nur 10%-iger Intensität) eher konstant zu
allen erfassten Messzeitpunkten aus;
Begründung: Blätterdach schirmt einfallendes Spektrum hervorragend ab
Windgeschwindigkeiten der 1415er Serie weichen am stärksten im offen Gelände “Wiese“ völlig vom
Standort Baum ab;
Begründung: An der Baumbasis ist Messplatz von niederen Sträuchern umgeben die sehr effizient
Luftströmungen abschwächen
Bodentemperaturwerte der -2er Serie der Gruppe Wiese sind auffällig erhöht; die lässt auf einen
intensiven Spektrumanteil schliessen welcher geringfügige aber doch messbare Eindringtiefe besitzt Der
Bodenoberflächen-Temperatur, der 1415er Serie resultiert durch die kurzfristige Sonnenstrahlung zum
gegenwärtigen Messzeitpunkt.
Verdunstungswerte der 1415er bis 1515er Serie liegt im freien Gelände während bis nach der
Sonneneinstrahldauer sehr hoch; speziell in bodennahen Bereich dürften mehr Strahlungswärme vom
Evaporimeter aufgenommen worden sein; hat eine Volumsausdehnung zur Folge, womit sich dieser
massive Schwund erklären liesse.
Lufttemperatur liegt aufgrund der kurzfristigen Sonneneinstrahlung während der 1415er Serie etwas höher
als in den Vergleichsmesszeiträumen.
Luftfeuchtigkeit ist in bodennahen Schichten stärker als in den höheren Messlagen;
Begründung: Wasserverbrauch (Bodenfeuchtigkeit) des Grasbewuchses bei Assimilationstätigkeit
Teilprotokoll 7/8
10
2.3 Datensammlung (Tabelle - links Gruppe “Wiese“ - rechts Gruppe “Baum“):
Zeit
Höhe
1345
1415
1445
1515
1545
Strahlung [µmol Fotonen /(s⋅m2)]
5 [cm] 10[cm] 50[cm] 200[cm]
280
327
441
481
351
444
533
611
1048
1214
1212
1124
245
802
752
472
239
339
362
440
Zeit
Höhe
1345
1415
1445
1515
1545
Strahlung [µmol Fotonen /(s⋅m2)]
5 [cm] 10[cm] 50[cm] 200[cm]
28.8
25.6
26.5
27.7
32.0
33.3
30.3
20.7
28.9
21.1
28.7
22.1
27.9
27.1
24.3
14.3
22.9
27.5
24.0
23.4
Zeit
Höhe
1345
1415
1445
1515
1545
Wind [m/s]
5 [cm] 10[cm]
0.07
0.11
0.19
0.18
0.07
0.10
0.11
0.07
0.03
0.22
200[cm]
0.07
0.85
0.63
0.14
0.76
Zeit
Höhe
1345
1415
1445
1515
1545
Wind [m/s]
5 [cm] 10[cm]
0.03
0.12
0.00
0.00
0.03
0.05
0.04
0.16
0.09
0.04
Zeit
Tiefe
1345
1415
1445
1515
1545
Bodentemperatur [°C]
-10[cm] -5 [cm] -2 [cm]
15.8
17.1
18.8
16.0
17.4
18.8
16.0
17.6
19.1
16.0
17.8
19.3
16.2
17.8
19.3
0 [cm]
21.9
23.0
26.4
24.9
21.9
Zeit
Tiefe
1345
1415
1445
1515
1545
Bodentemperatur [°C]
-10[cm] -5 [cm] -2 [cm]
15.0
16.0
17.0
15.0
16.0
18.0
16.0
17.0
18.0
16.0
17.0
17.0
16.0
17.0
17.0
Zeit
Höhe
1345
1415
1445
1515
1545
Wasserverdunstung [ml]**
5 [cm] 10[cm] 50[cm]
0
0
0
0
0.1
0
0.2
0
0.1
0.1
0.2
0.5
0.1
0.1
0.1
Zeit
Höhe
1345
1415
1445
1515
1545
Temperatur [°C]*
5 [cm] 10[cm]
21.4
20.6
22.0
21.6
24.0
22.2
23.2
23.0
21.8
23.0
50[cm]
22.4
21.2
23.0
24.0
23.0
200[cm]
21.4
22.8
25.0
24.8
24.2
Zeit
Höhe
1345
1415
1445
1515
1545
Temperatur [°C]*
5 [cm] 10[cm]
21.3
20.1
21.0
21.9
22.4
22.4
23.2
22.8
22.2
22.2
50[cm]
21.0
22.0
22.4
22.6
22.2
200[cm]
22.0
22.0
23.0
22.6
22.6
Zeit
Höhe
1345
1415
1445
1515
1545
Luftfeuchtigkeit [%]***
5 [cm] 10[cm] 50[cm]
86
64
88
71
77
81
73
57
70
67
56
74
76
65
93
200[cm]
67
64
47
45
62
Zeit
Höhe
1345
1415
1445
1515
1545
Luftfeuchtigkeit [%]***
5 [cm] 10[cm] 50[cm]
77
77
77
69
68
84
58
56
59
57
57
62
68
66
70
200[cm]
68
68
51
56
64
50[cm]
0.18
0.70
0.19
0.23
0.55
Zeit
Höhe
1345
1415
1445
1515
1545
50[cm]
0.05
0.00
0.18
0.26
0.19
200[cm]
0.04
0.02
0.24
0.61
0.10
0 [cm]
20.7
20.2
21.0
22.3
20.6
Wasserverdunstung [ml]**
5 [cm] 10[cm] 50[cm]
0
0
0
0
0.2
0.1
0.1
0.15
0.15
0.1
0.2
0.1
0.2
0.1
0
*) Lufttemperatur mittels Aspirationspsychometer erfasst.
**) Wasserverdunstungs-Volumen: relativänderung zum vorigen Messwert
***) ?????????????
Methods in Ecology
Sub-Protocol 8/8
1
Methods in Ecology
Bioindicators
Protocol 8/8
October 10th 1997
Instructor: Dr. R. Türk
Handed in by:
Salzburg, 31ten Oktober 1997
Bioindicators
Methods in Ecology
Sub-Protocol 8/8
2
Bioindicators
Introduction: An indicator is a species indicating the state of both natural and man-made (antropogen)
environments. Such physical and chemical disturbances will result in a change in species composition of the biotic
community. Such community changes are useful in monitoring current states of the environment and quite helpful in
environmental assessment. Biological material and indicator species
used for monitoring of pollutants are many and varied, ranging
Monitor Organism
from cells, tissues and organs to whole organisms, including
protists, lower plants, lichens, higher plants, coelenterates,
aquatic and terrestrial invertebrates, even fish, and birds.
active
passive
monitoring
monitoring
Plant and Animal Indicators: Throughout history, different
cultures have known that the presence of certain species,
reaction
accumulation
especially plant species, indicated certain conditions. The
indicators
indicators
presence, absence and condition of every plant and
animal is a measure of the conditions under which it is existing or existed previously.
• Occurrence of plants like the Common Stinging Nettles (Urtica dioica) indicate high levels of N in soil.
• The insect group ephemeroptera (Mayflies) which have aquatic larvae contains species that are intolerant
to eutrophication, and so have been incorporated into programs monitoring water quality.
• The appearance of Rosebay Willow Herb (Chamaenerion angustifolium) indicates disturbed soil or some
kind of perturbation.
• Aborigines of West Africa recognized the Gau Tree (Acacia albida) as a fertile soil instrument.
• The presence of basil (Ocimum homblei) in Zimbabwe indicates high copper content in the soil.
Behavior and physiology: Some animals have been used in monitoring the quality of the environment.
• Dawn chorus bird of polluted and disturbed urban areas are less likely to participate in chorus singing.
• Miners have used caged canary to give biological warning signals when detecting methane gases.
• The behavior and respiratory physiology of several aquatic organisms including fish have successfully
been used to monitor water quality.
Microevolution: One classical example of an indicator of the extent of pollution has been the spread of melanic
forms of the Peppered moth (Biston betularia) throughout polluted areas of Britain and Europe. Particularly
striking, was the spread but then later decline of melanic forms after the Clean Air Act in Britain. This
decline in coincided with a period of increasing species richness of lichens on trees.
Community indicators: Populations of animals and plants occur in communities and therefore the species indicator
concept can be extended to communities of indicator species.
Different soils (serpentine, chalk, acids) all support indicator plant communities.
• The characteristic flora of serpentine soils, which are low in Ca and high in Mg, is a good example of a
plant indicator community.
• Acids soils, in which heathland plants reside, are the low-growing, dwarf ericoid shrubs.
• Best quality water indicators were discovered in association with dominance of Alopecurus pratensis,
Agropyron pectiniforme and Stipa capillata in the former USSR.
• Diatoms, are still used to monitor river and stream water quality.
Indicators of pollution: It has long been known that heavy metals and organochlorides penetrate ecosystems, as a
result, some organisms will accumulate pollutants in varying amounts.
In polluted parts of the River Thames, the mollusk Anodonta spp. Has been found to have twenty times the
level of cadmium compared to the same species from the River Test.
Although bioaccumulation occurs in a wide variety of taxonomic groups, it does not necessarily follow that
the source of pollution is near those organisms in which the pollutants have accumulated.
• The discovery of DDE (variant of DDT) in bodies of Penguins in the Antarctic, thousands of miles from
any use of agrochemicals.
• Detector species occurring naturally in the area of interest and which may show a measurable response to
environmental change, e.g. changes in behavior, mortality, age-class structure, etc.
• Exploiter species whose presence indicates the probability of disturbance or pollution. They are often
abundant in polluted areas because of lack of competition from eliminated species.
• Accumulator organisms that take up and accumulate chemicals in measurable quantities.
• Biossay organisms are selected for use as a laboratory reagent to detect the presence and/or concentration
of pollutants, or to rank pollutants in order of toxicity.
Methods in Ecology
Sub-Protocol 8/8
3
Bioindicators
Such organisms used as detector and exploiter types should have the following characteristics:
1. Narrow tolerance to environmental variables (stenothermal, stenohaline) instead of high tolerance
(erythermal, euryhaline).
2. Easy to sample.
3. Accumulation of pollutants should occur without killing the organism.
4. Sedentary or limited dispersal like: plants, common chronic symptoms: premature senescence and
bronzing or chlorosis due to disease of insects, environmental stress, drought, etc.
5. Long-lived so that different age-classes can be sampled; e.g.: lichens and mosses are very sensitive to airborne pollutants and in the case of lichens have the potential to flourish for centuries (under favorable
conditions).
In the case of lichens, pollutants such as SO2 affects the algae component of the lichen and thus the symbiotic
relationship between algae and fungus breaks down. Lichens have long been used as a bioindicator for more
than 100 years. Lichens are also detector, exploiter and accumulator, these characteristics make them a good
indicator of air pollution. Monitoring air pollutants by lichen mapping itself because lichens are also sensitive
to HF, HCl, NOX, O3, and pAN (known to be detrimental). Lichens can be used as a biological material
instead of physical and chemical apparatus for air pollution measurements.
Many lichens are widespread and can be used over wide areas. Epiphytic lichens should be investigated on
one or a limited number of similar tree species which are not influenced by microenvironmental conditions.
Mapping of lichens requires a high degree of experience. It should be done in periodic time intervals and
should cover a great diversity of species. Interpretations and results should be done by lichenologists.
In alpine valleys the lichen growth on mountain maple trees (Acer pseudoplatanus, Alnus incana) are useful
indicators of SO2 pollution.
Even though lichen mapping is a valuable tool in estimating air quality, it should be supplemented by the use
of lichen transplants and determination of sulfur and chlorophyll content of the lichen thalli.
Mosses on tree barks are valuable indicators of pollution of heavy metals. Since mosses lack epidermis and
cuticle, they accumulate metals in a passive way by acting as ion exchangers. These bioaccumulation is
enforced by the fact that mosses do not have organs for the take up of nutrients from the substrate.
Trees selected for the pollution mapping should have the following properties:
a) Tree should be free standing, (except for extensive agricultural use, because the herbicides and
pesticides use can influence lichens cover and falsifies mapping results).
b) The bark of road side trees are usually exposed of exhausted pollutants and dust caused by traffic.
c) The buffer capacity of the tree bark play an important role in lichen distribution. Tree with an acidic
bark are unsuitable for studies, because the buffer capacity is very low. Although, many ecologists
made use of tree bark as a bioindicator of environment acidity.
d) Some species are not suitable for mapping since they support a rich lichen flora, such as Aesculus
hipocastanum and Fraxinus excelsior.
e) The particular different water capacities of tree barks and of rain tracks (runoff) have to be considered
in micro-environmental influence;
f) The percentage cover of Lecanora conizaeoides is a valuable indicator of pollution levels, because in
highly polluted areas this species only occurs in the bark crevices; whereas in less highly polluted
areas tally occur on bark ridges.
g) Since the layer structure of mosses produce organic matter; therefore, accumulate metals in a passive
way by ion exchangers.
An other interesting organism often used to monitor air quality is Tobacco (Nicotiana tabacum), or BEL 3 as
it is known for short. It is a very easy to use indicator plant for ground-level ozone. Because it is sensitive to
phytotoxic constituents, it reacts to even very low concentrations of O3, and shows characteristic symptoms
(spots). These spots are small white lesions on the adaxial surfaces of the leaves and are the cause of
photochemical reactions from incompleted combustion of fossil fuels.
There are many other biological indicators which could successfully be used, not only as effective warning systems
but also as cheap and reliable components of long-term pollution monitoring programs.
Methods in Ecology
Sub-Protocol 8/8
4
Bioindicators
Right: Active biomonitoring with exposed lichen samples
Left: Bonitierungsskala von Blattnekrosen bei tausalzgeschädigten Linden.
1) ungeschädigt
2) Chlorose des >Randes
3) starke Chlorose bei Spreite (gelbfärbung des Randes)
4) breite Randnekrose mit gelber Grenzzone
5) grösster Teil der Spreite abgestorben
Flechenrekrosen (silberflecken) auf den Blättern des Tabaks Nicotiana tabacum. BelW3 als charakteristisches OzonSAchadbild. Die Nekrosen bilden sich bei jungen Blättern nur an der Blattspitze
Methods in Ecology
Sub-Protocol 8/8
5
Bioindicators
Practical Observations around the backyard of the University:
Paved square at the back entrance of the University building reveals that moss growth in the gaps of the
blocks is very limited due to excessive pedestrian traffic. Whereas other sections not as heavily
frequented by people show a more advanced level of succession (grass, etc.).
Marble walls of the west-side wing of the University building are covered with a grayish film. The most
concentrated patches are found at those locations where rain water run off is heaviest. The Ca-rich
substrate provides an ideal spot for cyanobacterial growth. Heterocysts autotrophic organism can fix
nitrogen from the air and chlorophyll enables them to utilize sunlight to convert CO2 to O2 for their
energetical requirements.
Caleoplaca cytrina, a lichen found on nitrogen rich substrates; is found preferably at locations periodically
fertilized by urination of Pincelin canine (common name: dog).
Almost every tree trunk is covered with a greenish film; the presence of Pleurococcus sp., indicates that
excess fertilization from relocated artificially fertilized soil (soil erosion by wind) nourishes their
growth. This particular pattern is not found in areas lacking farming. In distinct sections of tree trunks,
frequent visitors (cats) sharpen their claws, therefore minimizing recolonialization of epiphytic
organisms.
Counting epiphytic lichens: An easy procedure in which a plot is filed by pinning a self made transparent census
overlay against the tree bark. The plastic foil is divided into squared compartments, measuring 10 x 10 [cm]
each, with a total area of 0.2 x 0.5 [m2].
Identification and determination of the frequencies of the species present within this area reflects species
diversity. If this procedure is repeated in frequent intervals of time (taking pictures), the plot technique is a
powerful tool to compare past and present changes of sensitive lichen colonies.
Quercus robur
Height: 1.2 to 1.45 [m];
Exposition: west
Frequency
Species found
units
Remarks:
∑
Termini
Bioindicators reveals the presence of air pollutants by showing typical symptoms from the effects of other natural or
antropogenic stress. BI may react either specifically to a certain pollutant or unspecifically to a mixture of
toxins.
Bioaccumulator has collected pollutants from the surrounding air in a given time reference. They are been analyzed
for the detection of those components which are not decomposed, released or translocated. These plants are
accumulators.
Biomonitor can be an indicator or accumulator: they can provide quantitative information and allow to identify
changes in pollution over the course of time. Pollutants are released by sources dispersed in the atmosphere
and transmitted to a certain location where the ambient concentration is called immission.
Monitoring:
Active M.: Organisms known to be sensitive (narrow tolerance) to certain pollutants are exposed intentionally
to various locations in order to monitor their reaction in periodic intervals of time.
Passive M.: The presence, absence and condition of every plant and animal is a measure of the conditions
under which it is existing or existed previously.
Reaction Indicators: An organism reacts in a visible way caused by antropogenic sources.

Census Techniques in Ecology

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