1 DINÂMICA DE ECOSSISTEMAS WHAT IS AN ECOSYSTEM?

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1 DINÂMICA DE ECOSSISTEMAS WHAT IS AN ECOSYSTEM?
DINÂMICA DE ECOSSISTEMAS
Módulos Programa:
-Tipos e características dos ecossistemas (terrestres, aquáticos e urbanos)
- Principais processos na dinâmica dos ecossistemas
- Impactos humanos nos ecossistemas
- Alterações globais e impactos nos ecossistemas
- Recuperação de ecossistemas
WHAT IS AN ECOSYSTEM?
Etymologically the word ecosystem derives
from the Greek oikos, meaning "home," and
systema, or "system."
Nineteenth- and early 20th-century ecologists,
who were well aware of the complex
interdependence of living and nonliving
matter, coined several terms, such as
biocoenosis, microcosm, holocoen, biosystem
and geobiocoenosis.
It was not until British ecologist A.G. Tansley
proposed the word "ecosystem" (1935)
that American Raymond L. Lindeman offered
the now classic definition (1942).
Ecosystems are composed of a variety of
abiotic and biotic components that function in
an interrelated way.
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COMMENT THIS DEFINITION
Ecosystem - A functional system which includes the organisms of a natural
community together with their environment. (McGraw Hill Dictionary of Scientific
and Technical Terms, 4th ed)
DO YOU AGREE?
HOW WOULD YOU DEFINE ECOSYSTEM?
WHAT ARE AQUATIC ECOSYSTEMS?
Freshwater lake ecosystem
Artic ecosystem
Ocean beach ecosystem
Temporary ponds ecosystem
WHAT BONDS THEM TOGETHER?
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WATER CYCLE RESIDENCE TIME AND ROBUSTNESS
Estimated Flows of Water in the Global Water Cycle
Flows given in units of 1015 kg/year
Inventory of Total amount of water:
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1,385,990.5 x 10 kg
Residence times
Data from Chahine, 1992, The hydrological cycle and its influence on climate, Nature, v. 359, p. 373-380;
WHAT ARE AQUATIC ECOSYSTEMS?
Basic ecological unit composed of living and non-living elements
interacting in an aqueous milieu
Any watery environment, such as rivers, lakes, wetlands, and
estuaries, in which plants and animals interact with the chemical
and physical features of the environment
WATER PHYSICAL-CHEMICAL CHARACTERISTICS + BIOTA COMMUNITIES
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SUSTAINING AQUATIC ECOSYSTEMS FUNCTIONS:
ECOHYDROLOGY APPROACH
“DUAL REGULATION”
Hydrology regulates biota and
shaping biota can regulate
hydrology
BIOTA
REGULATION
HYDROLOGY
HARMONIZATION
of hydrotechnical infrastructure
INTEGRATION
of various regulations acting in a synergistic
way to stabilize and improve the quality of
water resources
AQUATIC ECOSYSTEMS REQUIREMENTS..?
NEED TO BE PERMANENT?
and...TEMPORARY LAGOONS, PONDS
NATURAL OR ARTIFICIAL?
and...LAKES FROM DAMS
PRESENT STABLE
CHARACTERISTICS?
and...ESTUARIES
IS A MINIMUM OR MAXIMUM SIZE? and...SMALL PONDS / OCEAN
NEED TO BE IN PRISTINE FOR
FUNCTIONING?
and CHRONIC POLLUTION
HIGH VARIABILITY IN
SPATIAL, TEMPORAL, BIOTIC AND ABIOTIC FEATURES
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TYPES OF AQUATIC ECOSYSTEMS
Marshes are defined as wetlands frequently or
continually inundated with water, characterized by
emergent soft-stemmed vegetation adapted to
saturated soil conditions.
Mangroves are trees and shrubs that grow in
saline coastal habitats in the tropics and subtropics.
Mangals are found in depositional coastal
environments with fine sediments, often with high
organic content, in areas protected from high
energy wave action.
TYPES OF AQUATIC ECOSYSTEMS
•SWAMP (PÂNTANO)- like a marsh but with
bushes and trees growing from the water as
well
•PUDDLES (CHARCO) - and body of water
that lasts for a few days or more may attract
aquatic life
•TIDAL POOL (POÇA DE MARÉ) – A pool of
water remaining after a tide has retreated
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TYPES OF AQUATIC ECOSYSTEMS
•RIVER (RIO) - a moving body of water that
flows from one place to another.
•POND (LAGO PEQUENO)- a small and
shallow body of water with plants growing
above water level only on the edges;
generally freezes solid during winter.
TYPES OF AQUATIC ECOSYSTEMS
•ESTUARY (ESTUÁRIO) - part of a river
where it nears the sea; fresh and salt water
mix
•OCEAN (OCEANO) –The entire body of salt
water that covers more than 70 percent of
the earth's surface
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TYPES OF AQUATIC ECOSYSTEMS
•SALT LAKE (LAGO SALGADO) - A salt lake is a
lake which has a concentration of salts higher than
sea water
•HYDROTHERMAL VENTS (FONTES
HIDROTERMAIS) - A hot spring on the ocean floor
where hydrothermal fluids mix into the overlying
ocean.
MAIN CHARACTERISTICS OF AQUATIC ECOSYSTEMS
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CHARACTERISTICS OF LAKES
CHARACTERISTICS OF LAKES : CIRCULATION AND PRODUCTIVITY
oligotrophic lake— Low nutrients and transparent water characterize these lakes. There is low productivity, and the
benthic fauna is highly diverse but low in number. The basin is typically deep with steep banks. The sediments are typically
low in organic matter.
eutrophic lake— This is a lake with high nutrients and, therefore, high primary productivity (algae and plants). Bluegreen algae are characteristically extensive in these lakes, especially in summer. The littoral zone is typically broad with
abundant plants. Due to high production, there is a great deal of biomass and decomposition in the profundal zone with
few benthic species. In the summer, there is often depleted oxygen in the hypolimnion.
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CHARACTERISTICS OF ESTUARIES: SALT-FRESHWATER MIX
CHARACTERISTICS OF ESTUARIES: SALINITY AND BIOTA
HIGH ESTUARY
MIDDLE ESTUARY
LOW ESTUARY
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CHARACTERISTICS OF OCEANS
CHARACTERISTICS OF OCEANS
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CHARACTERISTICS OF OCEANS
Africa
100 Km
1000 Km
CHARACTERISTICS OF OCEANS
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biomas
DEFINIÇÃO E TIPOS DE BIOMAS
Bioma – major regional community of plants and animals with
similar life forms and environmental conditions. It is the largest
geographical biotic unit, and is named after the dominant type
of life form, such as tropical rain forest, grassland, or coral reef.
O número de biomas que são reconhecidos pelos biogeógrafos
variam. Apenas nos EUA podem ser encontradas 150 ecoregiões
diferentes. No entanto, normalmente consideram-se 2 biomas
aquáticos e 8 biomas terrestres.
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BIOMAS AQUÁTICOS
BIOMAS DE ÁGUA DOCE
► zonas lênticas – águas paradas (ex. lagos)
► zonas lóticas – águas em movimento (ex. rios)
Factores ambientais que caracterizam os biomas de água doce.
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BIOMAS MARINHOS
► zona pelágica : (factor determinante
capacidade de natação)
• plâncton – organismos flutuadores
• necton – organismos nadadores
► zona bentónica : (factor determinante
profundidade)
• zona costeira
• zona oceânica
Diferentes zonas do bioma marinho e principais factores
que condicionam as comunidades nas várias zonas
BIOMAS TERRESTRES: DISTRIBUIÇÃO E CAUSAS
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BIOMAS TERRESTRES: VARIAÇÃO EM ALTITUDE
E EM LATITUDE
BIOMAS TERRESTRES: TIPOS
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Ecossistemas urbanos
ACLIMATAÇÃO HUMANA AO CALORILHAS DE CALOR URBANO
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ACLIMATAÇÃO HUMANA AO CALORILHAS DE CALOR URBANO
CAPACIDADE DE ACLIMATIZAÇÃO Short-term
Long-term
SAÚDE HUMANA
COLD EVENTS
FACTORS CONTROLLING ECOSYSTEMS DYNAMICS
1. THE VARIABILITY OF EXTERNAL ENVIRONMENTAL FACTORS
PRECIPITATION,
AIR TEMPERATURE
RIVER DISCHARGE,
TIDES, WIND,
2. INTERNAL ECOSYSTEMS PROCESSES
FOOD WEB
WATER-SEDIMENT EXCHANGE
NUTRIENTS CYCLES
CARRYING CAPACITY
3. IMPACTS FROM EXTERNAL SOURCES AND ECOSYSTEMS
POLLUTION
DEFORESTATION
DAMMING, …
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DYNAMIC IN COASTAL ECOSYSTEMS
EXTREME SHORT-TERM CONDITIONS ARE MORE IMPORTANT THAN LONG-TERM ONES
(AMBROSE, 1984)
HIGHLY DYNAMIC ECOSYSTEMS
COASTAL ECOSYSTEMS KEY FACTORS AND PROCESSES
RESIDENCE TIME
RESIDENCE TIME (T)
TIDES
WAVES
CURRENTS
KNOWLEDGE ABOUT KEY-FACTORS
AND SYSTEM FUNCTIONING IS
FUNDAMENTAL TO MANAGEMENT
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