Forest, Woodland and Shrubland Health in Southwest WA

Climate Adaptation: Forest, Woodland
and Shrubland Health in Southwest WA
Giles Hardy
Tom Lyons, Neil Enright, Richard Hobbs, Erik
Veneklaas, Sue Moore, Paul Barber, Katinka
Ruthrof, Bernie Dell, Trish Fleming, Michael
Renton, Catherine Baudains, Renato Schibeci,
Brad Evans, Kobus Wentzel, Ray Froend, Keith
Smettem, Colin Yates, Guy Midgley, Pieter Poot,
Erik Veneklaas
Forest, Woodland and Shrubland
Health in Southwest WA
• South West of WA is a Global biodiversity
‘hotspot’
• Very high levels of endemism
• Higher temperatures and lower rainfall in SWA
under projected climate change  increased
drought stress
– Substrate constraints mean that community
composition must re-sort locally in relation to species
resilience thresholds (rather than migrate)
Shrubland Health
• The dune - swale topography of the biodiverse
northern sandplain shrublands provides a
natural laboratory for exploring the effects of
water availability on plant growth and
community assembly
• This study will develop an integrated climatesoil-plant model to predict the likely impacts of
projected climate change on major plant
functional types (PFT’s)
N. Enright et al
Equipment & monitoring set-up:
Sites with contrasting water availabilities based on soil
volumes available for water storage and root proliferation
Weather station
Soil moisture profile probes
Rain gauges
Sap flow
sensors
8 m
Water
level
well
4 m
Unconsolidated sand
Lateritic layer
High dune Swale dune
Horizontal scale: 0
Low 100 m
0 m
Forest and Woodland Health
• Failing tree health widespread in endemic
species of eucalypts such as tuart, wandoo,
flooded gum, marri, jarrah, and in banksia
woodlands and heathlands
• Causes either simple or complex (the
majority)
• Need to understand the causes (biotic and
abiotic) in order to manage and implement
control methods in face of climate change
Tuart decline (Eucalyptus gomphocephala)
Wandoo Decline - widespread
• Insects and
associated fungal
pathogens
• Armillaria basal rot
• Reduced rainfall & soil
moisture
• Tree physiology and water use
• Loss of fauna engineers
Eucalyptus rudis (swamp gum)
• Insect pests (psyllids)
• Foliar and soilborne
pathogens
• Clearing of understorey
•
•
•
•
Salinity
Increased nutrients
Changing water tables
Two Phytophthora species
MARRI DECLINE
K. Wentzel
Quambalaria piterika –Introduced
pathogen
NATIVE Fungal pathogen –
Quambalaria coyrecup
Agonis flexuosa- Peppermint decline
Healthy
Lesion
‘Flagging’
Phytophthora dieback
Jarrah Forest
Fitzgerald River National Park
Introduced pathogen
In WA alone kills over 41% of the 5710 described
plant species
Listed as a KEY THREATENING PROCESS to
Australia’s Biodiversity
CAUSES OF DECLINES
• BIOTIC
•
•
•
•
•
•
•
FUNGAL PATHOGENS
BACTERIAL PATHOGENS
VIRUSES/PHYTOPLASMAS
INSECT PESTS
LOSS OF NATIVE FAUNA
LOSS OF BENEFICIAL
MICROBES
LOSS OF MYCORRHIZAL
FUNGI
• ENVIRONMENTAL
•
•
•
•
•
CLIMATE CHANGE
– Rainfall
– Temperature (extremes)
– Ground water
– Carbon dioxide
FIRE REGIMES
SALINITY
NUTRIENTS
POLLUTION
INTERACTIONS BETWEEN BOTH BIOTIC
And ENVIRONMENTAL DRIVERS
FOUR RESEARCH PROGRAMS
• Program 1: Climate change; forest, woodland
and shrubland health
• Program 2. Decline Ecology
• Program 3: Restoring Biodiversity Values
• Program 4: Education, Training and
communication
Dryandra Woodland: Trends in the
Relative Soil Moisture
0.9
Soil Moisture
Linear Trend
Mean (Fraction) of Yearly Soil Moisture
0.8
Polynominal Trend (60)
y mean
y std
0.7
0.6
0.5
0.4
0.3
0.2
1900
1920
1940
1960
Year
1980
2000
2020
– Linear trend shows a clear decrease in soil moisture since 1900
– Clear step down, evident in the polynomial trend, post 1950’s clearing policy and stabilizing with the 1970’s change in rainfall
Note: Data Source date CSIRO’s Australian Water Availability Project (AWAP) model Lower Layer
Relative Soil Moisture. (Raupach et al, 2008)
B. Evans
0.8
0.65
0.6
0.6
0.4
0.55
0.2
1999
2000
2001
2002
2003
2004
2005
2006
Yearly Mean NDVI
Yearly Mean Relative Soil Moisture
Dryandra Woodland: Normalised difference
vegetation index (NDVI) & Relative Soil Moisture
0.5
2007
Year
– The trend is evident in the 1999‐2007 Vegetation (VITO‐SPOT) data
– The sharp decline in the 2001‐2002 season and subsequent recovery the most noticeable events in this period
– Trend within the NDVI standard deviation for same period
Note: Data Source: Vito, Vegetation; Data Source date CSIRO’s Australian Water Availability Project (AWAP) model Lower Layer Relative Soil Moisture. (Raupach et al, 2008) B. Evans
Dryandra: Temporal-spatial trends show an ‘Edge Effect’
2000
2007
FEB
JULY
NOV
Can we restore crown health of trees?
PCD Change Image 2006-2005, 1m resolution
Digital Multispecteral Imagery
•Change in PCD @ injection trial
over 12 months
•Geometrically & radiometrically
corrected
•Very powerful tool for spatial and
temporal analysis of canopy health
at an individual tree level
May 2006, True Colour Image, 1m resolution
Many reptiles are negatively
affected by tuart decline
3.5
3
2.5
2
1.5
1
0.5
0
50
y=2.0358-0.0154*x
y=13.4802+4.9001*x
Abundance
Litter depth (cm)
Reduced litter due to tuart decline impacts reptile abundance
40
30
20
10
0
20
40
Tuart dieback (%)
60
80
0
0
Abundance
Two-toed mulch-skinks are seriously affected
16
14
12
10
8
6
4
2
0
y=7.4727-0.1054*x
0
20
40
Tuart dieback (%)
K. Wentzel
60
80
1
2
Litter depth (cm)
3
4
Impact of tuart decline on birds
Some bird guilds benefit
Granivores
Abundance = -0.5564+0.063*x
Abundance
Canopy insectivores
Nectarivores are
negatively affected
Abundance = 2.3015+0.1191*x
Nectarivores
Abundance = 5.1615-0.0551*x
Tuart dieback (%)
K. Wentzel
IN SUMMARY
WA ECOSYSTEMS ARE DECLINING IN
HEALTH – Role of CC??
•Remote sensing tools and historical
records can be used to provide some
degree of prediction
•Well designed long-term monitoring and
manipulation plots are being established to
develop datasets for climate adaptation
•Multi-disciplinary and large team approach
Shannon Dundas
R. Armistead
R. Armistead
K. Wentzel
Acknowledgements
•Western Australian Government
www.tuarthealth.murdoch.edu.au