Global warming, biodiversity and land-use of south eastern Australia - - PowerPoint PPT Presentation

Global warming, biodiversity and land-use

• f south eastern Australia

Paper presented by Dr Ian Mansergh to Global Public Services Network of the RFGOV. Louvain - la Neuve Campus - Belgium, June, 2006.

• potential effects greenhouse on the

biodiversity assets in eastern Australia

• the historical effects of land use on natural

capital

• current socio-economic drivers of land-use

change in rural s.e. Australia, constraints and

• pportunities for adaptation through biolinks

for biodiversity conservation

Australia

• Geographic and genetic isolation for millions of years
• c. 10% of the worlds biodiversity, high endemism
• Driest inhabited continent - most variable climate
• “Old continent” - low nutrient soils, low mountains
• > 60, 000 years of continuous human occupation
• Anglo-celt colonialisation from 1778.

Melbourne

Geo - bio physical context of Australia

Climate change - the major threat to biodiversity in the 21st Century

• Greenhouse climate change is happening - IPCC - 2002 - the major new threat to

Biodiversity in the 21st Century

• “a Globally coherent fingerprint of climate change impacts across natural systems”
• “between 15 and 35 percent of species are ‘committed to extinction”

Nature 2004: 42: 37-42;

• Debate is evolving solely from amelioration to necessary adaptation
• Australia is a mega-diverse region (10 % of global biodiversity), climate is driest

inhabited continent and most variable - major ecosystems under stress Montane Wet Tropics, Great Barrier Reef, Alps

• Major problem in eastern Australia is due to fragmentation of native habitats
• It is anticipated that climate change will produce dramatic shifts in species

distribution, and extinctions

Coastal plain, relictual landscapes with intensive agriculture and urban development ecosystem processes are collapsing (salinity/ soil degradation) Arid and semi-arid zone, rangelands with degraded native vegetation Inland plains, intensive agriculture with irrigated areas, relict native vegetation, ecosystem function collapsing (salinity/ soil degradation) Foothills and tablelands, fragmented landscapes some public land on poorer soils. Great dividing range highlands and escarpment Principally public land Native vegetation cover high some degradation

Future trajectories of landuse ?

Brachychiton populneus Currajong

SRESA1F High Estimate

Modelling - High temperature scenario

1990

• species exist in a bio-climatic envelope
• the distribution of the current bio-climatic envelope of Currajong
• bio-climatic envelopes can be modelled on to future climate scenarios.

(Modelling courtesy CSIRO & ARIER)

Brachychiton populneus SRESA1F High Estimate

2100

• The distribution of bio-climate envelopes move under global warming
• Assume current distribution determined by climate does not account

for fundamental niche, genetic adaptation, interactions

• empirical evidence ? Genetic studies on fruit flies have shown

movements of 40 latitude south in the last 30 years

Source: Australian Native Vegetation Assessment, NLWA 2001

Eastern Australia: Major Vegetation Groups

Coasts, foothill , escapement, divide, inland foothill, semi arid, arid Victoria most alienated and cleared yet species coming south

Victoria

Decline of bio-climate envelopes of Victorian fauna

• bioclimatic envelope. (alpine, mallee, coastal, riparian)
• 100
• 80
• 60
• 40
• 20

20 1 2 3

Increasing temperature Percentage change (%)

Eastern Bristlebird (Coastal) Malleefow l (Mallee) Spotted Tree Frog (Riparian forest) Mountain Pygmy-possum (Alpine)

(oC)

Alpine is one of 3 most vulnerable Australian ecosystems

The land use and management problem?

• “Disappearing” ecosystems
• The changing distributions indicate migration (in the geological sense)

– this implies space and habitat availability to avoid extinction and allow evolutionary processes

• In eastern Australia, historical land use, driven by export - orientated

agricultural production, has left vast areas devoid of large areas of native vegetation, this is particularly evident in Victoria

• Historically, biodiversity and related services (water, soil) externalities of

economic production

Migration - bottlenecks: no habitat no movement.

Mansergh et al. 2006

Habitats in present distribution change (food, competition, climate etc.) and become less habitable for some species Future habitats evolve availability dependent on space and species

Principles and propositions

• Connectivity and landscape permeability are an existing land-use issue (Soule et
• al. 2004)
• Maximise the extent and robustness of current reserve system - improve resilience
• Maximise the capacity for biodiversity assets to move and evolve into “new”

spaces - this requires planning for availability and long implementation time

• Extent, condition and place in the landscape of native vegetation key attribute -

remnants (rear-view definition) are actually reservoirs (forward definition)

• Land use change has caused major fragmentation - biodiversity has been an

externality of production

• Must keep options open in land use change context
• Land-use change will continue but biodiversity conservation and restoration must

be embedded in and influence that change - use socioeconomic change

Victoria 1800’s

Natural Capital husbanded by Kooris (Victorian Aboriginals)

Victorian Aboriginal (Koori) boundaries

1861 Koori population 16% of pre-settlement levels 1891 population 6% of pre-settlement (0.007% of total Victorian)

Victoria 1840’s

Squatters - pastoral sheep, exploit Koori husbanded native vegetation

Victoria 1850’s

Gold rushes - forest depletion “environment” - external to production

Victoria 1860’s

Population x 7 in a decade Closer settlement (Yoeman farmer versus squatters)

Victoria 1890’s

wheat as second staple (drier north) railways - vast natural capital depletion (clearing) Yoeman farmer - major social policy

Victoria 1930’s

WW1 Closer (Soldier) settlement - drier Mallee Peak area under crop Emergent problems - soil erosion

Victoria 1960’s

Wool boom Little Desert

• To clear or not to clear ?
• That is the question

Victoria 1970’s

Peak of land under sheep Little Desert was not cleared - debate set up Land Conservation Council 25 years parks went from 4% to 16 %

Victoria 2000

Broad scale clearing over and “net gain” policy for native vegetation Land Conservation Council 25 years parks went from 4% to 16% 1990 - dismounted the sheep’s back

Changing land-uses in Victoria - decline of native pasture, soils

Sub and super revolution phosphorus / nitrogen

Water effects land-use -water storages

Early irrigation - Trusts 120,000 acres in 1895 25 Trusts broke in 1905 From 1950’s x 5 growth in capacity Franklin dam issue1983 Last large dams Thomson - 1983 Blue Rock 1984

Alfred Deakin Irrigation from rivers Mildura