Global warming, biodiversity and land-use of south eastern Australia • 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 opportunities for adaptation through biolinks for biodiversity conservation Paper presented by Dr Ian Mansergh to Global Public Services Network of the RFGOV. Louvain - la Neuve Campus - Belgium, June, 2006.
Geo - bio physical Melbourne context of Australia 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.
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
Inland plains, intensive Great dividing range agriculture with irrigated highlands and escarpment Future trajectories of landuse ? areas, relict native Principally public land vegetation, ecosystem Native vegetation cover function collapsing (salinity/ high some degradation soil degradation) Foothills and Arid and semi-arid zone, tablelands, rangelands with degraded fragmented native vegetation landscapes some public land on poorer soils. Coastal plain, relictual landscapes with intensive agriculture and urban development ecosystem processes are collapsing (salinity/ soil degradation)
SRESA1F High Estimate 1990 Modelling - High temperature scenario • 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 Currajong
2100 SRESA1F High Estimate • 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 4 0 latitude south in the last 30 years Brachychiton populneus
Eastern Australia: Major Vegetation Groups Victoria Coasts, foothill , escapement, divide, inland foothill, semi arid, arid Victoria most alienated and cleared yet species coming south Source: Australian Native Vegetation Assessment, NLWA 2001
Decline of bio-climate envelopes of Victorian fauna - bioclimatic envelope. (alpine, mallee, coastal, riparian) 20 0 0 1 2 3 Percentage change (%) -20 Eastern Bristlebird (Coastal) Malleefow l (Mallee) Spotted Tree Frog (Riparian forest) -40 Mountain Pygmy-possum (Alpine) -60 Alpine is one of 3 most vulnerable -80 Australian ecosystems -100 ( o C) Increasing temperature
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. 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 Mansergh et al. 2006
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 Alfred Deakin Last large dams Irrigation from rivers Thomson - 1983 Mildura Blue Rock 1984
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