This just published paper looks of significant local interest - its
a free access download (URLs below)
Robin Hide
Fischer, Joern, Andre Zerger, Phil Gibbons, Jenny Stott and Bradley
S. Law (2010). “Tree decline and the future of Australian farmland
biodiversity.” Proceedings of the National Academy of
Sciences of the USA (PNAS, Published online before print
October 25, 2010, doi: 10.1073/pnas.1008476107)
.
Keywords: Australia; countryside biogeography; grassy box woodlands;
ranchland; regime shift; scattered trees;
Abstract: Farmland biodiversity is greatly enhanced by the presence
of trees. However, farmland trees are declining worldwide, including
in North America, Central America, and parts of southern Europe. We
show that tree decline and its likely consequences are particularly
severe in Australia's temperate agricultural zone, which is a
threatened ecoregion. Using field data on trees, remotely sensed
imagery, and a demographic model for trees, we predict that by 2100,
the number of trees on an average farm will contract to two-thirds
of its present level. Statistical habitat models suggest that this
tree decline will negatively affect many currently common animal
species, with predicted declines in birds and bats of up to 50% by
2100. Declines were predicted for 24 of 32 bird species modeled and
for all of six bat species modeled. Widespread declines in trees,
birds, and bats may lead to a reduction in economically important
ecosystem services such as shade provision for livestock and pest
control. Moreover, many other species for which we have no empirical
data also depend on trees, suggesting that fundamental changes in
ecosystem functioning are likely. We conclude that Australia's
temperate agricultural zone has crossed a threshold and no longer
functions as a self-sustaining woodland ecosystem. A regime shift is
occurring, with a woodland system deteriorating into a treeless
pasture system. Management options exist to reverse tree decline,
but new policy settings are required to encourage their widespread
adoption.
URL:
http://www.pnas.org/content/early/2010/10/21/1008476107.full.pdf+html
and 8 pp of Supporting Information:
http://www.pnas.org/content/suppl/2010/10/22/1008476107.DCSupplemental/pnas.201008476SI.pdf
and two of the authors are Canberrans...
Joern Fischer a,b,
Andre Zerger c,
Phil Gibbons a,
Jenny Stott a,
Bradley S. Law d
Author Affiliations
aThe Fenner School of Environment and Society, Australian National
University, Canberra ACT 0200, Australia;
bDepartment of Sustainability Sciences, Leuphana University
Lueneburg, 21335 Lueneburg, Germany;
cCommonwealth Scientific and Industrial Research Organization
Sustainable Ecosystems, Canberra ACT 2601, Australia; and
dForest Science Centre, Industry and Investment NSW, Beecroft NSW
2119, Australia
|
|
