COS 1-7 - Rapid assessment of biodiversity and ecosystem function in urban remnants reveals ecological integrity and resilience in novel ecosystems

Monday, August 8, 2011: 3:40 PM
Ballroom B, Austin Convention Center
Dieter F. Hochuli, School of Biological Sciences, The University of Sydney, Sydney, Australia

Strong links between biodiversity and ecosystem function offer valuable insights into the quality of remnant vegetation in urban landscapes. These novel ecosystems often support depauperate assemblages dominated by disturbance specialists, generating concerns over their ecological integrity and long term viability. There is an urgent need to develop effective sampling regimes that permit ecologists to survey biodiversity in these areas rapidly and couple biodiversity assessments with ecosystem function. We surveyed ant assemblages in remnant vegetation along an urban-rural gradient in Sydney, Australia , using protein and carbohydrate baits as well as pitfall traps.  We also assessed rates of seed removal by ants using seed trays containing Acacia suaveolens and A. longifolia.


Although baits surveyed a relatively small proportion of the ant fauna compared to pitfall traps, both techniques were effective in characterizing shifts in assemblages associated with the degrees of urbanization. Estimates of seed removal were consistently high independently of where on the gradient they were surveyed, reflecting the resilience of this interaction and the potential of many species of ant to provide this service for myrmecochorous plants in our system. Ultimately, the simple field surveys of ants using baited traps could be coupled with measures of seed removal to offer insights on the state of remnant vegetation although the data from pitfall traps provided a more comprehensive perspective of biotic responses to urbanization, particularly with respect to shifts in ant functional groups. Further developments of these techniques have offered significant opportunities for community engagement through citizen scientists applying these techniques to enhance their understanding of urban ecosystems in their local environments.

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