New Zealand Journal of Ecology (1996) 20(1): 17- 26

Predicting the impacts of biological and physical disturbances: Does theoretical ecology hold any answers?

Research Article
Russell G. Death 1,2
  1. Zoology Department, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
  2. Present address: Department of Ecology, Massey University, Private Bag 11 222, Palmerston North, New Zealand

Biological and physical disturbance has had a severe impact on New Zealand's endemic flora and fauna. Along with the lessons of the past, predicting the sensitivity of communities to disturbance in the future may help direct more attention to those communities with a greater need for preservation (i.e., a lower ability to recover from any such disturbances). In theory it is possible to measure the resilience (or local stability) of a community by constructing a matrix to describe that community and then examining its eigenvalues. Local stability characteristics of invertebrate communities in 11 aquatic habitats were examined with respect to differing levels of habitat disturbance. It was predicted that communities in more unstable habitats would be more resilient in order to persist despite more frequent disturbances. All communities had eigenvalues outside the stability criteria, although those in the unstable habitats did have eigenvalues closer to these criteria. The open and/or patchy nature of stream communities may explain why local stability is not a prerequisite for these communities, however examining the local stability of community matrices still remains a potentially useful tool for predicting the effects of physical and biological disturbances.