Disturbance and change in biodiversity

Abstract

Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numerous composite disturbances can be defined including any combination of these three types of ecological effects. The consequences of D, B and K disturbances, as well as of composite DBK disturbances are examined by comparing metrics before and after a disturbance, in disturbed and undisturbed communities. I use simulations of neutral communities and examine species richness, total abundance and species abundance distributions. The patterns of change in biodiversity metrics are consistent among different types of disturbance. K disturbance has the most severe effects, followed by D disturbance, and B disturbance has nearly negligible effects. Consequences of composite DBK disturbances are more complex than any of the three types of disturbance, with unimodal relationships along a disturbance gradient arising when D, B and K are negatively correlated. Importantly, regardless of disturbance type, community isolation enhances the negative consequences and hinders the positive effects of disturbances.

Biological diversity in a changing world

“…In contrast, never before has a single species driven such profound changes to the habitats, composition and climate of the planet. To deal with the challenges raised by these large-scale and intense modifications of the planet, we need to develop quantitative tools to quantify (Chao et al 2010;Gotelli et al 2010;Magurran & Henderson 2010) and understand (Colwell & Rangel 2010;Dornelas 2010) change; we must document change at multiple scales of space, time and organizational levels (Morris 2010;White et al 2010;Womack et al 2010); and we must develop management tools that take change into account (Mace et al 2010;MacNeil et al 2010).…”

“…Biological diversity in a changing world A. E. Magurran & M. Dornelas 3595 dramatic consequences for biodiversity and ecosystem functioning. Dornelas (2010) develops a theoretical framework to explore how ecological disturbances change biodiversity patterns. In this framework, disturbances are defined by their effects on community dynamics.…”

Stochastic and deterministic processes interact in the assembly of desert microbial communities on a global scale

“…However, as variance partitioning itself may not sufficiently disentangle the signature of different assembly processes (see the recent critique by Smith and Lundholm, 2010) we further conducted analysis with null and neutral models, which were used to test null hypotheses framed in terms of species cooccurrence and level of community dissimilarity expected under neutrality (Gotelli, 2000;Dornelas et al, 2006;Etienne, 2007;Dornelas, 2010;Gotelli et al, 2010).…”

Microbial diversity and the “lower-limit” problem of biodiversity

“…The relationship between diversity and ecosystems properties such as stability, decomposition or primary productivity has become a most fertile area of ecological investigation (e.g. Loreau et al 2001;Naeem 2002;Petchey and Gaston 2006;Dornelas 2010).…”