Loss of habitat is a pervasive problem affecting species and ecological communities, yet our ability to predict the effects of habitat loss on the population sizes of the species is surprisingly limited; this can, in turn, be a hindrance to conservation planning. However, there is increasing correlative evidence that the structure of food webs might provide important clues to the patterns of population change, and Gotelli and Ellison confirm this with experimental evidence from invertebrate communities inhabiting Sarracenia pitcher plants. The experiments involved reducing the volume of water in the pitchers and removing the predators at the top of the food chain (which are often the first casualty of habitat loss), and then monitoring the changes in abundance of the remaining species. The observed patterns of population change most closely conformed to path analytical models that incorporated food web structure. Despite the small size and relative simplicity of the Sarracenia microecosystem, the structure of its food web is similar to that of larger ecosystems. Hence, it is plausible that these models can be used to predict patterns of abundance in response to habitat loss at larger scales. -- AMS
PLoS Biol. 4, 10.1371/journal.pbio.0040324 (2006).
