Our planet is changing at paces never observed before. Species extinction is happening at
faster rates than ever, greatly exceeding the five mass extinctions in the fossil record …

This article surveys current answers to the factual question posed in the title and reviews the
kinds of information that are needed to make these answers more precise. Various factors …

Populations and communities of organisms are influenced by a host of abiotic and biotic
factors. Climate, nutrients, natural enemies (including parasites and pathogens), symbionts …

Community ecology: the study of the patterns and processes involving two or more species-
has developed rapidly in the last two decades, driven by new and more sophisticated …

Summary 1 A fundamental goal of ecological network research is to understand how the
complexity observed in nature can persist and how this affects ecosystem functioning. This is …

The global biodiversity crisis concerns not only unprecedented loss of species within
communities, but also related consequences for ecosystem function. Community ecology …

Food webs in the real world are much more complex than food-web literature would have us
believe. This is illustrated by the web of the sand community in the Coachella Valley desert …

Parasitism is the most common consumer strategy among organisms, yet only recently has
there been a call for the inclusion of infectious disease agents in food webs. The value of …

Neuroanatomy places critical constraints on the functional connectivity of the cerebral cortex.
To analyze these constraints we have examined the relationship between structural features …

In 1960, Hairston, Smith, and Slobodkin published their revolutionary paper in which a
relatively reductionist approach, interaction ecology, was joined to a relatively holistic one …