The 450-million-year-old symbiosis between the majority of land plants and arbuscular mycorrhizal fungi (AMF) is one of the most ancient, abundant, and ecologically important mutualisms on Earth. Yet, the evolutionary stability of mycorrhizal associations is still poorly understood, as it follows none of the constraints thought to stabilize cooperation in other well-known mutualisms. The capaci...

It is often claimed that we do not understand the forces driving the global diversity gradient. However, an extensive literature suggests that contemporary climate constrains terrestrial taxonomic richness over broad geographic extents. Here, we review the empirical literature to examine the nature and form of the relationship between climate and richness. Our goals were to document the support...

Vector-borne parasites are commonly predicted to be less virulent to the vector than to the definitive host as the parasite gains little by harming its main route of transmission. Here we assess the empirical evidence from systems in which insects are vectors for vertebrate, plant, and invertebrate parasites. The body of evidence supports lower (but nonzero) parasite virulence to vectors than t...

The recognition that predators play important roles in ecosystems has prompted research to resolve how combinations of predator species influence ecosystem functions. Interactions among predator species and their prey can lead to a host of linear and nonlinear effects. Understanding the conditions causing these effects is critical for assigning predator species to functional groups in ways that...

Ecological surprises, substantial and unanticipated changes in the abundance of one or more species that result from previously unsuspected processes, are a common outcome of both experiments and observations in community and population ecology. Here, we give examples of such surprises along with the results of a survey of well-established field ecologists, most of whom have encountered one or ...

The metacommunity framework predicts that local coexistence depends on the outcome of local species interactions and regional migration. In analogous fashion, spatial structure among populations can shape species interactions through evolutionary mechanisms. Yet, most metacommunity theories assume that populations do not evolve. Here, we evaluate how evolution shapes local species coexistence a...

Despite extensive empirical research and previous reviews, no clear patterns regarding the effects of habitat loss and fragmentation on predator–prey interactions have emerged. We suggest that this is because empirical researchers do not design their studies to test specific hypotheses arising from the theoretical literature. In fact, theoretical work is almost completely ignored by empirical r...

When an animal settles preferentially in a habitat within which it does poorly relative to other available habitats, it is said to have been caught in an ‘‘ecological trap.’’ Although the theoretical possibility that animals may be so trapped is widely recognized, the absence of a clear mechanistic understanding of what constitutes a trap means that much of the literature cited as support for t...

Climate gradients shape spatial variation in the richness and composition of plant communities. Given future predicted changes in climate means and variability, and likely regional variation in themagnitudes of these changes, it is important to determine how temporal variation in climate influences temporal variation in plant community structure. Here, we evaluated how species richness, turnove...