John L. Orrock

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A. Sih (, Dept of Environmental Science and Policy, Univ. of California, Davis, CA 95618, USA. – D. I. Bolnick, Section of Integrative Biology, Univ. of Texas at Austin, Austin, TX 78712, USA. – B. Luttbeg, Dept of Zoology, Oklahoma State Univ., OK 74074, USA. – J. L. Orrock, Dept of Biology, Washington Univ., St. Louis, MO 63130, USA. – S.(More)
Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical(More)
JOHN L. ORROCK, DOUGLAS J. LEVEY*, BRENT J. DANIELSON† and ELLEN I. DAMSCHEN‡ Ecology and Evolutionary Interdepartmental Graduate Program, 353 Bessey Hall, Iowa State University, Ames, IA 50011, USA, * Department of Zoology, University of Florida, Gainesville, FL 32611-8525, USA, † Ecology, Evolution, and Organismal Biology Department, Iowa State(More)
Predator effects on prey dynamics are conventionally studied by measuring changes in prey abundance attributed to consumption by predators. We revisit four classic examples of predator-prey systems often cited in textbooks and incorporate subsequent studies of nonconsumptive effects of predators (NCE), defined as changes in prey traits (e.g., behavior,(More)
For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity.(More)
Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity(More)
We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest's edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75%(More)
Despite the ubiquity of invasive organisms and their often deleterious effects on native flora and fauna, the consequences of biological invasions for human health and the ecological mechanisms through which they occur are rarely considered. Here we demonstrate that a widespread invasive shrub in North America, Amur honeysuckle (Lonicera maackii), increases(More)
Predators can affect prey populations through changes in traits that reduce predation risk. These trait changes (nonconsumptive effects, NCEs) can be energetically costly and cause reduced prey activity, growth, fecundity, and survival. The strength of nonconsumptive effects may vary with two functional characteristics of predators: hunting mode (actively(More)
A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities, and external factors. We modified this framework to generate predictions for species richness dynamics of fragmented plant communities and tested them in(More)