Effects of Predator Hunting Mode on Grassland Ecosystem Function

• Published in: Science (American Association for the Advancement of Science) 2008-02, Vol.319 (5865), p.952-954
• Main Author: Schmitz, Oswald J
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal behavior; Animal, plant and microbial ecology; Animals; Araneae; Behavior, Animal; Biodiversity; Biological and medical sciences; Connecticut; Ecological function; Ecology; Ecosystem; Ecosystems; Feeding Behavior; Food Chain; Fundamental and applied biological sciences. Psychology; Grasses; Grasshoppers; Grasslands; Herbivores; Herbs; Hunting; Nitrogen - analysis; Photosynthesis; Plant communities; Plants; Plants - metabolism; Poaceae - metabolism; Predation; Predators; Predatory Behavior; Random Allocation; Solidago - metabolism; Species; Spiders; Synecology; Terrestrial ecosystems
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1152355

The way predators control their prey populations is determined by the interplay between predator hunting mode and prey antipredator behavior. It is uncertain, however, how the effects of such interplay control ecosystem function. A 3-year experiment in grassland mesocosms revealed that actively hunting spiders reduced plant species diversity and enhanced aboveground net primary production and nitrogen mineralization rate, whereas sit-and-wait ambush spiders had opposite effects. These effects arise from the different responses to the two different predators by their grasshopper prey--the dominant herbivore species that controls plant species composition and accordingly ecosystem functioning. Predator hunting mode is thus a key functional trait that can help to explain variation in the nature of top-down control of ecosystems.