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摘要
Nutritional ecology predicts consumer behavior based on the biochemistry of species and biogeochemistry of the environment. It is thus well suited as a tool for predicting the effects of specific nutrients on consumer activity, abundance, and diversity across the landscape. We tested hypotheses from nutritional ecology in a Neotropical litter ant community by supplementing forest plots with carbohydrates (CHOs) and protein in a blocked factorial design. We tested the Compensation Hypothesis, which posits that consumers accumulate in patches of the rarest food type relative to demand, and the Economics Hypothesis, which assumes that species differ in nutrient based-functional traits, and that changes in nutrient availability will generate changes in species composition and community behavior. We found that CHO and protein had distinct effects on ant density, community composition, and per-worker activity. Ant density increased by 35% on +CHO plots but not +Protein plots, a result supporting the Compensation Hypothesis because CHO-rich plant exudates are uncommon and CHO-demanding microbial productivity is high in this brown food web. Consistent with the Economics Hypothesis, we found that +CHO plots had higher per-capita ant activity (the Metabolic Fuel Hypothesis) and attracted ants averaging 10% lower delta N-15 values. Species composition changed as well, with Wasmannia auropunctata, an invasive outside its native range, elsewhere, increasing five-fold on +CHO plots. Nutritional ecology can thus account for some of the patchiness and behavior of consumers in diverse communities.
- 出版日期2012-11
