Bottom-up effects of woodland eutrophication: interacting limiting nutrients determine herbivory frequency in Northwestern Patagonia

FERNÁNDEZ, MARGARITA; GARIBALDI, LUCAS A.; VAN DOORN, LIZA; MARTÍNEZ, LUCÍA; PÉREZ-MÉNDEZ, NÉSTOR; CATALÀ-FORNER, MARÍA DEL MAR

SCIENCE OF THE TOTAL ENVIRONMENT

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021

0048-9697

Nutrient enrichment is disrupting animal-plant interactions and ecosystem functioningglobally. In woodland systems, the mechanisms of bottom-up cascades on plantherbivore interactions remains understudied. Here, we performed a full-factorial fieldexperiment to evaluate the interactive effects of nutrient addition (nitrogen,phosphorous, and/or potassium) on the assemblage of foliar herbivores and theinteraction frequency with Berberis microphylla , a dominant shrub species inPatagonian woodlands. Additionally, we assessed whether these effects could bemediated by changes in vegetative traits and microhabitat characteristics (i.e., lightavailability) that may ultimately influence the foraging behavior of herbivores. Additionof nitrogen reduced the frequency of herbivory by 41%, yet this effect was diluted in thepresence of potassium. We found no effects of P addition. Our results suggest that theimpact of multiple nutrient addition (N and K) on herbivory patterns could be mediatedby changes in two important foliar traits such as leaf area and leaf density. This studyshows how multiple nutrient addition can change the magnitude of antagonistic animalplant interactions in woodlands. Since herbivory by arthropods have a relevant role onnet primary productivity, our results highlight the importance of buffering human-drivenwoodland eutrophication in order to maintain important ecological functions (e.g.,herbivory) associated with antagonistic animal-plant interactions and avoid ecosystemmisfunctioning.