| Title: | Defoliation-induced changes in foliage quality may trigger broad-scale insect outbreaks |
| Author(s): | De Grandpre L; Marchand M; Kneeshaw DD; Pare D; Boucher D; Bourassa S; Gervais D; Simard M; Griffin JM; Pureswaran DS; |
| Address: | "Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada. louis.degrandpre@canada.ca. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada. Centre for Forest Research, Department of Biology, Universite du Quebec a Montreal, Montreal, QC, Canada. Department of Geography, Centre for Forest Research, Laval University, Quebec City, QC, Canada. Department of Biological Sciences, Edgewood College, Madison, WI, USA. Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, Fredericton, NB, Canada" |
| DOI: | 10.1038/s42003-022-03407-8 |
| ISSN/ISBN: | 2399-3642 (Electronic) 2399-3642 (Linking) |
| Abstract: | "Top-down effects, like predation, are drivers of insect outbreaks, but bottom-up effects, like host nutritional quality, also influence outbreaks and could in turn be altered by insect-caused defoliation. We evaluated the prediction that herbivory leads to a positive feedback on outbreak severity as nutrient concentration in plant tissues increases through improved soil nutrient availability from frass and litter deposition. Over seven years of a spruce budworm outbreak, we quantified litter nutrient fluxes, soil nitrogen availability, and host tree foliar nutrient status along a forest susceptibility gradient. As the outbreak progressed, both soil nutrient fluxes and availability increased which, in turn, improved foliage quality in surviving host trees. This is consistent with boosted insect fitness and increased population density and defoliation as outbreaks grow. Our results suggest that a positive bottom-up feedback to forest ecosystems from defoliation may result in conditions favorable to self-amplifying population dynamics in insect herbivores that can contribute to driving broad-scale outbreaks" |
| Keywords: | Animals Disease Outbreaks Ecosystem *Hemiptera Insecta *Moths Soil Trees; |
| Notes: | "MedlineDe Grandpre, Louis Marchand, Maryse Kneeshaw, Daniel D Pare, David Boucher, Dominique Bourassa, Stephane Gervais, David Simard, Martin Griffin, Jacob M Pureswaran, Deepa S eng Research Support, Non-U.S. Gov't England 2022/05/17 Commun Biol. 2022 May 16; 5(1):463. doi: 10.1038/s42003-022-03407-8" |
