Defoliation-induced changes in foliage quality may trigger broad-scale insect outbreaks

© 2022. Crown..

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.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:5

Enthalten in:

Communications biology - 5(2022), 1 vom: 16. Mai, Seite 463

Sprache:

Englisch

Beteiligte Personen:

De Grandpré, Louis [VerfasserIn]
Marchand, Maryse [VerfasserIn]
Kneeshaw, Daniel D [VerfasserIn]
Paré, David [VerfasserIn]
Boucher, Dominique [VerfasserIn]
Bourassa, Stéphane [VerfasserIn]
Gervais, David [VerfasserIn]
Simard, Martin [VerfasserIn]
Griffin, Jacob M [VerfasserIn]
Pureswaran, Deepa S [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Research Support, Non-U.S. Gov't
Soil

Anmerkungen:

Date Completed 19.05.2022

Date Revised 16.07.2022

published: Electronic

Citation Status MEDLINE

doi:

10.1038/s42003-022-03407-8

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM341007269