Title: Cross-scale drivers of natural disturbances prone to anthropogenic amplification: Dynamics of biome-wide bark beetle eruptions
Author: Raffa, Kenneth F.; Aukema, Brian H.; Bentz, Barbara J.; Carroll, Allan L.; Hicke, Jeffrey A.; Turner, Monica G.; Romme, William H.
Source: BioScience. 58(6): 501-518.
Publication Series: Scientific Journal (JRNL)
Description: Biome-scale disturbances by eruptive herbivores provide valuable insights into species interactions, ecosystem-function, and impacts of global change. We present a conceptual framework using one system as a model, emphasizing interactions across levels of biological hierarchy and spatiotemporal scales. Bark beetles are major natural disturbance agents in western North American forests. However, recent bark beetle population eruptions have exceeded the frequencies, impacts, and ranges documented during the previous 125 years. Extensive host abundance and susceptibility, concentrated beetle density, favorable weather, optimal symbiotic associations, and escape from natural enemies must occur jointly for beetles to surpass a series of thresholds and exert widespread disturbance. Opposing feedbacks determine qualitatively distinct outcomes at junctures at the biochemical through landscape levels. Eruptions occur when key thresholds are surpassed, prior constraints cease to exert influence, and positive feedbacks amplify across scales. These dynamics are bidirectional, as landscape features influence how lower-scale processes are amplified or buffered. Climate change and reduced habitat heterogeneity increase the likelihood that key thresholds will be exceeded, and may cause fundamental regime shifts. Systems in which endogenous feedbacks can dominate after external forces foster the initial breach of thresholds appear particularly sensitive to anthropogenic perturbations.
Keywords: thresholds, plant-insect interactions, landscape disturbance, forest management, anthropogenic change
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Raffa, Kenneth F.; Aukema, Brian H.; Bentz, Barbara J.; Carroll, Allan L.; Hicke, Jeffrey A.; Turner, Monica G.; Romme, William H. 2008. Cross-scale drivers of natural disturbances prone to anthropogenic amplification: Dynamics of biome-wide bark beetle eruptions. BioScience. 58(6): 501-518.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility