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Harvard Forest Symposium Abstract 2006
- Title: Being in the right place at the right time: a historical perspective on Japanese barberry invasion
- Primary Author: Brian DeGasperis (Harvard Forest)
- Additional Authors: Glenn Motzkin (University of Massachusetts - Amherst )
- Abstract:
Attempts to determine the characteristics of habitats that render them invasible to non-native species have met with limited success. One possible explanation for this shortcoming may be that by focusing on modern biotic and abiotic differences, most studies fail to consider invasibility in the context of a historically dynamic landscape. Despite the recognized importance of historical factors in controlling modern species distributions, few studies have incorporated historical landscape changes into models of invasive species distribution and abundance. We explore the possibility that the current distribution of invasive species may reflect legacies of historical land-use despite nearly a century of forest succession and subsequent disturbances. We surveyed 159 currently forested sites for the occurrence and abundance of Japanese barberry, a problematic non-native shrub in Northeastern forests, relative to two distinct periods of historical land-use, modern forest harvesting activity, and environmental and edaphic characteristics.
Barberry occurred more frequently and was more abundant in sites historically cleared for agriculture than in historically wooded sites. This relationship was strongest for areas in agriculture from 1927 onwards when barberry is known to be present in the landscape. While confounded by modern soil fertility and distance to putative seed sources, we suggest this pattern reflects historical colonization of abandoned agricultural lands and persistence through subsequent reforestation. Contrary to our expectations, subsequent and recent forest harvesting did not influence barberry occurrence or abundance at the landscape scale. Multiple regressions indicate that although historical land-use is an important predictor of barberry abundance, occurrence is primarily determined by edaphic characteristics. Our results indicate that habitat invasibility must be considered in the context of a dynamic landscape. Interpretations of modern plant invasions must consider the importance of historical factors along with current environmental and edaphic conditions.
- Research Category: Historical and Retrospective Studies
Invasive Plants, Pests & Pathogens
