Link to Albany Pine Bush Preserve

Ecological consequences of black locust invasion in a globally rare pine – oak ecosystem

Invasive species are one of the most significant threats to natural areas. They not only influence community structure and function directly by displacing or eliminating native species, but they may also alter ecosystem processes like nutrient cycling or light availability and indirectly affect natural communities. Thus, reducing the impacts of an invasive species requires a multi-level understanding of the ecological consequences of its invasion. Working together with managers at the Albany Pine Bush Preserve, I and my students have been evaluating the mechanisms by which black locust, a non-native, nitrogen-fixing tree species, alters community and ecosystem function in the globally rare Inland Pitch Pine – Scrub Oak Barrens Community. A native of the Appalachian uplands, the early successional black locust has been planted widely in the northeast. Characteristics that make it an effective early successional species (rapid clonal spread, fast growth rate, nitrogen-fixing) have favored its spread from agricultural systems to native ones. Our results from a series of field studies conducted on six pairs of black locust and native stands that were begun in 2000 suggest that black locust increases nitrogen content and availability between 2-10 fold in invaded areas and reduces light by a similar amount. In addition to having these effects on ecosystem properties, stands of black locust are dominated by other non-native species like raspberry, Japanese honeysuckle, and garlic mustard that are found in more nutrient rich soils. I am extending this ecological understanding to help manage degraded portions of the Albany Pine Bush Preserve. Presently, over 20% of the preserve is suffering from black locust invasion and I am working with preserve managers to develop strategies to reduce the impacts of black locust and to restore native communities in degraded sites.

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