|Conceptualizing Melaleuca quinquenervia invasion: a feedback system between the plant and its soil biota.
Dorota L. Porazinska, Monica L. Elliot, and Robin M. Giblin-Davis.
University of Florida, Fort Lauderdale, FL
Paul D. Pratt
USDA/ARS. Fort Lauderdale, FL
There are several leading theories to explain the extraordinary success of invasive plants but most focus on mechanisms associated with plants themselves (e.g., life history traits, physiological properties, or diversity of invaded plant communities). Other theories suggest that disturbance, release from natural enemies, and alteration of the soil chemistry intensify the invasion process. Soil biota are rarely suggested to have an important role in the plant invasion process.
Aboveground and belowground components of ecosystems are implicitly dependent on each other as plants provide sources of carbon and nitrogen for soil biota and soil biota provide plants with simple nutrients. Soil organisms are involved in processes of decomposition and nutrient mineralization, and the composition, abundance, and activity of decomposer communities are crucial in regulating these processes. Composition and density of the soil community can vary markedly with different plant species. It is likely, therefore that soil community structure and their activity change following invasion. Alternatively, soil organisms associated with plant communities have profound effects on plant performance. It is possible, therefore that soil biota have a significant role in structuring plant communities and in promoting or preventing plant invasions.
We model plants-soil biota interactions in the form of a feedback system, where plant species affect the composition and abundance of soil biota (alteration of soil community) and the soil biota in turn feeds back to the plant community (alteration of aboveground diversity and productivity). I propose this feedback system as a mechanism explaining the success of M. quinquenervia in the Florida Everglades ecosystems. If true, soil biota have a potential in indicating the status and extent of plant invasions and therefore could be crucial in establishing successful management and restoration programs.
Dorota L Porazinska
FLREC, University of Florida, 3205 College Avenue, Fort Lauderdale, FL 33314
Phone: 954.577.6333, Fax: 954.475.4125, E-mail: email@example.com