The spatial pattern and dispersion of Lygodium microphyllum in the Everglades wetland ecosystem
| Autor: | Naiming Wang, Jason Godin, Ken Rutchey, Yegang Wu |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
geography
geography.geographical_feature_category Ecology biology ved/biology ved/biology.organism_classification_rank.species Introduced species Wetland Vegetation biology.organism_classification Shrub Invasive species Lygodium microphyllum Wildlife refuge Ecosystem Ecology Evolution Behavior and Systematics |
| Zdroj: | Biological Invasions. 8:1483-1493 |
| ISSN: | 1573-1464 1387-3547 |
| Popis: | Since 1958, L. microphyllum (Old World Climbing Fern), which originated from the Old World Tropics, has become a nuisance exotic and has rapidly spread and is being established system-wide in extremely remote and undisturbed areas such as the Florida Everglades. Of particular concern is that L. microphyllum is disrupting, at an alarming rate, the flora and fauna of the native ecosystem at the same time that a major 8.4 billion dollar Everglades restoration program is trying to enhance these same attributes. This research utilized IKONOS satellite data to map L. microphyllum within the 58,000-ha Loxahatchee National Wildlife Refuge wetland in south Florida. Results show that approximately 11.6% of the tree/shrub vegetation within the impoundment has been infected by L. microphyllum. These data were then utilized to explore the spatial spread patterns of L. microphyllum within the Refuge. Results suggest that L. microphyllum is more likely to establish on the southeast side of a tree/shrub island and then spread to the northwest, which corresponds to the prevailing wind direction in south Florida. Spatial pattern analysis of L. microphyllum spread indicated that it is correlated with the density and spatial distribution of tree/shrub island vegetation. It appears that the dispersion of L. microphyllum is density dependent, which can be expressed as a logistic function and has a catastrophic threshold of 160 m of mean distance between tree/shrub islands in the Everglades. It is predicted that 38% (or 1910 ha) of tree/shrub islands in the Refuge will be invaded by L. microphyllum by 2012. Tree islands in the Everglades wetland could be considered similar to oceanic islands throughout the world that are notoriously vulnerable to biological invasions. |
| Databáze: | OpenAIRE |
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