Bachelor Thesis : Diversity & Spatial Distribution of Alien Species


Under supervision of AGUS HIKMAT and LILIK BUDI PRASETYO

Invasive alien plant species in a disturbed forest ecosystem could reduce composition of native vegetation, as such could threaten the biodiversity of the ecosystem. The process of invasion by alien plants has been reported to occur in several protected areas in Indonesia such as the Wasur National Park, Baluran National Park, and the Komodo National Park. One of the conservation area also allegedly invaded by alien plant species is Kamojang Natural Reserve Area. Thus, there is a need of research on the diversityand spatial distribution pattern of the invasive alien plant species in the area.

The research was conducted in July-August 2011 at the Kamojang Natural Reserve Area. The data collection of the invasive alien plants species’ diversity was conducted by analyzing the vegetations using double plots method. The identification of invasive alien plants species used references from Weber (2003) and ISSG (2005). The data collection of the spatial distribution pattern of invasive alien plants species was conducted by marking every observation plots using GPS and the result was then interpolated. The distributions of individual invasive alien plant species that are dominant were analyzed using linier regression analysis to acquire the invasive alien plants species’ influence toward its distance from the road.

The number of analyzed vegetation species identified comprises of 86 species from 50 families. The invasive alien plants species identified was 13 species which consist of 8 families: Ageratum conyzoides (Asteraceae), Rubus moluccanus (Rosaceae), Clidemia hirta (Melastomaceae), Cynodon dactylon (Poaceae), Panicum repens (Poaceae), Mimosa pudica (Fabaceae), Mimosa pigra (Fabaceae), Austroeupatorium inulifolium (Asteraceae), Passiflora edulis (Passifloraceae), Lantana camara (Verbenaceae), Mikania micrantha (Asteraceae), Piper aduncum (Piperaceae) and Ageratina riparia (Asteraceae). According to the index of Morisita and the result of IDW interpolation on dominant invasive alien plant species, it was found that the distribution’s pattern of the invasive alien plant species tend to clump except for A. inulifolium which have uniform distribution.

Invasive alien plant species are identified as many as thirteen species of 8 families with dominant species, namely A. inulifolium, A. riparia and L. camara.  Spatial distribution patterns of invasive alien plant species in Kamojang Natural Reserve Area tend to clump in relatively open forest conditions. The effect of distance from the road towards the the number of the invasive plant species distribution only occured to A. Inulifolium, while A. riparia and L. camara was not effected by the distance from the road.

Keywords:    Diversity, Spatial distribution pattern, Invasive alien plant species, Vegetation analysis, Interpolation.




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