Abstract:
Exotic species can cause a major threat to ecosystems, because of its effect on reducing natural biodiversity. The aim of this paper is to study the effects of the exotic Acacia saligna on native plant biodiversity of northern part of Jordan. Within each studied area we estimated plant species cover in six replicates of a 0.5 m2 quadrate distributed randomly inside and outside the canopy of A. saligna. From these plant cover we estimated the total number of species, Shannons diversity index, Simpsons diversity index and Margalefs diversity index of the associated annual and perennial species. The overall results showed that the effect of A. saligna on plant diversity depends largely on the proximity to the tree canopy. Namely, it has been found that native plant species diversity such as Shannons diversity index, Simpsons diversity index are reduced under canopy (1.88, 0.8831) compared to the outside canopy of the trees (2.21, 0.876), respectively (One-way ANOVA; F = 14.99, 12.46; Pvalues< 0.001). Moreover, observed and cumulative species richness of native plant biodiversity of Jordan is significantly affected by the presence of this exotic tree. It can be concluded that competition and intrinsic characteristics of tree i.e., nutrient uptake efficiency, are among the possible mechanisms responsible for the impact of A. saligna trees on native plants of Jordan.
Page(s):
823-826
DOI:
DOI not available
Published:
Journal: International Journal of Agriculture and Biology, Volume: 13, Issue: 5, Year: 2011