HUMAN AND ENVIRONMENTAL INFLUENCES ON PLANT DIVERSITY AND COMPOSITION IN BEN EN NATIONAL PARK, VIETNAM

In order to understand the influence of human disturbance and the physical environment on plant biodiversity in Ben En National Park, Vietnam, we analysed species composition and density in forest plots with diverse soils and varying degrees of human disturbance. Soil factors significantly influenced tree species composition, although they only explained 5.7% of the observed data variance. Human factors (disturbance) were second most important in explaining species composition and density, accounting for 4.4% of variance. Changes in species composition related to human disturbance varied mostly independently of soils. The species composition of slightly and heavily disturbed forest differed significantly, with species of low conservation value being most common in heavily disturbed forest, while endangered species and important timber trees were most common in least disturbed forest. Density of treelets was higher in limestone forest than in non-limestone forest. Timber trees and other useful plant species used for a whole range of non-timber forest products (NTFPs) were more abundant in the less disturbed plots, which were located far away from villages and roads. Basal area in less disturbed forest was also larger than in heavily disturbed forest, indicating that the pressures of illegal logging and harvesting were closely connected to travel distances to nearest villages. Limiting the accessibility to forest resources should therefore be a priority in forest conservation as a first step to safeguard the rich biodiversity and stocks of useful plants in the park. Demi memahami pengaruh gangguan manusia serta persekitaran fizikal terhadap kepelbagaian biologi di Taman Negara Ben En, Vietnam, kami menganalisis komposisi spesies serta kepadatannya di plot hutan yang mempunyai tanah serta tahap gangguan manusia yang berbeza. Faktor tanah mempengaruhi secara signifikan komposisi spesies pokok. Bagaimanapun, faktor-faktor tersebut hanya menerangkan 5.7% varians data yang dicerap. Faktor manusia (gangguan) ialah faktor kedua penting dalam menerangkan komposisi serta kepadatan spesies, iaitu sebanyak 4.4% varians. Perubahan komposisi spesies yang berkait dengan gangguan manusia kebanyakannya berubah secara bebas daripada faktor tanah. Komposisi spesies bagi hutan yang sedikit terganggu berbeza dengan signifikan berbanding dengan hutan yang banyak terganggu. Spesies yang mempunyai nilai pemuliharaan yang rendah sangat banyak di hutan yang terganggu dengan teruk. S