Effect of forest fragment size on tree diversity and population structure of humid subtropical forest of Meghalaya, India

作     者：Om Prakash Tripathi Khongjee Rangdajied Reynald 

作者机构：Department of Botany North Eastern Hill University Shillong-793 022 India Department of Forestry NERIST Nirjuli-791109 India 

出 版 物：《生物多样性》 (Biodiversity Science)

年 卷 期：2010年第18卷第2期

页      面：208-214页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 

主　　题：生物多样性 相异性指数 生态学 森林 

摘      要：The present study was conducted in subtropical humid forests of Meghalaya to study the distributional pattern of species, floristic composition, community structure and tree population *** fragments of varying sizes(0.5 ha, 1 ha, 2 ha and 5 ha) were used in the *** of the forest fragments are distributed within the same altitudinal range, and had similar rainfall and temperature *** forest fragments were sampled using random quadrats to analyze the impact of fragment size on tree diversity and population *** were used to compare the dispersion pattern of plant species, species diversity among fragments, and the heterogeneity and homogeneity of the fragments.A total of 45 tree species were recorded from all the fragments and simple correlation showed that the species richness was positively related to fragment size(n = 4, P0.05).Other measures such as stand density, basal cover, diversity and dominance indices were unrelated to fragment *** canopy was composed mainly of Castonopsis indica, ***, Schima khasiana and Engelhardtia spicata in all of the fragments.A majority of woody tree species were contagiously distributed which made the forest community highly patchy in *** values of Sorensen s similarity index and high values of Whittaker s β-diversity index between the fragments suggest marked difference in the species composition among the *** maximum stand density, basal area, Shannon diversity index and Simpson dominance index was recorded in a 5-ha *** in lower girth classes(15-55 cm circumference at breast height, CBH) accounted for 52-86% of stand density in all fragments except in 0.5-ha fragments where middle girth class(55-95 cm CBH) accounted for 47% of the total stand *** overall density of seedlings, saplings and adult trees formed a pyramidal structure, indicating that the period between the sapling and adult stage was a critical stage in tree life cycles, as the