广西玉林市4种人工林林下植被物种多样性研究

通过样地调查,运用重要值、丰富度、多样性、均匀度等指标,研究玉林市福绵管理区大义林场马尾松人工林、杉木人工林、巨尾桉人工林和红椎人工林林下植物的物种多样性。结果表明:(1)人工林林下植物种类比较丰富,群落物种数为54~62种,平均为58±3.36,灌木层的物种数为39~51种,平均45±4.97,草本层的物种数为11~15种,平均13±2.31。(2)Shannon-W iener指数的变化值在0.6915~2.9972之间,灌木层的物种多样性高于草本层的多样性;灌木层的多样性比较接近,变化在2.7985~3.3037之间;草本层的多样性变化较大,在0.2626~1.8930之间;多样性最大值出现在巨尾桉人工林,马尾松人工林最小;均匀度变化在0.1710~0.7318之间,均匀度的变化规律与Shannon-W iener指数的变化规律相似。(3)各种人工林林下植物的相似程度比较高,共有种达37.78%~53.78%。(4)人工林林下植物多样性取决于环境条件、林分结构和人为干扰强度,与人工林树种无关。

A Study on Species Diversity in Undergrowth Vegetation of Four Plantations at Yulin,Guangxi

An investigation was conducted on the species diversity of different plantations(including:Pinus massoniana,Cunninghamia lanceolata,Eucalyptus grandis×Eucalyptus urophylla,and Castanopsis hystrix plantations) in Dayi Forest Farm,Yulin City of Guangxi.The results were as follows:(1) The plant species of the plantations were rich,there were 54~62 species in community(average was 58±3.36),39~51 species in shrub layer(average was 45±4.97) and 11~15 species in herb layer(average was 13±2.31).(2) The variation of Shannon-Wiener index among plantations was 0.6915~2.9972 in community,2.7985~3.3037 in shrub layer,0.2626~1.8930 in herb layer.Eucalyptus grandis×Eucalyptus urophylla plantation had the biggest Shannon-Wiener index and Pinus massoniana plantation had the smallest index.The variation of evenness index among plantations was from 0.1710 to 0.7318 and similar to Shannon-Wiener index.(3) The plantations were high in similarity,and the species numbers in the two plantations mentioned above were from 37.78% to 53.78%.(4) The plant species diversity of plantations depended on environmental condition,structure of stand and disturbance,and had nothing to do with the tree species of plantation.