2种短周期人工林的林下植物多样性与生物量研究

Study on the Undergrowth Plant Diversity and Biomass of Two Short-period Plantations

2002年3月在经过炼山同一坡面相同海拔高度的杉木人工林采伐迹地上营造尾巨桉（Eucalyptus urophylla×E．grandis）和厚荚相思（Acacia crassicarpa）人工林。2007年10～12月以灌草坡自然恢复植被作为对照，设置样方调查2种短周期人工林的林下植物多样性和生物量。结果表明，2种短周期人工林的林下植物物种均为27种，均比对照的43种减少37．2％；对于灌木层，尾巨桉和厚荚相思人工林的物种丰富度指数分别比对照的减少36．4％和18．2％，Shannon—Wiener指数分别比对照的增加8．9％和27．4％，Pielou均匀度指数分别比对照增加27．5％和36．3％；对于草木层，尾巨桉和厚荚相思人工林物种丰富度指数分别比对照的减少38．1％和57．1％，尾巨桉Shannon—Wiener指数比对照的减少72．7％、厚荚相思比对照的增加29．8％，尾巨桉人工林Pielou均匀度指数比对照的减少67．6％，而厚荚相思人工林比对照的增加79．9％；尾巨桉和厚荚相思人工林的林下植物生物量分别比对照的减少40．8％和83．2％，2种短周期人工林的林下灌草植物生物量分配分别与对照的分配规律相一致。

Eucalyptus urophylla × E. grandis and Acacia crassicarpa plantations were planted on the same slope and altitude, where on the fir plantation was cutting and burning in March 2002. The undergrowth plant diversity and biomass of two short-period plantations were investigated between October and December 2007,which the natural vegetation recovery of shrub-herb slope was used as control. The results showed that the species of both two short-period plantations＇ undergrowth plant was 27, which is 37.2% less than that on shrub-herb slope （43 species）. Compared with, in shrub layer, the species richness index of E. urophylla × E. grandis and A. crassicarpa plantations was 36.4% and 18.2% respectively less than that on the shrub-herb slope. Shannon-Wiener index was 8.9% and 27.4% respectively higher than that on the shrub herb slope. Pielou evenness index was 27.5% and 36.3% respectively higher than that on the shrub herb slope. In herb layer, the species richness index of E. urophylla × E. grandis and A. crassicarpa plantations were 38. 1% and 57.1% respectively less than that on the shrub herb slope ; Shannon-Wiener index of E. urophylla ×E. grandis was 72. 7 % less and A. crassicarpa was 29.8% higher than that on the shrub herb slope. Pielou evenness index of E. urophylla× E. grandis is 67. 6% less and A. crassicarpa 79. 9% higher than that on the shrub herb slope. The undergrowth biomass of E. urophylla × E. grandis and A. crassicarpa plantations were 40.8% and 83.2% respectively less than that on the shrub herb slope. The biomass distribution of the shrub and herb layer was the same as that of natural recovery vegetation of shrub-herb slope.