黄土丘陵区人工油松林下植物多样性和更新调查

采用野外调查和室内分析相结合的方法,对黄土丘陵区45a人工油松林下的植物组成、多样性及幼苗更新等方面进行了研究,探讨了坡向和不同干扰对林下植物多样性和幼苗更新的影响。结果表明,阴、阳坡林下的物种组成相似性系数达到74%;原状林与去枯落物林,原状林与采伐上层乔木林地的相似性系数分别为74%和38%。灌木的物种丰富度(S)、多样性指数(H,D)在不同坡向表现为:阴坡>阳坡;均匀度指数(J)表现为:阳坡<阴坡,草本的各项指数均表现为:阴坡>阳坡;3种处理下灌木的丰富度、多样性指数均表现为:去枯落物林>原状油松林>采伐上层乔木林,均匀度指数表现为:采伐上层乔木林>去枯落物林>原状林,草本各项指数均表现为:去枯落物林>采伐上层乔木林>原状林。采伐上层乔木林下幼苗更新最好,在阴坡表现出良好的更新能力。

Biodiversity and Regeneration of Pinus Tabulaeformis Forest in Loess Hilly Region

In order to understand the effects of slope aspect and human disturbances on the diversity and community regeneration,field and laboratory analyses were conducted on Pinus tabulaeformis artificial forest in loess hilly region.The results showed that the community similarity coefficient of undergrowth was 74%,74% and 38% between shady and sunny slopes,between the natural and litter removed conditions,and between natural and timbered conditions,respectively.The indices of richness(R),Shannon-Wiener(H),and Simpson(D) of the shrub layer on the shady slopes were larger,while Pielou(J) in the shady was smaller than those on the sunny slopes.For herbaceous layer,R,H,D and J on the shady slopes were larger than those on the sunny slopes.The values of R,H and D in shrub layer were the highest under litter removed condition,then followed by natural state and timbered land;however J showed the exactly opposite trend.The values of R,H,D and J in herbaceous layer were the highest under litter removed,then followed by timbered and natural forests.The best regeneration of seedlings was found in the timbered land and on the shady slopes,respectively.