退耕还林模式核桃林下植被多样性及生物量调查

Vegetational Diversity and Biomass in Juglans regia Forest under Conversion Cultivated Land into Forests Model

为桂西北地区石漠化治理、植被恢复以及促进地方经济的发展提供科学依据,采用典型样地法对广西凤山县和乐业县退耕还林模式核桃林下植被多样性及生物量进行了研究。结果表明：灌木层的丰富度指数为0.229 2-0.388 3,Simpson多样性指数为0.676 7-0.779 9,Shannon-Wiener多样性指数为1.209 2-1.927 9;草本层Simpson多样性指数为0.517 4-0.681 5,Shannon-Wiener多样性指数为1.261 68-1.568。不同退耕时间核桃林下灌木及草本植物物种多样性指数没有显著的差异,其中,1-5号标准地灌木层总生物量低于草本层,2002年退耕的5号标准地的生物量总量较小,1号、4号和5号标准地地上生物量与地下生物量比值均小于1。核桃林下灌木层和草本层的生物量与经营方式、人为干扰程度和土壤立地条件有关。

The vegetational diversity and biomass in Juglans regia forest under conversion cultivated land into forests were studied by using typical plot sample method in Fengshan and Leye Counties of Guangxi Zhuang Autonomous Region to provide the scientific basis for comprehensive improvement of rocky desertification,revegetation and development of local economy.The results showed that the richness,Simpson and Shannon-Wiener indexes of the shrub layer were 0.2292 ～0.3883,0.6767 ～0.7799 and 1.2092 ～ 1.9279 respectively,the Simpson and Shannon-Wiener indexes of the herb layer were 0.5174～0.6815 and 1.261 68～1.568,there was no significant difference in diversity indexes of shrub and herb species among different times of conversion cultivated land into forests,total biomass of the shrub layer was lower than the herb layer in 1～5 standard plot samples,total biomass of the fifth standard plot sample with conversion cultivated land into forest in 2002 was the minimum,the aerial biomass/underground biomass ratios of the first,fourth and fifth standard plot samples were all below 1.The biomass of the shrub layer and herb layer in Juglans regia forest is correlated to management,artificial disturbance degree and soil environment condition.