退耕还林模式板栗林下多样性及生物量研究

[目的]为桂西北地区石漠化治理、植被恢复以及促进地方经济发展提供科学依据。[方法]采用典型样地法对广西东兰县退耕还林模式板栗林下多样性及生物量进行研究,并以未退耕地(玉米地)作为对照。[结果]板栗林下灌木层的丰富度指数为0.283 2~0.431 4,Simpson多样性指数为0.675 1~0.838 9,Shannon-Wiener多样性指数为2.042 0~2.771 2;草本层的Simpson多样性指数为0.624 5~0.737 8,Shannon-Wiener多样性指数为1.715 2~2.471 5。未退耕地(玉米地)灌木层的丰富度指数为0.202 3~0.226 1,Simpson多样性指数为0.543 3~0.572 8,Shannon-Wiener多样性指数为1.289 6~1.318 8;草本层的Simpson多样性指数为0.382 3~0.436 9,Shannon-Wiener多样性指数为1.106 0~1.164 1。板栗林下生物量随着退耕年限的增长呈现出上升的趋势,且灌草地上部分的生物量均大于地下部分。经方差分析可得,6~9年生板栗林下灌草多样性和总生物量具有显著差异,未退耕地(玉米地)灌草植被多样性和总生物量无显著差异。[结论]退耕还林对板栗林下植被的恢复具有很好的促进作用,有必要加大退耕还林力度。

Diversity and Biomass in the Castanea moUissima Forest under Conversion Cultivated Land into Forests Model

[ Objective ] The research aimed to provide the scientific basis for rocky governance, vegetation restoration and promotion of local economic development in the northwest of Guangxi. [ Method ] The diversity and biomass in the Castanea mollissima forest and frumentum farmland in Donglan County, Guangxi Province was studied by typical sampling method with maize land as control. [ Result] In the shrub layer of Castanea mollissima forest, richness index is 0.283 2 - 0.431 4, Simpson diversity index is 0.675 1 - 0.838 9, Shannon - Wiener diversity index is 2.042 0 - 2.771 2, in the herbaceous layer, Simpson diversity index is 0. 624 5 - 0. 737 8, Shannon-Wiener diversity index is 1. 715 2 -2. 471 5. And in the shrub layer of frumentum farmland, the richness index is 0. 202 3 - 0. 226 1, Simpson diversity index is 0. 543 3 -0. 572 8, Shannon-Wiener diversity index is 1. 289 6 - 1. 318 8, in the herbaceous layer, Simpson diversity index is 0.382 3 - 0.436 9, Shannon-Wiener diversity index is 1. 106 0 - 1. 164 1. The biomass in the Castanea mollissima forest showed a rising trend as the in- creasing of returning time, and the biomasses of ground part from shrub and grass are all more than those of underground part. Through vari- ance analysis it can be obtained that, there are significant differences in the diversity and the total biomass of the shrub layer and herbaceous layer in Castanea mollissima forest of 6 -9 years, and those in frumentum farmland have no significant differences. [ Conclusion ] It is a good effect to the recovery of the Castanea moUissima forest under conversion cultivated land into forests, so it is necessary to increase the intensity of conversion cultivated land into torests.