桂西喀斯特地区3种典型灌丛生物量及生产力研究

Biomass and productivity of 3 typical shrub communities in karst areas of Western Guangxi

采用样方收获法研究了桂西喀斯特地区黄荆、红背山麻杆、灰毛浆果楝3种典型灌丛的生物量及生产力。结果表明:3种灌丛群落的总生物量分别为15.98、16.04和11.86 t·hm-2,其中木本层、草本层、凋落物层的生物量占群落总生物量的比例为:黄荆群落68.9%、14.1%、17.0%,红背山麻杆群落74.7%、9.3%、16.0%,灰毛浆果楝群落47.0%、28.1%、24.9%;群落地上部分生产力分别为3.64、3.02和2.75 t·hm-2a-1;对群落优势种及灌木层根、干枝、叶、果、地上部分及全株生物量进行回归分析,结果表明各组分生物量与基径(D)的平方乘以树高(H)(D2·H)间存在极显著的相关关系,相对生长方程W=a(D2·H)b较好地描述了灌丛的生长过程,可为具有相似立地条件、群落类型及结构的林分生物量估测提供依据。

The biomass and productivity of 3 typical shrub communities （Vitex negundo;Alchornea trewioides;Cipadessa baccifera） in karst areas of western Guangxi were investigated by quadrat harvest method. The total biomasses of the 3 shrub communities were： 15.98, 16.04 and 11.86 t·hm-2, respectively; of them, the woody, herb and litter layer respectively accounted for 68.9%, 14.1% and 17% of the total biomass forV. negundocommunity; 74.7%, 9.3%, 16% forA. trewioides community; and 47%, 28.1%, 24.9% for C. baccifera community. The above-ground productivities were 3.64, 3.02 and 2.75 t·hm-2a-1,respectively.A regression analysis of dominant species and shrub layer biomass components （root, stem, leaf and fruit biomasses, above-ground biomasses） showed that all the biomass components were signiifcantly correlated with the square of basal diameter multiplying by tree height （D2·H）, and the equationW=a（D2·H）b could appropriately describe the growth of the shrub communities, thus providing a basis for the estimation of stand biomass for similar shrub communities in karst regions.