长江三峡地区典型灌丛的生物量及其再生能力

STUDIES ON THE BIOMASS OF TYPICAL SHRUBLAND AND THEIR REGENERATION CAPACITY AFTER CUTTING

灌丛是三峡地区典型的退化生态系统类型。本文采用收获法和模拟砍伐实验研究了三峡地区铁仔灌丛、木灌丛、荆条灌丛和黄栌灌丛的生物量及黄栌灌丛、木灌丛地上部分砍伐后的再生能力。研究结果表明，这４种类型的灌丛总生物量分别为２２．５±５．１、２１．０±３．７、１６．９±７．５和１３．６±２．４ｔｈｍ－２，相当于同纬度地带性生态系统常绿阔叶林（３０年林龄）的１０％～２５％４种灌丛灌木层占总生物量、地上部分生物量和地下部分生物量的９０％以上。在生物量－物种序列中，前５种植物占总生物量的８４％以上。不同地点灌丛生物量的比较表明，同一种类型灌丛，亚热带和暖温带地区总生物量没有明显差异。通过模拟砍伐实验，黄栌灌丛、木灌丛地上部分全部砍伐后１年地上部分生物量就可以恢复到对照的４２．７％和６２．０％，说明这些灌丛类型具较高的生长速度和很大的恢复潜力。

Shrubland is the typical degraded ecosystems in the Three Gorges Region.In this paper, the biomasses of 4 types of shrublands,such as Myrsine africana,Loropetalum chinense,Vitex negundo and Cotinus coggygria,and their responses to cutting were investigated with harvest method and cutting experiment.The results show that the biomass of these 4 types of shrublands were 225±51,210±37,169±75 and 136±24t·hm-2,respectively,being equal to about 10%～25% of that of the typical natural evergreen broadleaved forests (30 years).The shrub layer accounted for 90% of the community in terms of the total or the underground or the aboveground biomass.In the biomass species sequence,the top 5 species amounted to over 84% of the total biomass.The shrublands of the same type were similar in biomass between temperate and subtropical area.That Cotinus coggygria shrub and Loropetalum chinense shrub recovered to 427% and 620% of aboveground biomass of the control due to one year restoration after cutting, suggests their high growth rate and recovery potential.