【目的】研究林下灌木层地上与地下生物量的分配关系探究不同起源森林在不同生长发育阶段灌木层地上地下生物量是否符合等速生长规律,抚育管理等人工经营措施是否会影响其地上地下生物量分配关系,为开展森林生态系统其他相关研究提供基础数据和科学依据。【方法】以天然常绿阔叶林和杉木人工林为研究对象,分别基于其不同龄组及所有灌木层样方植物的地上生物量(y)与地下生物量(x)数据,应用SMATR软件,采用对数方程lgy = b + a lg x拟合灌木层地上、地下生物量分配关系,并对不同起源森林各龄组灌木层的a(生长指数)和b(生长常数)值进行分析。【结果】不同龄组天然常绿阔叶林的灌木层生长指数a值分别为幼龄林0.942、中龄林1.003、近熟林0.946和成熟林0.951,各龄组间差异不明显(P =0.136),其地上地下生物量分配均遵循等速生长规律;不同龄组杉木人工林灌木层a值分别为幼龄林0.837,中龄林0.817,近熟林1.011,成熟林0.984,各龄组间差异也不明显(P =0.515),且其95%置信区间也均包含理论预测值1.0,其地上地下生物量分配也遵循等速生长规律。【结论】天然常绿阔叶林和杉木人工林灌木层地上地下生物量均遵循等速生长规律;不同区域、不同树种及不同龄组的人工林灌木层地上地下生物量分配均遵循等速生长规律。
英文摘要:
【Objective】Understanding the relationship between above- and below-ground biomass is of profound significance to predict the biomass of forest ecosystem and global climate changes. This paper was aimed to test whether the aboveground biomass scaled isometrically with under-ground biomass of shrub layer plants and how forest management measures influenced such scaling relationships. 【Method】Above-(y) and under-ground biomass(x) of shrub layer plants in natural evergreen broad-leaved forest and Chinese fir plantation in Fujian province (Nanping and Sanming) were harvested to test the biomass allocation patterns,a. Software SMATR (standardized major axis tests and routines) was used to calculate and analyze the allometric scaling a and exponent constant b,as the equation: log y = b + a log x. 【Result】 The scaling exponents for the shrub layer plants of young,middle-age,pre-mature and mature natural evergreen broadleaved forests were 0.942,1.003,0.946, and 0.951,respectively. Furthermore,the scaling exponents were not differ significantly among the four stand ages of natural evergreen broad-leaved forests,indicating that above-ground biomass scaled isometrically with under-ground biomass. For the shrub layer plants of young,middle-age,pre-mature and mature Chinese fir plantations,the scaling exponents were 0.837,0.817,1.011, and 0.984,respectively. The 95% confidence intervals of such scaling exponents all covered the predicted theoretical value 1.0,showing that above-ground biomass scaled isometrically with below-ground biomass. 【Conclusion】The above-ground biomass of understory scales nearly one to one with under-ground biomass in different regions and different types of forests. Although different forest tending measures appeared to affect the scaling constants,but not the scaling exponents of above-vs. under-ground biomass of shrub layer plants. Generally,the above- and under-ground biomass allocation patterns of shrub layer plants in natural evergreen broad-leaved forest and Chinese fir plantation in Fujian province were in consistence with the isometric biomass allocation theory. The research validated and developed the theory of isometric scaling of above-and under-ground biomass of forest vegetation.