中文摘要：

森林粗根分布和生物量的研究是生态学研究的热点与难点,传统破坏性取样方法费时、费力,而且只能获得有限的调查样本,限制了我们对森林生态系统的整体描述与森林碳储量的准确估算.此外,土壤、地形、树种丰富度、树木密度、优势种多度等环境和生物因素对粗根碳存储能力影响的研究也很少,内部机制未知.本文应用探地雷达技术对浙江古田山24 hm2大样地粗根（直径〉1.5 cm）分布和生物量进行了测定.研究发现：（ⅰ）15个10 m×10 m样方,土壤深度60 cm的探地雷达扫描范围内,粗根生物量平均为1105.38 g m-2,3个生境、5个海拔梯度之间粗根生物量差异显著（P〈0.05）;20~40 cm土层粗根生物量占0~60 cm粗根生物量的71.58%.（ⅱ）40~60 cm深层土壤全磷、氮矿化速率与粗根生物量线性回归关系显著（P〈0.01）,0~60 cm土层全碳、氮矿化速率与粗根生物量线性回归关系显著（P〈0.01）;地形因子对粗根生物量的影响不显著（P〉0.05）.（ⅲ）随树种丰富度、稀疏丰富度的增加,40~60 cm深层土壤粗根生物量显著降低,解释量分别为53.2%和29.2%,树种丰富度、稀疏丰富度比优势树种个体数更能反映树木粗根的碳存储能力.同时,我们发现古田山自然保护区24 hm2监测样地内,环境资源供应的差异可能导致了生境内树种丰富度的不同,树种丰富度及树种稀疏丰富度的变化显著影响了粗根生物量的大小.因此,从粗根较大空间尺度及非破坏性研究的角度出发,探地雷达对粗根生物量分布的研究具有很大潜力.

英文摘要：

Coarse root distribution and biomass are important characteristics in ecological studies on forest ecosystems. Traditional methods for sampling coarse roots are destructive, time-consuming and laborious, which limits the collection of data for estimating carbon storage/sequestration at the whole ecosystem level. Furthermore, there have been few studies on the relationships between coarse root biomass and abiotic and biotic factors. In this study, the coarse root biomass and distribution were investigated using a ground-penetrating radar technique in a 24-hm2 old-growth subtropical broadleaved forest plot in Gutianshan, Zhejiang Province, China. The mean of the coarse root biomass across 15 quadrats was 1105.38 g m-2 for soil depth of 0-60 cm. The habitat and altitude had significant （P 〈 0.05） effects on coarse root biomass. 71.58% of the total coarse root biomass was distributed at 20-40 cm. There were significant （P 〈 0.01） linear regressions between coarse root biomass and soil total phosphorus content and nitrogen mineralization rate at soil depth of 40--60 cm, while across soil depth of 0-60 cm, a significant （P 〈 0.01） linear regression between the coarse root biomass and soil total carbon content and nitrogen mineralization rate occurred. Topographic traits had no significant effects on coarse root biomass distribution. The coarse root biomass decreased with an increase in tree species richness and rarefied tree species richness at 40-60 cm and this accounted for 53.2% and 29.2% of the variation, respectively. Tree species richness and rarefied tree species richness had a closer relationship with coarse root biomass than the dominant tree species abundance did. The resource variations across the 24-hm2 Gutianshan plot might contribute to the difference in tree species abundance, and the tree species richness and rarefied tree species richness had significant effects on the coarse root biomass. This study shows that the ground-penetrating radar technique has great potential for coarse root