应用微根管法测定细根指标方法评述

树木细根(直径<2mm)在森林生态系统能量流动和物质循环中起着重要的作用。原有的细根生产周转研究中常采用的土钻法、内生长法、挖掘法、根室法和土柱法等,均不能直接观察到细根的动态变化。微根管法是一种非破坏性、可定点直接观察和研究植物根系的方法,为研究细根的生长、衰老、死亡、分解和再生长的过程提供了有效的工具,尤其适用于细根周转、寿命和分解等方面的研究。但该技术不能直接测定单位面积的细根生物量、细根化学组成及细根周转对土壤碳和养分循环的影响,需要与土钻法结合。本文就运用微根管法对细根生物量、生产、周转和寿命等指标的研究方法进行了评述。

Minirhizotron technique in measuring fine root indices: A review

Fine root(D<2 mm)plays a significant role in the energy flow and matter cycling of forest ecosystem.Many methods including those with soil core,in-growth core,excavation,rhizotron and soil column,have been used in researching the production and turnover of fine roots,but cannot observe their dynamic changes directly.Minirhizotron technique provides a nondestructive method to directly observe and study the dynamics of fine roots in situ,which allows the simultaneous measurement of fine root growth,senescence,mortality,decomposition,and re-growth,being especially available to the study of fine root turnover,longevity,and decomposition.However,minirhizotron technique cannot be used to directly determine the unit area fine root biomass and its chemical composition,and study the effects of its turnover on soil carbon and nutrients cycling.To study the fine root production and turnover more directly,minirhizotron technique needs to be combined with the method of soil coring.This paper reviewed the applications of minirhizotron technique in measuring fine root indices,e.g.,biomass,production,turnover,and longevity,etc.