不同林龄云杉人工林的根系分泌物与土壤微生物  

Root exudates and soil microbes in three Picea asperata plantations with different stand ages

作　　者：李娇[1,2] 蒋先敏[3] 尹华军[1] 尹春英[1] 魏宇航[1,2] 刘庆[1] 

机构地区：[1]中国科学院成都生物研究所生态恢复重点实验室,成都610041 [2]中国科学院大学,北京100049 [3]四川省阿坝州川西林业局,四川阿坝623102

出　　处：《应用生态学报》2014年第2期325-332,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31070533;31270552);中国科学院碳专项(XDA01050303);中国科学院方向项目(KSCX2-EWJ-22);国家科技支撑计划项目(2011BAC09B04-01)资助

摘　　要：采用野外原位收集方法,对川西米亚罗林区不同林龄(9、13、31年)的粗枝云杉人工林根系分泌物和土壤微生物进行了研究.结果表明:不同林龄粗枝云杉人工林根系的单位质量、长度、面积及根尖分泌速率存在显著差异,表现为9年生云杉林的分泌速率显著大于13年生和31年生云杉林.13年生云杉林的根系活力显著小于9年生和31年生云杉林.不同林龄粗枝云杉人工林的根际土、非根际土微生物量碳(MBC)和氮(MBN)存在显著差异,根际土表现为31年生>13年生>9年生,非根际土为13年生>31年生>9年生.随林龄的增加,粗枝云杉的根际土细菌、真菌、放线菌磷脂脂肪酸含量及总量呈现出高-低-高的变化趋势,而非根际土细菌、真菌磷脂脂肪酸含量、总量及真菌/细菌呈低-高-低的趋势.粗枝云杉根系对土壤MBC、MBN及功能群磷脂脂肪酸含量具有正根际效应.This study investigated the dynamics of in situ root exudates and soil microbial composition among three Picea asperata plantations with different stand ages （9, 13 and 31 a） in Miyaluo, west Sichuan, China. The results showed that the secretion rates of root exudation per fine biomass, length, surface area and tip were significantly different among the three plantations with different stand ages. The secretion rate of root exudation was the highest in the 9-year-old plantation stand. The root activity of P. asperata was the weakest in the 13-year-old plantation stand. Besides, soil microbial biomass C （MBC） and N （MBN） between rhizosphere and non-rhizosphere soils were significantly different among the three plantation stands. MBC and MBN contents of rhizosphere soil gradually increased with stand ages, while those of non-rhizosphere soil were the largest in the 13-year-old plantation stand. The phospholipid fatty acids （PLFAs） of bacteria, fungi, actinomycetes and their summation in rhizosphere soil presented a trend of high-low-high with stand ages. The opposite pattern was found in the PLFAs of bacteria, fungi, the summation of PLFA, and the ratio of fungi number to bacteria in non-rhizosphere soil. It is suggested that root exudates might have a positive rhizosphere effect on soil microbial biomass C, N and PLFAs of functional groups.

关 键 词：粗枝云杉 林龄根系分泌物 根系活力 土壤微生物生物量碳氮 

分 类 号：S791.18[农业科学—林木遗传育种]