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不同林龄云杉人工林的根系分泌物与土壤微生物

李娇1,2,蒋先敏3,尹华军1,尹春英1,魏宇航1,2,刘庆1**   

  1. (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)
  • 出版日期:2014-02-18 发布日期:2014-02-18

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

LI Jiao1,2, JIANG Xian-min3, YIN Hua-jun1, YIN Chun-ying1, WEI Yu-hang1,2, LIU Qing1   

  1. (1Key Laboratory of Ecological Restoration, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; 2University of Chinese Academy of Sciences, Beijing 100049, China; 3West Sichuan Forestry Bureau of Aba Prefecture, Aba 623102, Sichuan, China)
  • Online:2014-02-18 Published:2014-02-18

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.

Abstract: 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.