文献类型：期刊文献

英文题名：The effects of salt stress and arbuscular mycorrhiza on plant neighbour effects and self-thinning

作者：Yu, Z. X.[1] Zhang, Q.[1,2] Yang, H. S.[1] Tang, J. J.[1] Weiner, J.[3] Chen, X.[1]

第一作者：Yu, Z. X.

通信作者：Chen, X[1]

机构：[1]Zhejiang Univ, Coll Life Sci, Hangzhou 310058, Zhejiang, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, Beijing 100091, Peoples R China;[3]Univ Copenhagen, Dept Agr & Ecol, DK-1958 Frederiksberg, Denmark

年份：2012

卷号：13

期号：8

起止页码：673-680

外文期刊名：BASIC AND APPLIED ECOLOGY

收录：;Scopus(收录号：2-s2.0-84870413722);WOS:【SCI-EXPANDED(收录号:WOS:000314143800004)】；

基金：This work was supported by the National Natural Science Foundation of China (NSFC, Nos. 30870405 and 31070389) and the Key Laboratory of Ministry of Agriculture of the People's Republic of China (No. KYJD09021). We thank the anonymous reviewers for extensive, helpful comments on the manuscript.

语种：英文

外文关键词：Salinity stress; Arbuscular mycorrhizal fungi; Plant neighbour effects; Biomass-density relationship; Self-thinning trajectory; Medicago sativa L.

摘要：Abiotic and biotic factors can alter the nature and strength of plant plant interactions and therefore self-thinning (density-dependent mortality), but few studies have looked at how such factors interact. We investigated how salt stress and arbuscular mycorrhizal fungi (AMF) influence plant neighbour effects and self-thinning in experimental populations of Medicago sativa. We obtained two mycorrhizal levels by applying the fungicide benomyl (low AMF) or not (high AMF) at three salinity levels (0.05%, 0.2% and 0.5%). In experiment 1, we investigated how salinity and AMF interact to influence plant interaction intensity using a neighbour removal treatment. In experiment 2, we investigated how self-thinning dynamics vary under salinity conditions and different AMF levels at two initial plant densities (6000 and 17,500 seeds m(-2)). Shoot biomass and plant density were measured 30, 60 and 90 days after sowing. Standardized major axis regression was used to estimate self-thinning parameters. In experiment 1, AMP increased competitive plant neighbour effects when there was no salinity stress, but this enhancement was not significant with increasing salinity. In experiment 2, there were effects of salinity and AMF on the self-thinning trajectory. The slope of the log (mean shoot biomass per unit area) vs. log density relationship was significantly steeper for the high AMF treatment than for the low AMF treatment without salinity, but the effect of AMF level on the self-thinning exponent was not significant under the two higher salinity levels. The effect of AMP treatments on the intercept of the self-thinning line was not significant at 0.2% salinity but was significant at 0.5% salinity, higher elevation for high AMP treatment. In self-thinning populations, AMF decreased the survival rate without salinity; but increased the survival rate at the highest salinity level. Our results support the hypothesis that salinity and AMP interact to influence plant neighbour effects and self-thinning. Under no-salinity conditions, AMF increased competition, steepened the self-thinning line and decreased survival rate, but these effects of AMP were not significant in the presence of salinity.