植物对土壤养分空间异质性分布响应的荟萃分析

Meta analysis of plant responses to the spatial heterogeneity distribution of soil nutrients

为了描述植物响应养分异质性的普遍规律,解析造成不同研究间的结论存在差异可能原因,本研究收集了55篇已发表的文章进行荟萃分析(meta-analysis),用以评估植物功能群分类、驯化水平和研究周期对7个有关植物地上部分和根系生长变量(地上部生物量、根系生物量、根冠比、地上部氮累积量、地上部磷累积量、根长密度和根系觅食精度)响应养分异质性环境的影响。分析结果表明,除了根冠比,养分异质性分布对其他6个植物响应变量均有正效应。根系形态的改变比率(26.5%~44.1%)显著高于植物生物量分配(7.3%~13.8%)和地上部养分含量(14.8%~18.0%)。非豆科类双子叶植物和禾本科植物相比,养分异质性分布对豆科根系形态的改变比率显著高于禾本科植物,而对植物生物量分配和地上部养分含量没有显著的影响。农作物与野生植物的生物量和养分累积量对养分异质性的响应程度相同,但农作物具有更高的根系觅食精度。养分异质性分布对植物生长响应的正效应表现出随研究周期的延长而呈下降的趋势。

To describe the general patterns of plant response to nutrient heterogeneity and explain the possible reasons for the differences in conclusions between different studies,we conducted a meta-analysis of 55 published studies to evaluate the response patterns of seven plant variables related to shoot and root growth(shoot biomass,root biomass,root:shoot ratio,shoot nitrogen and phosphorus accumulation,root length density and root foraging precision)in heterogeneous environments,including effects of plant functional group,domestication history and test duration.Overall,nutrient heterogeneity had positive effects on six response variables,except for root:shoot ratio.The percentage of change for root morphology(26.5%~44.1%)was higher than that for plant biomass allocation(7.3%~13.8%)and that for shoot nutrient content(14.8%~18.0%).Compared with gramineous plants,nutrient heterogeneity distribution for non-leguminosae dicotyledonous plants had a higher percentage of change of root morphology,but had no significant effect on biomass distribution and shoot nutrient content.Wild species and crops showed similar responses to soil nutrient heterogeneity in biomass and nutrient accumulation,but crops had higher root foraging precision than wild species.The positive effect of nutrient heterogeneity distribution on plant growth responses showed a decreasing trend with prolonged test duration.This study found that plant response to nutrient heterogeneous environments are affected by plant functional group types,domestication levels and test duration,which provides a theoretical basis for in-depth understanding of plant-plant and plant-soil interaction in natural and farmland systems.