施肥和刈割是草地生态系统管理的重要方式，然而目前尚不清楚它们如何交互影响草地群落结构和功能，本研究采用双因子裂区试验探究了施肥和刈割对内蒙古典型草原群落特征的短期影响。主区为刈割处理包括不刈割和留茬6 cm两个处理，副区为施肥处理包括不施肥对照、施氮[10 g N/(m2·a)]、施磷[3 g P/(m2·a)]和氮磷同施[10 g N/(m2·a)和3 g P/(m2·a)]4个处理。结果显示，无论刈割与否，氮磷同施处理的群落盖度、群落生物量和羊草生物量显著高于对照，施肥对群落生物量的提升作用可被刈割的负效应所抵消。刈割可显著提升糙隐子草生物量，而糙隐子草生物量对施肥的响应受到刈割的调控。刈割显著提升了物种丰富度和香浓多样性，而施肥对物种丰富度没有影响。物种丰富度随着基尼系数和凋落物量的增加均呈现显著降低趋势。综上，物种丰富度和Shannon-Wiener多样性指数对刈割响应敏感，群落生物量和优势种生物量对施肥响应敏感，施肥和刈割分别对生物量和物种多样性具有正效应。
Effects of Fertilization and Mowing on Plant Community Characteristics in Typical Steppe of Inner Mongolia
Fertilization and mowing are critical management activities in grassland ecosystems.How-ever,the interactive effects of fertilization and mowing on grassland community structure and function remain unclear.This study investigated the interactive effects of fertilization and mowing on the community characteristic of a typical steppe in Inner Mongolia.A split-plot design was employed,with mowing treat-ments(no-mowing,M0 and mowing at 6 cm,M1)as the main plots and fertilization treatments(control as CK,0 g N/(m2·a)as N,3 g P/(m2·a)as P,and 10 g N/(m2·a)and 3 g P/(m2·a)as NP)as the subplots.The results showed that the NP treatment significantly increased community coverage,community bio-mass,and the biomass of Leymus chinensis compared to the CK group regardless of mowing treatment.However,mowing reduced the positive effect of fertilization on community biomass.Mowing significantly increased the biomass of Cleistogenes squarrosa,and the response of this species to fertilization was depen-dent on mowing regime.Species richness and Shannon-Wiener diversity index were significantly enhanced by mowing,while fertilization had no significant effect on species richness.Interestingly,species richness showed a negative correlation with the Gini coefficient and litter production.In conclusion,these findings suggest that species richness and the Shannon‒Wiener diversity index are responsive to mowing,while com-munity biomass and dominant species biomass are sensitive to fertilization.Overall,fertilization and mow-ing have opposing effects,with fertilization promoting biomass production and mowing promoting species diversity.
FertilizationMowingPlant community characteristicsTypical steppe of Inner Mongolia
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