母体放牧历史对羊草后代功能性状的影响

Effects of Maternal Grazing History on Functional Traits of Clonal Offspring of Leymus chinensis

放牧是我国草原历史最悠久、应用最广泛的利用方式,放牧干扰下草原植物功能性状会产生适应性变化并可能形成遗留效应。为验证这一科学假设,以温性典型草原主要优势植物羊草为研究对象,采用室内同质化盆栽试验,对放牧样地和围封样地的羊草无性系后代的表型功能性状进行测定。结果表明:放牧羊草无性系后代与围封羊草无性系后代相比,叶片数、叶长、叶面积、比叶面积、茎长分别显著降低了13.79%、29.71%、18.74%、6.98%和31.06%(P<0.01或P<0.05),而分蘖子株数极显著增加了93.26%(P<0.01);放牧和围封来源下的羊草无性系后代单株地上总生物量、单株茎生物量及单株叶生物量具有极显著差异(P<0.01);表明放牧干扰对羊草无性系后代功能性状有显著影响,进而对植物生产力造成遗留效应。

Grazing is the oldest and most widely used method in the grassland of China.The functional traits of grassland plants will change adaptively and may form legacy effect under grazing disturbance.In order to verify this scientific hypothesis,the main dominant plant Leymus chinensis in the temperate typical steppe was taken as the research object,and the phenotypic functional traits of clonal offspring in grazing and enclosed plots were determined by indoor homogenization pot experiment.The results showed that the number of leaves,leaf length,leaf area,specific leaf area and stem length of the clonal offspring of L.chinensis under grazing were significantly decreased by 13.79%,29.71%,18.74%,6.98%and 31.06%,respectively,compared with the clonal offspring of L.chinensis under enclosure(P<0.01 or P<0.05),while the number of tillers significantly increased by 93.26%(P<0.01).Under grazing and enclosure sources,the total above ground biomass,stem biomass and leaf biomass per plant of clonal offspring of L.chinensis were significantly different(P<0.01).Therefore,grazing disturbance could cause significant responses of functional traits of L.chinensis clone offspring,and then cause the legacy effect on the plant productivity.