封育对退化草原植被恢复及土壤理化性质影响的研究进展

封育是退化草原生态系统恢复的有效措施之一。在梳理现有封育研究成果的基础上,归纳封育对植物多样性、生物量、植被演替、土壤物理与化学性状的影响效应,发现:受地理区域、气候条件及封育前退化程度等本底条件的影响,封育条件下植被多样性呈现出显著增加、基本稳定和明显下降3种结果,生物量则表现为围封初期增加,围封时间过长不利于维持较高生物量的变化趋势;封育使得种群拓殖能力与群落资源冗余,土壤种子库结构改善、密度增长,退化草原呈正向演替,并可能出现3种演替模式。封育消除了土壤紧实层,改善了土壤结构与性状,但对土壤养分的影响效应不一致。基于研究现状,提出今后应深入研究的6个内容与方向,对丰富封育条件下退化草原恢复效应具有指导意义。

Advances in research on enclosure effects on vegetation restoration and soil physicochemical property of degraded grassland

Enclosure is one of the effective measures for ecological restoration of degraded grassland.On the basis of existing research,the effect of enclosure on plant diversity,biomass,vegetation succession,soil physical and chemical property were summarized and six contents and directions were proposed about degraded grassland enclosure research in future.Conclusion： As a result of different geographical area,climatic conditions and degradation degree before enclosure,vegetation diversity under enclosure appeared three results,significant increase,stability and dramatic decline.Biomass increased in the early period of enclosure,and for long time enclosure biomass could not keep the increasing tendency.In addition,enclosure could increase population colonizing ability and community resources redundancy,prompt the improvement of soil seed bank structure,increases of density and positive succession of prairie which may appear three succession modes.Enclosure improved the physics properties of soil,since at soil surface ＂tight layer＂ was eliminate,but conclusions of enclosure effect on soil nutrients were not too consistent.