克隆植物空间拓展及在退化生境修复中的应用

Research progress on spatial expansion of clonal plants and its utilization for restoring degraded ecosystems

克隆植物空间拓展特性可使其高效利用斑块化资源,对其生长具有重要意义,同时对斑块化退化生境也具有潜在修复价值。本文首先对克隆植物适应异质环境的生存策略进行归纳,指出克隆植物多基于克隆整合,通过调控表型塑性、觅食行为及权衡生物量分配,强化克隆内分工,使不同生境分株表现出"趋富特化"特性,以提高斑块化资源利用效率和适应能力。同时基于"竞争–胁迫–干扰competition–stress–ruderal(C–S–R)"生活史对策理论,介绍了干扰、胁迫、竞争等环境因素对克隆植物拓展的影响及驱动机制,认为适度干扰(放牧、刈割等)可促进克隆植物拓展。本文对利用克隆植物拓展修复退化生境的应用进行了总结与展望。克隆植物通过拓展产生发达的网状结构,有利于防风固沙、改良土壤环境,且繁殖体的拓展起到先锋物种作用,对退化生境物种更新、群落重建以及生态系统生产力具有重要影响,这均利于退化生境的恢复演替。指出今后应注重克隆植物生物学和恢复生态学交叉领域的研究,为退化草地的修复和治理开辟新的研究思路。

The spatial expansion ability of clonal plants can help them successfully colonize adverse habitats and make efficient use of patchily distributed resources,which is crucial for growth and adaptation of such plants.Spatial expansion characteristics of clonal plants also hold considerable potential for restoration of degraded ecosystems.One important characteristic of clonal plants is physiological integration,which consitutes resource translocation and sharing between ramets(i.e.,potentially physiologically independent units or individuals)connected by horizontal structures such as rhizomes,stolons,and horizontally growing roots.In this review,adaptive strategies of clonal plants to colonize heterogeneous habitats are summarized.Based on physiological integration,clonal plants enhanced the division of labor by modifying phenotypic plasticity,foraging behavior,and the tradeoff of biomass allocation;thus,ramets in heterogeneous patches performed"specialization for abundance",which substantially improved resource use efficiency and adaption potential.Moreover,based on the"C–S–R(competition–stress–ruderal)"life history strategy theory,effects of environmental factors including disturbance,stress,and competition on spatial expansion of clonal plants are discussed,and the driving mechanisms of expansion were also revisited.We assumed that intermediate disturbance(e.g.,grazing,mowing,etc.)may improve spatial expansion of clonal plant populations.Furthermore,we summarized the application potential of expansion of clonal plants for the restoration of degraded ecosystems.Clonal plants produce large and dense multilayered rhizomes/roots during the expansion process which increases soil consolidation and sand fixation,improves water conservation capacity,and thus ameliorates the soil environment.Moreover,propagules of clonal plants play a pioneering role in colonizing poor or bared habitats,which is important for species diversity regeneration,community structure variation,and productivity in degraded ecosystems.Based on their expansion functions in both above-and below-ground environmental recovery,clonal plants improve the restoration succession of degraded ecosystems.It is suggested that future research should focus on spatial expansion of clonal plants from the perspective of restoration of degraded environments in order to increase knowledge on the overlapping fields of clonal plant biology and restoration ecology and to provide a new research ideas for the restoration and management of degraded grasslands.