[Objective]The aim of the study was to investigate the plant community structure,plant dive-rsity,soil physic-chemical properties and their correlations among rocky desertification ecosystems under different degrees in karst plateau canyon region of Guizhou Province.This study could provide a scienti-fic reference for forest ecological conservation and vegetation restoration of karst plateau canyon region in Southwest China.[Method]The"space instead of time"method was used to study the response of plant community characteristics and soil physic-chemical properties during the process of rocky desertificat-ion. And redundancy analysis (RDA) was used to reveal the relationships between plant community characteristics and soil physic-chemical properties.[Result]The vegetation composition of the studied area was relatively simple and the majority of the species belong to one genus of one family.The comm-unity height,average ground diameter,average crown and aboveground biomass decreased with increasing degree of rocky desertification. The four plant diversity indices was low in all communities and had no obvious relationship with rocky desertification grades.Eccept for richness index,the indices of dominance, diversity and evenness were significantly different among different degrees of rocky desertification. Most soil physic-chemical variables showed significant differences among rocky desertfication degrees and they decreased firstly and then increased with increasing degree of rocky desertification. The redundancy analysis showed that soil respiration,available potassium,soil dry and wet degree,available phosphorus and pH were the main soil factors affecting plant community characteristics and they together explained 68.5% varitions of community characteristics.[Conclusion]Soil respiration,soil nutrient,moisture and soil porosity are key factors that promote the vegetation restoration of karst plateau rocky desertification ecosystem. However,greater soil bulk density and alkaline soil are not favor-able to local vegetation restoration.%[目的]研究不同等级石漠化生态系统植物群落结构组成、植物多样性和土壤理化性质特征及其两者间的相关性,为我国西南喀斯特高原峡谷森林生态保护和植被恢复重建提供科学依据.[方法]运用空间代替时间方法,研究石漠化演替过程中植物群落特征与土壤理化性质的响应;对喀斯特高原峡谷脆弱生态系统植物群落与土壤理化性质的内在关系进行了冗余分析.[结果]研究区植被物种组成简单,绝大多数为1科1属1种生活型;随着石漠化强度的增加,群落高度、平均地径、平均冠幅和地上生物量趋于减少.不同等级石漠化环境植物多样性4种指数均很低,且与石漠化等级无明显的耦合关系;除丰富度指数外,不同等级石漠化的优势度指数、多样性指数和均匀度指数具有显著差异.大多数土壤理化因子在不同等级石漠化环境中具有显著的差异,并显示随着石漠化程度的增加表现为先退化后改善的趋势.冗余分析表明,土壤呼吸、速效钾、土壤干湿程度、有效磷和酸碱度是影响植物群落特征的主要土壤因子,对群落特征的解释量为68.5%.[结论]土壤呼吸、土壤养分、含水量和土壤孔隙状况是促进喀斯特高原峡谷石漠化生态系统植被恢复的主要土壤因素,而过大的土壤容重以及土壤的偏碱性则不利于当地植被的恢复.
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