以深陷塘退化天坑倒石堆阴坡乔灌层植物群落为对象,研究倒石堆不同坡位的物种多样性变化特征及其主要影响因子。结果表明:　深陷塘南侧乔木层物种有13科17属21种,灌木层物种有14科20属20种,群落属于亚热带湿润针阔混交林类型;微气候环境使坑口与坑坡植被差异明显,倒石堆上的二次崩塌使中坡位能够涵养更多的水分,为需水性植物提供了优质的生态位。各α多样性指数均在坑底边缘坡位达到最大值,Margalef丰富度指数、Shannon指数、Simpson指数、Pielou均匀度指数分别为3.58、2.47、0.79、0.86,但整体上差异较小,变异系数最高仅为0.226;β多样性指数波动较大,沿坑口、坑坡和坑底边缘间,Routledge指数、Whilson-Shmida指数均呈现减小-增大-减小趋势,其最大值分别为15.95、1.20,物种更替率总体呈上升趋势,共有种的数量逐渐减少。土壤是各坡位间差异最主要的影响因子,各坡位上植物多样性主要与土壤全氮、全磷、有效磷、有机碳含量有关。.We　investigated　the　characteristics　of　plant　species　diversity　in　tree　and　shurb　layers　and　the　main　influencing　factors　in　different　slope　positions　of　a　shady　slope　of　degraded　tiankeng　talus.　The　results　showed　that　there　were　21　species　in　17　genera　and　13　families　in　the　tree　layer,　and　20　species　in　20　genera　and　14　families　in　shrub　layer　in　the　south　side　of　the　Shenxiantang.　Plant　communities　were　subtropical　moist　coniferous　and　broad-leaved　mixed　forest.　Micro-climate　led　to　obvious　vegetation　variation　between　the　pit　and　the　pit　slope　at　the　tiankeng.　The　secondary　collapse　over　the　talus　with　mid-slope　could　conserve　more　water,　which　supported　the　water-demanding　species　in　a　high-quality　niche.　All　the　α　diversity　indices　including　Margalef　(3.58),　Shannon　(2.47),　Simpson　(0.79)　and　Pielou　(0.86)　reached　the　maximum　at　the　pit　bottom　edge　with　slight　variability,　and　the　maximum　coefficient　of　variation　was　only　0.226.　The　β　diversity　index　fluctuated　greatly　among　the　pit-pit,　slope-pit,　bottom　edge.　The　Routledge　and　Whilson-Shmida　indices　showed　the　trends　of　decrease-increase-decrease,　with　the　maximum　values　of　15.95　and　1.20,　respectively.　Species　turnover　demonstrated　the　upward　trend　overall,　and　the　number　of　co-species　was　decreased.　Plant　diversity　on　each　slope　position　was　mainly　related　to　the　contents　of　total　nitrogen,　total　phosphorus,　available　phosphorus　and　organic　carbon　in　soil.　Soil　was　the　most　important　factor　leading　to　the　difference　among　slope　positions.