关键词: 珍稀濒危植物, 优先保护级别, 内蒙古, 濒危等级

Abstract: To investigate the habitat suitability for juveniles Eriocheir sinensis in Langshan sandbank and Xinkai sandbank of the lower reaches of Yangtze River, custombuilt netting gears were used to obtain the abundance  of juveniles and six water environmental factors from June 2016 to May 2017. Three factors including water depth, transparency and Chiromantes dehaani abundance were selected by the oneway analysis of variance, correlation analysis and canonical correspondence analysis. After that, habitat suitability curves were established and habitat suitability index was calculated. The results showed that sites with aquatic plants possessed high abundance of juvenile E. sinensis. Significant differences in turbidity, transparency and depth of water existed among different sites. The abundance of juvenile E. sinensis was significantly correlated to abundance ofC. dehaani, water depth, and water transparency. Sites withaquatic plants in both sandbanks had relatively high HSI (>0.5) than those with lower or no aquatic plants (generally lower than 0.4). Moreover, juvenile E. sinensispreferred shallow waters with aquatic plants and water transparency between 10 cm and 20 cm. Our results suggest that both sandbanks are suitable for the growth and development of juvenile E. sinensis and more protection is required.

Key words: rare and endangered plants, Inner Mongolia., endangered grade, conservation priority