兰州市永登县不同草地类型植物多样性特征及其影响因子分析OA

Elucidating the distribution patterns and driving mechanisms of herbaceous plant diversity provides a criti-cal scientific basis for developing ecological protection strategies.This study conducted a systematic survey of herba-ceous plant communities in Yongdeng County,Lanzhou City,using a grid sampling method.We investigated four distinct habitat types-temperate steppe,temperate desert steppe,alpine meadow,and cultivated grassland-to explore the effects of topographic and soil factors on species diversity.The results indicated that:(1)A total of 356 wild herbaceous species belonging to 197 genera and 53 families were recorded.Poaceae,Asteraceae,and Fabaceae were the 3 dominant families,accounting for 38%of the total species richness.(2)The effects of topographic fac-tors on diversity were habitat-specific.The trends of alpha-diversity indices along the elevational gradient differed significantly among grassland types,with the temperate steppe showing the most sensitive response.Species rich-ness exhibited a significant unimodal non-linear response to slope gradient and aspect;notably,species richness peaked on shady slopes and gentle slopes due to favorable hydrothermal conditions.(3)Soil nutrients were identi-fied as key drivers of diversity variation.Species richness was positively correlated with soil total carbon,but it showed significant negative correlations with soil total nitrogen and total phosphorus(P<0.05).(4)Multivariate analysis further revealed that species richness was primarily driven by soil carbon content(P<0.01).The Simpson index was significantly correlated with soil phosphorus content(P<0.01),while the Shannon-Wiener index showed a significant co-variation with the evenness index(P<0.05).