开矿对四川马边白家湾河流域植物多样性格局的影响

开矿导致地表植被破坏,并使植物群落结构发生改变。以零星矿井式开采的四川马边白家湾矿区为研究区域,通过群落调查,采用重要值和物种多样性指数,结合除趋势典范对应分析(DCCA)排序和多元回归进行数据分析,研究了开矿对植物多样性格局的影响。结果表明:(1)随着开矿干扰减弱,植物群落分为明显的四个群丛,依次由草本向灌木、乔木顺序演替;(2)开矿干扰与DCCA轴紧密相关,是影响植物多样性的重要环境因素,导致乔木层盖度变化且对多样性有直接影响;(3)群落间相似性与开矿干扰负相关,而物种替代速率与开矿干扰呈U型关系。

Impacts of Mining on the Pattern of Plant Species Diversity in Baijiawan Watershed,Mabian County,Sichuan

Mining can cause ground vegetation destructed and result in structure changing of plant communities.This research selected Baijiawan mining area with the main way of sporadic mining in the southwest of Sichuan,China as the study area.Through surveying plant communities,calculating the important value and diversity indices,and applying DCCA and multiple regression methods,we researched mining impacts on species diversity pattern.The results showed that:(1) the communities are divided into four obvious groups along the gradient of mining disturbance.With decreasing of mining disturbance,the plant species distributes with the sequence of grass-herbs,shrubs and trees.(2) Mining factor is strongly correlated with the DCCA axes and an important influencing factor of all environmental variables to plant species diversity.(3) There is a negative correlation between community similarity and mining disturbance;while a U-shape relationship occurred between species replacement rate and mining disturbance.