海南省文昌市废弃钛矿区物种多样性特征与环境因子的关系

目的]研究钛矿开采对周边植被物种多样性和分布格局的影响,为废弃钛矿区生物多样性保护和植被恢复提供基础数据。方法]以海南省文昌市废弃钛矿区为例,利用方差分析、冗余分析(RDA)研究钛矿区土壤因子与乔木、灌木和草本物种多样性差异及分布格局影响。结果]文昌市废弃钛矿区辐射区域仅有植物28科37属45种,其中乔木类13种,灌木11种,草本21种。钛矿开采不仅对矿区植被产生破坏,同时对辐射区域200 m范围内的植被群落结构也有明显影响;废弃钛矿区物种α多样性指数除Pielou均匀度指数外都以草本最高,显著高于乔木和灌木。随着辐射区域距离的增加,物种多样性指数逐渐递减;通过土壤环境因子与物种多样性RDA排序得出,土壤pH值、土壤含水率、有效磷、有机质和铵态氮是影响物种多样性差异的主要环境因子,它们分别解释了废弃钛矿辐射区物种多样性42.6%,12.4%,8.5%,8.2%和7.9%的差异。结论]钛矿周边植物物种多样性和分布格局受土壤pH值、土壤含水率等多个环境因子共同影响。矿区周边物种多样性是否受土壤重金属的影响,尚待进一步研究。

Relationship Between Species Diversity Characteristics and Environmental Factors of Abandoned Titanium Mine Area in Wenchang City of Hainan Province

Objectve] The impacts of Titanium mining on the diversity and distribution pattern of surrounding vegetation were studied in order to provide basic data for biodiversity protection and vegetation restoration in abandoned Titanium mines. Methods] The differences and distribution patterns of soil factors and tree, shrub and herbaceous species in the titanium mine area were investigated by using ANOVA and Redundancy analysis (RDA). Results] There were only 45 species, 33 families and 37 genera in the study area, including 13 tree species, 11 shrub species, and 21 herb species. The activities of mining had destructive effects on the vegetation in the abandoned Titanium mining area, and obviously affected the vegetation communities structure within a 200 m buffer area. Except for Pielou evenness index, the diversity index of species in the abandoned Titanium mining area was herb, which was significantly higher than that of trees and shrubs. The species diversity index decreased gradually with the increase of the distance to the buffer zone. According to the Redundancy analysis (RDA), the soil pH value, soil water content, available phosphorus, organic matter, ammonium nitrogen and buffer distance were the main environmental factors affecting the difference of species diversity, which explained 42.6%, 12.4%, 8.5%, 8.2%, 7.9% and 7.8% of the difference of species diversity in the abandoned Titanium ore buffer, respectively. Conclusion] The plant species diversity and distribution pattern around the titanium mine were affected by multiple environmental factors such as soil pH value and soil water content. Whether the species diversity around the mining area is affected by soil heavy metals remains to be further studied.