高寒草地不同退化类型对植物多样性与种间关系的影响研究——以理县为例

Study on the effects of different degradation types on plant diversity and interspecific relationship in alpine grassland:a case study in Lixian County

群落结构和种间关系是草地群落退化和评价的主要指标。通过四川省理县草原健康与退化评估工作,分析调查样地物种多样性、种间联结性和生态位宽度,探讨高寒草地不同退化类型各物种之间的相互作用和种间关系,有助于高寒草地的科学恢复及合理利用。研究结果表明理县调查区主要有145种植物,隶属于37科,106属,其中糙野青茅、白莲蒿和早熟禾为重要值前三的优势物种。毒害型退化草地中,毒害草和本土种的生态位重叠值增加,加剧种间竞争程度,联结关系较其他退化类型中物种更加紧密;石漠型退化草地中,主要物种的生态位重叠数量最低,较多植物种对联结松散,种间联结AC值主要以负联结为主,明显区别于未退化草地和毒害型草地。因此,针对两种不同退化类型草地应采用不同恢复措施,因地制宜,因时制宜的实现可持续性恢复。

The structure of plant communities and interspecific relationships are the main indicators for assessing degradation in grasslands.Base on the evaluation of grassland health and degradation in Lixian County,Sichuan Province,the species diversity,interspecific association and niche breadth of the sampling plots in grasslands under different types of degradation were analyzed and investigated,and the interactions and interspecific relationships among species were discussed,which was helpful for the scientific restoration and rational utilization of these alpine grasslands.The results showed that there were 145 plant species belonging to 37 families and 106 genera in Lixian survey area,among which Deyeuxia scabrescens,Artemisia stechmanniana,and Poa annua were the top three dominant species.In toxicologically degraded grasslands,the niche overlap value of toxic grass and native species increased,which aggravated the competition between species and made the connection relationship closer than that of other degraded types.Conversely,in the degraded grassland of rocky desert type,the number of niche overlap of main species was the lowest,and many plant species were loosely connected.The AC alue of interspecific association was mainly negative,which was distinctly different from undegraded and toxicologically degraded grasslands.Therefore,different restoration measures should be adopted for two different types of degraded grasslands,and sustainable restoration should be realized according to local conditions and time.