大渡河中游干暖河谷植被种间关系与稳定性

Interspecific association and stability of vegetation in the dry-warm valley of the middle reaches of Dadu River

为了解大渡河中游干暖河谷植物群落的稳定程度,促进川西干暖植被恢复与重建,采用方差比率法(VR)、x2检验统计、Person相关性分析、Spearman秩相关分析与M.Godron稳定性测度方法,分析大渡河中游干暖河谷植被种间关系与群落稳定性.结果表明:大渡河中游干暖河谷典型植物群落物种的种间总体关联性表现为不显著正关联,物种间存在的各种作用及相互依赖和相互竞争不强,植物更倾向于以少数几种物种组成的植物群落生长方式进行演替,正联结是该区域重要的种间关系之一,这与物种对环境的长期适应而形成稳定的生态系统类型和相同或者相似的适应策略有关.成对物种种间关系中,包含乔木的种对相关性显著的种对数量多,且仅表现为正相关,该区域植物具有植物群落正向演替的基础.M.Godron稳定性测度法得到的测量曲线与经过(0,100)、(100,0)的线段交点处坐标为(38.12,61.85),距离稳定点(20,80)距离为25.65.本研究表明群落依然处于不稳定状态,具有低阈值生态安全和高风险生态退化的特点,应从自然和人工植被恢复等途径提高植被覆盖率,促进植物群落正向演替.(图5表4参42)

Analysis of species associations and the stability of plant communities in the dry-warm valley of the middle reaches of the Dadu River is helpful for understanding the relationship between species and vegetation stability,which is of particular significance to the restoration and reconstruction of vegetation.The varianceratio test,x2 test,Pearson correlation analysis,Spearman’s rank correlation analysis,and M.Godron’s stability measure were used to analyze the interspecific associations and stability of the vegetation community.The results show that there is no significant positive correlation between species in the typical plant communities and the interactions,interdependence,and competition between species are not strong.Plants are also more likely to be successional in the form of a few species.The results also reveal that positive association is one of the most important interspecific relationships in this region,and is related to differences in geographical distribution,separating the interspecific associations by microhabitat and the long-term impact of species on the environment.The correlation of tree species was significant and only showed a positive correlation.The coordinates of community stability measured by M.Godron’s stability measurement method were 38.12,61.85,and the distance from the stable point(20,80)was 25.65,which indicates that the community is still in an unstable state,with the characteristics of low threshold ecological security and high-risk ecological degradation.The vegetation coverage in this area should be improved by natural and artificial vegetation restoration,which will continue to guide the positive succession of plant communities.