Dynamics in Niche and Interspecific Association of Dominant Species in Natural Secondary Forest of Xingdou Mountain
[Objective]The evergreen-deciduous broadleaved mixed forest is a unique natural forest type in China,as the main vegetation type in the subtropical mountains.The niche and interspecific association dynamics of dominant species in typical subtropical evergreen-deciduous broadleaved mixed forest are ex-plored to elucidate the adaptive capacity,interspecific relationships and change patterns of dominant spe-cies in short-term community development,and also to provide a theoretical basis for biological resource conservation,restoration and forest management in subtropical regions.[Method]Based on the natural secondary forest in Hubei Xingdoushan National Nature Reserve,combined with the survey and monitor-ing data of 48 fixed plots in 2013 and 2018,the dynamic changes of niche breadth,niche overlap index,variance ratio method,χ2 test,association coefficient,Jaccard index and Spearman rank correlation coeffi-cient of the top 10 dominant species(importance value greater than 2％)were analyzed.[Result](1)There were smaller changes in species composition in 2013 and 2018,with a decrease in the number of species,families and genera.Only one of the top 10 dominant species in terms of species importance value changed.(2)The two surveys showed that the niche overlap index was mainly between 0.2 and 0.5,and the number of species pairs increased with the development of the community.With the development of the community,the niche overlap degree,niche breadth and resource utilization ability of most dominant species decreased gradually.(3)Over the past 5 years,the importance ranking and niche width ranking were not exactly the same,and community resources were not fully utilized.Sorbus alnifolia and Eurya al-ata have always dominated the ecological niche overlap index with other dominant species,showing a stable or increasing trend.(4)The overall association of dominant species in the two surveys was signific-antly positive.The results of χ2test,association coefficient,Jaccard index and Spearman rank correlation coefficient for the 10 dominant species in the two surveys were generally consistent.The number of posit-ively associated species pairs was greater than that of negatively associated species pairs,and the num-ber of extremely significant or significantly positively associated species pairs was greater than that of ex-tremely significant or significantly negatively associated species pairs.The pairs of non-significant associ-ated species also accounted for an important proportion.Moreover,with the development of the com-munity,the significant positive correlation of the overall association gradually increased,the number of positively correlated pairs and the ratio of positive to negative correlations gradually increased,and the number of negatively correlated pairs gradually decreased.[Conclusion]The natural secondary forests in Hubei Xindushan National Nature Reserve are in the early to middle stages of natural succession,and in-terspecific associations are loose and not tight.Among them,S.alnifolia and E.alata are highly competit-ive,and the evergreen species of Rhododendron stamineum,Quercus multinervis and Lithocarpus cleisto-carpus are increasing their ability to utilize environmental resources.
the evergreen-deciduous broadleaved mixed forestXingdoushan National Nature ReserveSouthwestern Hubeiimportant valuenicheinterspecific associationsecondary forestdynamics
万方数据
维普
