南岭国家级自然保护区森林群落β多样性随海拔梯度的变化

Variations in β Diversity of Forest Communities along Altitudinal Gradient in Nanling National Nature Reserve, China

摘要:

在广东南岭国家级自然保护区海拔300-1 900 m的范围内，海拔每升高100 m设置一条水平样带，共计调查了17条样带，样地面积20 400 m2。运用相关分析、回归分析和方差分析研究森林群落β多样性随海拔梯度的变化。结果表明：无论是相邻样带还是基准样带，Cody指数以及物种周转速率βC与海拔均呈显著的线性负相关(P＜0.05)；森林群落各层的共有种数随物种周转速率βC的增加而减少(P＜0.05)；单因素方差分析及多重比较揭示，Cody指数能较好地反映各层之间物种沿海拔梯度的变化差异。与相异性系数(community dissimilarity)、Bray-Curtis指数和Morisita-Horn指数、以及物种周转速率Sβ和物种周转速率t相比，Cody指数和物种周转速率βC能较好地反映南岭国家级自然保护区森林群落β多样性的海拔梯度格局。

Abstract:

Variations in β diversity of forest communities along an altitudinal gradient were studied in Nanling National Nature Reserve, China. A horizontal transect (10 m × 120 m) was established at each 100-m altitudinal interval from an elevation of 300 m up to 1 900 m a.s.l. Correlation analysis, regression analysis and ANOVA were used to determine altitudinal patterns of β diversity and its relationship with environmental factors. Results were as follows: the Cody index and species turnover rate βC showed linearly and significantly negative correlations with altitude (P＜0.05) in base and adjacent belt transects. Shared species of community, canopy stratum, understory stratum decreased with increasing species turnover rate βC (P＜0.05). The Cody index could better reveal the species differences along altitude among communities, canopy stratum and understory stratum, based on analysis of one-way ANOVA, Fish’s LSD and Tukey’s HSD. Compared with community dissimilarity, the Bray-Curtis index, the Morisita-Horn index, species turnover rate Sβ and species turnover rate t, the Cody index and species turnover rate βC were useful to characterize the β diversity of forest communities along an altitudinal gradient in Nanling National Nature Reserve.