新薛河底栖动物物种多样性与功能多样性研究

研究功能多样性与物种多样性关系及其随环境梯度的变化规律,有助于理解生物在群落中的共存机制;然而,二者间关系的研究在淡水生态学中尚鲜见报道。通过对新薛河典型河段(A缓流河段、B断流河段、C有机污染河段、D对照河段、E人为干扰河段)底栖动物季节性调查,就物种多样性和功能多样性时空动态及关系进行了研究。结果表明:在空间序列上,物种多样性指数在B河段均最低,表明间歇性断流对物种多样性影响重大。功能丰富度在D河段最高,A河段最低;功能均匀度在A河段高于其他河段;功能分离度在A、B河段最高,D河段最低。在时间序列上,物种丰富度和Shannon指数均值在10月份最低,4月份最高;均匀度指数在12月份最低,10月份最高。3个功能多样性指数于各季节间差异显著、相互独立,主要受水文条件和底栖动物生活史影响。相关分析表明,功能多样性指数间无显著相关性;功能丰富度同物种丰富度和Shannon指数相关显著,功能均匀度同物种均匀度相关显著。逐步回归分析发现,功能丰富度受物种丰富度和Shannon指数影响显著,功能均匀度受物种均匀度影响显著;功能多样性和物种多样性指数间拟合度总体不高。研究结果进一步表明:相对物种多样性,功能多样性对生境梯度变化响应更加全面。

Study of macroinvertebrate species and functional diversity in the New Xue River, Shandong Province, China

Understanding the relationship between functional and species diversities as well as their association with habitat heterogeneity can help reveal the mechanisms of species coexistence in ecological communities. However, these interactions have been poorly studied in freshwater ecosystems. In this study, we evaluated the spatio-temporal dynamics of functional diversity and traditional species diversity indices, and the relationships between them. The main results were as follows:In the space sequence, species diversity indices were the lowest in reach B, and the results showed that intermittent disconnection had a significant influence on species diversity. Functional richness was the highest in reach D and the lowest in reach A, functional evenness was highest in reach A, and functional divergence was the highest in reaches A and B and the lowest in reach D. In the time series, the lowest mean value of species richness and Shannon index were recorded in October and the highest in April, and the evenness index was the lowest in December and the highest in October. The three functional diversity indices were significantly different and orthogonal among seasons, and they were mainly affected by hydrological conditions and benthic animal life history. Correlation analysis was used to analyze the relationship of the biodiversity indices, and the results showed no significant correlations among functional diversity indices. Functional richness was significantly correlated with species richness and Shannon index and also with functional evenness and species evenness. Stepwise regression analysis was used to analyze the influence of species diversity on functional diversity, and the results showed that functional richness was significantly affected by species richness and Shannon index, and also by functional evenness and species evenness. Furthermore, we also found that the fitting degrees among this indices were not high. By further analysis and discussion, we found that compared to species diversity, functional diversity was more comprehensive in revealing habitat gradient.