鄱阳湖湿地大型底栖无脊椎动物多样性对群落次级生产力及稳定性的影响

理解生物多样性对生态系统功能及稳定性的影响对于制定有效的保护管理策略有重要意义。然而,目前生物多样性与群落生产力、稳定性的关系仍存在争议。在鄱阳湖湿地布设30个采样点,于2019年秋季开展大型底栖无脊椎动物群落野外调查。基于底栖动物群落数据,采用广义加性模型分析物种、谱系、功能多样性对鄱阳湖湿地底栖动物群落次级生产力与稳定性的影响。结果表明:底栖动物群落的次级生产力与反映物种多样性的指数(Simpson多样性指数、Shannon-Wiener多样性指数、Pielou均匀度指数)、分类多样性指数、平均分类差异指数、功能丰富度指数等呈显著的负相关,其中Pielou均匀度指数与次级生产力的相关度最高(r²=0.33)。功能多样性对群落次级生产力的空间分异有最高的解释度(r²=0.75)。P/B值(次级生产力与生物量之比代表群落稳定性)与物种、谱系、功能多样性指数均呈正相关,其中功能丰富度与P/B值的相关度最高(r²=0.22)。反映物种多样性的三个指数总体上对P/B值的空间分异解释度最高(r²=0.37)。谱系多样性与次级生产力、P/B值的相关性相对较弱。生物多样性指数总体分别解释了次级生产力和群落稳定性中81.9%、54.8%的变异。上述研究结果表明,生物多样性与群落生产力、稳定性的关系可能因具体的生物群落而异。研究结果对于鄱阳湖湿地的底栖生物多样性保护有参考价值。

Effects of macroinvertebrate diversity on community secondary productivity and stability in the Poyang Lake wetland

Understanding the impact of biodiversity on ecosystem function and stability is crucial for developing effective conservation and management strategies. However, relationships of biodiversity with community productivity and stability are still controversial. Here, we investigated how the biodiversity indices were correlated with the secondary productivity and stability of benthic macroinvertebrate communities in the Poyang Lake wetland. Thirty sites were sampled in the Poyang Lake wetland for obtaining benthic macroinvertebrate community data in the autumn of 2019. Twelve biological indices representing taxonomic, phylogenetic and functional diversity, as well as indices of the secondary productivity and community stability, were calculated for each sample site. We first investigated the relationships of secondary productivity and community stability with single biodiversity indices by using generalized additive models (GAMs). Then, we quantified the explanatory power of taxonomic, phylogenetic and functional diversity on secondary productivity and community stability. Biodiversity indices totally explained 81.9% and 54.8% of the variation in secondary productivity and community stability, respectively. Functional diversity had the strongest explanatory power on secondary productivity (r²=0.75), while taxonomic diversity had the highest predictive ability on community stability (r²=0.37). Secondary productivity showed significant and negative relationships with taxonomic indices (including Simpson''s diversity index, Shannon''s diversity index, and Pielou''s evenness index), taxonomic diversity, average taxonomic distinctness and functional richness index, which was contrast with previous findings. Among them, Pielou''s evenness index had the highest correlation with secondary productivity (r²=0.33). Community stability (calculated as the ratio of second productivity to community biomass) had significant and positive relationships with Simpson''s diversity index, Shannon''s diversity index, Margalef''s richness index, functional evenness index and functional richness index, among which functional richness index had the highest correlation (r²=0.22). Taxonomic, phylogenetic and functional diversity hadsignificant correlations with secondary productivity and community stability, whereas their effects might vary depending on the specific biological communities. Our results can provide valuable insights and guidance for the protection of benthic biodiversity in the Poyang Lake wetland.