河岸无脊椎动物多样性维持机制研究进展

Maintaining mechanisms of riparian invertebrate biodiversity:A review

河岸是河流与陆地之间重要的生态界面,生物多样性丰富,但受到人为活动的严重威胁。无脊椎动物在河岸生物多样性中占有重要地位,发挥着非常重要的生态功能,也是水生生态系统和陆地生态系统之间物质和能量联系的重要纽带。尽管已有很多学者对河岸无脊椎动物群落进行了研究,但缺乏对河岸无脊椎动物多样性维持机制的总结。本文结合洪水和干旱、营养物质、微生境多样性、河岸植被、微气候梯度、食物资源以及河流空间梯度等影响因素,初步讨论和归纳了河岸无脊椎动物多样性的维持机制。周期性洪水和干旱引发了无脊椎动物的繁殖和迁移等行为,增加了河岸无脊椎动物群落周转率,为无脊椎动物创造了理想的条件。充足的营养物质使河岸具有较高的初级生产力,支撑了较高的无脊椎动物多样性。较高的微生境多样性为无脊椎动物提供了多样的生态位空间,孕育了特殊的河岸无脊椎动物种类。复杂的河岸植物群落不但是河岸无脊椎动物的食物来源之一,也为河岸无脊椎动物提供了多样的生态位空间和重要的避难场所。微气候环境的空间分异提供了复杂多样的生境条件,为水生无脊椎动物和陆生无脊椎动物种类在河岸共存创造了条件。跨越界面的资源补给增加了河岸无脊椎动物的食物可利用率,为河岸无脊椎动物提供了特殊的食物来源。这些因素在空间上呈现出明显的纵向梯度和侧向梯度,从更大尺度上为河岸无脊椎动物的多样化提供了条件。因此,探讨河岸无脊椎动物多样性的维持机制对于河岸生物多样性保护以及河流生态系统综合管理具有重要的指导意义。

Riparian zones,the critical ecological interfaces between terrestrial and aquatic ecosystems,are species rich habitats.However,riparian zones are seriously threatened by human activities in the world.Riparian invertebrates represent a large proportion of riparian biodiversity,perform various ecological functions,and provide an essential link between aquatic and terrestrial ecosystems.Although many studies have investigated the riparian invertebrate communities,there is lacking a comprehensive summary of maintaining mechanisms underlying riparian invertebrate diversity.This review discussed seven characteristics of riparian zones that might support high riparian invertebrate diversity:flood and drought,nutrient,microhabitat diversity,riparian vegetation,microclimate gradients,food resources and river spatial gradients.Further,we summarized the maintaining mechanisms of riparian invertebrate diversity.Disturbances of periodic flood and drought trigger the reproduction and migration of invertebrates,increase the turnover of invertebrate communities,and create suitable conditions for riparian invertebrates.Adequate nutrients support a high invertebrate diversity by increasing primary productivity of riparian habitats.Elevated microhabitat diversity provides a variety of niche space for specialist riparian invertebrates.Strong microclimate gradients provide complex and diverse habitats and thus facilitate the coexistence of aquatic and terrestrial invertebrates in riparian zones.Cross-ecosystem resource subsidies increase food availability and contribute unique food sources to riparian invertebrates.The differentiation of these factors along river longitudinal and lateral gradients provides conditions for the diversification of riparian invertebrates at a larger scale.Understanding the maintaining mechanisms of riparian invertebrate diversity is important for conservation of riparian biodiversity and integrated management of river ecosystems.