Subsidies of Aquatic Resources in Terrestrial Ecosystems
Subsidies of Aquatic Resources in Terrestrial Ecosystems
复制标题
陆地生态系统水生资源补贴
作者：
D. Schindler;A. Smits
洪水、空间复杂的水流和生物运动都产生了水生物质进入陆地栖息地的重要通量，抵消了由重力驱动的物质从陆地到水生生态系统的下坡运输。这些水生补贴的规模通常小于对水生生态系统的陆地补贴，但在营养质量、能量密度和营养浓度方面更高。生物水生补贴的横向范围通常很小，仅向河岸栖息地延伸几米；然而，地面消费者往往聚集在海岸线上，以利用这些高质量的资源。尽管对水生补贴的生态效应仍有部分了解，但很明显，人类对水生生态系统、河岸栖息地和河流洪泛平原的持续改造影响了陆地景观中水生补贴的规模、质量和时空格局。这些变化将改变水陆耦合的特征，并对依赖这些高质量和暂时可靠的资源补贴的陆生生物产生影响。景观和水流形态的同质化、富营养化、外来物种和污染物都对水生资源进入陆地生态系统的重要流动构成威胁。需要进行研究，强调景观是陆水综合系统，以生境之间的生物和水文流动为特征，以了解水生补贴的后果和管理正在进行的人类发展的生态风险。
Floods, spatially complex water flows, and organism movements all generate important fluxes of aquatic-derived materials into terrestrial habitats, counteracting the gravity-driven downhill transport of matter from terrestrial-to-aquatic ecosystems. The magnitude of these aquatic subsidies is often smaller than terrestrial subsidies to aquatic ecosystems but higher in nutritional quality, energy density, and nutrient concentration. The lateral extent of biological aquatic subsidies is typically small, extending only a few meters into riparian habitat; however, terrestrial consumers often aggregate on shorelines to capitalize on these high-quality resources. Although the ecological effects of aquatic subsidies remain partially understood, it is clear that ongoing human modification to aquatic ecosystems, riparian habitats and river floodplains affect the magnitude, quality, and spatial and temporal patterning of aquatic subsidies in terrestrial landscapes. These changes will alter the character of aquatic–terrestrial coupling and have consequences for terrestrial organisms that rely on these high-quality and temporally dependable resource subsidies. Homogenization of landscapes and flow regimes, eutrophication, exotic species, and contaminants all represent threats to the vital flows of aquatic-derived resources into terrestrial ecosystems. Research emphasizing that landscapes are integrated terrestrial–aquatic systems, characterized by both biological and hydrological flows among habitats, is needed for understanding the consequences of aquatic subsidies and managing ecological risks of ongoing human development.