Implications of species addition and decline for nutrient dynamics in fresh waters
Implications of species addition and decline for nutrient dynamics in fresh waters
复制标题
物种增加和减少对淡水营养动态的影响
作者：
K. Capps;C. Atkinson;A. Rugenski
摘要：在陆地和水生生态系统中，生物体通过生长隔离营养物质和通过排泄和排泄吸收营养物质直接影响营养物质的储存和循环。因此，物种的引进和灭绝可以深刻地影响营养物质的储存和再矿化率，并提出了一个挑战，在淡水沃茨的生态系统功能的保护。消费者驱动的营养动态的文献正在迅速增长，但消费者对跨物种和生态系统的营养储存和再矿化的影响的研究是有限的。我们比较了3放牧类群，非本地装甲鲶鱼在墨西哥流，本地贻贝在俄克拉荷马州流，本地蝌蚪在巴拿马流，营养物质的储存和矿化的影响。我们研究了生物化学计量和生物量，营养物质储存，矿化率和生态系统大小之间的相互作用，在这3组物种下降（蝌蚪和贻贝）或引进（装甲鲶鱼），以更好地了解生物体特定的影响，对淡水生态系统中的营养动态。总的来说，我们的研究结果表明，消费者驱动的营养动态的生态系统水平的影响是强烈的环境变量的影响，是特定的类群。化学计量上独特的生物体的生物量的重大变化可能导致随后的变化，在生态系统中的元素的通量和存储，但水生动物对营养动态的整体影响也是由溪流和河流的排放和营养限制模式。
Abstract: In terrestrial and aquatic ecosystems, organisms directly affect nutrient storage and cycling by sequestering nutrients via growth and remineralizing nutrients via excretion and egestion. Therefore, species introductions and extirpations can profoundly affect nutrient storage and remineralization rates, and present a challenge for conserving ecosystem function in fresh waters. The literature of consumer-driven nutrient dynamics is growing rapidly, but studies of consumer effects on nutrient storage and remineralization across species and among ecosystems are limited. We compared the effects of 3 grazing taxa, nonnative armored catfish in Mexican streams, native mussels in Oklahoma streams, and native tadpoles in Panamanian streams, on nutrient storage and remineralization. We examined interactions among organismal stoichiometry and biomass, nutrient storage, remineralization rates, and ecosystem size across these 3 groups following species decline (tadpoles and mussels) or introduction (armored catfish) to gain a better understanding of organism-specific effects on nutrient dynamics among freshwater ecosystems. Collectively, our results suggest that the ecosystem-level effect of consumer-driven nutrient dynamics is strongly influenced by environmental variables and is taxon specific. Major changes in biomass of stoichiometrically distinctive organisms can lead to subsequent changes in the flux and storage of elements in an ecosystem, but the overall effect of aquatic animals on nutrient dynamics also is determined by discharge and nutrient-limitation patterns in streams and rivers.