Evaluation of nutrient stoichiometric relationships among ecosystem compartments of a subtropical treatment wetland. Do we have “Redfield wetlands”?
Evaluation of nutrient stoichiometric relationships among ecosystem compartments of a subtropical treatment wetland. Do we have “Redfield wetlands”?
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亚热带处理湿地生态系统区划之间营养化学计量关系的评估 我们有“雷德菲尔德湿地”吗？
DOI：
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发表时间：
2019
影响因子：
4.8
通讯作者：
Jacob Dombrowski
中科院分区：
文献类型：
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作者：
Paul Julian;S. Gerber;R. Bhomia;J. King;T. Osborne;A. Wright;M. Powers;Jacob Dombrowski
背景评价水生态系统和陆地生态系统中碳(C)、氮(N)和磷(P)的比例可以促进我们对这些生态系统中的生物过程、营养循环和有机质(OM)去向的了解。水生生态系统的富营养化可以改变有机物的积累和分解，从而改变生物地球化学循环，改变水生食物网的基础。研究了两个具有不同植被群落的亚热带湿地生态系统内和之间的营养化学计量学。选择了美国佛罗里达州南部大沼泽地雨水处理区网络中的两个流道(FW)进行了研究。结果表明，C、N和P的化学计量学在不同生态系统间和不同FW之间存在很大的差异。表层水团、土壤和植被中C、N和P的幂函数斜率在FW之间和沿FW之间存在显著差异。结论湿地生态系统内和生态系统间的养分化学计量学评估表明，与P相关的无限制化学计量学符合生态系统中P限制的概念。絮体和土壤N：P比值的差异表明不同FW之间有机养分积累和保持的途径不同。表层养分化学计量学具有高度的可变性和解偶性(或如 25%所示接近解偶性)，特别是关于P。我们推测，解偶性可能是流入养分化学计量学的变异性印记。然而，尽管活跃的生物地球化学循环可以恢复FW沿岸的营养物质化学计量，但几乎没有证据表明这种平衡发生了，因为水柱中的化学计量脱钩程度确实随着下游距离的变化而变化。这些信息只是了解湿地生态系统内化学计量过程及其与生态系统功能的关系的更大旅程的开始。
BackgroundEvaluation of carbon (C), nitrogen (N), and phosphorus (P) ratios in aquatic and terrestrial ecosystems can advance our understanding of biological processes, nutrient cycling, and the fate of organic matter (OM) in these ecosystems. Eutrophication of aquatic ecosystems can change the accumulation and decomposition of OM which can alter biogeochemical cycling and alter the base of the aquatic food web. This study investigated nutrient stoichiometry within and among wetland ecosystem compartments (i.e., water column, flocculent, soil, and aboveground vegetation biomass) of two subtropical treatment wetlands with distinct vegetation communities. Two flow-ways (FWs) within the network of Everglades Stormwater Treatment Areas in south Florida (USA) were selected for this study. We evaluated nutrient stoichiometry of these to understand biogeochemical cycling and controls of nutrient removal in a treatment wetland within an ecological stoichiometry context.ResultsThis study demonstrates that C, N, and P stoichiometry can be highly variable among ecosystem compartments and between FWs. Power law slopes of C, N, and P within surface water floc, soil, and vegetation were significantly different between and along FWs.ConclusionsAssessment of wetland nutrient stoichiometry between and within ecosystem compartments suggests unconstrained stoichiometry related to P that conforms with the notion of P limitation in the ecosystem. Differences in N:P ratios between floc and soil suggest different pathways of organic nutrient accumulation and retention between FWs. Surface nutrient stoichiometry was highly variable and decoupled (or close to decoupled as indicated by < 25% explained variation between parameters), in particular with respect to P. We hypothesize that decoupling may be the imprint of variability in inflow nutrient stoichiometry. However, despite active biogeochemical cycles that could act to restore nutrient stoichiometry along the FW, there was little evidence that such balancing occurred, as the degree of stochiometric decoupling in the water column did change with distance downstream. This information is only the beginning of a larger journey to understand stoichiometric processes within wetland ecosystems and how they relate to ecosystem function.