Nutrient and stoichiometry dynamics of decomposing litter in stream ecosystems: A global synthesis

作者：Caleb J. Robbins, David W. P. Manning, Halvor M. Halvorson, Beth C. Norman, Rebecca A. Eckert, Ada Pastor, Allyn K. Dodd, Jérémy Jabiol, Elliot Bastias, Alice Gossiaux, Andrew S. Mehring · 发表于：Ecology · 年份：2023 · DOI：10.1002/ecy.4060 · 被引用次数：28 · 研究领域：Freshwater macroinvertebrate diversity and ecology、Soil and Water Nutrient Dynamics、Fish Ecology and Management Studies

Decomposing organic matter forms a substantial resource base, fueling the biogeochemical function and secondary production of most aquatic ecosystems. However, detrital N (nitrogen) and P (phosphorus) dynamics remain relatively unexplored in aquatic ecosystems relative to terrestrial ecosystems, despite fundamentally linking microbial processes to ecosystem function across broad spatial scales. We synthesized 217 published time series of detrital carbon (C), N, P, and their stoichiometric ratios (C:N, C:P, N:P) from stream ecosystems to analyze the temporal nutrient dynamics of decomposing litter using generalized additive models. Model results indicated that detritus was a net source of N (irrespective of inorganic or organic form) to the environment, regardless of initial N content. In contrast, P sink/source dynamics were more strongly influenced by the initial P content, in which P-poor litters were sinks for nutrients until these shifted to net P mineralization after ~40% mass loss. However, large variations surrounded both the N and P predictions, suggesting the importance of nonmicrobial factors such as fragmentation by invertebrates. Detrital C:N ratios converged and became more similar toward the end of the decomposition, suggesting predictable microbial functional effects throughout detrital ontogeny. C:P and N:P ratios also converged to some degree, but these model predictions were less robust than for C:N, due in part to the lower number of published detrital C:P ...