Leaf litter decomposition in streams is a fundamental ecosystem process that allows for the cycling of nutrients. The rate at which leaf litter decomposes is greatly controlled by its intrinsic characteristics. However, intraspecific variation in leaf litter characteristics poses a major challenge for large-scale studies aiming at identifying the environmental moderators of leaf litter decomposition. Thus, several standardized organic substrates have been proposed as surrogates for leaf litter. Tea bags were proposed as a standardized alternative to leaf litter for studies in soil and their use in aquatic ecosystems has been growing in recent years. It is therefore necessary to evaluate how tea is colonized and decomposed by aquatic microbial decomposers to assess its usefulness as a surrogate for leaf litter in litter decomposition studies. Here we compared the microbial colonization (based on the reproductive activity of aquatic hyphomycetes) and decomposition of green and rooibos teas and native alder leaf litter in two streams differing in environmental conditions. Colonization of green tea was lower than that of alder leaf litter, but their decomposition rates were similar. In contrast, colonization of rooibos tea was similar to that of alder leaf litter, but it decomposed 3–4 × slower. Results were consistent in both streams. Despite differences in magnitude, dynamics of microbial colonization and decomposition of tea were similar to those of alder leaf litter and were sensitive to substrate characteristics. Tea may be used as a surrogate for leaf litter in studies addressing microbial-driven leaf litter decomposition in streams.

溪流中的落叶分解是一个基本的生态系统过程，它允许养分循环。凋落物分解的速度很大程度上受其内在特性的控制。然而，落叶特征的种内变异对旨在确定落叶分解的环境调节剂的大规模研究提出了重大挑战。因此，已经提出了几种标准化的有机基质作为落叶的替代物。茶包被提议作为土壤研究中落叶的标准化替代品，近年来它们在水生生态系统中的使用一直在增长。因此，有必要评估茶如何被水生微生物分解者定殖和分解，以评估其作为凋落物分解研究中落叶替代物的有用性。在这里，我们比较了两种环境条件不同的溪流中的微生物定植（基于水生丝状菌的繁殖活动）和绿茶和路易波士茶以及天然桤木落叶的分解。绿茶的定植率低于桤叶凋落物，但它们的分解率相似。相比之下，路易波士茶的定植与桤木凋落物的定植相似，但分解速度慢 3-4 倍。结果在两个流中都是一致的。尽管大小不同，茶的微生物定植和分解动力学与桤木枯枝落叶相似，并且对底物特征敏感。在解决溪流中微生物驱动的落叶分解的研究中，茶可用作落叶的替代物。