Photosynthesis, growth, and decay traits in Sphagnum – a multispecies comparison

Peat mosses (Sphagnum) largely govern carbon sequestration in Northern Hemisphere peatlands. We investigated functional traits related to growth and decomposition in Sphagnum species. We tested the importance of environment and phylogeny in driving species traits and investigated trade-offs among them. We selected 15 globally important Sphagnum species, representing four sections (subgenera) and a range of peatland habitats. We measured rates of photosynthesis and decomposition in standard laboratory conditions as measures of innate growth and decay potential, and related this to realized growth, production, and decomposition in their natural habitats. In general, we found support for a trade-off between measures of growth and decomposition. However, the relationships are not strong, with r ranging between 0.24 and 0.45 for different measures of growth versus decomposition. Using photosynthetic rate to predict decomposition in standard conditions yielded R2 = 0.20. Habitat and section (...泥炭藓属（Sphagnum）是北半球泥炭地碳固存过程的主导调控者。本研究针对泥炭藓物种的生长与分解相关功能性状开展系统调查，解析了环境与系统发育对物种性状的驱动作用，并探究了性状间的权衡关系。研究选取了15种全球分布的重要泥炭藓物种，涵盖4个组（亚属），覆盖多种泥炭地生境类型。我们在标准实验室条件下测定了光合速率与分解速率，以此作为物种内在生长与分解潜力的表征指标，并将该结果与物种在自然生境中的实际生长、生产力及分解过程进行关联分析。总体而言，本研究结果支持泥炭藓生长相关性状与分解相关性状间存在权衡关系。但二者的关联强度较弱，不同生长指标与分解指标间的相关系数r介于0.24至0.45之间。以光合速率预测标准条件下的分解速率时，决定系数R²为0.20。生境与组（亚属）的影响（……