Department of Integrative Biology, University of Guelph, Guelph ON N1G 1G2, Canada.
Joint Global Change Research Institute, DOE Pacific Northwest National Laboratory, 5825 University Research Ct, College Park, MD, USA.
New Phytol. 2012 Oct;196(1):49-67. doi: 10.1111/j.1469-8137.2012.04254.x.
Mosses in northern ecosystems are ubiquitous components of plant communities, and strongly influence nutrient, carbon and water cycling. We use literature review, synthesis and model simulations to explore the role of mosses in ecological stability and resilience. Moss community responses to disturbance showed all possible responses (increases, decreases, no change) within most disturbance categories. Simulations from two process-based models suggest that northern ecosystems would need to experience extreme perturbation before mosses were eliminated. But simulations with two other models suggest that loss of moss will reduce soil carbon accumulation primarily by influencing decomposition rates and soil nitrogen availability. It seems clear that mosses need to be incorporated into models as one or more plant functional types, but more empirical work is needed to determine how to best aggregate species. We highlight several issues that have not been adequately explored in moss communities, such as functional redundancy and singularity, relationships between response and effect traits, and parameter vs conceptual uncertainty in models. Mosses play an important role in several ecosystem processes that play out over centuries - permafrost formation and thaw, peat accumulation, development of microtopography - and there is a need for studies that increase our understanding of slow, long-term dynamical processes.
在北方生态系统中，苔藓是植物群落中普遍存在的组成部分，强烈影响着养分、碳和水的循环。我们使用文献综述、综合和模型模拟来探讨苔藓在生态稳定性和恢复力方面的作用。苔藓群落对干扰的响应在大多数干扰类别中表现出了所有可能的响应（增加、减少、不变）。来自两个基于过程的模型的模拟表明，北方生态系统需要经历极端干扰，才能使苔藓被消除。但是，另外两个模型的模拟表明，苔藓的丧失将主要通过影响分解速率和土壤氮素供应来减少土壤碳积累。很明显，苔藓需要作为一个或多个植物功能类型纳入模型，但需要更多的实证工作来确定如何最好地聚合物种。我们强调了一些在苔藓群落中尚未得到充分探讨的问题，例如功能冗余和单一性、响应和效应特征之间的关系，以及模型中的参数与概念不确定性。苔藓在几个需要数百年才能完成的生态系统过程中发挥着重要作用——多年冻土的形成和融化、泥炭的积累、微地形的发展——需要开展更多的研究来加深我们对缓慢的、长期动力过程的理解。
