Stand-level variation drives canopy water storage by non-vascular epiphytes across a temperate-boreal ecotone

Epiphytes, including bryophytes and lichens, can significantly change the water interception and storage capacities of forest canopies. However, despite some understanding of this role, empirical evaluations of canopy and bole community water storage capacity by epiphytes are still quite limited. Epiphyte communities are shaped by both microclimate and host plant identity, and so the canopy and bole community storage capacity might also be expected to vary across similar spatial scales. We estimated canopy and bole community cover and biomass of bryophytes and lichens from ground-based surveys across a temperate-boreal ecotone in continental North America (Minnesota). Multiple forest types were studied at each site, to separate stand level and latitudinal effects. Biomass was converted into potential canopy and bole community storage on the basis of water-holding capacity measurements of dominant taxa. Bole biomass and potential water storage was a much larger contributor than outer can...

附生植物（epiphytes）包括苔藓植物（bryophytes）和地衣（lichens），可显著改变森林林冠的截水与储水能力。尽管学界对该类群的生态功能已有一定认知，但针对附生植物对林冠及树干附生群落储水能力的实证评估仍相当匮乏。附生群落的组成同时受微气候（microclimate）与宿主植物种类的影响，因此林冠及树干附生群落的储水能力在相似空间尺度下也可能存在差异。本研究通过地面调查，对北美大陆温带-北方林交错带（temperate-boreal ecotone，美国明尼苏达州）内的苔藓植物与地衣的林冠及树干附生群落盖度与生物量进行了估算。各研究样地均设置了多种林型，以区分林分水平与纬度效应的影响。基于优势类群的持水能力测定结果，将生物量换算为林冠及树干附生群落的潜在储水量。树干附生生物量及其潜在储水量的贡献远高于林冠外层……