1 Department of Plant Sciences, University of Cambridge , Downing Street, Cambridge CB2 3EA , UK.
2 Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling , Stirling FK9 4LA , UK.
Proc Biol Sci. 2019 Jan 30;286(1895):20182284. doi: 10.1098/rspb.2018.2284.
Liverworts and mosses are a major component of the epiphyte flora of tropical montane forest ecosystems. Canopy access was used to analyse the distribution and vertical stratification of bryophyte epiphytes within tree crowns at nine forest sites across a 3400 m elevational gradient in Peru, from the Amazonian basin to the high Andes. The stable isotope compositions of bryophyte organic material (C/C and O/O) are associated with surface water diffusive limitations and, along with C/N content, provide a generic index for the extent of cloud immersion. From lowland to cloud forest δC increased from -33‰ to -27‰, while δO increased from 16.3‰ to 18.0‰. Epiphytic bryophyte and associated canopy soil biomass in the cloud immersion zone was estimated at up to 45 t dry mass ha, and overall water holding capacity was equivalent to a 20 mm precipitation event. The study emphasizes the importance of diverse bryophyte communities in sequestering carbon in threatened habitats, with stable isotope analysis allowing future elevational shifts in the cloud base associated with changes in climate to be tracked.
地钱和苔藓是热带山地森林生态系统中附生植物区系的主要组成部分。为了分析在秘鲁 3400 米海拔梯度上 9 个森林地点树冠内附生苔藓的分布和垂直分层情况，我们采用了树冠进入法。苔藓植物有机物质的稳定同位素组成（C/C 和 O/O）与地表水扩散限制有关，与 C/N 含量一起，为云浸的程度提供了一个通用指标。从低地到云雾林，δC 从-33‰增加到-27‰，而 δO 从 16.3‰增加到 18.0‰。在云浸区，附生苔藓和相关的树冠土壤生物量估计高达 45 吨干物质公顷，总持水能力相当于 20 毫米的降水事件。本研究强调了在受到威胁的栖息地中，多样化的苔藓群落固定碳的重要性，通过稳定同位素分析，可以跟踪与气候变化相关的云底海拔的未来变化。
