Examining the production, export, and immediate fate of kelp detritus on open-coast subtidal reefs in the Northeast Atlantic
Examining the production, export, and immediate fate of kelp detritus on open-coast subtidal reefs in the Northeast Atlantic
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检查东北大西洋开放海岸潮下礁石上海带碎屑的生产、出口和直接命运
DOI：
10.1002/lno.11970
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发表时间：
2021
影响因子：
4.5
通讯作者：
Smale D
中科院分区：
文献类型：
--
作者：
Smale D
海带森林是高生产力的沿海生境，正在成为其他生态系统有机物质的重要来源。虽然它们的高生产率和碎屑释放率预计将导致大量的碳出口，但很少有研究实际量化了出口率或碎屑的持久性。我们在横跨英国长度（纬度9°）的8个潮下带海带森林（Laminaria hyperborea）中解决了这一问题。具体而言，我们量化了碎屑生产，保留/出口从源和邻近的栖息地，并在原地分解率。通过整个植物的移位和“五月铸造”脱落的老增长释放的碎屑是高度可变的网站之间的最大值记录在我们的寒冷，北方网站。这可归因于北方地区较大的植物大小生物量，而不是植物密度或迁移率。平均而言，海带碎屑的年产量为4706 ± 700 g FW m− 2 yr − 1或301 g C m− 2 yr −1。海带森林和邻近沉积生境中碎屑的低保留表明出口率非常高（整个研究中> 98%）。垃圾袋实验表明，碎屑可能需要超过4个月的时间才能分解，这表明长距离运输的潜力很大。总的来说，我们的研究结果表明，L.深林在其分布范围内输出大量的碎屑补贴，这可能会影响遥远的海底群落的结构，并构成沿海碳循环中一个相关但在很大程度上被忽视的通量，而这可能是自然固碳的一个重要组成部分。
Kelp forests are highly productive coastal habitats and are emerging as important sources of organic matter for other ecosystems. Although their high rates of productivity and detritus release are expected to lead to substantial export of carbon, few studies have actually quantified rates of export or the persistence of detritus. We addressed this in eight subtidal kelp forests (Laminaria hyperborea) spanning the length (9° of latitude) of the United Kingdom. Specifically, we quantified detritus production, retention/export from source and adjacent habitats, and in situ decomposition rates. Detritus released via both dislodgment of whole plants and “May cast” shedding of old growth was highly variable between sites with greatest values recorded in our colder, northern sites. This was attributable to greater plant size biomass in northern regions, rather than plant density or dislodgement rates. On average, the annual production of kelp detritus was 4706 ± 700 g FW m−2yr−1or 301 g C m−2yr−1. Low retention of detritus within the kelp forest and adjacent sedimentary habitats indicated very high rates of export (> 98% across the study). A litterbag experiment showed detritus may take > 4 months to decompose, suggesting great potential for long distance transport. Overall, our findings suggest thatL. hyperboreaforests export large amounts of detritus subsidies across their range, which can potentially shape the structure of distant benthic communities and constitute a relevant and largely overlooked flux in the coastal carbon cycle, which may represent an important component of natural carbon sequestration.