PDF(Pubmed)
Abstract：
Coastal habitats are increasingly recognized as fundamentally important components of global carbon cycles, but the rates of carbon flow associated with marine macrophytes are not well resolved for many species in many regions. We quantified density, rates of primary productivity, and detritus production of intertidal stands of two common intertidal kelp species-Laminaria digitata (oarweed) and Saccharina latissima (sugar kelp)-on four NE Atlantic rocky shores over 22 months. The density of L. digitata was greater at exposed compared to moderately exposed shores but remained consistently low for S. latissima throughout the survey period. Individual productivity and erosion rates of L. digitata did not differ between exposed and moderately exposed shores but differed across exposure levels throughout the year at moderately exposed sites only. Productivity and erosion of S. latissima remained low on moderately exposed shores and showed no clear seasonal pattern. Patterns of productivity and total detrital production (erosion and dislodgement) per m2 of both L. digitata and S. latissima followed closely that of densities per m2, peaking in May during both survey years. Temperature and light were key factors affecting the productivity rates of L. digitata and S. latissima. Erosion rates of L. digitata were affected by wave exposure, temperature, light, grazing, and epiphyte cover, but only temperature-affected erosion of S. latissima. Production of biomass and detritus was greater in L. digitata than in S. latissima and exceeded previous estimates for subtidal and warmer-water affinity kelp populations (e.g., Laminaria ochroleuca). These biogenic habitats are clearly important contributors to the coastal carbon cycle that have been overlooked previously and should be included in future ecosystem models. Further work is required to determine the areal extent of kelp stands in intertidal and shallow subtidal habitats, which is needed to scale up local production estimates to entire coastlines.
摘要：
沿海栖息地越来越被认为是全球碳循环的重要组成部分，但是对于许多地区的许多物种来说，与海洋大型植物相关的碳流速率并没有得到很好的解决。我们量化了密度，初级生产力，在22个月的时间里，在四个东北大西洋岩石海岸上，两种常见的潮间带海带种类-海带（卵草）和Saccharinalatissima（糖海带）的潮间带林的碎屑生产。与中等暴露的海岸相比，暴露时的杜鹃花的密度更大，但在整个调查期间，拉迪西马的密度一直很低。在暴露和中度暴露的海岸之间，digitata的个体生产力和侵蚀率没有差异，但仅在中度暴露的地点，全年的暴露水平有所不同。在中等暴露的海岸上，拉迪斯玛的生产力和侵蚀仍然很低，没有明显的季节性模式。L.digitata和S.latissima每平方米的生产力和总碎屑产量（侵蚀和移位）的模式紧随每平方米的密度，在两个调查年度中均在5月达到峰值。温度和光照是影响洋地黄和落叶松的生产率的关键因素。数码管的侵蚀率受波浪暴露的影响，温度,光,放牧,和附生植物的覆盖物，但只有受温度影响的拉氏链球菌的侵蚀。digitataL.digitata的生物量和碎屑产量高于拉迪斯西玛S.，并且超过了先前对潮下和温暖水亲和力海带种群的估计（例如，海带）。这些生物生境显然是沿海碳循环的重要贡献者，以前被忽视了，应该包括在未来的生态系统模型中。需要进一步的工作来确定潮间带和潮下浅层生境中海带林的面积范围。这需要将当地的产量估计扩大到整个海岸线。
