All greenhouse gas (CH4, CO2, and N2O) fluxes and associated in-chamber environmental parameters (sediment and vegetation C:N, sediment and vegetation moisture, and light.

Vegetated coastal ecosystems (i.e., salt marshes, mangroves, and seagrasses) provide a range of important ecosystems services including significant carbon storage. These ecosystems also export carbon during senescence, however the impact of this carbon export on coastal greenhouse gas budgets remains largely unconstrained. Here we examined the impact of seagrass organic matter deposition on a sandy, temperate beach. We hypothesized that this natural seagrass amendment would increase greenhouse gas fluxes compared to background (i.e., bare sandy beach). To test this hypothesis, we measured methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) fluxes using chamber incubations across three substrate cover types (bare sediment, wrack and sediment, or wrack alone) on a sandy beach near <i>Zostera marina</i> meadows. We also measured environmental parameters to identify potential drivers of GHG emissions from the beach. CO₂, CH_4,and N₂O fluxes did not differ across cover types, with average values of 2,910.73 ± 329.38 µmol CO₂ m^-2 h^-1, 0.33 ± 0.14 µmol CH₄ m^-2 h^-1, and 0.22. ± 0.16 µmol N₂O m^-2 h^-1. CH₄ and N₂O fluxes from seagrass wrack were relatively low when compared to literature values from living seagrass meadows, while CO₂ fluxes were on par with previously reported values. In contrast to our hypothesis, environmental factors, such as sediment moisture and air temperature, played a larger role in driving GHG fluxes than the presence of wrack. This work suggests that seagrass wrack likely plays a minimal role in temperate seagrass meadow GHG budgets.

滨海植被生态系统（即盐沼、红树林与海草床）可提供一系列重要的生态系统服务，其中包括显著的碳储存能力。这类生态系统在衰老过程中也会向外输出碳，然而该碳输出对沿海温室气体（greenhouse gas, GHG）收支的影响目前仍未得到充分明确。本研究针对温带沙质海滩，探究了海草源性有机质沉降的影响。我们提出假设：相较于裸沙海滩背景值，这类天然海草枯落物输入会提升温室气体通量。为验证该假设，我们在大叶藻（Zostera marina）草甸附近的沙质海滩上，针对三种底质覆盖类型（裸沉积物、沉积物附生海草枯落物、仅海草枯落物），采用箱式培养法测定了甲烷（CH₄）、二氧化碳（CO₂）与氧化亚氮（N₂O）的通量。同时我们还测定了环境参数，以明确该海滩温室气体排放的潜在驱动因子。三种覆盖类型下的CO₂、CH₄与N₂O通量均无显著差异，平均通量分别为2910.73±329.38 μmol CO₂·m⁻²·h⁻¹、0.33±0.14 μmol CH₄·m⁻²·h⁻¹以及0.22±0.16 μmol N₂O·m⁻²·h⁻¹。相较于已发表的活体海草草甸相关研究数据，海草枯落物样地的CH₄与N₂O通量相对偏低，而CO₂通量则与既往报道值持平。与本研究的初始假设相悖，沉积物含水量、气温等环境因子对温室气体通量的调控作用显著强于海草枯落物的存在。本研究结果表明，海草枯落物对温带海草草甸的温室气体收支的贡献极小。

搜集汇总

背景与挑战

背景概述

该数据集记录了在温带沙滩上，针对海草有机质沉积对温室气体通量影响的研究，测量了甲烷、二氧化碳和氧化亚氮的通量以及相关环境参数（如沉积物和植被的碳氮比、湿度和光照）。研究发现，温室气体通量在不同覆盖类型（裸沙、海草残骸和沙、或仅海草残骸）间无显著差异，且环境因素（如沉积物湿度和气温）比海草残骸的存在更关键地驱动了通量变化，这挑战了海草残骸会增加温室气体排放的假设。