Uncertainty in United States coastal wetland greenhouse gas inventorying
Uncertainty in United States coastal wetland greenhouse gas inventorying
复制标题
DOI：
10.1088/1748-9326/aae157
复制
发表时间：
2018-11-01
影响因子：
6.7
通讯作者：
Weller, Donald E.
中科院分区：
文献类型：
--
作者：
Holmquist, James R.;Windham-Myers, Lisamarie;Weller, Donald E.
沿海湿地储存二氧化碳（CO2）并排放CO2和甲烷（CH 4），使其成为温室气体（GHG）清单的重要组成部分。在毗连的美国（CONUS），沿海湿地清单最近计算相结合的湿地类型和变化与土壤，生物量和CH 4通量数据的文献综述的地图。我们评估了这个发展中的碳监测系统的不确定性，以量化库存过程本身的信心，并优先考虑未来的研究。我们通过定义假设、埋藏和排放数据集以及湿地地图的不确定性的类型和尺度，模拟简化版本清单的10000次迭代，并进行敏感性分析，来提供增值分析。沿海湿地可能是2006-2011年净CO2当量（CO（2）e）排放的一个来源。虽然稳定的河口湿地可能是一个CO（2）e汇，这种影响被抵消了灾难性的土壤流失在墨西哥湾沿岸，和CH 4排放的潮汐淡水湿地。CONUS CO2 e总通量的方向和大小对排放和埋藏数据的不确定性以及如何计算清单的假设最为敏感。关键数据的不确定性包括稳定淡水湿地的甲烷排放量和所有沿海湿地的碳埋藏率。关键的假设包括受侵蚀事件影响的土壤平均深度、将CH 4通量转换为CO（2）e所用的方法以及侵蚀事件后流失到大气中的碳的比例。该清单对绘图的不确定性相对不敏感。可通过收集更多数据，特别是受损失事件影响的深度数据，以及通过更好地绘制与关键温室气体通量相关的盐度和淹没梯度图，改进未来版本。
Coastal wetlands store carbon dioxide (CO2) and emit CO2 and methane (CH4) making them an important part of greenhouse gas (GHG) inventorying. In the contiguous United States (CONUS), a coastal wetland inventory was recently calculated by combining maps of wetland type and change with soil, biomass, and CH4 flux data from a literature review. We assess uncertainty in this developing carbon monitoring system to quantify confidence in the inventory process itself and to prioritize future research. We provide a value-added analysis by defining types and scales of uncertainty for assumptions, burial and emissions datasets, and wetland maps, simulating 10 000 iterations of a simplified version of the inventory, and performing a sensitivity analysis. Coastal wetlands were likely a source of net-CO2-equivalent (CO(2)e) emissions from 2006-2011. Although stable estuarine wetlands were likely a CO(2)e sink, this effect was counteracted by catastrophic soil losses in the Gulf Coast, and CH4 emissions from tidal freshwater wetlands. The direction and magnitude of total CONUS CO(2)e flux were most sensitive to uncertainty in emissions and burial data, and assumptions about how to calculate the inventory. Critical data uncertainties included CH4 emissions for stable freshwater wetlands and carbon burial rates for all coastal wetlands. Critical assumptions included the average depth of soil affected by erosion events, the method used to convert CH4 fluxes to CO(2)e, and the fraction of carbon lost to the atmosphere following an erosion event. The inventory was relatively insensitive to mapping uncertainties. Future versions could be improved by collecting additional data, especially the depth affected by loss events, and by better mapping salinity and inundation gradients relevant to key GHG fluxes.