期刊
GLOBAL CHANGE BIOLOGY
卷 19, 期 10, 页码 3238-3244出版社
WILEY-BLACKWELL
DOI: 10.1111/gcb.12305
关键词
Australia; carbon accounting; carbon budgets; carbon dioxide; dust emission; soil organic carbon
资金
- CSIRO Sustainable Agriculture National Research Flagship
- Caring for Our Country project 'Wind Erosion Extent and Severity Maps for Australia' [A0000007341]
Soil erosion redistributes soil organic carbon (SOC) within terrestrial ecosystems, to the atmosphere and oceans. Dust export is an essential component of the carbon (C) and carbon dioxide (CO2) budget because wind erosion contributes to the C cycle by removing selectively SOC from vast areas and transporting C dust quickly offshore; augmenting the net loss of C from terrestrial systems. However, the contribution of wind erosion to rates of C release and sequestration is poorly understood. Here, we describe how SOC dust emission is omitted from national C accounting, is an underestimated source of CO2 and may accelerate SOC decomposition. Similarly, long dust residence times in the unshielded atmospheric environment may considerably increase CO2 emission. We developed a first approximation to SOC enrichment for a well-established dust emission model and quantified SOC dust emission for Australia (5.83Tg CO2-eyr(-1)) and Australian agricultural soils (0.4Tg CO2-eyr(-1)). These amount to underestimates for CO2 emissions of approximate to 10% from combined C pools in Australia (year=2000), approximate to 5% from Australian Rangelands and approximate to 3% of Australian Agricultural Soils by Kyoto Accounting. Northern hemisphere countries with greater dust emission than Australia are also likely to have much larger SOC dust emission. Therefore, omission of SOC dust emission likely represents a considerable underestimate from those nations' C accounts. We suggest that the omission of SOC dust emission from C cycling and C accounting is a significant global source of uncertainty. Tracing the fate of wind-eroded SOC in the dust cycle is therefore essential to quantify the release of CO2 from SOC dust to the atmosphere and the contribution of SOC deposition to downwind C sinks.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据