An expert system model for mapping tropical wetlands and peatlands reveals South America as the largest contributor
An expert system model for mapping tropical wetlands and peatlands reveals South America as the largest contributor
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DOI：
10.1111/gcb.13689
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发表时间：
2017-09-01
影响因子：
11.6
通讯作者：
Murdiyarso, Daniel
中科院分区：
文献类型：
--
作者：
Gumbricht, Thomas;Roman-Cuesta, Rosa Maria;Murdiyarso, Daniel
湿地是生态系统服务的重要提供者，也是气候变化的主要调节者。它们通过温室气体排放对全球变暖起到积极作用，通过有机质在有机土中的积累，特别是在泥炭地，起到消极作用。我们对湿地服务的理解目前受到对其分布、范围、体积、年际洪水变化和干扰水平的有限了解的限制。我们提出了一个专家系统的方法来估计湿地和泥炭地的面积，深度和体积，这依赖于三个生物物理指标相关的湿地和泥炭的形成：（1）长期供水超过大气水的需求;（2）每年或季节性积水的土壤;和（3）地貌的位置，水的供应和保留。热带和亚热带湿地估计达到470万公里（2）（Mkm（2））。根据目前的理解，美洲大陆是主要贡献者（45%），巴西及其亚马逊河间地区拥有最大的热带湿地面积（800，720平方公里）。然而，我们的模型表明，热带地区泥炭地的范围和体积是前所未有的（1.7 Mkm（2）和7，268（6，076 - 7，368）km（3）），是目前估计的三倍多。与目前的理解不同，我们的估计表明，南美洲而不是亚洲对热带泥炭地面积和体积的贡献最大。44%）部分与一些尚未解释的延伸深沉积有关，但主要与亚马逊盆地的延伸但浅的泥炭有关。巴西在泥炭地面积和数量贡献方面领先。亚洲拥有38%的热带泥炭面积和体积，印度尼西亚是主要的区域贡献者，仍然是热带最深和最广泛的泥炭面积的保持器。非洲拥有比以前报道的更多的泥炭，但气候和地形环境使其成为泥炭形成最少的大陆。我们的研究结果表明，我们目前对热带泥炭的分布，面积和体积及其大陆贡献的理解存在很大的偏差。
Wetlands are important providers of ecosystem services and key regulators of climate change. They positively contribute to global warming through their greenhouse gas emissions, and negatively through the accumulation of organic material in histosols, particularly in peatlands. Our understanding of wetlands' services is currently constrained by limited knowledge on their distribution, extent, volume, interannual flood variability and disturbance levels. We present an expert system approach to estimate wetland and peatland areas, depths and volumes, which relies on three biophysical indices related to wetland and peat formation: (1) long-term water supply exceeding atmospheric water demand; (2) annually or seasonally water-logged soils; and (3) a geomorphological position where water is supplied and retained. Tropical and subtropical wetlands estimates reach 4.7 million km(2) (Mkm(2)). In line with current understanding, the American continent is the major contributor (45%), and Brazil, with its Amazonian interfluvial region, contains the largest tropical wetland area (800,720 km(2)). Our model suggests, however, unprecedented extents and volumes of peatland in the tropics (1.7 Mkm(2) and 7,268 (6,076-7,368) km(3)), which more than threefold current estimates. Unlike current understanding, our estimates suggest that South America and not Asia contributes the most to tropical peatland area and volume (ca. 44% for both) partly related to some yet unaccounted extended deep deposits but mainly to extended but shallow peat in the Amazon Basin. Brazil leads the peatland area and volume contribution. Asia hosts 38% of both tropical peat area and volume with Indonesia as the main regional contributor and still the holder of the deepest and most extended peat areas in the tropics. Africa hosts more peat than previously reported but climatic and topographic contexts leave it as the least peat-forming continent. Our results suggest large biases in our current understanding of the distribution, area and volumes of tropical peat and their continental contributions.