Soil carbon stocks and their variability across the forests, shrublands and grasslands of peninsular Spain
Soil carbon stocks and their variability across the forests, shrublands and grasslands of peninsular Spain
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DOI：
10.5194/bg-10-8353-2013
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发表时间：
2013-01-01
期刊：
影响因子：
4.9
通讯作者：
Vayreda, J.
中科院分区：
文献类型：
--
作者：
Doblas-Miranda, E.;Rovira, P.;Vayreda, J.
为了评估气候和土地利用变化对土壤碳吸收和碳排放的影响，需要准确估算土壤碳储量和碳通量。在这里，我们提出了一个评估SOC股票在森林，灌木丛和草原的西班牙半岛的基础上实地测量900多个土壤剖面。SOC的深度为1米的植被覆盖，年平均温度，年降水量，海拔和温度和海拔之间的相互作用的函数建模，而纬度和经度被用来模拟误差的相关结构。由此产生的统计模型用于估计西班牙森林地图（29.3 x 10（6）公顷）中类似于800万像素的SOC。我们提出了我们认为是最可靠的估计目前SOC在森林，灌木丛和草原的西班牙半岛迄今为止，基于使用的空间建模，大量的配置文件和有效性和完善的数据层。有机碳的平均浓度为8.7 kg m（-2），从地中海干旱地区的2.3 kg m（-2）到北方湿润地区的20.4 kg m（-2）不等。这个值对应于2.544 Tg SOC的总库存，这是西班牙森林生物量中估计储存的C量的四倍。气候和植被覆盖是影响SOC的主要变量，在面对全球变化的西班牙半岛生态系统具有重要的生态意义。事实上，SOC是正相关的年降水量和负相关的年平均温度表明，未来的气候变化预测的温度升高和降水量减少可能会大大降低西班牙土壤的C汇的潜力。然而，这可能是由于植被覆盖的变化（例如，有利于发展与较高SOC值相关的森林），并因火灾等扰动而加剧。这里提出的估计为估计土壤碳储量的未来变化和评估其对关键全球变化驱动因素的脆弱性提供了一个基线，并应告知未来旨在保护和管理碳储量的行动。
Accurate estimates of C stocks and fluxes of soil organic carbon (SOC) are needed to assess the impact of climate and land use change on soil C uptake and soil C emissions to the atmosphere. Here, we present an assessment of SOC stocks in forests, shrublands and grasslands of peninsular Spain based on field measurements in more than 900 soil profiles. SOC to a depth of 1 m was modelled as a function of vegetation cover, mean annual temperature, total annual precipitation, elevation and the interaction between temperature and elevation, while latitude and longitude were used to model the correlation structure of the errors. The resulting statistical model was used to estimate SOC in the similar to 8 million pixels of the Spanish Forest Map (29.3 x 10(6) ha). We present what we believe is the most reliable estimation of current SOC in forests, shrublands and grasslands of peninsular Spain thus far, based on the use of spatial modelling, the high number of profiles and the validity and refinement of the data layers employed. Mean concentration of SOC was 8.7 kg m(-2), ranging from 2.3 kg m(-2) in dry Mediterranean areas to 20.4 kg m(-2) in wetter northern locations. This value corresponds to a total stock of 2.544 Tg SOC, which is four times the amount of C estimated to be stored in the biomass of Spanish forests. Climate and vegetation cover were the main variables influencing SOC, with important ecological implications for peninsular Spanish ecosystems in the face of global change. The fact that SOC was positively related to annual precipitation and negatively related to mean annual temperature suggests that future climate change predictions of increased temperature and reduced precipitation may strongly reduce the potential of Spanish soils as C sinks. However, this may be mediated by changes in vegetation cover (e.g. by favouring the development of forests associated to higher SOC values) and exacerbated by perturbations such as fire. The estimations presented here provide a baseline to estimate future changes in soil C stocks and to assess their vulnerability to key global change drivers, and should inform future actions aimed at the conservation and management of C stocks.