Carbon balancing of BSCs under application of a newly developed remote sensing monitoring technique

生物土壤结皮是土壤颗粒与蓝藻、绿藻、地衣、苔藓植物和微真菌以不同比例紧密结合而形成的结皮，在干旱和半干旱地区普遍存在。尽管它们具有改善土壤肥力和稳定性、影响种子萌发和土壤水文的深刻功能，但迄今为止它们在世界范围内的分布格局尚不清楚，而且它们在当地、大陆和全球碳平衡中的比例尚未得到考虑。在最近的一个案例研究中，我们开发了一种遥感方法，可以在高分辨率高光谱图像的基础上对bsc进行高精度分类。BSCs的这种分类方法将作为获得一种通用方法的基础，该方法可应用于各种传感器、尺度和不同环境。南非多肉卡鲁的一个特征区域将利用高光谱卫星数据（CHRIS Proba）进行分类。通过这样做，我们希望为绘制和监测整个大陆/全球范围内BSCs的分布模式设定先决条件。在第二步中，将在肉质卡鲁的分类区域内评估BSCs的碳平衡。在气体交换和长期小气候测量的基础上，模拟了不同类型BSCs的年碳平衡。第三步，将研究区域内BSCs的分类与碳平衡相结合，获得更大区域内复杂BSCs的第一个空间相关的健全碳平衡。

Biological soil crusts (BSCs), which are formed by a close association between soil particles and cyanobacteria, green algae, lichens, bryophytes and microfungi in different proportions occur worldwide in arid and semiarid regions. Despite their profound functions improving soil fertility and stability, influencing seed germination and soil hydrology, their worldwide distribution patterns are not known up to now and their proportion within the local, continental and global carbon balances is not being considered. In a recent case study we developed a remote sensing methodology, that allows to classify BSCs with high precision on the basis of high resolution hyperspectral imagery. This classification method for BSCs will be used as a basis to obtain a universal methodology which can be applied on a variety of sensors, scales and in different environments. A characteristic area in the Succulent Karoo, South Africa, will be classified utilizing hyperspectral satellite data (CHRIS Proba). By doing this we expect to set the prerequisites to map and monitor distribution patterns of BSCs on a continental/worldwide basis.In a second step, the carbon balance of BSCs will be assessed within the classified area in the Succulent Karoo. On the basis of gas exchange and long-term microclimate measurements, the annual carbon balance of the different types of BSCs will be modelled.In a third step, the classification and carbon balance of BSCs within the investigated area will be combined to obtain the first spatially related sound carbon balance for complex BSCs of a larger region.