Verlässliche Abschätzung von CH4-Bilanzen für Ökosysteme auf der Basis der Extrapolation von Punktmessungen unter Benutzung von Vegetationsmustern und weiteren Umweltparametern

生态系统的气体通量和物质平衡对于在预测的气候变化下评估土地利用的气候影响至关重要。封闭小室(CC)和涡动协方差(EC)测量是评估生态系统温室气体(GHG)排放的两种最常用的方法。CC测量显示出由物候发展(时间变异性)以及植被复盖及其相关微生物群落的空间变异性引起的相当大的时空变异性。在规划的项目中，应使用退化、再湿、微咸水沼泽的植被组成--连同相关环境参数的连续地图--作为外推甲烷通量速率的CC测量的代理，以获得生态系统/生境规模的可靠的甲烷排放量估计。植被评估是在规则的等距网格中进行的。在考虑空间效应的情况下，用回归克立格法模拟了CH4排放量与植被组成及其他环境参数之间的关系。我们的结果将有助于通过将点测量(CC)提升到生态系统规模来获得更好、更准确、因此更可靠的CH4平衡，同时允许将排放的CH4归因于植物群落特征。

Gas fluxes and matter balances of ecosystems are of crucial importance for the evaluation of the climate impact of land use under predicted climate change. Closed chamber (CC) and eddy covariance (EC) measurements are the two most widely used methods to assess greenhouse gas (GHG) emissions from ecosystems. CC measurements exhibit a considerable spatial and temporal variability caused by the phenological development (temporal variability) and by the spatial variability of the vegetative cover and their associated micro-organism communities. In the planned project the vegetation composition of a degraded, rewetted, brackish fen shall be used - together with continuous maps of relevant environmental parameters - as a proxy to extrapolate CC measurements of CH4 flux rates to obtain reliable CH4 emission estimates for the ecosystem/habitat scale. The vegetation assessment is carried out in a regular equidistant grid. The relationship between CH4 emissions and vegetation composition and further environmental parameters is modeled under the consideration of spatial effects with regression kriging. Our results will help to obtain better, more exact, and thus, more reliable CH4 balances by upscaling of point measurements (CC) to the ecosystem scale whilst allowing to attribute the emitted CH4 to plant community characteristics.