Potentials and impacts of short-rotation coppice plantation with aspen in Eastern Germany under conditions of climate change

摘要

Woody biomass generated in short-rotation coppice (SRC) plantations with aspen (Populus tremula L.) has good properties for bioenergy crop production: annual yields are high, labour input per year is low, and it is ecologically valuable because of the multi-year rotation periods. Eastern Germany has a special advantage in producing bioenergy crops: the former "agricultural cooperatives" built up quite large farms with, compared to Western Germany, comparatively large fields. Therefore, a modelling study of the potential and the impacts of aspen SRC plantations in the five eastern federal states of Germany under the recent climate and future climate projections was conducted. The ecophysiological forest growth model 4C was used to simulate the growth of aspen SRC plantations and their impacts on carbon in soils, and groundwater recharge, on selected suitable areas currently under crops but with marginal site conditions for cropping. A clear signal to enhanced growth condition over the whole area can be seen in the simulation of the mean annual woody biomass yield under conditions of climate change, which increased from 7.47 t DW ha~(-1)a~(-1) under the recent climate to 9.26 t DW ha~(-1) a~(-1) at the end of the considered future period 2034-2055 under climate change. The mean soil carbon sequestration rate was 0.81 t C ha~(-1) a~(-1) underrnthe recent climate and could rise up to 0.93 t C ha~(-1)a ~(-1) under the assumption of climate change. On the other hand, the mean annual percolation rate, used as an indicator of impacts on the regional water budget, will diminish under future climatic conditions. The results suggest that aspen SRC plantations are a suitable contribution to regional CO_2 mitigation and carbon sequestration under possible change of climate, but that negative impacts on the regional water budget are possible.