In Central Europe, short rotation coppice systems for the production of woody biomass come increasingly into focus as these wood plantations offer an opportunity to sustainably produce biomass for energy production and to sequester substantial amounts of CO2 within the plantations and the soils at the same time. In this study, a modeling analysis of the C cycle of a poplar (Populus suaveolens Fisch. x Populus trichocarpa Torr. et Gray cv Androscoggin) and a black locust (Robinia pseudoacacia L.) SRC is presented. The calculations were performed with the bookkeeping C-model shortcar. The calculated estimates of C accumulation within the biomass, the litter layer, and the soil were validated against field data and published results from a selection of scientific studies. For the SRC on reclaimed mine sites a high C sequestration potential was found which amounted in the reference scenario over a period of 36 years to an accumulated net biome production of about 65 Mg C ha-1 for R. pseudoacacia and about 9 Mg C ha-1 for poplar, while the latter clearly suffered from the harsh growth conditions at the reclamation sites. Summarizing, the results suggested a high potential of SRC for C sequestration and C emission mitigation, especially on marginal sites.
Alley cropping system is an agroforestry practice in which arable crops are cultivated between tree hedgerows. For more than 15 ye ars we have been doing research in agroforestry which has been carried out on different experimental sites in the field covering about 250 acres of alley cropping, more areas with short rotation coppice, and other tree-based field experiments located close to C ottbus / Germany. The presence of woody species in the alley cropping production system has been shown to contribute significantly to carbon sequestration, nutrient cycling, improved water availability for crops, stimulation of higher soil faunal activities, soil erosion control, soil fertility improvement and sustained levels of crop production.
Alley cropping systems have also come into focus for reclamation of post-mining areas where the initial content of soil organic matter (SOM) is generally close to zero and soil fertility is very low. The increase of SOM in reclamation areas depends on amount of biomass production and return to soil, and mechanisms of C protection. Production of Robinia pseudoacacia L. under alley cropping system has received considerable interest in these areas as an alternative to agricultural crops and an additional wood source, while acting as a potential C sink to counterbalance greenhouse gases emissions. The woody biomass accumulation of R. pseudoacacia reached 29.8 t drymass ha-1 after 6 years of establishment on reclaimed mine sites in northeastern Germany. Due to its high potential of litterfall production and N2 fixation, R. pseudoacacia contributed to improve soil physical, chemical and biological properties though increasing SOM, converting spoils into productive and sustainable soils. For this reason, in the temperate zone, agroforestry systems attract more and more public attention as they offer a promising and comprising way for adapting agricultural production to climate change and providing comprehensive ecosystem services. A comprehensive assessment of the ecosystem services in agroforestry systems in temperate regions should consider the potential to produce biomass and food, the evaluation of the carbon and nutrient budgets, the assessment of the potential impact of agroforestry on biodiversity at landscape scale and finally the exploration of the sustainability functions and socio-economic cross-cutting issues. These key parameters are relevant to policy by providing current and reliable information on the interactions between land management, ecosystem services and society.