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The cultivation of bioenergy plants in fertile, arable lands increasingly results in new land use conflicts with food production and cannot be considered as sustainable. Marginal lands have been frequently considered as potential alternatives for producing bioenergy from biomass. However, clear definitions and assessment methods for selecting marginal lands and for calculating potentials are still widely missing.The project "SEEMLA" aims at triggering the exploitation of currently underused marginal lands for biomass production for energy purposes. Study sites have been selected in different European countries: Germany, Greece, and Ukraine. The selected sites represent a wide variety of different types of marginal lands. Based on a soil assessment set given by the Muencheberg Soil Quality Rating (SQR) system potentially "marginal" sites have been investigated. The SQR system allows for clearly distinguishing between soils of higher and lower quality. Soils with SQR scores below 40 are regarded as "marginal". They can be classified into different groups with regard to the importance of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores correlate significantly with biomass yields of bioenergy plants.Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in Europe. Thus, 46 % of the investigated European area could be classified as "marginal" with SQR scores below 40. From that area 22.6 % can be considered as potentially suitable for producing renewable resources after eliminating protected sites or other places not suitable for any kind of land use. Taking the ecological demands of selected bioenergy plants into account it is possible to give first preliminary recommendations for regional crop cultivation.It can be concluded that Europe offers a large potential for renewable resources from marginal sites. However, the implementation into practice is often impeded by missing or varying policies and regulations. A proper implementation needs clear regulations and also incentives for farmers at the European level.

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Ecosystems are characterized as complex systems with abiotic and biotic processes interacting between the various components that have evolved over long‐term periods. Most ecosystem studies so far have been carried out in mature systems. Only limited knowledge exists on the very initial phase of ecosystem development. Concepts on the development of ecosystems are often based on assumptions and extrapolations with respect to structure–process interactions in the initial stage. To characterize the effect of this initial phase on structure and functioning of ecosystems in later stages, it is necessary to disentangle the close interaction of spatial and temporal patterns of ecosystem structural assemblages with processes of ecosystem development. The study of initial, less complex systems could help to better identify and characterize coupled patterns and processes. This paper gives an overview of concepts for the initial development of different ecosystem compartments and identifies open questions and research gaps. The artificial catchment site “Chicken Creek” is introduced as a new research approach to investigate these patterns and processes of initial ecosystem development under defined boundary conditions. This approach allows to integrate the relevant processes with related pattern and structure development over temporal and spatial scales and to derive thresholds and stages in state and functioning of ecosystems at the catchment level.

An artificial catchment of 6 ha was established in the Lusatian lignite mining district 2 (Germany). A comprehensive monitoring program was launched immediately after the 3 construction was finished in autumn 2005. The setup of the monitoring and first results of the 4 period 2005-2008 are presented in this paper. From the monitoring measurements it is 5 obvious that the establishing ecosystem is highly dynamic. In addition, important components 6 of the artificially created system are governed by characteristic, often seasonal trends. These 7 observations make clear that the performance of the artificial catchment is generally in 8 agreement with naturally formed watersheds but the system is still in a very initial phase of 9 establishment. Especially, soil properties, hydrological behaviour and vegetation succession 10 illustrate that the development of the system started very close to "point zero". Even if the 11 construction of the site itself left different initial structures the starting conditions of the 12 catchment can be characterized in general as relatively homogenous in comparison with other 13 close to "point zero" systems. However, new structures emerging at the surface of the site but 14 also in the subsurface differentiated the system significantly soon after "point zero". 15 16 Keywords 17 artificial catchment, environmental monitoring, ecosystem development, initial ecosystem, 18 ecosystem succession 19 Cottbus (BTU), the Technische Universität München (TUM) and the Swiss Federal Institute 5 of Technology Zurich (ETH). The overall objective of this interdisciplinary project is to 6 elucidate the role of structures and processes during the initial establishment of an ecosystem. 7 The central hypothesis of the project assumes that initial patterns substantially define and 8 shape the development and later stages of an ecosystem. The central objectives of this 9 collaborative project are (1) to reveal which abiotic and biotic structures and processes control 10 the initial phase of ecosystem development; (2) to investigate the interactions existing 11 between both abiotic and biotic processes and patterns in the initial phase; (3) to characterize 12 differences between processes and patterns of initial systems compared to mature ecosystems; 13 (4) to derive and define different stages during this early ecosystem development; and (5) to 14 find indicators that allow the transfer of results to other ecosystems in an initial stage. 15 The project uses an artificially built catchment with defined initial and boundary conditions. 16 This paper describes the setup of the comprehensive ecosystem monitoring that was initiated 17 immediately after the completion of the catchment in autumn 2005 and its first results. 18 19 2. Site description 20 The artificial catchment was constructed in the Lusatian lignite district (Brandenburg, 21 Germany). A general overview of the technical construction works is given by Kendzia et al. 22 (2008). The research site is located close to the city of Cottbus (about 150 km ...