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Summary: Invasion of natural ecosystems by weedy grasses is often associated with increasing levels of disturbance. However, there is substantial evidence that cessation of disturbance can also lead to plant invasions. This paper explores vegetation development on a former military training area in eastern Germany. Many military training areas have a high nature conservation value as they offer large un-fragmented areas and valuable open landscapes. In eastern Germany, 4.4% of the land is covered by military training facilities. Following German reunification in 1990 large tracts of land that had been used for military training purposes were converted to civil use. Cessation of military activity is leading to a decline of open habitats through natural succession. The study investigates whether succession is accompanied by a spread of dominant species, e.g. Purple moor grass (Molinia caerulea L. Moench) and whether this process results in a decline of pioneer species (e.g., Drosera species). As a potential management option we explored grazing by moose (Alces alces L.) and other wild animals. The current state of the vegetation and its development was investigated at landscape and species levels. The influence of animals was documented by determining the type of ground disturbance and the impact on the herbaceous vegetation. The trajectory of succession involves the increase of species with high competitive abilities, particularly Molinia caerulea, and a decline of less competitive Drosera species. The pattern of development of the vegetation suggests that the Drosera species will soon survive in only a few locations. Wild animals exerted a significant influence on the vegetation, with most disturbances being the result of trampling. Tracks left by animals can provide regeneration niches for the Drosera species. However to guarantee the maintenance of large open habitats other management practices such as sod cutting are required. [Copyright &y& Elsevier]

Abstract: The membrane life-time has a strong impact on competitivity and viability of MBRs. This study critically analyzes the membrane life-time concept, approaching it through different assessment methods. A full scale MBR''s membrane life-time was assessed on the following: (i) maintaining the permeate flow throughput to the MBR; (ii) the permeability decline; (iii) oxidative aging; (iv) the increase in energy costs; and (v) mechanical aging. The method based on permeability decline provides a membrane life-time estimate up to a theoretical end. It was further elaborated inherently to operations with no long-term flux decline. The increase in operating pressure remains the main end-of-life trigger for deciding when to replace membrane modules. On the contrary, mechanical and permeate flow throughput analysis of the data are not able to provide a clear estimate of the membrane life-time. As for the membrane life-time estimation based on chlorine contact, it was found to be too optimistic. Complete irreversible fouling occurs before maximum contact time with chlorine is reached. At end-of-life operating conditions, the energy consumption raised of 170% due to the reduced flow rate. The cost raise appears high but still affordable. Earlier membrane replacement thus can never be counterbalanced by energy costs saving. [Copyright &y& Elsevier]