FG Bodenschutz und Rekultivierung
In many ecosystems of the earth, biocrusts influence the successive development of vegetation through their influence on the soil formation. This change in soil structure, e.g. due to the accumulation of organic material and the ability of biological nitrogen fixation, results in significant feedback and controls of ecosystem processes, especially in arid regions. In Brandenburg, located in NE Germany, the dry grasslands on sand dunes and the post-mining landscapes, characterized by edaphic drought and lack of nutrients as well as disturbances, are ecologically interesting locations for investigations of the biocrusts. In recent years, the species composition, structure, N-fixation, C-fluxes, and accumulation as well as their soil hydrological properties of biocrusts have been characterized and ecophysiological measurements of biocrust activity and CO2 exchange of different biocrust types under standardized environmental conditions have been performed in the laboratory. These ecophysiological measurements were correlated for the first time with NDVI measurements using a modified consumer camera, thus enabling a spatial analysis of the photosynthesis hotspots and a transfer from the lab into the landscape. The development and physiological activity of biocrusts are significantly influenced by microclimatic boundary conditions and moisture-dry cycles. The duration of these moisture phases is decisive for their spatial and temporal development and for the differentiation of the developmental stages. The permanent recording of moisture in the biocrusts in the uppermost millimeters using a newly developed biocrust wetness sensor in combination with NDVI measurements enable detailed information about biocrust activities and carbon fluxes. These continuous measurements of NDVI and physiological activity with PRI sensors allows determining seasonal activity phases in relation to microclimatological site conditions. More recent technological developments in sensor technology make it possible to carry out detailed and cost-effective investigations of the biocrust activity over the course of the year.
Assessing multiple ecosystem functions of linear woody-features in the agricultural landscape
(2019)
A practical approach to hedgerow management for improving the provision of ecosystem services
(2019)
This study aims at investigating the iron cyanide (CN) degradation potential of two natural bacterial isolates with the purpose of their application in iron CN phytoremediation. The strains were isolated from contaminated soil and incubated over 4 months with 50mg L⁻¹CN (as ferrocyanide) as the sole iron and nitrogen source. Unlike previous reports, the study provides control for bacterial growth, biotic and abiotic CN losses. Bacterial growth, CN, ammonium, and nitrate concentrations were monitored regularly. Both strains grew less rapid with iron CN compared with the positive control. However, the growth was diauxic. The CN concentration in the media decreased with 20% and 25% respectively, while that in the sterile controls remained stable. Ammonium was detected in the media of both strains implying that a fraction of the initially applied ferrocyanide has been converted. The nitrogen lost from the system evened out with that in the cells at the end of the experiments. These results showed that the investigated strains were undoubtedly able to grow on iron CN as an alternative nitrogen source, but contrary to some previous findings, the iron CN utilization is much slower and takes place only after complete exhaustion of the cellular nitrogen reserves.
Agroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in north-western France, Denmark, Central Spain, north and south-western Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha −1 a −1 . Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a −1 (7.78 and 234.85 million t CO 2eq a −1 ) depending on the type of agroforestry. This corresponds to between 1.4 and 43.4% of European agricultural greenhouse gas (GHG) emissions. Moreover, promoting agroforestry in the Priority Areas would contribute to mitigate the environmental pressures identified there. We conclude that the strategic and spatially targeted establishment of agroforestry systems could provide an effective means of meeting EU policy objectives on GHG emissions whilst providing a range of other important benefits.
Land nachhaltig nutzen
(2019)