@article{ZethofJulichFegeretal., author = {Zethof, Jeroen H. T. and Julich, Stefan and Feger, Karl-Heinz and Julich, Dorit}, title = {Legacy effect of 25 years reduced atmospheric sulphur deposition on spruce tree nutrition}, series = {Journal of Plant Nutrition and Soil Science}, volume = {187}, journal = {Journal of Plant Nutrition and Soil Science}, number = {6}, issn = {1436-8730}, doi = {10.1002/jpln.202400097}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-9099}, pages = {834 -- 843}, abstract = {Abstract Background Since the mid-1990s, sulphur (S) pollution was drastically reduced in Central Europe. Over time, this has led to a distinct reduction in S availability for Norway spruce ( Picea abies Karst.), which is still the most important timber species in Central European forestries. Aims Determination of the Norway spruce nutritional status of former strongly affected areas by S pollution (Saxony) with different degrees of liming by assessing their foliar element contents and comparing them to regions remote from historical high S deposition. Methods Sites were selected based on levels of S deposition in the 1970-1990s with historical high deposition in Saxony (NE Germany), low deposition at Schluchsee (SW Germany) and Davos (Switzerland) as a clean air reference. Needles were sampled in late autumn 2019/2020 and elemental contents determined. Additional historical data on foliar S contents were available. Results Historical data showed a clear decrease in foliar S contents in the Saxonian sites over the last 25 years, independent of liming. No difference between all study sites was found in the most recent sampling, whereas S together with other macronutrients strongly indicates deficiencies for forest growth and health. Conclusions After 25 years of reduced S deposition, S nutrition became low for Norway spruce trees in Saxony, whereas soil parent material determines the overall tree nutritional status with respect to other nutrients. As such, no difference between sites with historical high, low or no S deposition was found. Further studies should focus on the mineralization of organic S in the topsoil to understand if S is effectively recycled within the forest ecosystem and on the effect of other diminishing nutrients such as Mg and P.}, subject = {-}, language = {en} } @article{JulichJulichFegeretal., author = {Julich, Dorit and Julich, Stefan and Feger, Karl-Heinz and Klauder, Tobias and Zethof, Jeroen H. T.}, title = {Effects of Past Sulfur Deposition on the Soil Microbial Biomass at Spruce Forest Sites}, series = {Soil Systems}, volume = {8}, journal = {Soil Systems}, number = {2}, editor = {Viti, Carlo}, publisher = {MDPI}, issn = {2571-8789}, doi = {10.3390/soilsystems8020037}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-9404}, abstract = {
During the last decades, forest soils in Central Europe recovered from former sulfur and acid deposition. As external S input into forests has strongly decreased and legacy S pools in the soils are diminishing, internal S cycling through mineralization will increasingly become important for ecosystem nutrition. However, it is not known how microbial biomass is affected by the S pool change in the formerly S surplus soils. Here, we present data on the status quo of C, N, and S in microbial biomass in relation to contents in mineral soil and organic layer. The results of forest soil in Eastern Germany (low and high liming), which is slowly recovering from former pollution, are compared to those of a site remote from air pollution in the Swiss Alps. The contents of C, N, and S in soil as well as in microbial biomass were clearly higher in the organic layer than in mineral topsoil at all sites. Despite the generally low content in the mineral A-horizon, the clean-air site showed indications of a more active S-turnover as compared to the high-pollution site. Liming at the high-pollution site improved the conditions for microbial growth (pH increase) in the organic layer resulting in more mobile S.
}, subject = {-}, language = {en} } @article{KamamiaStrauchMwangietal., author = {Kamamia, Ann W. and Strauch, Michael and Mwangi, Hosea M. and Feger, Karl-Heinz and Sang, Joseph and Julich, Stefan}, title = {Modelling crop production, river low flow, and sediment load trade-offs under agroforestry land-use scenarios in Nyangores catchment, Kenya}, series = {Frontiers in Forests and Global Change}, volume = {5}, journal = {Frontiers in Forests and Global Change}, publisher = {Frontiers Media S.A.}, issn = {2624-893X}, doi = {10.3389/ffgc.2022.1046371}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-3831}, abstract = {The largest impact of land-use change on catchment hydrology can be linked to deforestation. This change, driven by exponential population growth, intensified food and industrial production, has resulted in alterations in river flow regimes such as high peaks, reduced base flows, and silt deposition. To reverse this trend more extensive management practices are becoming increasingly important, but can also lead to severe losses in agricultural production. Land-use optimization tools can help catchment managers to explore numerous land-use configurations for the evaluation of trade-offs amongst various uses. In this study, the Soil and water assessment tool (SWAT) model was coupled with a genetic algorithm to identify land-use/management configurations with minimal trade-offs between environmental objectives (reduced sediment load, increased stream low flow) and the crop yields of maize and soybean in Nyangores catchment (Kenya). During the land-use optimization, areas under conventional agriculture could either remain as they are or change to agroforestry or conservation agriculture (CA), where the latter was represented by introducing contour farming and vegetative filter strips. From the sets of the resulting Pareto-optimal solutions we selected mid-range solutions, representing a fair compromise among all objectives, for further analysis. We found that a combined measure implementation strategy (agroforestry on certain sites and conservation agriculture on other sites within the catchment) proved to be superior over single measure implementation strategies. On the catchment scale, a 3.6\% change to forests combined with a 35\% change to CA resulted in highly reduced sediment loads (-78\%), increased low flow (+14\%) and only slightly decreased crop yields (<4\%). There was a tendency of the genetic algorithm to implement more extensive management practices in the upper part of the catchment while leaving conventional agriculture in the lower part. Our study shows that a spatially targeted implementation strategy for different conservation management practices can remarkably improve environmental sustainability with only marginal trade-offs in crop production at the catchment-level. Incentive policies such as payments for ecosystem services (PES), considering upstream and downstream stakeholders, could offer a practical way to effect these changes.}, subject = {-}, language = {en} } @article{ViranoRiquelmeFegerJulich, author = {Virano-Riquelme, Victoria and Feger, Karl-Heinz and Julich, Stefan}, title = {Variation in Hydraulic Properties of Forest Soils in Temperate Climate Zones}, series = {Forests}, volume = {13}, journal = {Forests}, number = {11}, publisher = {MDPI}, issn = {1999-4907}, doi = {10.3390/f13111850}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-3741}, abstract = {The structure of forests in temperate climates has been changing to ensure the resilience of trees. This change affects the local water balance. Knowledge of soil hydraulic properties (SHP) is essential to assess the water cycle in ecosystems. There is little knowledge about the impact of tree species on SHP and the water balance. Based on a compilation of 539 related studies we aimed at identifying the effects of tree species and age on SHP in temperate climates. However, most studies concentrated on soil biogeochemical properties, whereas only 256 studies focused on SHP. The literature presents no standard methods for assessing SHP and there is no knowledge of their variations in forests. We present a systematic overview of the current state of knowledge on variations in SHP based on forest type in temperate climates. We identify the gaps and weaknesses in the literature and the difficulties of evaluating the reviewed studies. More studies following standardised methodologies are needed to create a robust database for each forest type and soil texture. It would improve the assessment of the forest water balance through calibrated plot/site-scale process models. Such a database does not yet exist, but it would greatly improve the management and development of future forest ecosystems.}, subject = {-}, language = {en} }