@inproceedings{SesermanPohleFreeseetal., author = {Seserman, Diana-Maria and Pohle, Ina and Freese, Dirk and Veste, Maik}, title = {Climate Change Impacts on the Growth of Hybrid Poplar Trees in an Agroforestry System in Brandenburg, NE Germany}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Climate change is expected in Brandenburg, eastern Germany, in terms of increasing annual temperature and changes in climate variability, as well as the number of extreme weather events. Since agroforestry systems have a planning horizon of several decades, long-term yield assessments are required in order to evaluate the economic profitability and environmental sustainability of such systems. Accordingly, our aim was to simulate the tree growth of poplar trees (Populus nigra x P. maximowiczii) in an agroforestry system in Brandenburg for the next forty years. For this purpose, we used the process-oriented Yield-SAFE model, a parameter-sparse, biophysical model developed for the simulation of plant growth in agroforestry systems. For the investigated period from 2011 to 2014, the validation simulations showed clear correlations with the observed values for woody tree biomass. For the unfolding period from 2015 to 2055, a variety of possible climate changes (including higher evaporation requirements and reduced water availability) and their uncertainties were incorporated into our assessment. The tree yield sensitivity to future climatic conditions was evaluated using 100 realizations of a scenario of the statistical regional climate model Statistical Analogue Resampling Scheme (STAR), which assumes an increase in annual temperature of 2K, as well as decreasing annual precipitation by 30-40 mm. The Yield-SAFE model responded sensitively to changes in the meteorological input data, showing that (1) shifts in temperature and/or precipitation would have a directly proportional influence on tree growth and (2) the impact of potential climate changes on tree growth must be assessed in terms of the complex interaction of various influencing factors. This was evidenced, for example, by the fact that higher average annual temperatures could either increase the tree growth due to a prolonged vegetation period or, on the contrary, decrease the tree growth due to higher potential evapotranspiration. The model results are important for the sustainable planning and management of agroforestry systems, upcoming risk assessments, and example analysis of adaptation scenarios in the near and distant future.}, language = {en} } @misc{GypserDiezBoellietal., author = {Gypser, Stella and Diez, Miriam and Boelli, Daniel and Wachendorf, Magnus and K{\"u}ppers, Manfred and Veste, Maik}, title = {Monitoring of biocrust development and physiological activity in disturbed ecosystems in Central Europe}, series = {Biocrust 4 - 4th International Workshop on Biological Soil Crusts}, volume = {2019}, journal = {Biocrust 4 - 4th International Workshop on Biological Soil Crusts}, address = {North Stradbroke Island, Queensland , Australia}, doi = {10.13140/RG.2.2.11042.99523}, pages = {1}, abstract = {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.}, language = {en} } @misc{GypserVeste, author = {Gypser, Stella and Veste, Maik}, title = {Hotspot biocrusts: Combining chlorophyll fluorescence and NDVI to analyze spatial and temporal variations of photosynthesis}, series = {Gf{\"O} 2019, Science Meets Practice, 49th Annual Meeting of the Ecological Society of Germany, Austria and Switzerland, university of M{\"u}nster, 9-13 September 2019}, journal = {Gf{\"O} 2019, Science Meets Practice, 49th Annual Meeting of the Ecological Society of Germany, Austria and Switzerland, university of M{\"u}nster, 9-13 September 2019}, pages = {199}, abstract = {Biological soil crusts (biocrusts) play an important role as pioneering organisms on initial soils and in open landscapes after natural and human disturbances. Even though they only cover the topsoil, biocrusts are key drivers for biogeochemical and ecological processes and influencing ecosystem development. Microclimatic conditions, texture, water holding capacity, and chemical soil properties lead to the formation of spatial patterns. Sandy nutrient-poor soils in pine forests in the open-cast lignite mining district in Brandenburg are covered by biocrust, dominated by different functional types and species (e.g. algae, mosses, lichens). The photosynthetic activity of these poikilohydric organisms, strongly depending on moisture, affects biocrust function and their impact on soil C pools and dynamics. Therefore, the evaluation of photosynthesis in relation to the spatial distribution pattern variation is fundamental. For this purpose, we combined different remote sensing techniques, spectral reflectance sensors, and chlorophyll fluorescence imaging to analyze the photosynthetic dynamics in relation to biocrust species composition and wetness. Desiccation of the biocrusts was detected with a miniature moisture sensor and related to their activity. A low-cost consumer grade camera was used to determine NDVI and to map the distribution and heterogeneity of chlorophyll for a comprehensive characterization of spatial photosynthetic activity pattern. Basic as well as maximum fluorescence, the maximum photochemical efficiency, and NDVI decreased during desiccation of the biocrusts, whereby moss and moss/lichen biocrusts showed higher water holding capacities relative to green algae biocrusts. The combination of different sensor technologies is a powerful tool for monitoring long-term biocrust development and their implication for soil C dynamics.}, language = {en} } @inproceedings{MantovaniVesteBoehmetal., author = {Mantovani, Dario and Veste, Maik and B{\"o}hm, Christian and Freese, Dirk}, title = {Black locust (Robinia pseudoacacia L.) in agroforestry systems: spatial and temporal variation of the plant water status and growth}, series = {2nd European Agroforestry Conference: Integrating Science and Policy to Promote Agroforestry in Practice, June 2014, Cottbus, Germany}, booktitle = {2nd European Agroforestry Conference: Integrating Science and Policy to Promote Agroforestry in Practice, June 2014, Cottbus, Germany}, editor = {Palma, Joao H. N.}, isbn = {978-972-97874-4-7}, pages = {263 -- 264}, abstract = {Short-rotation forestry and agroforestry systems have the potential to become an ecologically valuable and economically profitable land use alternative on marginal lands. Therefore, our project focuses on determining the water demand for biomass production of black locust in the Lusatia region (Eastern Germany). The area is characterized by relative low annual rainfall (560-600 mm/yr) and drought periods during spring and summer. Black locust (Robinia pseudoacacia L.) is planted in short rotation plantations as well as in agroforestry systems at reclaimed post-mining sites of the opencast mining area "Welzow S{\"u}d" and on a conventionally managed field near the town Forst (both study sites are located about 120 km to the south of Berlin). Due to mining activities the ground water table in "Welzow-S{\"u}d" is below 100 m, while on the field site in Forst the ground water table is about 2 m below the soil surface. Because of the water accessibility directly affecting the yield, it is crucial to identify the spatial variation of the soil water availability and its influence on black locust growth. The main question of this study is how the drought periods affect black locust's growth and recovery and about the drought mitigation effect obtainable by an accessible water table. The growth rate is being estimated monthly by measuring the maximum height and the trunk diameter at 10 and 130 cm. Furthermore, several trees are equipped with dendrometers to record their diameter increment in daily intervals. The pre-dawn water potential for selected trees is evaluated periodically to quantify plant water stress and relate it to the growth pattern. Water availability and microclimatic condition are monitored continuously. At the end of the vegetation period, information gathered from the field will be used to develop a growth model to link the soil water availability and plant water status with the growth rate of the trees.}, language = {en} } @misc{SeitzVeste, author = {Seitz, Steffen and Veste, Maik}, title = {Bryophyte-lichens dominated biological soil crusts affect soils and ecohydrology in temperate forests in Germany}, series = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, doi = {10.5194/egusphere-egu22-12352}, abstract = {Forest dieback can be both a consequence and a cause of climate change. The changing climate does not only lead to temperature increases but also changes in the precipitation regime. Extreme events have increased sharply in recent years, making drought and heat waves ubiquitous. Meanwhile, for temperate forests, drought stress is considered one of the most serious impacts of climate change. In this context, forest soils are of great importance in their hydrological functions, as well as their feedbacks with ground vegetation. In this context, biological soil crusts are key drivers of functional processes and ecosystem development, also under forest, where they have been less studied so far. Bryophyte and lichen dominated communities can importantly affect e.g. water storage and discharge as well as soil development and stabilization. Moreover, they contribute to carbon and nitrogen cycling and play an important role in biogeochemical processes. Their species composition depends on soil properties such as texture and pH, on microclimate and as poikilohydric plants, their ecophysiology is strongly dependent on water availability, differing in time and space.}, language = {en} } @misc{MaWeberRaggioQuilezetal., author = {Ma, Yunyao and Weber, Bettina and Raggio Qu{\´i}lez, Jos{\´e} and Colesie, Claudia and Veste, Maik and Bader, Maaike Y. and Porada, Philipp}, title = {Determining key drivers of the annual carbon budget of biocrusts in different climatic zones}, series = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, doi = {10.5194/egusphere-egu22-3714}, abstract = {Biocrusts are distributed over all climate zones of the world and they substantially contribute to ecosystem functioning. Their growth, determined by their carbon balance, can be affected by various climatic drivers. The effects of individual drivers are clear from laboratory experiments, but the relative importance of different drivers along climatic gradients and their underlying mechanisms are largely unknown. Moreover, the effects of seasonal acclimation on the annual carbon balance are not fully understood either. Therefore, we aim at determining the level and variation of annual biocrust carbon balances and their connection to climatic drivers along environmental gradients. In addition, we explore the role that acclimation plays in the carbon balance of biocrusts}, language = {en} } @inproceedings{KanzlerBoehmMircketal., author = {Kanzler, Michael and B{\"o}hm, Christian and Mirck, Jaconette and Schmitt, Dieter and Veste, Maik}, title = {Einfluss agroforstlicher Nutzung auf das Mikroklima, den Ackerfruchtertrag und die potentielle Evaporation}, series = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, booktitle = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, editor = {B{\"o}hm, Christian}, publisher = {BTU}, address = {Cottbus}, isbn = {978-3-940471-27-7}, pages = {127 -- 131}, abstract = {Der folgende Beitrag widmet sich der Frage, inwieweit sich mikroklimatische {\"A}nderungen in einem Agroforstsystem (AFS) bedingt durch die Geh{\"o}lzkomponente kleinr{\"a}umig auf die gemessene Evaporation sowie auf die Produktivit{\"a}t von Winterweizen (Triticum aestivum) auswirken. Hierf{\"u}r wurden im Zeitraum von M{\"a}rz bis August 2016 Untersuchungen auf einem ca. 40 ha großen Agroforstschlag und einer angrenzenden, konventionell bewirtschafteten Freifl{\"a}che bei Neu Sacro (Landkreis Spree-Neiße, Brandenburg) durchgef{\"u}hrt. Neben mikroklimatischen Kenngr{\"o}ßen wie der Lufttemperatur, der relativen Luftfeuchte, der Windgeschwindigkeit und der Globalstrahlung wurde auch die Evaporation nach Piche bestimmt. Erg{\"a}nzend wurden Ertragsmessungen zum Kornertrag und Messungen zum Blattfl{\"a}chenindex (LAI) des angebauten Winterweizens durchgef{\"u}hrt. Neben {\"A}nderungen der Tagesminima der relativen Luftfeuchtigkeit im Nahbereich der Geh{\"o}lzstreifen wurde eine Reduktion der durchschnittlichen Windgeschwindigkeit von bis zu 51 \% gegen{\"u}ber der Freifl{\"a}che festgestellt. Die Minderung der Evaporation im Vergleich zur Freifl{\"a}che betrug je nach Witterung bzw. N{\"a}he zum Geh{\"o}lzstreifen bis zu 58 \% und wurde dabei maßgeblich durch die Windgeschwindigkeit beeinflusst. R{\"a}umliche Unterschiede ergaben sich auch bez{\"u}glich des Kornertrags sowie beim LAI. So fielen die Kornertr{\"a}ge im Agroforstsystem mit bis zu 9,2 t ha-1 gegen{\"u}ber ca. 7,0 t ha-1 f{\"u}r die Referenzfl{\"a}che {\"u}berwiegend h{\"o}her aus. Mit Ausnahme des Leebereichs in 3 m Entfernung zum Geh{\"o}lzstreifen lagen auch die LAI-Werte des AFS {\"u}ber jenen der angrenzenden Freifl{\"a}che. Diese ersten Ergebnisse deuten darauf hin, dass in AFS durch Geh{\"o}lzstrukturen neben der Windgeschwindigkeit auch die Wasserverdunstung im Bereich der angrenzenden Ackerkulturen gemindert werden kann. Die mikroklimatischen Unterschiede wirkten sich dabei potentiell auch positiv auf das Wachstumsverhalten bzw. den Ertrag des Winterweizens aus. Vor dem Hintergrund einer Verringerung der potentiellen Evaporation und einer hieraus resultierenden h{\"o}heren Wasserverf{\"u}gbarkeit f{\"u}r die Ackerkulturen k{\"o}nnte die agroforstliche Landnutzung zuk{\"u}nftig auch f{\"u}r trockenheitsgef{\"a}hrdete Gebiete Mitteleuropas eine vorteilhafte Anpassungsstrategie des Ackerbaus an den Klimawandel darstellen.}, language = {de} } @inproceedings{VesteBoehmQuinkensteinetal., author = {Veste, Maik and B{\"o}hm, Christian and Quinkenstein, Ansgar and Freese, Dirk}, title = {Estimation of biological nitrogen fixation by black locust in short-rotation forests using natural 15N abundance method}, series = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, booktitle = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The importance of short rotation forests and agroforestry systems for woody biomass production for bioenergy will increase in Central Europe within the next decades. In this context, black locust (Robinia pseudoacacia) has a high growth potential especially at marginal, drought-susceptible sites such as occur in Brandenburg State (Eastern Germany). As a pioneer tree species black locust grows under a wide range of site conditions. The native range of black locust in Northern America is classified by a humid to sub-humid climate with a mean annual precipitation of 1020 to 1830 mm. In Central and Eastern Europe, this species is cultivated in a more continental climate with an annual precipitation often below 600 mm. Therefore, black locust is known to be relatively drought tolerant compared to other temperate, deciduous tree species. Because of its N2-fixation ability black locust plays generally an important role for the improvement of soil fertility. This effect is of particular interest at marginal sites in the post-mining landscapes. In order to estimate the N2-fixation potential of black locust at marginal sites leaf samples were taken from black locust trees in short rotation plantations planted between 1995 and 2007 in post-mining sites south of Cottbus (Brandenburg, NE Germany). The variation of the natural 15N abundance was measured to evaluate the biological nitrogen fixation. The nitrogen derived from the atmosphere can be calculated using a two-pool model from the quotient of the natural 15N abundances of the N2-fixing plant and the plant available soil N. Because representatively determining the plant available soil N is difficult, a non-N2-fixing reference plant growing at the same site with a similar root system and temporal N uptake pattern to the N2-fixing plant is often used. In our case we used red oak (Quercus rubra) as a reference. The average nitrogen content in the leaves of black locust ranged from 3.1\% (C/N 14.8) in 15 years old trees to 3.4\% (C/N 14.4) in 3 year-old trees, respectively. A higher content of nitrogen was found in leaves of re-sprouted trees with 4.3\% (C/N 11.5). The estimated percentage of nitrogen derived from the atmosphere (\% NdfA) in black locust was 63\% - 83\% compared to 56\% in seabuckthorn (Hippopha{\"e} rhamnoides) and 79\% in common broom (Genista scuparia). The annual leaf biomass production of black locust varied between 1325 (2 years old trees) and 2576 kg/ha a (4 years old trees). The estimated leaf nitrogen fixed by Robinia was approx. 30.5 - 59.2 kg/ha a. From the results, we can conclude that the biological nitrogen fixation by Robina is an important factor for the nitrogen balance of short-rotation plantations on nutrient poor-soils.}, language = {en} } @inproceedings{FischerVesteEiseleetal., author = {Fischer, Thomas and Veste, Maik and Eisele, Andreas and Bens, Oliver and Spyra, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {High resolution mapping of Normalized Difference Vegetation Indices (NDVI) of biological soil crusts}, series = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, booktitle = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{SesermanVesteFreeseetal., author = {Seserman, Diana-Maria and Veste, Maik and Freese, Dirk and Swieter, Anita and Langhof, Maren}, title = {Benefits of agroforestry systems for land equivalent ratio - case studies in Brandenburg and Lower Saxony, Germany}, series = {Proceedings of the 4th European Agroforestry Conference Agroforestry as Sustainable Land Use 28-30 May 2018, Nijmegen, The Netherlands}, booktitle = {Proceedings of the 4th European Agroforestry Conference Agroforestry as Sustainable Land Use 28-30 May 2018, Nijmegen, The Netherlands}, publisher = {University of Santiago de Compostela}, address = {Santiago de Compostela}, isbn = {978-84-09-02384-4}, pages = {26 -- 29}, abstract = {Transitioning towards agroforestry demands systematic productivity assessments of such systems under different climatic and edaphic conditions. In this regard, the Land Equivalent Ratio (LER) serves as a valuable productivity indicator of agroforestry since it evaluates yields from growing trees and crops together in comparison to yields from monocultures over the same period. Consequently, our objective was to evaluate the overall productivity of two agroforestry systems in Forst (Brandenburg) and Wendhausen (Lower Saxony) by means of LER. Our approach followed two assumptions: (i) the yields of trees and crops had equal economic importance and (ii) the economic importance was given solely by the annual crop, the yield of trees representing a supplementary profit. The resulted values for LER were consistently above their specific threshold, corroborating the greater efficiency of agroforestry systems rather than monoculture. Additionally, this study highlighted the importance of choosing the appropriate assumptions when calculating the LER.}, language = {en} } @inproceedings{SesermanPohleVesteetal., author = {Seserman, Diana-Maria and Pohle, Ina and Veste, Maik and Freese, Dirk}, title = {Variabilit{\"a}t der holzigen Biomasseproduktion von Pappel und Robinie als Folge des Klimawandels in einem Alley-Cropping System in der Lausitz}, series = {1. Erfurter Tagung "Schnellwachsende Baumarten - Etablierung, Management und Verwertung", vom 16.11.-17.11.2017}, booktitle = {1. Erfurter Tagung "Schnellwachsende Baumarten - Etablierung, Management und Verwertung", vom 16.11.-17.11.2017}, publisher = {Fachhochschule Erfurt}, address = {Erfurt}, pages = {88 -- 89}, language = {de} } @inproceedings{GypserVeste, author = {Gypser, Stella and Veste, Maik}, title = {Biological soil crusts as driver for ecosystem structures and functions on reclaimed post-mining sites in Lower Lusatia, Germany}, series = {9th International Symposium on Ecosystem Behavior BIOGEOMON, Litomysl, Czech Republic, August 20-24, 2017}, booktitle = {9th International Symposium on Ecosystem Behavior BIOGEOMON, Litomysl, Czech Republic, August 20-24, 2017}, editor = {Nov{\´a}k, Martin and Kr{\´a}m, Pavel and Step{\´a}nov{\´a}, M.}, pages = {33 -- 34}, language = {en} } @inproceedings{VesteHalke, author = {Veste, Maik and Halke, Christian}, title = {{\"O}kophysiologische Plastizit{\"a}t der Photosynthese von Robinien (Robinia pseudoacacia L.) und Hybrid-Pappeln (Populus nigra L. x P. maximowiczii Henry) bei Hitzestress und Sommertrockenheit in der Niederlausitz}, series = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, booktitle = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, editor = {B{\"o}hm, Christian}, address = {Cottbus}, isbn = {978-3-940471-27-7}, pages = {144 -- 157}, abstract = {Mit der Zunahme von extremen Witterungsereignissen ist die Auswahl von angepassten Baumarten und Klonen von großer Bedeutung f{\"u}r den Agrarholzanbau in der Lausitz. So z{\"a}hlte der Sommer 2015 zu den drittw{\"a}rmsten Sommern in Deutschland mit langanhaltenden Trockenzeiten und Hitzeperioden auch in Brandenburg. Die {\"o}kophysiologischen Reaktionen von Robinien und Hybrid-Pappeln (Klon Max 1) auf Hitze- und Trockenstress wurden in einem Agroforstsystem bei Neu Sacro, Brandenburg untersucht. Die {\"o}kophysiologische Anpassungsf{\"a}higkeit wurde hinsichtlich der Photosyntheseleistung (Chlorophyllfluoreszenz), dem Wasserpotential, der 13C/12C Diskriminierung und dem Blatt-N-Gehalt untersucht. Gut wasserversorgte B{\"a}ume der beiden Arten zeigten keine wesentlichen Einschr{\"a}nkungen in Bezug auf die Photosyntheseleistung und dem N{\"a}hrstoffhaushalt, da am Standort ein Grundwasseranschluss auch w{\"a}hrend der Trockenheit gew{\"a}hrleistet war. Bedingt durch kleinr{\"a}umige Bodenheterogenit{\"a}ten kann es allerdings auch {\"o}rtlich zu Wassermangel kommen. An diesen Standorten zeigten die Pappeln deutliche morphologische und {\"o}kophysiologische Anzeichen von Trockenstress. Bei der sommerlichen Hitze zeigte die Photosynthese der beiden Baumarten eine hohe Plastizit{\"a}t.}, language = {de} } @inproceedings{GypserVeste, author = {Gypser, Stella and Veste, Maik}, title = {Application of chlorophyll fluorescence, CO2 gas exchange, and NDVI for the detection of spatial variances of photosynthesis of biological soil crusts on anthropogenic degraded soils}, series = {3rd International Workshop on Biological Soil Crusts BIOCRUST3, September 26-30, 2016, Star Hall-Moab, Utah, USA}, booktitle = {3rd International Workshop on Biological Soil Crusts BIOCRUST3, September 26-30, 2016, Star Hall-Moab, Utah, USA}, pages = {24 -- 25}, abstract = {Degradation of soils and the destruction of vegetation as a result of anthropogenic disturbances affect ecosystem functions and properties worldwide. In Brandenburg (NE Germany) various ecosystems were degraded by different human activities like surface mining and military activities on sand dunes. These resulted in degraded open landscapes with an initial soil development. These new ecosystems are characterized by a high vulnerability to erosion, low water holding capacity, lack of nutrients, or low pH. For rehabilitation of degraded soils and vegetation, these post-mining and mobile sand dunes need specific restoration measures, but beside inappropriate soil characteristics, insufficient water availability can limit plant growth. Even located in the temperate zone of Europe, Brandenburg belongs to the driest regions in Germany and faces long drought periods. In this context, the determination of the influence of biocrusts on carbon accumulation during initial ecosystem succession, small-scale investigations on photosynthetic capacity and active phase regarding biocrust formation and developmental stage, which vary from initial green algae-crusts to biocrusts dominated by soil lichens or mosses, are necessary. Hence, succession of biocrusts result in a spatiotemporal heterogeneity and distribution pattern. We could show that varying species abundance, composition, and crust succession affect photosynthetic capacity, and hence, carbon fixation capability. Different spatial hotspots could be analyzed under field conditions and monitored during the season. Long-term measurements of climatic parameters, which include radiation, temperature, precipitation, and desiccation of biocrusts, will be linked to photosynthetic performances under lab conditions. This spatial model can help to understand the impact of biocrusts on carbon accumulation in initial soils. Due to the potential to colonize soil surface under harsh conditions without human support, advantages of biocrusts can be used systematically as a supporting rehabilitation measure for physical stabilization, gain of organic carbon, and hence, facilitates the growth of indigenous vegetation during primary succession.}, language = {en} } @inproceedings{KleefeldVeste, author = {Kleefeld, Andreas and Veste, Maik}, title = {Robuste and strukturerhaltende Bildentrauschung via Medianfilterung und Bildsegmentierung}, series = {20. und 21. Workshop Computer-Bildanalyse in der Landwirtschaft, 3. Workshop Unbemannte Autonom Fliegende Systeme (UAS) in der Landwirtschaft, 26. Mai 2014, Osnabr{\"u}ck 07. Mai 2015, Braunschweig}, booktitle = {20. und 21. Workshop Computer-Bildanalyse in der Landwirtschaft, 3. Workshop Unbemannte Autonom Fliegende Systeme (UAS) in der Landwirtschaft, 26. Mai 2014, Osnabr{\"u}ck 07. Mai 2015, Braunschweig}, publisher = {ATB, Leibniz-Institut f{\"u}r Agrartechnik}, address = {Potsdam-Bornim}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:186-opus4-75951}, pages = {92 -- 100}, language = {de} }