@misc{GypserVesteFischeretal., author = {Gypser, Stella and Veste, Maik and Fischer, Thomas and Lange, Philipp}, title = {Infiltration and water retention of biological soil crusts on reclaimed soils of former open-cast lignite mining sites in Brandenburg, north-east Germany}, series = {Journal of hydrology and hydromechanics}, volume = {64}, journal = {Journal of hydrology and hydromechanics}, number = {1}, doi = {10.1515/johh-2016-0009}, pages = {1 -- 11}, abstract = {Investigations were done on two former open-cast lignite mining sites under reclamation, an artificial sand dune in Welzow S{\"u}d, and a forest plantation in Schlabendorf S{\"u}d (Brandenburg, Germany). The aim was to associate the topsoil hydrological characteristics of green algae dominated as well as moss and soil lichen dominated biological soil crusts during crustal succession with their water retention and the repellency index on sandy soils under temperate cli-mate and different reliefs. The investigation of the repellency index showed on the one hand an increase due to the cross-linking of sand parti-cles by green algae which resulted in clogging of pores. On the other hand, the occurrence of moss plants led to a de-crease of the repellency index due to absorption caused by bryophytes. The determination of the water retention curves showed an increase of the water holding capacity, especially in conjunction with the growth of green algae layer. The pore-related van Genuchten parameter indicate a clay-like behaviour of the developed soil crusts. Because of the inho-mogeneous distribution of lichens and mosses as well as the varying thickness of green algae layers, the water retention differed between the study sites and between samples of similar developmental stages. However, similar tendencies of water retention and water repellency related to the soil crust formation were observed. Biological soil crusts should be considered after disturbances in the context of reclamation measures, because the ini-tial development of green algae biocrusts lead to an increasing repellency index, while the occurrence of mosses and a gain in organic matter enhance the water holding capacity. Thus, the succession of biocrusts and their small-scale succes-sion promote the development of soil and ecosystem.}, language = {en} } @misc{LiGaoWangetal., author = {Li, Bai and Gao, Jiarong and Wang, Xiuru and Ma, Lan and Cui, Qiang and Veste, Maik}, title = {Effects of biological soil crusts on water infiltration and evaporation Yanchi Ningxia, Maowusu Desert, China}, series = {International Journal of Sediment Research}, volume = {31}, journal = {International Journal of Sediment Research}, number = {4}, issn = {1001-6279}, doi = {10.1016/j.ijsrc.2016.05.005}, pages = {311 -- 323}, abstract = {Biological soil crusts serve as a vanguard for improving the ecological environment in arid, semi-arid desertification areas.It is a good indicator of the level of improvement which the local ecological evironment is undertaking. In desert areas, water condition is a key factor of improving the ecological environment. As a first layer protection, biological crusts play an important role in local vegetation succession due to their abilities to conserve and maintain moisture. Using Maowusu desert in Yanchi of Ningxia province as an example, after three years of research, this paper chooses three kinds of biological crusts including lichen, moss and cyanobacterial which are under the cover of Artemisia ordosicaas research objects. The results of this study indicate that, the closer biological crusts are to Artemisia ordosica vegetation, the thicker they become. In the same position of Artemisia ordosica vegetation, the thickness of moss crusts is the highest, followed by lichen crusts, and the thickness of cyanobacterial crusts is the lowest. Biological soil crusts coverage protects the natural water content of soil layers from 0 to 5cm. Also, it effects falling water to infiltrate deeper, and cannot prevent the surfacewater content from evaporating effectively. The effect of biological crusts blocking water infiltration decreases with the increase of rainfall. At the same rainfall level, moss crusts provide the strongest water infiltration blockage, followed by lichen crusts and cyanobacterial crusts. With the increase of rainfall, the depth of water infiltration increases.At the same rainfall level, the relationship of water infiltration depth is as follows: cyanobacterial crusts > lichen crusts > moss crusts. With the increase of biological crusts thickness, they blocking water infiltration capacity is stronger, and the depth of water infiltration is smaller. Analysis on the characteristic of simulated rainfall process on biological crusts shows that sandy land can be fixed by applying appropriate artificial biological crusts to build a sustainable forest protection system and to create a stable ecosystem in desertification area.}, language = {en} } @misc{XiaoVeste, author = {Xiao, Bo and Veste, Maik}, title = {Moss-dominated biocrusts increase soil microbial abundance and community diversity and improve soil fertility in semi-arid climates on the Loess Plateau of China}, series = {Applied Soil Ecology}, volume = {117-118}, journal = {Applied Soil Ecology}, doi = {10.1016/j.apsoil.2017.05.005}, pages = {165 -- 177}, abstract = {Various ecological functions of biocrusts are mostly determined by their bacterial and fungal abundance and community diversity, which has not yet been fully investigated. To provide more insights into this issue, we collected samples of moss biocrusts, fixed sand, and mobile sand from a watershed with semi-arid climate on the Loess Plateau of China. The relative abundances and community diversities of soil bacteria and fungi of the samples were determined using high-throughput DNA sequencing. Finally, we analyzed the characteristics of bacterial and fungal community of the moss biocrusts and their relationships to the content of soil nutrients. Our results showed that the moss biocrusts had 1048 bacterial OTUs (operational taxonomic units) and 58 fungal OTUs, and their Shannon diversity indexes were 5.56 and 1.65, respectively. The bacterial community of the moss biocrusts was dominated by Acidobacteria (24.3\%), Proteobacteria (23.8\%), Chloroflexi (15.8\%), and Actinobacteria (14.5\%), and their fungal community was dominated by Ascomycota (68.0\%) and Basidiomycota (23.8\%). The moss biocrusts had far more bacterial OTUs (≥56.9\%) but similar number of fungal OTUs as compared with the uncrusted soil, and their Sorenson's similarity coefficients of bacterial and fungal communities were less than 0.768 and 0.596, respectively. Moreover, the contents of soil nutrients (C, N, P) were significantly correlated with the OTU numbers of bacteria and the relative abundances of bacteria and fungi. Our results indicated that moss biocrusts harbor a large number and high diversity of bacteria and fungi, and these diversified bacteria and fungi play important roles in ecosystem functioning through improving soil fertility.}, language = {en} } @misc{MantovaniVesteFreese, author = {Mantovani, Dario and Veste, Maik and Freese, Dirk}, title = {Effects of Drought Frequency on Growth Performance and Transpiration of Young Black Locust (Robinia pseudoacacia L.)}, series = {International Journal of Forestry Research}, journal = {International Journal of Forestry Research}, issn = {1687-9376}, doi = {10.1155/2014/821891}, pages = {11}, abstract = {Black locust (Robinia pseudoacacia L.) is a drought-tolerant fast growing tree, which could be an alternative to the more common tree species used in short-rotation coppice on marginal land. The plasticity of black locust in the form of ecophysiological and morphological adaptations to drought is an important precondition for its successful growth in such areas. However, adaptation to drought stress is detrimental to primary production. Furthermore, the soil water availability condition of the initial stage of development may have an impact on the tree resilience. We aimed to investigate the effect of drought stress applied during the resprouting on the drought tolerance of the plant, by examining the black locust growth patterns. We exposed young trees in lysimeters to different cycles of drought. The drought memory affected the plant growth performance and its drought tolerance: the plants resprouting under drought conditions were more drought tolerant than the well-watered ones. Black locust tolerates drastic soil water availability variations without altering its water use efficiency (2.57 g L-1), evaluated under drought stress. Due to its constant water use efficiency and the high phenotypic plasticity, black locust could become an important species to be cultivated on marginal land.}, language = {en} } @misc{KueppersSchmittLineretal., author = {K{\"u}ppers, Manfred and Schmitt, Dieter and Liner, Susanne and B{\"o}hm, Christian and Kanzler, Michael and Veste, Maik}, title = {Photosynthetic characteristics and simulation of annual leaf carbon gains of hybrid poplar (Populus nigra L. x P. maximowiczii Henry) and black locust (Robinia pseudoacacia L.) in a temperate agroforestry system}, series = {Agroforestry Systems}, volume = {92}, journal = {Agroforestry Systems}, number = {5}, issn = {0167-4366}, doi = {10.1007/s10457-017-0071-z}, pages = {1267 -- 1286}, abstract = {A leaf net photosynthesis model is presented driven by light and modulated by temperature and air humidity. From this the seasonal variation of CO2 uptake and release could be modelled to estimate the annual carbon fluxes of sun and shade leaves. In fully expanded leaves light is the major factor determining daily carbon balances, and highest observed daily carbon gains in sun leaves amounted to 748.9 mmol CO2 m-2 day-1 in poplar and to 536.3 mmol CO2 m-2 day-1 in black locust, while the annual carbon gains amounted to 46,824 mol CO2 m-2 in black locust and 66,803 mol CO2 m-2 in hybrid poplar. Results obtained via gas exchange measurements and from the leaf model clearly indicate a potentially better growth performance of the poplar compared to black locust on the investigated site. The presented photosynthesis model provides a good and realistic estimation for seasonal carbon balances on the leaf level for both species.}, language = {en} } @misc{GypserVesteFischeretal., author = {Gypser, Stella and Veste, Maik and Fischer, Thomas and Lange, Philipp}, title = {Formation of soil lichen crusts at reclaimed post-mining sites, Lower Lusatia, North-east Germany}, series = {Graphis Scripta}, volume = {27}, journal = {Graphis Scripta}, number = {1-2}, issn = {0901-7593}, pages = {3 -- 14}, abstract = {Biological soil crusts were investigated at reclaimed post-mining sites near Welzow and Schlabendorf in Lower Lusatia (Brandenburg, Germany). Various development stages from initial biological soil crusts built up by green algae, to more developed soil crusts with mosses, as well as moss-soil lichen crusts, were classified. The spatial-temporal dynamics during the development resulted in a moss-lichens cover with discrete patches of pioneer organisms like green algae in between. At the study sites, 13 species of terricolous lichens were identified. The formation of the biological soil crust is important for the accumulation of soil organic matter in the first millimeters of the topsoil of these pioneer ecosystems. A correlation between cryptogamic biomass and soil carbon content were found.}, language = {en} } @misc{MantovaniVesteFreese, author = {Mantovani, Dario and Veste, Maik and Freese, Dirk}, title = {Black locust (Robina pseudoacacia L.) ecopysiological and morphological adaptations to drought and their consequence on biomass production and water-use efficiency}, series = {New Zealand Journal of Forestry Science}, volume = {44}, journal = {New Zealand Journal of Forestry Science}, number = {1}, doi = {10.1186/s40490-014-0029-0}, pages = {11}, abstract = {Background: Successful plantation efforts growing Robinia pseudoacacia L. (black locust) in the drier regions of Hungary and East Germany (Brandenburg), have demonstrated the potential of black locust as an alternative tree species for short-rotation biomass energy plantations. Methods: The response of black locust to water limitation was investigated in a lysimeter experiment. Plants were grown under three different soil moisture regimes, with values set at 35\%, 70\%, and 100\% of the soil water availability, namely WA35, WA70, and WA100. Their morphological adaptation and productivity response to water constraint were assessed together with their water-use efficiency. Furthermore, the ecophysiological adaptation at the leaf level was assessed in terms of net photosynthesis and leaf transpiration. Results: During the growing season, plants in the WA35, WA70, and WA100 treatments transpired 239, 386, and 589 litres of water respectively. The plants subjected to the WA35 and WA70 treatments developed smaller leaves compared with the plants subjected to the WA100 treatment (66\% and 36\% respectively), which contributed to the total leaf area reduction from 8.03 m2 (WA100) to 3.25 m2 (WA35). The total above-ground biomass produced in the WA35 (646 g) and WA70 (675 g) treatments reached only 46\% and 48\% of the biomass yield obtained in the WA100 (1415 g). The water-use efficiency across all treatments was 2.31 g L-1. At vapour pressure deficit (VPD) values <1.4 kPa trees growing under the WA35 soil moisture regime showed a stomatal down-regulation of transpiration to 5.3 mmol m-2 s-1, whereas the trees growing under the WA100 regime did not regulate their stomatal conductance and transpiration was 11.7 mmol m-2 s-1, even at VPD values >2 kPa. Conclusions: Black locust plants can adapt to prolonged drought conditions by reducing water loss through both reduced transpiration and leaf size. However, under well-watered conditions it does not regulate its transpiration, and therefore it cannot be considered a water-saving tree species.}, language = {en} } @misc{HowellTuckerGroteetal., author = {Howell, Armin and Tucker, Colin and Grote, Ed and Veste, Maik and Belnap, Jayne and Kast, Gerhard and Weber, Bettina and Reed, Sasha C.}, title = {Manufacturing Simple and Inexpensive Soil Surface Temperature and Gravimetric Water Content Sensors}, series = {Journal of Visualized Experiments}, volume = {154}, journal = {Journal of Visualized Experiments}, issn = {1940-087X}, doi = {10.3791/60308}, pages = {13}, abstract = {Quantifying temperature and moisture at the soil surface is essential for understanding how soil surface biota responds to changes in its environment. However, at the soil surface these variables are highly dynamic and standard sensors do not explicitly measure temperature or moisture in the upper few millimeters of the soil profile. This manuscript describes methods for manufacturing simple, inexpensive sensors that simultaneously measure the temperature and moisture of the upper 5 mm of the soil surface. In addition to sensor construction, steps for quality control, as well as for calibration for various substrates, are explained. The sensors incorporate a Type E thermocouple to measure temperature and assess soil moisture by measuring the resistance between two gold-plated metal probes at the end of the sensor at a depth of 5 mm. The methods presented here can be altered to customize probes for different depths or substrates. These sensors have been effective in a variety of environments and have endured months of heavy rains in tropical forests as well as intense solar radiation in deserts of the southwestern U.S. Results demonstrate the effectiveness of these sensors for evaluating warming, drying, and freezing of the soil surface in a global change experiment.}, language = {en} } @misc{KueppersKueppersHornaetal., author = {K{\"u}ppers, Manfred and K{\"u}ppers, Barbara I. L. and Horna, Viviana and Veste, Maik and Zimmermann, Reiner and Lauerer, Marianne and Aas, Gregor}, title = {Green barks of trees from drought deciduous forests ("bosque seco") in northern Peru/southern Ecuador do not perform CAM}, series = {Basic and Applied Dryland research}, journal = {Basic and Applied Dryland research}, issn = {1864-3191}, doi = {10.1127/badr/2015/0002}, pages = {15}, abstract = {Trees from drought deciduous forests ("bosque seco") in northern Peru and southern Ecuador regularly shed their leaves at the onset of seven months-long periods without rain. This way they very effectively reduce the bulk water consumption by leaf transpiration, still loosing small amounts of water through their bark, but at the risk of too little or no carbon gain when leaf-less. Seven species studied here have good developed green cortex tissue on stems and axes, as especially evident for the "bottle tree" Ceiba trischistandra (A. Gray) Bakhuisen (Bombacaceae). In several leaf-less tree species at the end of summer drought, when xylem sap flows are very low, indications of higher xylem flows at night as compared to day-time were found, which led to the question of whether the trees are capable of performing CAM in their axes. However, although quite low in some cases, the pH of the cortex tissues did not fluctuate diurnally. In addition, no night-time carbon uptake could be observed. Although no net carbon gain was measured in C. trischistandra and Erythrina smithiana Krukoff (Fabaceae) photosynthetic activity of the green cortex was sufficient to re-assimilate between 50\% to 60\% of the carbon released by mitochondrial respiration. In contrast, the obligate CAM plant Cereus diffusus (Britton \& Rose) Werdermann (Cactaceae), which was studied as a reference in the same environment, showed both diurnal pH-fluctuations in its green tissue with lowest values before sun rise, and net carbon fixation at night.}, language = {en} } @misc{XiaoHuVesteetal., author = {Xiao, Bo and Hu, Kelin and Veste, Maik and Kidron, Giora J.}, title = {Natural recovery rates of moss biocrusts after severe disturbance in a semiarid climate of the Chinese Loess Plateau}, series = {Geoderma}, volume = {337}, journal = {Geoderma}, issn = {0016-7061}, doi = {10.1016/j.geoderma.2018.09.054}, pages = {402 -- 412}, abstract = {Biocrusts are vulnerable to large scale disturbances including trampling activities, and their recovery rates are highly variable with estimates fluctuating by more than one order of magnitude, from<5 years (very fast) to>250 years (very slow). Also, the development of microbial abundance and community diversity of biocrusts after disturbances is poorly understood. In a semiarid climate of the Chinese Loess Plateau, we conducted a recovery experiment on well-developed moss biocrusts after a severe disturbance, during which the entire upper 3 cm of the surface was removed. In the following nine years, the general characteristics and microbial community of the recovering and undisturbed biocrusts as well as a substrate with no crust (bare sand) were periodically determined. Through linear or logistic extrapolation of the observed recovery rates, the recovery time of the biocrusts after disturbance was estimated by both biocrust characteristics and microbial community. Recovery time yielded the following estimates: a) coverage within 3 years, b) thickness within 8 years, c) biomass within 9-13 years, and d) cultivable microbial density within 11-13 years. More importantly, the recovery time of the disturbed moss-biocrusts estimated by the number of bacteria and fungi was ~10 and 20 years, respectively, and that estimated by the bacterial and fungal community diversity was 12-14 and 12-16 years, respectively. In conclusion, moss biocrusts would take 15-20 years to achieve full recovery, which was shorter than many previously published estimates that regarded biocrusts and especially moss-dominated biocrusts to have a long recovery time of hundreds of years. However, it should be also kept in mind that very fast recovery (< 5 years) of biocrusts was less reliable because such estimations are mostly based on visual cover only rather than on the multi-variables of the recovering biocrusts.}, language = {en} } @misc{KanzlerBoehmMircketal., author = {Kanzler, Michael and B{\"o}hm, Christian and Mirck, Jaconette and Schmitt, Dieter and Veste, Maik}, title = {Microclimate effects on evaporation and winter wheat (Triticum aestivum L.) yield within a temperate agroforestry system}, series = {Agroforestry Systems}, journal = {Agroforestry Systems}, issn = {1572-9680}, doi = {10.1007/s10457-018-0289-4}, pages = {21}, abstract = {This study investigates the spatial and temporal impact of microclimate conditions caused by poplar hedgerows in a short rotation alley cropping system (SRACS), and their effect on the atmospheric evaporative demand (AED) and the grain crop yield of winter wheat (Triticum aestivum var. Patras) in direct comparison to a common agricultural crop system. Microclimate was measured at nine positions distributed at the SRACS and an adjacent open field in Brandenburg State (Germany) from March to August 2016. Our hypothesis was that microclimate and AED was improved at SRACS, with traceable effects on the crop yield. The analysis of air temperature and water vapour deficit (VPD) data revealed significantly (p B 0.05) lower daytime values from June to August at the crop alley of the SRACS, which were generally most frequent at the poplar hedgerow and 3 m west positions. By contrast, wind speed was reduced at almost all the positions of our crop alley and during the entire measurement period during both day and night. The AED measured on sampling days in July was significantly (p B 0.001) reduced at the whole crop alley, with values from 24 to 32\% in comparison to the open field. We observed a strong linear relationship (R2 \& 0.78-0.99) between AED on one side and wind speed and VPD on the other side. The average grain yield within the SRACS was 16\% higher than on the OF. However, our microclimate data were insufficient to explain this yield surplus.}, language = {en} } @misc{RieserVesteThieletal., author = {Rieser, Jakob and Veste, Maik and Thiel, Michael and Sch{\"o}nbrodt-Stitt, Sarah}, title = {Coverage and Rainfall Response of Biological Soil Crusts Using Multi-Temporal Sentinel-2 Data in a Central European Temperate Dry Acid Grassland}, series = {Remote Sensing}, volume = {13}, journal = {Remote Sensing}, number = {16}, issn = {2072-4292}, abstract = {Biological soil crusts (BSCs) are thin microbiological vegetation layers that naturally develop in unfavorable higher plant conditions (i.e., low precipitation rates and high temperatures) in global drylands. They consist of poikilohydric organisms capable of adjusting their metabolic activities depending on the water availability. However, they, and with them, their ecosystem functions, are endangered by climate change and land-use intensification. Remote sensing (RS)-based studies estimated the BSC cover in global drylands through various multispectral indices, and few of them correlated the BSCs' activity response to rainfall. However, the allocation of BSCs is not limited to drylands only as there are areas beyond where smaller patches have developed under intense human impact and frequent disturbance. Yet, those areas were not addressed in RS-based studies, raising the question of whether the methods developed in extensive drylands can be transferred easily. Our temperate climate study area, the 'Lieberoser Heide' in northeastern Germany, is home to the country's largest BSC-covered area. We applied a Random Forest (RF) classification model incorporating multispectral Sentinel-2 (S2) data, indices derived from them, and topographic information to spatiotemporally map the BSC cover for the first time in Central Europe. We further monitored the BSC response to rainfall events over a period of around five years (June 2015 to end of December 2020). Therefore, we combined datasets of gridded NDVI as a measure of photosynthetic activity with daily precipitation data and conducted a change detection analysis. With an overall accuracy of 98.9\%, our classification proved satisfactory. Detected changes in BSC activity between dry and wet conditions were found to be significant. Our study emphasizes a high transferability of established methods from extensive drylands to BSC-covered areas in the temperate climate. Therefore, we consider our study to provide essential impulses so that RS-based biocrust mapping in the future will be applied beyond the global drylands}, language = {en} } @misc{SheppardBohnReckziegelBorrassetal., author = {Sheppard, Jonathan P. and Bohn Reckziegel, Rafael and Borrass, Lars and Chirwa, Paxie W. and Cuaranhua, Claudio J. and Hassler, Sibylle K and Hoffmeister, Svenja and Kestel, Florian and Maier, Rebekka and M{\"a}licke, Mirko and Morhart, Christopher and Ndlovu, Nicholas P. and Veste, Maik and Funk, Roger and Lang, Friedericke and Seifert, Thomas and du Toit, Ben and Kahle, Hans-Peter}, title = {Agroforestry: An Appropriate and Sustainable Response to a Changing Climate in Southern Africa?}, series = {Sustainability}, volume = {12}, journal = {Sustainability}, number = {17}, doi = {10.3390/su12176796}, abstract = {Agroforestry is often discussed as a strategy that can be used both for the adaptation to and the mitigation of climate change effects. The climate of southern Africa is predicted to be severely affected by such changes. With agriculture noted as the continent's largest economic sector, issues such as food security and land degradation are in the forefront. In the light of such concerns we review the current literature to investigate if agroforestry systems (AFS) are a suitable response to the challenges besetting traditional agricultural caused by a changing climate. The benefits bestowed by AFS are multiple, offering ecosystem services, influence over crop production and positive impacts on rural livelihoods through provisioning and income generation. Nevertheless, knowledge gaps remain. We identify outstanding questions requiring further investigation such as the interplay between trees and crops and their combination, with a discussion of potential benefits. Furthermore, we identify deficiencies in the institutional and policy frameworks that underlie the adoption and stimulus of AFS in the southern African region. We uphold the concept that AFS remains an appropriate and sustainable response for an increased resilience against a changing climate in southern Africa for the benefit of livelihoods and multiple environmental values}, language = {en} }