@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{MantovaniVesteFreese, author = {Mantovani, Dario and Veste, Maik and Freese, Dirk}, title = {Biomass production and water use of Black Locust (Robinia pseudoacacia L.) for short-rotation plantation}, 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{SproeteVesteFischeretal., author = {Spr{\"o}te, Roland and Veste, Maik and Fischer, Thomas and Lange, Philipp and Bens, Oliver and Raab, Thomas and H{\"u}ttl, Reinhard F.}, title = {Wie beeinflussen Kiefern (Pinus sylvestris L.) die Entwicklung der Benetzungshemmung auf Sandb{\"o}den?}, series = {B{\"o}den verstehen - B{\"o}den nutzen - B{\"o}den fit machen, Jahrestagung der Deutschen Bodenkundlichen Gesellschaft, 3. - 9. September 2011}, booktitle = {B{\"o}den verstehen - B{\"o}den nutzen - B{\"o}den fit machen, Jahrestagung der Deutschen Bodenkundlichen Gesellschaft, 3. - 9. September 2011}, language = {de} } @inproceedings{SproeteVesteFischeretal., author = {Spr{\"o}te, Roland and Veste, Maik and Fischer, Thomas and Lange, Philipp and Bens, Oliver and Raab, Thomas and H{\"u}ttl, Reinhard F.}, title = {Development of biologicalsoil crusts in initial ecosystems in Lusatia, Germany}, series = {DBG Jahrestagung 2009 Bonn "B{\"o}den - eine endliche Ressource", 05.-13.09.2009, Bonn}, booktitle = {DBG Jahrestagung 2009 Bonn "B{\"o}den - eine endliche Ressource", 05.-13.09.2009, Bonn}, language = {en} } @misc{SchaafGerwinBiemeltetal., author = {Schaaf, Wolfgang and Gerwin, Werner and Biemelt, Detlef and Veste, Maik and Fischer, A.}, title = {Monitoring of Soil-Plant-Atmosphere patterns and processes in an artificial catchment}, series = {EGU General Assembly 2009, Vienna, Austria, 19 - 24 April 2009}, journal = {EGU General Assembly 2009, Vienna, Austria, 19 - 24 April 2009}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{VesteDominikDimitrovetal., author = {Veste, Maik and Dominik, R. and Dimitrov, M. and Fischer, A. and Gerwin, Werner and Schaaf, Wolfgang}, title = {Novel drone-based system for ecosystem monitoring - application, analysis and interpretation}, series = {EURECO-GFOE 2008, Proceedings}, journal = {EURECO-GFOE 2008, Proceedings}, editor = {Stadler, Jutta and Sch{\"o}ppe, Felix and Frenzel, Mark}, publisher = {Gesellschaft f{\"u}r {\"O}kologie}, address = {Berlin}, isbn = {978-3-00-025522-9}, pages = {S. 809}, language = {en} } @misc{FischerVesteEiseleetal., author = {Fischer, Thomas and Veste, Maik and Eisele, Andreas and Bens, Oliver and Spyra, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {Small Scale Spatial Heterogeneity of Normalized Difference Vegetation Indices (NDVI) and Hot Spots of Photosynthesis in Biological Soil Crusts}, series = {Flora}, volume = {207}, journal = {Flora}, number = {3}, doi = {10.1016/j.flora.2012.01.001}, pages = {159 -- 167}, abstract = {Normalized Difference Vegetation Indices (NDVIs) are typically determined using satellite or airborne remote sensing, or field portable spectrometers, which give an averaged signal on centimetre to metre scale plots. Biological soil crust (BSC) patches may have smaller sizes, and ecophysiological, hydrological as well as pedological processes may be heterogeneously distributed within this level of resolution. A ground-based NDVI imaging procedure using low-cost equipment (Olympus Camedia 5000z digital camera equipped with a Hoya R72 infrared filter) was developed in this study to fill this gap at the level of field research, where carrying costly and bulky equipment to remote locations is often the limiting factor for data collection. Method principle and field data are presented, and the field experiment was deepened comparing NDVI measurements and CO2 turnover of soil crust samples in the laboratory, backing the reliability of the approach. A commercially available colour rendition chart with known red (600-700 nm) and NIR (800-900 nm) reflectances was placed into each scene and used for calibration purposes on a per-image basis. Generation of NDVI images involved (i) determination of red and NIR reflectances from the pixel values of the red and NIR channels, respectively, and (ii) calculation and imaging of the NDVI, where NDVI values of -1 to +1 were mapped to grey values of 0 to 255. The correlation between NDVI values retrieved from these images and NDVI values determined using field spectrometry was close (r2 = 0.91), the 95\% confidence interval amounted to 0.10 NDVI units. The pixel resolution was 0.8 mm in the field and 0.2 mm in the laboratory, but can still be improved significantly with closer distance to the crust or with higher camera resolution. NDVI values obtained using the new method were related to the net CO2 uptake of BSCs, where both slope and correlation coefficient of the respective regression function conformed with literature data. Geostatistical analysis revealed that both spatial variability of net CO2 uptake as well as size of individual hot spots of this parameter increased with crust development. The latter never exceeded 4 mm in the investigated crusts, which points to the necessity of high resolution imaging for linking remote sensing with ecophysiology. Perspectively, the new method could be used for field monitoring of both biological soil crusts and vascular vegetation.}, language = {en} } @misc{KleefeldGypserHerppichetal., author = {Kleefeld, Andreas and Gypser, Stella and Herppich, Werner B. and Bader, Georg and Veste, Maik}, title = {Identification of spatial pattern of photosynthesis hotspots in moss- and lichen-dominated biological soil crusts by combining chlorophyll fluorescence imaging and multispectral BNDVI images}, series = {Pedobiologia}, volume = {68}, journal = {Pedobiologia}, issn = {1873-1511}, doi = {10.1016/j.pedobi.2018.04.001}, pages = {1 -- 11}, abstract = {Although biological soil crusts can be found in open landscapes worldwide, their species composition depends on soil properties such as texture and pH, on microclimate, and their respective developmental stage. In addition, local variations in water holding capacity and/or chemical properties of soils influence the formation of spatial patterns and different types of biocrusts on the landscape level. For the evaluation of biocrusts functions and their impact on soil carbon pools, the analysis of the interrelationship between photosynthetic activity and the variations of spatial distribution pattern and types of biocrust is indispensable. For this purpose, an image processing approach was applied that combined chlorophyll fluorescence analyses and multispectral BNDVI to comprehensively characterize the spatial patterns of photosynthetic hotspots in biological soil crusts. For image analysis, five biological soil crust samples with different ratios of substrate, mosses and lichens were collected on an inland dune system in Lieberose, dominated by the moss Polytrichum piliferum, and the lichens Cladonia fimbriata and C. coccifera. RGB-images of the biocrusts were taken with a standard consumer camera Nikon 5200, BNDVI images with a modified Canon S110 NIR camera and chlorophyll fluorescence images with a modular open FluorCAM FC 800-O/1010, respectively. BNDVI and Fv/Fm were nearly in the same range for all biocrust samples related to the total surface area. Although mosses showed higher BNDVI than lichens within the separate biocrust samples. F0 and Fm increased with species coverage and with advancing biocrust development. Overlapping of BNDVI with F0 and Fm images showed that not all crustal organisms contribute to BNDVI and chlorophyll fluorescence. The overlapping areas of BNDVI and F0 ranged between 13\% and 29\%, that of BNDVI and Fm between 17\% and 47\%. Matching of RGB, BNDVI and CFI allows visualizing spatial pattern with high or low photosynthesis in biocrusts.}, language = {en} } @misc{VesteHerppich, author = {Veste, Maik and Herppich, Werner B.}, title = {Comparative ecophysiology of the leaf-succulents Augea capensis (C3) and Malephora purpureo-crocea (CAM) in the Knersvlakte, Succulent Karoo, South Africa}, series = {Flora}, volume = {278}, journal = {Flora}, issn = {1618-0585}, doi = {10.1016/j.flora.2021.151807}, pages = {9}, abstract = {The generally accepted assumption that CAM is an important adaptation to the drought conditions in arid deserts is mainly based on studies in controlled environments comparing the respective photosynthetic pathways in plants of different morphology. Comparative long-term field studies on the ecophysiology of C3- and CAM succulents co-occurring in the same desert habitat are too rare to satisfactorily answer the old question whether the metabolic pathway or the succulence is more important to guarantee survival in such a harsh habitat. Thus, relevant ecophysiological parameters were repeatedly monitored on plants of the leaf succulents Augea capensis (C3) and Malephora purpureo-crocea (CAM), which commonly dominate a habitat in the Knersvlakte, Namaqualand, South Africa. Under identical conditions in the same habitat, carbon gain of the C3 species was higher than that of the CAM plant, but their WUE lower and maximum photosynthetic activity nearly the same. In M. purpureo-crocea, irrigation induced rapid whole day stomatal opening at drastically increased daytime but decreased night-time CO2-uptake, while respective responses of the C3 species were delayed. These different response dynamics were due to different rooting depth, root morphology and water acquisition strategy of the flat rooting CAM and the deep-rooting C3 species. This, however, may not explain the highly similar growth success. Anyway, the results verify that CAM provides no advantage over C3 for long-term survival in the same desert environment in morphologically similar succulents.}, language = {en} } @misc{GriebenowMakungaPrivettetal., author = {Griebenow, Stian and Makunga, Nokwanda P. and Privett, Sean and Strauss, Paula and Veste, Maik and Kleinert, Aleysia and Valentine, Alexander J.}, title = {Soil pH influences the organic acid metabolism and exudation in cluster roots of protea species from the Mediterranean-type fynbos ecosystem, Western Cape, South Africa}, series = {Rhizosphere}, volume = {Vol. 21}, journal = {Rhizosphere}, doi = {10.1016/j.rhisph.2022.100486}, abstract = {In nutrient-poor ecosystems, certain plant families have evolved specific adaptations for phosphate acquisition, namely cluster roots or proteoid roots. Cluster rooted species have a unique suite of adaptations that enable them to survive in nutrient poor ecosystems, such as the Fynbos biome of South Africa. The Fynbos biome has heterogeneous soils which caused radiation of varying soil pH within small localised areas. Previous studies on cluster rooted species ignored the possibility that cluster root functioning may differ at varying soil pH levels and soil types. Therefore, two native Fynbos protea species, Protea cynaroides (L.) L. and Protea obtusifolia H.Buek ex Meisn. were compared to assess the impact of different soil pH levels on organic acid metabolism and exudation in cluster rooted species. Our results show that cluster roots of the acidic-soil grown P. cynaroides is more effective and more efficient than that of the alkaline-soil grown P. obtusifolia. Our findings indicate that the mechanisms for P acquisition vary greatly, depending on substrate and plant organ type. This suggests that the metabolism of each species is adapted to specific soil pH and that these species have evolutionary adapted their P acquisition mechanisms for these extreme soils. The limited nutrient availability and variation in soil pH South African soils has led to various localised adaptations for cluster rooted species.}, language = {en} }