TY - CHAP A1 - Fischer, Thomas A1 - Gypser, Stella A1 - Subbotina, Maria A1 - Veste, Maik T1 - Hydraulic and nutritional feedback controls surface patchiness of biological soil crusts at a post-mining site T2 - European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015 Y1 - 2015 N1 - EGU2015-4551 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Kleefeld, Andreas A1 - Veste, Maik T1 - Robuste und strukturerhaltende Bildentrauschung via Medianfilterung und Bildsegmentierung T2 - 20. und 21. Workshop Computer-Bildanalyse in der Landwirtschaft, 26. Mai 2014, Osnabrück N2 - Ein Medianfilter ist ein Werkzeug, das benutzt werden kann, um Bilder zu entrauschen. Allerdings verschwimmen vorhandene Strukturen, und eine gute Bildsegmentierung gestaltet sich schwierig. Daher wird hier ein Medianfilteralgorithmus vorgestellt, der in der Lage ist, Bilder zu entrauschen und gleichzeitig vorhandene Strukturen beizubehalten. Wir zeigen die Anwendbarkeit dieser Methode auf Bilder, die durch ein automatisches Minirhizotronsystem aufgenommen worden sind. Dieses dient zur zerstörungsfreien Observierung von Wurzelwachstum. Die verbesserten Bilder werden dann zur Bildsegmentierung benutzt, um automatisch die Wurzeln in den Bildern zu entdecken. KW - Medianfilter KW - Bildsegmentierung KW - automatisches Minirhizotronsystem Y1 - 2015 UR - http://www.atb-potsdam.de/?id=161 SN - 0947-7314 SP - 92 EP - 100 PB - Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. CY - Potsdam ER - TY - GEN A1 - Küppers, Manfred A1 - Küppers, Barbara I. L. A1 - Horna, Viviana A1 - Veste, Maik A1 - Zimmermann, Reiner A1 - Lauerer, Marianne A1 - Aas, Gregor T1 - Green barks of trees from drought deciduous forests ("bosque seco") in northern Peru/southern Ecuador do not perform CAM T2 - Basic and Applied Dryland research N2 - 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. Y1 - 2015 UR - https://www.researchgate.net/publication/280945188 U6 - https://doi.org/10.1127/badr/2015/0002 SN - 1864-3191 ER - TY - CHAP A1 - Kleefeld, Andreas A1 - Veste, Maik T1 - Robuste and strukturerhaltende Bildentrauschung via Medianfilterung und Bildsegmentierung T2 - 20. und 21. Workshop Computer-Bildanalyse in der Landwirtschaft, 3. Workshop Unbemannte Autonom Fliegende Systeme (UAS) in der Landwirtschaft, 26. Mai 2014, Osnabrück 07. Mai 2015, Braunschweig Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:186-opus4-75951 SP - 92 EP - 100 PB - ATB, Leibniz-Institut für Agrartechnik CY - Potsdam-Bornim ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Boldt-Burisch, Katja A1 - Fritsch, Simone A1 - Koning, Laurie Anne A1 - Freese, Dirk T1 - Carbon allocation, nodulation, and biological nitrogen fixation of black locust (Robinia pseudoacacia L.) under soil water limitation T2 - Annals of Forest Research N2 - The pioneer tree black locust (Robinia pseudoacacia L.) is a drought-resistant tree and, in symbiosis with Rhizobium, able to fix dinitrogen from the atmosphere. It is, therefore, an interesting species for marginal lands where soil amelioration is sought in addition to economic gain. However, the interaction between soil water availability, carbon allocation and nitrogen fixation is important for a successful establishment of trees on marginal lands and has not yet been investigated for black locust. Twoyear-old trees were grown under various soil water conditions and drought cycles. The stable isotopic composition of C (δ 13C) and N (δ 15N) of the leaves was used to identify i) the effective drought condition of the treatments and ii) the portion N accrued from the atmosphere by the biological nitrogen fixation. Drought-stressed plants significantly reduced their total aboveground biomass production, which was linearly linked to tree transpiration. The shoot:root ratio values changed from 2.2 for the drought-stressed to 4.3 for the well-watered plants. Our investigation shows that drought stress increases the nodule biomass of black locust in order to maintain biological nitrogen fixation and to counteract the lower soil nitrogen availability. The biological nitrogen fixation of drought-stressed trees could be maintained at relatively higher values compared to the well-watered trees. The average leaf nitrogen content varied between 2.8% and 3.0% and was not influenced by the drought stress. Carbon fixation, carbon allocation, and biological nitrogen fixation are to some extent balanced at low irrigation and allow Robinia to cope with long-term water constraints. The combination of black locust’s ecophysiological and morphological plasticity make it interesting as a biomass source for bioenergy and timber production, even in nutrient-limited and drought-affected areas of Europe. Y1 - 2015 U6 - https://doi.org/10.15287/afr.2015.420 SN - 2065-2445 VL - 58 IS - 2 SP - 259 EP - 274 ER - TY - GEN A1 - Koning, Laurie Anne A1 - Veste, Maik A1 - Freese, Dirk A1 - Lebzien, Stefan T1 - Effects of nitrogen and phsphate fertilization on leaf nutrient content, photosythesis, and growth of the novel bioenergy crop Fallopia schalinensis vc. 'Igniscum Candy' T2 - Journal of Applied Botany and Food Quality N2 - The aim of the study was to determine the effects of nitrogen and phosphate fertilization on the growth performance of the novel bioenergy crop Fallopia sachalinensis cv. ‘Igniscum Candy’ (Polygonaceae). In a controlled pot experiment various nitrogen (0, 50, 150, 300 kg N ha-1) and phosphate (20, 40, 80 kg P ha-1) fertilizer amounts were applied to measure the effect on the biomass, plant height, leaf area, and leaf nutrient (N and P) content. Furthermore, the ecophysiological processes of chlorophyll content, chlorophyll fluorescence, and gas exchange were measured. The application of nitrogen correlated positively with biomass production, while phosphate fertilization did not show a significant effect on plant growth or ecophysiological parameters. The leaf nitrogen contents were significantly correlated with the nitrogen applications, while the leaf phosphate contents did not show a correlation with the P fertilizations, but increased with the leaf nitrogen contents. A significant linear correlation between N-Tester chlorophyll meter values and chlorophyll contents as well as with leaf nitrogen contents could be determined. Under the influence of the nitrogen fertilization, net photosynthesis increased from 3.7 to 6.6 μmol m-2 s-1. The results of this experiment demonstrated that nitrogen fertilization has an overall positive correlation with leaf nitrogen content, photosynthesis, and growth of the bioenergy crop Fallopia sachalinensis var. Igniscum Candy. Y1 - 2015 U6 - https://doi.org/10.5073/JABFQ.2015.088.005 SN - 1439-040X VL - 88 SP - 22 EP - 28 ER - TY - GEN A1 - Veste, Maik A1 - Todt, Henning A1 - Breckle, Siegmar-W. T1 - Influence of halophytic hosts on their parasites - the case of Plicosepalus acaciae T2 - AOB Plants N2 - Halophytes develop various morphological and physiological traits that enable them to grow successfully on saline substrates. Parasitic plants on halophytic hosts may also encounter salt stress. We investigated the mistletoe Plicosepalus acaciae (syn: Loranthus acacia; Loranthaceae), which occurs on 5 halophytic and at least 10 non-halophytic hosts in the Southern Arava Valley (Israel). Plicosepalus acaciae is a common parasite north of Eilat to the Dead Sea area and in the Jordan Valley. Morphological and physiological responses of P. acaciae to salinity were investigated by comparison of plants on halophytic with those on non-halophytic hosts. Ion patterns of different host–parasite associations were determined as was the development of leaf succulence at different growth stages. The leaf water content of P. acaciae increased and leaves developed succulence when growing on halophytic hosts, especially on Tamarix species, where leaf water content was three times higher than that on non-halophytic hosts and the leaf volume increased four to five times. The reason for increased succulence was a higher ion concentration of, and osmotic adjustment with, Na+ and Cl2. Plicosepalus acaciae showed a high morphological and ecophysiological plasticity, enabling it to cope with salt stress, and can be classified as a facultative eu-halophyte, which increases its halo-succulence according to the host. Host–parasite associations are a model systemfor the investigation of halophytes under different salt stress conditions. Y1 - 2015 U6 - https://doi.org/10.1093/aobpla/plu084 SN - 2041-2851 VL - 7 SP - plu084 ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Böhm, Christian A1 - Vignudelli, Marco A1 - Freese, Dirk T1 - Spatial and temporal variation of drought impact on black locust (Robinia pseudoacacia L.) water status and growth T2 - iForest Biogeosciences and Forestry N2 - Stimulated by the rising demand for bioenergy, forestry practices for energy production are of increasing importance worldwide. Black locust (Robinia pseudoacacia L.) is a suitable tree species for biomass production in shortrotation plantations in East Germany, especially on marginal land where insufficient water and nutrients are a limiting factor for tree growth. Our study aims to clarify the spatial and temporal variability of the black locust growth through the analysis of the plant water status, and to evaluate the effect of adverse edaphic conditions on growth performances, amplified by periods of summer drought. The study was carried out at two sites presenting comparable climatic but different edaphic conditions: (i) fertile agricultural soil; and (ii) heterogeneous unstructured soil from a reclaimed post-mining area. During the vegetation period, the growth rate decreased in both sites following the plant water status in terms of pre-dawn leaf water potential. Particularly in the post-mining area, due to the adverse edaphic conditions, below the critical pre-dawn water potential value of -0.5 MPa, the stem growth was drastically reduced during a period of summer drought. However, the trees could cope with the extreme soil and weather conditions in the post-mining site without perishing. Y1 - 2015 U6 - https://doi.org/10.3832/ifor1299-008 SN - 1971-7458 VL - 8 SP - 743 EP - 747 ER - TY - GEN A1 - Gypser, Stella A1 - Veste, Maik A1 - Fischer, Thomas A1 - Lange, Philipp T1 - Formation of soil lichen crusts at reclaimed post-mining sites, Lower Lusatia, North-east Germany T2 - Graphis Scripta N2 - 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. Y1 - 2015 SN - 0901-7593 VL - 27 IS - 1-2 SP - 3 EP - 14 ER -