@misc{DimitrovaRepmannRaabetal., author = {Dimitrova, Tsvetelina and Repmann, Frank and Raab, Thomas and Freese, Dirk}, title = {Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment}, series = {Ecotoxicology}, volume = {24}, journal = {Ecotoxicology}, number = {3}, issn = {1573-3017}, doi = {10.1007/s10646-014-1398-0}, pages = {510}, abstract = {Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg-1 for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l-1. The maximum cyanide content in willow and poplar leaves was 518 mg kg-1 fresh weight (FW) and 148 mg kg-1 FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l-1 and for willow after 8 weeks of exposure—768 mg l-1. Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides.}, language = {en} } @misc{MantovaniVesteBoldtBurischetal., author = {Mantovani, Dario and Veste, Maik and Boldt-Burisch, Katja and Fritsch, Simone and Koning, Laurie Anne and Freese, Dirk}, title = {Carbon allocation, nodulation, and biological nitrogen fixation of black locust (Robinia pseudoacacia L.) under soil water limitation}, series = {Annals of Forest Research}, volume = {58}, journal = {Annals of Forest Research}, number = {2}, issn = {2065-2445}, doi = {10.15287/afr.2015.420}, pages = {259 -- 274}, abstract = {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.}, language = {en} } @misc{KoningVesteFreeseetal., author = {Koning, Laurie Anne and Veste, Maik and Freese, Dirk and Lebzien, Stefan}, title = {Effects of nitrogen and phsphate fertilization on leaf nutrient content, photosythesis, and growth of the novel bioenergy crop Fallopia schalinensis vc. 'Igniscum Candy'}, series = {Journal of Applied Botany and Food Quality}, volume = {88}, journal = {Journal of Applied Botany and Food Quality}, issn = {1439-040X}, doi = {10.5073/JABFQ.2015.088.005}, pages = {22 -- 28}, abstract = {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.}, language = {en} } @misc{MantovaniVesteBoehmetal., author = {Mantovani, Dario and Veste, Maik and B{\"o}hm, Christian and Vignudelli, Marco and Freese, Dirk}, title = {Spatial and temporal variation of drought impact on black locust (Robinia pseudoacacia L.) water status and growth}, series = {iForest Biogeosciences and Forestry}, volume = {8}, journal = {iForest Biogeosciences and Forestry}, issn = {1971-7458}, doi = {10.3832/ifor1299-008}, pages = {743 -- 747}, abstract = {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.}, language = {en} } @misc{KanzlerBoehmFreese, author = {Kanzler, Michael and B{\"o}hm, Christian and Freese, Dirk}, title = {Impact of P fertilisation on the growth performance of black locust (Robinia pseudoacacia L.) in a lignite post-mining area in Germany}, series = {Annals of Forest Research}, volume = {58}, journal = {Annals of Forest Research}, number = {1}, doi = {10.15287/afr.2015.303}, pages = {39 -- 54}, abstract = {Due to its ability to grow on marginal sites black locust (Robinia pseudoacacia L.) has been widely planted as a short rotation coppice (SRC) system that produce a renewable biomass feedstock in several post-mining areas of East Germany. However, as most of these sites are still in an initial stage of reclamation with low humus and nutrient contents, phosphorous can play a significant role as a plant limiting factor, because legumes require more P than other plants for their development. In April 2011, two experiments were conducted to evaluate the influence of higher rates and different applications of phosphorus fertiliser on the nutrition, survival, and biomass production of two different-aged black locust SRC plantations on the post lignite-mining site "Welzow-S{\"u}d", situated in NE Germany. Treatments were applied as triple superphosphate (30, 60 and 120 kg P ha-1) and PK fertiliser (60 kg P ha-1) through broadcasting or banding on recently harvested or planted trees, respectively. Soil, leaf and woody biomass data were analysed utilising the Mann-Whitney U test and the Spearman correlation coefficient (rS). Following two growing seasons, it was observed that the total dry weight yields of the black locust seedlings were increased strongly by up to 8 times when compared to the control group, particularly when TSP was applied through banding. P fertilisation, however, did not affect the biomass yield of six-year-old black locust trees, but P concentration in leaves among treatments of both sites was still significantly increased and sufficient from a quantity upwards of 60 kg P ha-1. Taken together, a comparably moderate amount of P fertiliser (60 kg ha-1) had a strong impact on P uptake and growth performance in the examined black locust seedlings, which reveals a high potential to improve the current fertilisation practices for SRC black locust plantations grown on our research site.}, language = {en} } @misc{TsonkovaBoehmQuinkensteinetal., author = {Tsonkova, Penka and B{\"o}hm, Christian and Quinkenstein, Ansgar and Freese, Dirk}, title = {Application of partial order ranking to identify enhancement potantials for the provision of selected ecosystem services by different land use strategies}, series = {Agricultural Systems}, volume = {135}, journal = {Agricultural Systems}, issn = {0308-521X}, doi = {10.1016/j.agsy.2015.01.002}, pages = {112 -- 121}, abstract = {Conventional agricultural practices have often been associated with negative externalities, such as land degradation, pollution of soil and water resources, loss of biodiversity, and decreased provision of ecosystem services (ES). In response to these negative effects, the number of indicator-based attempts to assess ES provided by land use systems has increased. However, decisions regarding the importance of the different ES are usually made subjectively. Following an objective approach through the use of a partial order ranking method, this study aimed to assess several non-provisioning ES supplied by alley cropping system (ACS) in comparison with conventional agriculture (CA). The main objective of the study was to verify the applicability of partial order ranking to an ecologically-based assessment, focusing on soil, water, and biodiversity indicators. Results from 40 hypothetical scenarios representing various site conditions of agricultural fields in Germany were calculated using the Ecosystem Services Assessment Tool for Agroforestry (ESAT-A), a toolbox designed to assess selected ES of ACS following an empirical approach. The results were ranked using partial order and were visualized by a Hasse diagram. The findings depict partial order ranking as a promising technique to support decision making in order to find priority scenarios and indicators where the provision of ES can be enhanced by establishing ACS. The minimal scenarios under CA identified with simultaneously low values of all indicators were perceived as target scenarios for establishing ACS. The values of the indicators for the current land use system need to be taken into account in order to avoid scenarios where high tradeoff was suggested. Additionally, this approach can be extended and utilized at the field level to aid farmer decisions on which land use strategy is the most suitable alternative to increase the provision of ES.}, language = {en} } @misc{MedinskiFreeseBoehm, author = {Medinski, Tanya V. and Freese, Dirk and B{\"o}hm, Christian}, title = {Soil CO2 flux in an alley-cropping system composed of black locust and poplar trees, Germany}, series = {Agroforestry Systems}, volume = {89}, journal = {Agroforestry Systems}, number = {2}, issn = {1572-9680}, doi = {10.1007/s10457-014-9764-8}, pages = {267 -- 277}, abstract = {Understanding of soil carbon dynamics after establishment of alley-cropping systems is crucial for mitigation of greenhouse CO2 gas. This study investigates soil CO2 fluxes in an alley-cropping system composed of tree strips of black locust (Robinia pseudoacacia L.) and poplar (Populus nigra 9 P. maximowiczii, Max 1) trees and adjacent to them crop strips (Lupinus/Solarigol). Soil CO2 flux was measured monthly over a period from March to November 2012, using a LI-COR LI-8100A automated device. Concurrently with CO2 flux measurements, soil and air temperature, soil moisture, microbial C and hot water-extractable C were determined for the soils nearby soil collars. Root biomass was determined to a depth of 15 cm. In all sampling areas, soil CO2 flux increased from May to July, showing a significant positive correlation with air and soil temperature, which can be a reflection of increase in photosynthesis, and therefore supply of carbohydrates from leaves to rhizosphere, over the warm summer months. A positive correlation between CO2 flux and soil moisture over the warm period indicates an enhancing role of soil moisture on microbial mineralization and root respiration. Average CO2 flux values observed over March-November period did not differ significantly between sampling areas, showing 2.5, 3.2, and 2.9 lmol m-2 s-1 values for black locust, poplar and crops, respectively. Significantly higher CO2 flux values over the summer period in trees could be attributed to the higher photosynthetic activity and higher root density compared to crops.}, language = {en} } @inproceedings{MirckBoehmKanzleretal., author = {Mirck, Jaconette and B{\"o}hm, Christian and Kanzler, Michael and Freese, Dirk}, title = {Blattstreumengen in Geh{\"o}lzstreifen und angrenzenden Ackerbreichen innerhalb eines Agroforstsystems}, series = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, booktitle = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, editor = {Kage, Henning and Sieling, K. and Francke-Weltmann, L.}, publisher = {Halm}, address = {G{\"o}ttingen}, pages = {219 -- 220}, language = {de} } @inproceedings{KanzlerBoehmMircketal., author = {Kanzler, Michael and B{\"o}hm, Christian and Mirck, Jaconette and Freese, Dirk}, title = {Variabilit{\"a}t des Mikroklimas im Einflussbereich der geh{\"o}lzstreifen eines Agroforstsystems}, series = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, booktitle = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, editor = {Kage, Henning and Sieling, K. and Francke-Weltmann, L.}, publisher = {Halm}, address = {G{\"o}ttingen}, pages = {77 -- 78}, language = {de} } @inproceedings{BoehmKanzlerMircketal., author = {B{\"o}hm, Christian and Kanzler, Michael and Mirck, Jaconette and Freese, Dirk}, title = {Effekte agroforstlicher Wirtschaftsweisen auf die Grundwasserqualit{\"a}t von Ackerstandorten}, series = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, booktitle = {Multifunktionale Agrarlandschaften - Pflanzenbaulicher Anspruch, Biodiversit{\"a}t, {\"O}kosystemdienstleistungen, 58. Jahrestagung der Gesellschaft f{\"u}r Pflanzenbauwissenschaften e.V., 22. bis 24. September 2015, Braunschweig}, editor = {Kage, Henning and Sieling, K. and Francke-Weltmann, L.}, publisher = {Halm}, address = {G{\"o}ttingen}, pages = {83 -- 84}, language = {de} }