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Auswirkungen von Klima und Landnutzung auf die Diversität und Funktion von Bestäubern, Zersetzern und Herbivoren

Das Projekt "Auswirkungen von Klima und Landnutzung auf die Diversität und Funktion von Bestäubern, Zersetzern und Herbivoren" wird vom Umweltbundesamt gefördert und von Julius-Maximilians-Universität Würzburg, Theodor-Boveri-Institut für Biowissenschaften, Biozentrum, Lehrstuhl für Zoologie III (Tierökologie und Tropenbiologie) durchgeführt. SP7 analyses two important ecosystem processes: pollination and decomposition. Species richness and abundance of pollinators sampled with coloured UV-reflecting pan traps will be related to floral diversity (SP4, SP5), vegetation type, altitude and climate (SP1 to SP3). Plant-pollinator interaction webs will be quantified to estimate specialization and connectance in relation to climatic variables (SP1), land use and biodiversity (SP4, SP5, SP8). Fruit and seed set of five abundant flowering plant species will be measured for open, hand-pollinated and exclosure treatments to evaluate pollinator limitation in relation to climate, land use and biodiversity. Transplant and pollination experiments with an endemic and a wide-spread Impatiens species will be performed to analyse the importance of pollinator-mediated gene flow (SP4). From combined litter and soil samples the meso- and macrofauna will be extracted. Furthermore the epigaeic fauna is sampled using pitfall traps. Identification to morphospecies, measuring of body size and DNA-barcoding will be applied to estimate biodiversity and size structure (SP 8). Diversity, abundance and size structure of soil fauna taxa will be related to floral diversity, climate, land use, biogeochemical processes (SP1-3) and aboveground diversity (SP4-8). Decomposition rates and the contribution of size classes of decomposers will be measured using litter bags differing in mesh size. Experiments with litter mixtures will be performed to test for adaptations of decomposers to local conditions as well as the effect of litter diversity on decomposition rates along altitudinal gradients.

Organic matter composition in the subsoil: Contribution of root litter and microbial-derived compounds

Das Projekt "Organic matter composition in the subsoil: Contribution of root litter and microbial-derived compounds" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Lehrstuhl für Bodenkunde durchgeführt. The aim of P2 within the Research Unit 'The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)' is to contribute to the understanding of the different sources and stabilization processes of subsoil organic matter. This will be achieved by the analysis of the soil organic matter composition in topsoil versus subsoil by 13C NMR spectroscopy in bulk soils as well as organo-mineral associations. This will be done on a number of soil profiles differing in parent material and mineralogy and therefore also in the relevance of organo-mineral associations for subsoil C stabilization. In addition, a specific sampling approach will allow to differentiate three zones associated with the dominating effect of (1) leaching of DOC (the 'bulk soil' between trees), (2) root litter decomposition (the 'root-affected zone'), and (3) direct rhizodeposition of root exudates (the 'rhizosphere' sensu strictu). The contribution of above-ground versus below-ground litter is differentiated by the analysis of cutin and suberin biomarkers. Organic matter derived from microbial sources will be identified by the microbial signature of polysaccharides in the subsoil through the analysis of neutral sugars and amino sugars. Organo-mineral associations will be further characterized by N2-BET analyses to delineate the coverage of the mineral phase with organic matter. With these analyses and our specific analytical expertise at the submicron scale (nanoSIMS) we will participate in selected joint experiments of the research unit.

Calcium cycling in the soil-fig-bat compartment of a neotropical rain forest on spatially heterogeneous substrate

Das Projekt "Calcium cycling in the soil-fig-bat compartment of a neotropical rain forest on spatially heterogeneous substrate" wird vom Umweltbundesamt gefördert und von Universität Bern, Geographisches Institut, Gruppe Bodenkunde durchgeführt. Calcium supply in tropical soils is variable and frequently low. In spite of the heterogeneous Ca supply, some plant species, such as figs, maintain high Ca concentrations in their tissues. Figs are keystone species with more than proportional importance for the functioning of a tropical rain forest. High Ca concentrations in fig fruits may render them particularly attractive for frugivorous vertebrates. We propose to study the whole Ca cycling from soil through a selected fig species, Ficus insipida Willd. and frugivorous bats, their main dispersers, back to soil. The study will be conducted in Panama on sites differing in soil Ca status to assess the importance of soil Ca availability for fig fruit content and bat reproduction. We will quantify aboveground Ca fluxes for 16 trees along a gradient of Ca availability in soil. We will determine (1) Ca concentrations in soils, figs and leaves, (2) nutritional quality of fig and other bat-dispersed fruits and their importance for Ca balance in relation to reproduction of fruit-eating bats, (3) Ca fluxes with litterfall, throughfall, stemflow, bat pellets and faeces, (4) the importance of the contribution of bats to the Ca cycle of individual fig trees, and (5) the effect of fig trees on soil Ca concentrations.

Neos-Quick - Testing of Novel Earth Observation Systems for Supporting Quality Control Activities required by the Kyoto Protocol

Das Projekt "Neos-Quick - Testing of Novel Earth Observation Systems for Supporting Quality Control Activities required by the Kyoto Protocol" wird vom Umweltbundesamt gefördert und von Technische Universität Wien, Institut für Photogrammetrie und Fernerkundung (IPF) durchgeführt. The Kyoto Protocol as a substantial extension to the UN Framework Convention on Climate Change (UNFCCC) contains quantified, legally binding commitments to reduce greenhouse gas (GHG) emissions and allows emissions to be balanced by terrestrial biological carbon sinks. The Austrian target for the first commitment period (2008 2012) is a reduction of GHG emissions of 13% below those of 1990, the EU aims at a reduction of 8%. Due to further increased GHG emissions since 1990, an actual reduction target of 22% can be expected for Austria. The KP and its implementation rules provide for human induced net changes of domestic sinks in the land-use, land-use change and forestry (LULUCF) sector to be counted in the emission balance of Annex 1 countries (developed countries and economies in transition). With the so called flexible mechanisms the Kyoto Protocol designated three international mechanisms, including sink projects abroad and GHG emission trading, to increase flexibility and costeffectiveness in achieving GHG emission reductions in the first commitment period 2008-2012. Under the UNFCCC and the KP, parties must follow clearly defined GHG inventory and reporting obligations including the verifiable and transparent documentation of the LULUCF sector. The latter is very precisely specified by the recently published IPCC Good Practice Guidance (GPG) for LULUCF, which suspects that in most countries the existing land use and inventory systems are inadequate to meet all the land reporting requirements of the Kyoto Protocol. Remote Sensing is attributed a significant role for LULUCF reporting and verification by the IPCC GPG. Remote sensing can be applied to supplement missing elements of existing land use and forest inventory systems, or to deliver the basic LULUCF information and to estimate (via models) above ground biomass changes on the one hand, and/or as an independent verification/validation tool for land use/forest area changes and above ground biomass. The development of RS as an independent verification tool as done in NEOS-QUICK, based on a multi-sensor approach, integrating GIS and ground observations, nevertheless leaves room for flexible applications of the elaborated RS techniques in either of the above mentioned ways.

Effects of climate change on plant-microbe interactions for nutrient acquisition in bogs: implications for carbon and nutrient dynamics (CLIMABOG)

Das Projekt "Effects of climate change on plant-microbe interactions for nutrient acquisition in bogs: implications for carbon and nutrient dynamics (CLIMABOG)" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft, Eidgenössisches Institut für Schnee- und Lawinenforschung durchgeführt. The research project CLIMABOG aims at assessing the relationships between plants and microbes for nutrient acquisition in peatlands (bogs) and potential feedbacks on soil biogeochemistry along a gradient of increasing peat soil temperature. Peatlands are important sinks of atmospheric carbon dioxide and although they cover about 3Prozent of world land cover, peatlands store about 30Prozent of world soil organic carbon or 60Prozent of the carbon present in the atmosphere. Bogs are peatlands dominated by Sphagnum mosses, a peculiar type of plants producing a litter extremely refractory to decomposition so that the remnants of Sphagnum plants accumulate as 'peat'. Because Sphagnum productivity is dependent on water surplus, bogs are particularly sensitive to climate change. Some laboratory experiments suggest that increasing peat soil temperature can promote the growth of vascular plants at expense of Sphagnum mosses through an alteration of plant competitive ability for nutrient acquisition with respect to soil microbes. A better understanding of the effects of climate warming on plant-microbe interactions in bogs is then crucial for predicting the potential alteration of peat accumulation rates. In CLIMABOG the increasing peat soil temperature will be obtained by selecting the study bogs along an altitudinal gradient so as to assess the effects of climate warming under conditions of long-term equilibrium between biogeochemistry, vegetation and local climatic conditions. The research project will include both field observations along one entire year (so as to include also the winter season), and a mesocosm experiment where peat monoliths will be transplanted to lower altitude so as to study the biological and physico-chemical reactions of the system to a sudden climate change. By means of information concerning soil enzymatic activity, microbial diversity and abundance, plant biomass and productivity, peat and water chemistry, we want to assess: 1) how microbial biomass nutrients change during the year in relation to vascular plant growth; 2) how soil enzymatic activity changes along the year and along the altitudinal gradient; 3) how standing biomass of vascular plants and Sphagnum growth vary along the altitudinal gradient; 4) if there is any difference in the microbial diversity in relation to increasing peat soil temperature. A better understanding of the aboveground and belowground interactions in peatlands in response to climate change will permit to better forecast the future carbon sinking ability of these ecosystems

Validierung eines einzelbaumbasierten Waldökosystemmodelles zur Simulation von C- und N-Kreisläufen

Das Projekt "Validierung eines einzelbaumbasierten Waldökosystemmodelles zur Simulation von C- und N-Kreisläufen" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Waldbau durchgeführt. Das räumlich explizite klimasensitive 3D-Waldökosystemmodell PICUS wurde kürzlich durch ein biogeochemisches Bodenmodul (TRACE) zur Simulation von C- und N-Kreisläufen ergänzt und steht derzeit in einer anhand von Literaturdaten und Expertenwissen parametrisierten Version für Szenarioanalysen zur Verfügung. Ziel des gegenständlichen Projektes ist es, das ergänzte Modell PICUS v1.41 anhand von Daten von Dauerversuchsflächen des BFW (unbehandelte Parzellen von Düngungsversuchen mit Beobachtungszeiträumen von bis zu 35 Jahren) zu validieren um es in einer überprüften und zuverlässigen Version für die Analyse von Konzepten zur nachhaltigen Waldbewirtschaftung zur Verfügung zu stellen. Für die hier beschriebenen Experimente konnten die Versuchsflächen Grottenhof, Helfenberg und Karlstift verwendet werden. Insgesamt kann festgestellt werden, dass die letztendliche Bereitstellung der Vergleichswerte für C und N Pools für die Versuchsflächen zahlreiche Probleme aufwirft, deren Lösung meist mit zusätzlicher Unsicherheit in den Vergleichswerten verbunden ist. Die Ergebnisse der Vergleiche von simulierten und beobachteten Systemgrößen waren für die oberirdische Biomasseentwicklung (Bestandesparameter) i.A. sehr zufriedenstellend. Bei den Boden-Pools für C und N konnte in den meisten Fällen der allgemeine Entwicklungstrend reproduziert werden. Details (Form der Ab- bzw. Zunahme über die Beobachtungsperiode, absolute Größenordnung der Veränderungen in den Poolgrößen) aber von PICUS nicht immer zufriedenstellend simuliert werden konnte. Grund dafür ist vor allem, dass kurzfristige Trendumkehren in C und N Pools von Bodenmodellen aufgrund deren Konzeption i.A. nicht simuliert werden können, soferne keine exogenen Faktoren den dafür benötigten Impuls liefern. Dies kann zum Beispiel durch Streuinput oder durch Veränderungen in der N-Deposition bewerkstelligt werden. Berücksichtigt man die generische Initialisierung und Parameterisierung von PICUS v1.41, dann sind die Ergebnisse als vielversprechend zu bezeichnen. Bei standorts- und parzellenspezifischen Kalibrierungsschritten ist eine noch bessere Anpassung der simulierten and die beobachteten C und N Pools zu erwarten. Damit einhergehen würde allerdings die Möglichkeit, PICUS v1.41 für großflächige regionale und nationale Simulationsstudien einzusetzen. Als Folgerung aus diesen Erkenntnissen wird demnächst versucht werden, den Initialisierungansatz für Erhebungspunkte der Waldinventur weiter zu verbessern.

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