Das Projekt "Consequences of (post-socialist) land use and climate change for landscape water budgets, soil degradation and rehabilitation in the forest steppe zone of Bashkortostan" wird vom Umweltbundesamt gefördert und von Universität Halle-Wittenberg, Institut für Geowissenschaften und Geographie, Arbeitsgruppe Geoökologie durchgeführt. The assessment of effects of the new economic situation and climate change on soil degradation of the Forest Steppe Zone in Bashkortostan is figured out as main research subject. To reach the overall goal we have defined 5 research targets: - Characterization of history, stages, and dynamics of land use - Characterization of soil degradation - Characterization of soil erosion - Characterization of influence of climate conditions on soil degradation esp. soil erosion and water balance - Characterization of measures against soil degradation and erosion in the past and present. The investigations will be organised within 5 work packages. Each work package focuses on one of these. Work package 5 Development of measures concerning soil and climate protection and sustainable land use integrates the results of the preceding 4 work packages. The investigations will focus on different spatial levels. Results will be gained beginning with laboratory scale to local scale (test plots) up to farm scale. This research results, like soil degradation patterns, will be verified at representative farms of different parts of the forest steppe zone. The joint research work and the quality management will be organised by the 5 work package leaders, who act as steering committee (SC) of the project. In extension to the structure of the current project we plan to assign an External Advisory Board (EAB), which includes representatives from involved stakeholders (agronomists), political decision makers (Ministry of Agriculture), and scientists. The EAB will evaluate project work and make suggestions to the SC regarding implementation and feasibility of project results. During the work at the current project in Bashkortostan new cooperation partners were gained from science, politics (Ministry of Agriculture), and regional (agricultural) businesses. They will be of great benefit to the success of future research studies. Hence we extended the group of applicants with partners from Bashkir State Agrarian University and Russian Academy of Sciences. Beside the research work the project will contribute also to the further development of education practice at the universities in Bashkortostan. This will be realised through the Phd thesis on one side and the adoption of new methods and techniques of soil degradation research.
Das Projekt "Vegetation und Struktur der Bestandeslücken in den Nebelwäldern der Sierra de Lema, Gran Sabana, Venezuela" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Waldbau-Institut durchgeführt. Die Doktorarbeit ist Teil eines großen Forschungsprojektes (Ökologie und Diversität der Nebelwälder der Sierra de Lema), das die biotischen und abiotischen Merkmale dieser Waldökosysteme entlang eines Höhengradienten und die Veränderung dieser Merkmale im Laufe der Zeit untersucht. Die Wälder der Sierra de Lema befinden sich im Südosten Venezuelas, im Ostabschnitt des Canaima National Parks. Bestandeslücken (kleine natürliche Störungen der Wälder) verursachen Dynamik in Waldökosystemen. Die Entstehung einer Bestandeslücke erzeugt Veränderungen in den Umweltbedingungen der Wälder (Lichtversorgung, Nährstoffe, Raum), die Ressourcen werden dadurch neu verteilt. Nach der 'gap partitioning Theorie besiedeln spezialisierte Pflanzenarten die unterschiedlichen Standorte in den Bestandeslücken. Die 'Chance Hypothese besagt, dass die Verjüngungsprozesse in Bestandeslücken stochastisch sind, und von den vorherigen Umweltbedingungen (vor der Entstehung der Bestandenlücken) abhängen. Ziele dieser Dissertation sind die Beschreibung der Bestandenlückenstruktur, die Charakterisierung der Verjüngung der Bäume und Palmen, sowie die Beschreibung der Lichtversorgung und Mikrohabitatsstrukturen. Die Verjüngung der Baumarten wurde in 62 Plots in 22 Bestandeslücken aufgenommen und einige Umweltbedingungen, wie die Lichtverhältnisse, gemessen. Zusammen mit den anderen Untersuchungen in der Region, tragen die Ergebnisse dieser Doktorarbeit zu einem weiteren Verständnis der Ökosystemdynamik der Nebelwälder der Sierra de Lema und der Gran Sabana bei.
Das Projekt "Molecular Ecology and Evolution of Bacterial Symbionts (SYMBIOMICS)" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für marine Mikrobiologie durchgeführt. Symbiosis research is currently in the midst of a revolution as molecular techniques are leading to major breakthroughs in our understanding of interactions between animals and microbes. There is an emerging recognition that all animals are intimately associated with a complex community of beneficial microbes that are essential for their development, nutrition, and health. Thus, modern symbiosis research has become a newly emerging supra-disciplinary field with novel and innovative methods for examining microbial symbiosis, the vast majority of which remain as yet uncultivable. As so often when novel technologies open up new areas of research, training for students lags behind. We propose to close this gap by offering a comprehensive and innovative training in the microbial ecology and evolution of animal symbionts. The proposed ITN Symbiomics will include 14 leading research groups as well as 4 top-tier participants from the private sector to provide 14 early stage researchers (ESRs) and 1 experienced research (ER) with an interdisciplinary and synergistic training. Cutting edge methods in molecular biology and image analysis will be used to analyze a broad range of hosts from protozoan and invertebrate animal groups. Symbiomics will provide training through a combination of local and network-wide activities that will include research, secondments, workshops and courses including soft skills training, networking and meetings, regular thesis committee meetings, and mentoring. By pooling the scientific, technological, and entrepreneurial expertise of the Symbiomics partners, this ITN will provide a synergistic research environment and training that extends far beyond what each partner would be able to offer with local training alone. At the end of their training, the early stage researchers will have the skills they need for successful careers in academia and industry in a broad range of disciplines in the fields of environmental, applied, and medical microbiology.
Das Projekt "Nachhaltigkeitsorientierte Diskontierung für Kosten-Nutzen-Analysen bei umweltrelevanten Entscheidungen unter besonderer Berücksichtigung der intergenerationellen Gerechtigkeit - Entwicklung eines Diskontierungsmodells und beispielhafte Anwendung (Laufende Dissertation)" wird vom Umweltbundesamt gefördert und von Universität Duisburg-Essen, Campus Essen, Lehrstuhl für Betriebswirtschaftslehre, insbesondere Umweltwirtschaft und Controlling durchgeführt. Diskontierung verursacht eine Ungleichgewichtung zwischen heutigen und zukünftigen Werten. Über die Legitimation dieser Tatsache sind sich die Fachdisziplinen nicht einig. Von den einen als notwendig erachtet und in 'wirtschaftlichen Ex-ante-Analysen' vielfach unhinterfragt angewendet, wird die Diskontierung von anderen als 'Diskriminierung zukünftiger Generationen' grundsätzlich abgelehnt. Von dieser Problematik ausgehend werden in der Dissertation die unterschiedlichen Argumente für und gegen Diskontierung analysiert und mit Anforderungen, die sich aus dem Konzept der Nachhaltigkeit ableiten lassen, abgeglichen. Die Dissertation soll zum einen zu einem besseren Verständnis zwischen den Disziplinen der Wirtschaftswissenschaften und jenen, die sich von normativen Blickwinkeln mit der Diskontierung beschäftigen beitragen und zum anderen wird ein Vorschlag für ein Modell geliefert, nach welchem in Zukunft in wirtschaftlichen Ex-ante-Analysen diskontiert werden kann, wenn diese dem Konzept der Nachhaltigkeit entsprechen sollen.
Das Projekt "Plant responses to long-term in situ CO2 enrichment and soil warming at treeline in the Swiss Alps" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. In situ studies lasting several years are essential for predicting how plant growth and ecosystem function will change under rising levels of atmospheric CO2 and the associated changes in climate. High-latitude and high-elevation ecosystems are predicted to be particularly sensitive to environmental change, but relatively few manipulation experiments have been conducted in these regions. This doctoral thesis describes responses of two co-occurring tree species, Larix decidua and Pinus uncinata, and understorey dwarf shrub heath vegetation to 9 years of CO2 enrichment (+200 ppm; 2001-2009) and 3 years of soil warming (+4 K; 2007-ongoing) at treeline in the Swiss Alps (Stillberg, Davos). We tested if elevated CO2 stimulates tree growth in an environment where there is strong evidence that low temperature limits growth despite an adequate carbon supply. For this investigation, we pooled across soil warming treatments in order to focus on long-term responses to elevated CO2. Larix ring width was stimulated by CO2 enrichment throughout the treatment period, with a significant stimulation in years 3-7, while Pinus ring width showed no CO2 effect. After 9 years of treatment, leaf canopy cover, stem basal area, and total new shoot production were greater in Larix trees growing under elevated CO2, whereas Pinus showed no cumulative growth response. Larix ring width was stimulated more by elevated CO2 in years with relatively high spring temperatures and an early snowmelt date, suggesting that temperatures were less limiting in these years and greater benefit was gained from extra carbon assimilated under elevated CO2. The CO2 effect size was also larger after relatively high temperatures and high solar radiation in the preceding growing season, perhaps reflecting gains due to larger carbon reserves. Contrasting responsiveness of these two species suggests that under future CO2 concentrations, especially in combination with warmer and sunnier conditions, Larix will have a competitive advantage over less responsive species such as Pinus. Dwarf shrubs are a major component of alpine plant communities, and changes in the growth, abundance and distribution of these species are likely to have important ecological consequences. We studied growth responses of three dominant dwarf shrub species, Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum, to CO2 enrichment and soil warming and how the treatments influenced understorey community composition. V. myrtillus growth was stimulated by elevated CO2, with no decline over time in the annual shoot growth response, and to an even greater extent by soil warming. V. gaultherioides growth showed a slight positive effect of elevated CO2, though only in experimental plots with Pinus, and no response to warming. E. hermaphroditum growth was not influenced by either treatment.
Das Projekt "Untersuchungen zur Mikrostruktur und zum Setzungsverhalten von Lössböden" wird vom Umweltbundesamt gefördert und von Universität der Bundeswehr München, Institut für Bodenmechanik und Grundbau durchgeführt. Forschungstätigkeiten auf dem Gebiet der Sackungsanfälligkeit von Lössböden waren insbesondere zwischen den 30er und 80er Jahren des 20. Jahrhunderts von nationaler Individualität gekennzeichnet. Erst seit Anfang der 80er Jahre, mit Aufstellung der Arbeitsgruppe 'Geotechnical Properties of Loess' der International Union for Quarternary Research (INQUA), ist eine international referenzierende Forschung auf dem Gebiet der Erfassung bodenmechanischer Eigenschaften von Lössböden zu verzeichnen. Der Schwerpunkt bisheriger Forschungsarbeiten lag auf der Erarbeitung sogenannter Kollapskriterien zur qualitativen Abschätzung des Sackungspotentials bei einem Anstieg des Wassergehalts. Bisher durchgeführten geochemischen Untersuchungen von Lössböden beschreiben zwar die mineralische Zusammensetzung, geben jedoch nur eingeschränkt Aufschluss über die Löslichkeit dieser Bestandteile in Wasser oder deren Einfluss auf das Sackungsverhalten. Sämtliche bis dato veranlassten Untersuchungen zum Kollapsverhalten der metastabilen Bodenstruktur von Lössböden wurden für den statischen Lastfall angestellt. Das Verformungsverhalten von Lössböden unter zyklischer Lasteinwirkung hingegen bedarf einer intensiveren wissenschaftlichen Betrachtung. In der vorliegenden Arbeit wird erstmals der Anteil leicht wasserlöslicher mineralischer Bestandteile eines afghanischen Lössbodens ermittelt und anhand von Parameterstudien der Einfluss des Ton- und Kalkgehalts auf das Hydrokonsolidationsverhalten untersucht. Betrachtungen der makro- und mikroskopischen Bodenstruktur ermöglichen belastbare Aussagen über das Verhalten und die Bedeutung des Porenraumes beim Übergang einer metastabilen Bodenstruktur in eine dichtere und somit stabilere Lagerung. Die aus den eigenen Untersuchungen gewonnenen Erkenntnisse dienen als Grundlage für die Formulierung einer neuen, empirisch-deduktiven Prognosemethode zur qualitativen Abschätzung der infolge Hydrokonsolidation zu erwartenden kollapsartigen Verformung (Kollapsverformung). Neben der Vorstellung der Prognosemethode für den statischen Lastfall wurden dynamische Triaxialversuche zur vergleichenden Untersuchung der dynamischen Stabilität metastabiler und idealverdichteter Lössböden angestellt. Sämtliche bodenmechanischen und bodenphysikalischen sowie physiko- und geochemischen Untersuchungen erfolgten an geologisch rezent gebildeten, alluvial und fluvial abgelagerten afghanischen Lössböden der Regionen BALKH und KUNDUZ.
Das Projekt "Carbon fluxes in a mature deciduous forest under elevated CO2'" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. This PhD thesis addressed several major aspects of the carbon (C) cycle in a c. 100-year-old, mixed deciduous forest under elevated CO2 with an emphasis on below-ground processes. The aim was to assess the responses of tree fine roots and soil respiration to canopy CO2 enrichment (ca.550 ppm) in this tallest forest studied to date. Furthermore, leaf gas-exchange of the five study species was examined to ascertain the long-term response of photosynthetic carbon uptake to elevated amospheric CO2. Investigations at the Swiss Canopy Crane (SCC) experimental site were guided by the following key questions: (1) Does below-ground C allocation to fine root production increase in response to CO2 enrichment in order to acquire more nutrients to match the enhanced C supply in the forest canopy? (2) Is below-ground metabolism enhanced and therefore forest soil respiration stimulated by canopy CO2 enrichment? (3) Is leaf-level photosynthesis persistently stimulated by elevated CO2 in this stand or had these mature broad-leaved trees reduced their carbon uptake by photosynthetic down-regulation under long-term CO2 enrichment? Findings from earlier studies at the SCC site, including 13C isotope tracing, all point towards an increased flux of C through CO2-enriched trees to the soil but neither fine root biomass nor soil respiration were stimulated by elevated CO2. Surprisingly, fine root biomass in bulk soil and ingrowth cores showed strong reductions by ca.30Prozent in year five and six but was unaffected in the following seventh year of CO2 enrichment. Given the absence of a positive biomass response of fine roots, we assumed that the extra C assimilated in the CO2-enriched forest canopy was largely respired back to the atmosphere via increases in fine root and rhizosphere respiration and the metabolization of increased root derived exudates by soil microbes. Indeed, 52Prozent higher soil air CO2 concentration during the growing season and 14Prozent greater soil microbial biomass both indicated enhanced below-ground metabolism in soil under CO2-enriched trees. However, this did not translate into a persistent stimulation of soil respiration. The lacking sink capacity for additional assimilates led us to assume downward adjustment of photosynthetic capacity in CO2-enriched trees thereby reducing carbon uptake in the forest canopy. Photosynthetic acclimation cannot completely eliminate the CO2-driven stimulation in carbon uptake, but a reduction could hamper the detection of a CO2 effect considering the low statistical power inevitably involved with such large-scale experiments. However, after eight years of CO2 enrichment we found sustained stimulation in leaf photosynthesis (42-49Prozent) indicating a lack of closure in the carbon budget for this stand under elevated atmospheric CO2.
Das Projekt "Fire regimes and forest dynamics: a study of spatio-temporal ecosystem processes in the Valais (Switzerland) using historical ecology and modeling" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. In many eco-regions of the world, fires are a major driver of vegetation development. Global warming is likely to change fire frequency and intensity at the regional scale, thus causing vegetation shifts. In regions where forest fires so far have played only a minor role, they may become a key element determining vegetation composition, landscape dynamics and ecosystem functions. However, fire regimes, i.e., the spatial extent, intensity, and frequency of fires, are determined by many factors in addition to climate. Human activities, vegetation composition and structure, fuel load, and landscape patterns also have to be taken into consideration to determine fire risk. Understanding and disentangling the various factors that are crucial for shaping the current fire regime and for predicting the likely future fire regime thus requires a multi-faceted approach. In the proposed project, we intend to analyze the past, present, and future fire regimes of a region that is likely to become more fire-prone in the future, i.e., the Canton of Valais (Switzerland), a dry, interior valley of the European Alps. Specifically, we will assess the relative impacts of climate, vegetation properties and human activities on the fire regime. Project aims: To elucidate the historical (100 to 180 years) patterns of the fire regime in the Valais (Switzerland). To perform an in-depth analysis of the changes of the historical fire regime in space and time. To compare these results with the findings on the fire regime of a neighboring region, the Ticino (Switzerland). Whereas one thesis focuses on the historical aspects, an other thesis, located at the ETH aims at using these data to test and improve the LANDCLIM model with respect to (a) its accuracy for historical and current climate and land-use conditions of the Valais and (b) its ability to project future changes in the fire regime in the Valais and the European Alps in general.
Das Projekt "Cell wall hemicelluloses as mobile carbon stores in plants" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. Non-structural carbohydrates (NSC) are the most important carbon reserves in most tissues and species. Beside NSC, cell wall hemicelluloses as the second most abundant polysaccharides in plants have often been discussed to serve as additional carbon reserves during periods of enhanced carbon-sink activity. By using a refined extraction method hemicelluloses were quantitatively and qualitatively determined in tissues of different plant functional groups and the ecophysiological importance of hemicelluloses as mobile carbon pools was investigated in two studies. In the first study hemicelluloses were investigated in newly synthesized tissues of 16 species of four different plant functional groups that were grown under extremely low (140 ppm), medium (280 ppm) or high (560 ppm) CO2 concentrations inducing a massive carbon-under or -oversupply. The changed carbon source-sink activities were evidenced by significant increments of biomass and NSC under elevated CO2 concentrations in tissues of all species. In contrast, hemicellulose concentrations remained remarkably stable with varying CO2 supply. Nevertheless, the monosaccharide spectrum of hemicelluloses showed a significant increase in glucose monomers in leaves of woody species as carbon supply increased. In contrast to the growing tissues of the first experiment the second study investigated the potential carbon reserve function of hemicelluloses by using the naturally occurring fluctuation in carbon-sink activity during bud break in mature forest trees (two deciduous species Carpinus betulus L., Fagus sylvatica L. and two evergreen species Picea abies L., Pinus sylvestris L.). NSC concentrations in branch sapwood of the deciduous trees declined strongly immediately before bud break and increased after bud break. Previous seasons' needles exhibited a significant increase in NSC concentrations shortly before bud break which declined again after flushing. Short-term fluctuations in hemicellulose concentrations were found in branch sapwood of Carpinus and previous seasons' needles of Picea and Pinus and correlated with those of NSC suggesting a mobile reserve function of hemicelluloses. The observed variations in hemicellulose concentrations in previous seasons' needles were due to variations in hemicellulose-bound glucose. In conclusion, this thesis showed that during 'de-novo' synthesis of cell-walls, hemicellulose concentrations do not vary strongly with changing carbon supply. Hemicelluloses are therefore unlikely to play a significant role as additional carbon sinks at future elevated atmospheric CO2 concentrations. On the other hand, apart from their predominant structural function, hemicelluloses can serve as additional carbon reserves in mature tissues during times of exceptionally high carbon demand.
Das Projekt "Functional morphology and productivity of a tussock grassland in the Bolivian Altiplano" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. Tropical and subtropical high elevation grasslands are generally dominated by tall tussock grasses, a life form that seems to dominante in year round cold climates but otherwise quite different soil moisture regimes, from very wet (New Guinea, New Zealand, Ecuador) to rather dry, even semi-arid, as is the case in the NW-Argentinan and Bolivian Altiplano. The biomass production of these vast areas is largely unknown, since the classical harvesting technique cannot be applied in perennial vegetation without affecting growth. Given the steady increase in land use intensity, such information is needed to estimate the carrying capacity of these vast rangelands. In this thesis, I developed the needed non-destructive tools and applied them for a 30-month productivity analysis in the Bolivian Altiplano. The work was conducted in Sajama National Park at 4250 m elevation. The study plant, Festuca orthophylla, is a tall (up to 1 m, mostly around 60 cm) tussock forming grass that represents more than 90Prozent of all biomass in many parts of the Altiplano, including the study area. Forming clones of initially compact, but later fragmented shape, persisting many decades, this species is characteristic for the appearance of the semi-arid, Andean landscape over thousands of square kilometers at elevations between 3600 and 4600 m a.s.l. As a first step, I analysed the clonal structure, the morphology and biomass allocation in representative tussocks. The core of the theses is related to the tussock biomass production using a demographic approach and land cover data (Chapter 3), followed by an assessment of seasonal leaf dynamics (Chapter 4). In conclusion, our data provide a quantitative characterisation of the architecture and dry matter investment of this dominant Altiplano species, the first year-round productivity estimation for a high-elevation tropical, grassland, and a detailed assessment of leaf dynamics for the rainy and the dry season. In a number of ways the traits exhibited, contrast Festuca orthophylla from other, non-woody, high elevation taxa. In particular, the foliage of these tussocks operates at temperature close to that of the free atmosphere, while at the same time, providing shelter to below-ground shoot meristems. The large amount of dead plant material constrains photosynthetic light interception, and reflects slow rates of decomposition, a likely trade-off of generally poor nutrional quality (Patty et al., 2010), which, in turn, relates to the heavy herbivory pressure. The rates of biomass accumulation per unit of tussock area are quite high, much higher than one would expect in such a semi-arid rangeland. The most plausible explanation is that these tussocks are utilizing a far greater land area for water and nutrient acquisition than represented by their projected canopy area. The space in-between tussocks is, thus, a most likely mechanism explaining these high rates of productivity.
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