Das Projekt "Effects of nurse tree species on growth, environment and physiology of underplanted Toona ciliata (F. Muell.)" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Waldbau-Institut durchgeführt. Toona ciliata (Australian red cedar) is highly valued for veneer and furniture production and endangered in its natural ecosystems due to exploitation. This work aims to improve the availability of this wood on the market and help reduce pressure on the species in its native environment. An afforestation project cultivating Toona ciliata was introduced to the study site in Misiones, Argentina. The local cultivation faces losses caused by drought and frost, because T. ciliata requires overstory protection when young. Consequently, Grevillea robusta, Pinus elliottii x Pinus caribaea, and Pinus taeda, nurse tree species which also produce sought-after wood were chosen to provide protection. One-year-old T. ciliata seedlings were planted underneath each of the six-year-old nurse species. An inventory after one year indicated that both survival and height increment were highest underneath G. robusta and lowest underneath P. elliottii x P. caribaea. In this study I am examining possible facilitation and competition mechanisms between the overstory and understory T. ciliata. Extensive empirical data collected over the course of 3 years will be utilized to project potential growth scenarios for several rotations using a computer based forest growth model.
Das Projekt "Abhaengigkeit des Ueberlebens von Mikroorganismen im Boden von ihrem Ernaehrungszustand" wird vom Umweltbundesamt gefördert und von Bundesforschungsanstalt für Landwirtschaft Braunschweig-Völkenrode, Institut für Bodenbiologie durchgeführt. Auf den Boden ausgebrachte Mikroorganismen koennen mehr oder weniger lange ohne zusaetzliche Naehrstoffe ueberleben. Ein wichtiger Ueberlebensfaktor ist offenbar die Ausstattung der Zellen mit Reservestoffen. Ziel dieser Untersuchungen ist es zunaechst, mikrobielle Biomasse mit unterschiedlichen Reservestoffgehalten, z.B. Lipide, Glykogen, Poly-Beta-Hydroxybuttersaeure, zu produzieren. Im Anschluss an diese Versuche soll das Ueberleben der Bakterien im Boden untersucht werden. Die Untersuchungen haben Bedeutung fuer den Einsatz von Mikroorganismen, einschliesslich gentechnisch veraenderter Zellen, zur Verbesserung der Pflanzenproduktion.
Das Projekt "Development and risk assessment of transgenic environmentally-friendly insect pest control methods for fruit flies and mosquitoes" wird vom Umweltbundesamt gefördert und von Universität Gießen, Institut für Phytopathologie und Angewandte Zoologie, Abteilung Angewandte Entomologie durchgeführt. Various species of pest insects cause substantial damage to agriculture every year, or transmit deadly diseases to animals and humans. A successful strategy to control pest insect populations is based on the Sterile Insect Technique (SIT), which uses the release of mass-reared, radiation sterilized male insects to cause infertile matings and thus reduce the pest population level. However, irradiation is not applicable to every insect species. Thus, new strategies based on genetic modifications of pest insects have been developed or are currently under investigation.The goal of the proposed research is to improve the development and ecological safety of genetically engineered (GE) insects created for enhanced biological control programs, including the SIT and new strategies based on conditional lethality. A major concern for GE insect release programs is transgene stability, and maintenance of their consistent expression. Transgene loss or intra-genomic movement could result in loss of strain attributes, and may ultimately lead to interspecies movement resulting in ecological risks. To address potential transgene instability, a new transposon vector that allows post-integration immobilization will be tested in the Mediterranean, Mexican and Oriental fruit fly tephritid pest species. In addition, the system will be established in the mosquito species Aedes and Anopheles - carriers of dengue and malaria.Random genomic insertion is also problematic for GE strain development due to genomic position effects that suppress transgene expression, and insertional mutations that negatively affect host fitness and viability. Diminished transgene expression could result in the unintended survival of conditional lethal individuals, or the inability to identify them. To target transgene vectors to defined genomic insertion sites having minimal negative effects on gene expression and host fitness, a recombinase-mediated cassette exchange (RMCE) strategy will be developed that. RMCE will also allow for stabilization of the target site, will be tested in tephritid and mosquito species, and will aid to the development of stabilized target-site strains for conditional lethal biocontrol. This will include a molecular and organismal evaluation of an RNAi-based lethality approach. Lethality based on an RNAi mechanism in the proposed insects would increase the species specificity and having multiple targets for lethality versus one target in existing systems. By seeking to improve transgene expressivity and stabilization of transposon-based vector systems, this proposal specifically addresses issues related to new GE insects by reducing their unintended spread after field release, and by limiting the possibilities for transgene introgression.
Das Projekt "Biological Regulation of Subsoil C-cycling under Field Conditions" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre, Fachgebiet Bodenbiologie durchgeführt. The nature of the microbial communities inhabiting the deeper soil horizons is largely unknown. It is also not clear why subsurface microorganisms do not make faster use of organic compounds under field conditions. The answer could be provided by a reciprocal soil transfer experiment studying the response of transferred soils to fluctuations in microclimate, organic inputs, and soil biota. The subproject P9 will be responsible for the establishment of reciprocal transfer experiments offering a strong link between subgroups interested in organic matter quality, transport of organic substances, as well as functions of the soil microbial community. A single, high molecular weight substrate (13C labelled cellulose) will be applied at two different levels in the pre-experiment to understand the dose-dependent reaction of soil microorganisms in transferred surface and sub-soils. Uniformly 13C labelled beech roots - representing complex substrates - will be used for the main reciprocal soil transfer experiment. We hypothesize that transferring soil cores between subsoil and surface soil as well as addition of labelled cellulose or roots will allow us to evaluate the relative impact of surface/subsurface habitat conditions and resource availability on abundance, function, and diversity of the soil microbial community. The second objective of the subproject is to understand whether minerals buried within different soil compartments (topsoil vs. subsoil) in the field contribute to creation of hot spots of microbial abundance and activity within a period of two to five years. We hypothesize that soil microorganisms colonize organo-mineral complexes depending on their nutritional composition and substrate availability. The existence of micro-habitat specific microbial communities could be important for short term carbon storage (1 to 6 years). The third objective is to understand the biogeography and function of soil microorganisms in different subsoils. Parent material as well as mineral composition might control niche differentiation during soil development. Depending on size and interconnectedness of niches, colonization and survival of soil microbial communities might be different in soils derived from loess, sand, terra fusca, or sandstone. From the methodological point of view, our specific interest is to place community composition into context with soil microbial functions in subsoils. Our subgroup will be responsible for determining the abundance, diversity, und function of soil microorganisms (13C microbial biomass, 13C PLFA, enzyme activities, DNA extraction followed by quantitative PCR). Quantitative PCR will be used to estimate total abundances of bacteria, archaea and fungi as well as abundances of specific groups of bacteria at high taxonomic levels. We will apply taxa specific bacterial primers because classes or phyla might be differentiated into ecological categories on the basis of their life strategies.
Das Projekt "Evaluation of the effects of endocrine active chemicals (EACs) for sensitive aquatic wildlife species with the test organism Potamopyrgus antipodarum (Mollusca)" wird vom Umweltbundesamt gefördert und von Universität Frankfurt am Main, Institut für Ökologie, Evolution und Diversität, Abteilung Aquatische Ökotoxikologie durchgeführt. Recent reports have shown that a number of xenobiotics in the environment are able of interfering with the normal endocrine function in animals and also in humans. Suspected effects of such compounds, often referred to as endocrine disruptors (EDs) or endocrine active chemicals (EACs), in humans include decreased sperm counts, increased cases of breast, testicular and other forms of reproductive cancers, genital abnormalities (e.g. hypospadia, cryptorchidism), premature puberty in females, and increased cases of endometriosis. In contrast to these suspicious cases in humans there is convincing evidence for chemically-induced endocrine disruption from wildlife studies. However, the overwhelming majority of investigations on effects of EACs is laboratory based and focuses on vertebrates while much less has been done in the field to address potential population-level effects. More detailed information about the effects on and mechanisms of action in invertebrates has only been obtained from a few cases although invertebrates represent more than 95Prozent of the known species in the animal kingdom. The limited number of examples for endocrine disruption in invertebrates is partially due to the fact that their hormonal systems are rather poorly understood in comparison with vertebrates. Deleterious endocrine changes following an exposure to certain compounds may therefore easily be missed or simply be unmeasurable at present, even though a number of field investigations and laboratory studies show that endocrine disruption has probably occurred. The example of tributyltin (TBT) compounds and their masculinising effects in more than 150 species of prosobranch molluscs shows that apparently trivial biochemical changes can have drastic effects up to the community level by a final sterilisation of affected females with a consequent demise and local extinction of populations. However, with the exception of TBT in marine prosobranchs, it has never been convincingly shown that EACs are capable to exert such far-reaching effects in field populations and pose a risk for their survival at environmentally relevant concentrations. The objective of the proposed project is: (1) to analyse the degree to which aquatic wildlife in central Europe is exposed to EACs in its natural habitat by assessing the well-defined effects in the test with Potamopyrgus antipodarum and (2) to evaluate the potential role of EACs for population declines of sensitive aquatic wildlife species with the example of prosobranch snails by correlating effect data with results from analyses of the macrozoobenthic community.
Das Projekt "Uncertainty and the bioeconomics of near-natural silviculture" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Fachgebiet für Waldinventur und nachhaltige Nutzung durchgeführt. Research in 'silviculture' and 'forest economics' very often takes place largely independent from each other. While silviculture predominantly focuses on ecological aspects, forest eco-nomics is sometimes very theoretic. The applied bioeconomic models often lack biological realism. Investigating mixed forests this proposal tries to improve bioeconomic modelling and optimisation under uncertainty. The hypothesis is tested whether or not bioeconomic model-ling of interacting tree species and risk integration would implicitly lead to close-to-nature forestry. In a first part, economic consequences of interdependent tree species mixed at the stand level are modelled. This part is based on published literature, an improved model of timber quality and existing data on salvage harvests. A model of survival over age is then to be developed for mixed stands. A second section then builds upon data generated in part one and concentrates on the simultaneous optimisation of species proportions and harvest-ing ages. It starts with a mean-variance optimisation as a reference solution. The obtained results are compared with data from alternative approaches as stochastic dominance, down-side risk and information-gap robustness.
Das Projekt "Saprophytisches und symbiotisches Verhalten eingefuehrter Rhizobienstaemme im Boden" wird vom Umweltbundesamt gefördert und von Bundesforschungsanstalt für Landwirtschaft Braunschweig-Völkenrode, Institut für Bodenbiologie durchgeführt. In Versuchen mit sterilen Pflanzen und mit unsteril im Boden angezogenen Pflanzen soll das Verhalten ausgewaehlter Rhizobien in Konkurrenz mit bestimmten Bodenmikroorganismen und mit natuerlicher Bodenmischflora untersucht werden. Dabei sollen kompetitives Wachstum und Knoellchenbildung an Wurzeln von Wirtspflanzen bzw. das kompetitive Wachstum an Wurzeln von Graesern geprueft werden. Zusammenarbeit mit dem Hollaendischen Forschungsinstitut 'Stichting Ital', Wageningen, ist vorgesehen.
Das Projekt "Effects of climate change on past, recent, and future biodiversity of alpine/arctic plants: Integrative evidence from phylogenies, population genetics, ecological niche modelling and new insights for conservation" wird vom Umweltbundesamt gefördert und von Universität Heidelberg,Heidelberger Institut für Pflanzenwissenschaften (HIP) Einrichtung: Botanischer Garten durchgeführt. Responding to the twin crises of global warming and biodiversity loss requires a deep understanding of how climate affects the processes that generate and destroy biodiversity, primarily through its effects on the ecology and distribution of species. Recent improvements in our ability to reconstruct the history of biodiversity through timed phylogenies, estimate changes in genetic diversity, and predict the potential distribution of selected species with ecological niche models (ENMs) now allow us to infer the evolution of ecological preferences and distributional ranges at different temporal scales. Our two case studies focus on alpine/arctic regions, because they are among those most endangered by global warming. The first study will use, for the first time, a combination of ENM and phylogeny to test the model of hybrid, polyploid speciation by secondary contact in arctic/alpine plants. We selected Primula sect. Aleuritia (simply Aleuritia, from here on), because our previous phylogenetic work provided clear hypotheses for the parental origins of polyploids, yet the distributions of the inferred progenitors do not currently overlap. Did the ranges of the proposed parents overlap at the time of allopolyploid origins, as predicted by the secondary contact model? To answer this question, we will produce a high-resolution, dated phylogeny of Aleuritia, optimize the ecological preferences of the hypothesized progenitors onto the dated phylogeny, and project their past distributional ranges onto the fine-resolution climatic scenarios recently developed for the Pleistocene. In the second case study, we will try to explain how small populations persisted on summits in the past and how they are affected by current and future climate change. Here we selected Saxifraga florulenta, a rare, endemic species of the Maritime Alps, because hypotheses of its phylogenetic relationships are available from our previous work, it occurs exclusively above 2000 m, and has very narrow ecological requirements. Consequently, if current trends of global warming continue, the strict ecological adaptation of S. florulenta to siliceous substrates at the highest altitudes of the Maritime Alps may represent a serious extinction risk. We will investigate whether the phylogeographic history, genetic diversity, climatic niche and dispersal mode of S. florulenta can explain its long persistence in the Maritime Alps, a hot spot of biodiversity, and predict its future survival or extinction on mountain tops. We will use a combination of genetic analysis and niche modeling to reconstruct changes in the niche, geographic distribution, and genetic diversity of this cold-adapted species.
Das Projekt "DFG Trilateral collaboration Deutschland-Israel-Palestine: Nematodes as potential vectors for human pathogens" wird vom Umweltbundesamt gefördert und von Julius Kühn-Institut, Bundesforschungsinstitut für Kulturpflanzen, Arbeitsgruppe Wirbeltierforschung durchgeführt. Outbreaks of foodborne illness linked to consumptions of fresh, or partially processed, agricultural products are a growing concern in industrialized and developing countries. The incidence of human pathogens on fresh fruits and vegetables is often related to the use of recycled wastewaster in surface irrigation as well as high amounts of animal manure in agricultural management practice. Thereby the soil inhabiting fauna plays an important role in the transport and dissemination of microorganisms. The focus of the proposed project is on nematodes, well known vectors for bacteria and viruses in soil. The major goals are to: (1) survey human pathogens in soil and on/in free-living and plant parasitic nematodes in agriculture field sites irrigated with recycled wastewater or fertilized with fresh animal manure in Israel and the Palestinian Authority, (2) assess the function of nematodes as vectors in transmitting bacteria from microbial hot spots to plants, and (3) localize bacteria on and/or within the nematode and identify bacterial factors required for survival in the nematode host. Understanding the mechanisms involved in dissemination of human pathogens by nematodes will enhance the ability to develop practical means to minimize contamination of fresh produce and increase safety in food production.
Das Projekt "Drought induced leaf protein alterations in wheat (DILPA)" wird vom Umweltbundesamt gefördert und von Universität Bern, Departement Biologie, Institut für Pflanzenwissenschaften durchgeführt. Climate models predict more frequent and more severe extreme events in Europe during the next decades. The potential impact of extended drought periods on agricultural production represents a key aspect in this context. Drought causes metabolic changes in cereals related to protein metabolism (alterations in protein synthesis and adaptation of the protein pattern, protein degradation). The relation of these changes to yield quantity and quality is not yet well understood. Plant exposure to various environmental stresses often leads to the synthesis of stress-inducible proteins with chaperonine functions, dehydrins or proteases. The relationship among the stress-inducible proteins is very important for the survival of plants during drought stress and for the subsequent recovery phase. One of the major signals to be considered during drought stress is the plant hormone abscisic acid (ABA). Drought triggers the production of ABA which induces various genes involved in a signaling cascade for the regulation of downstream biochemical protective mechanisms. Wheat (Triticum aestivum L.) is a widely cultivated crop plant with high sensitivity to water deprivation. In view of this, it is important for agricultural practice to understand the relation between the stress-inducible proteins and the growth of wheat varieties differing in their drought sensitivity. The comparison of selected wheat genotypes may be relevant for basic research on one hand (identification of mechanisms and of potentials in wheat lines differing in their drought tolerance) and may be relevant for agronomy on the other hand (selection of wheat lines for agronomic use in a changing climate). A team from the Bulgarian Academy of Sciences (leader: Professor Klimentina Demirevska-Kepova) and a team from the Institute of Plant Sciences of the University of Bern (leader: Prof. Urs Feller) will collaborate in this project. Successful interactions between the two institutions started several years ago. Initially the contacts were restricted to correspondence and the exchange of reprints. In 2002 a direct collaboration started, when Prof. Klimentina Demirevska-Kepova was as a guest researcher for three months at the Institute of Plant Sciences of the University of Bern. Antibodies previously raised by her team in Bulgaria were helpful tools for the joint experiments. This project will allow to intensify the interactions between the two institutions and to involve more scientists from the Bulgarian Academy of Sciences in this collaboration.
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