Flowering time (FTi) genes play a key role as regulators of complex gene expression networks, and the influence of these networks on other complex systems means that FTi gene expression triggers a cascade of regulatory effects with a broad global effect on plant development. Hence, allelic and expression differences in FTi genes can play a central role in phenotypic variation throughput the plant lifecycle. A prime example for this is found in Brassica napus, a phenotypically and genetically diverse species with enormous variation in vernalisation requirement and flowering traits. The species includes oilseed rape (canola), one of the most important oilseed crops worldwide. Previously we have identified QTL clusters related to plant development, seed yield and heterosis in winter oilseed rape that seem to be conserved in diverse genetic backgrounds. We suspect that these QTL are controlled by global regulatory genes that influence numerous traits at different developmental stages. Interestingly, many of the QTL clusters for yield and biomass heterosis appear to correspond to the positions of meta-QTL for FTi in spring-type and/or winter-type B. napus. Based on the hypothesis that diversity in FTi genes has a key influence on plant development and yield, the aim of this study is a detailed analysis of DNA sequence variation in regulatory FTi genes in B. napus, combined with an investigation of associations between FTi gene haplotypes, developmental traits, yield components and seed yield.
This project focuses on the long-term stability (or otherwise) of vegetation, based on a series of multi-proxy records in southern South America. We will build a network of sites suitable for high-resolution reconstructions of changes in vegetation since the Last Glacial Maximum, and use these to test a null hypothesis that changes in vegetation over the past 14,000 years are driven by internal dynamics rather than external forcing factors. The extent to which the null hypothesis can be falsified will reveal the degree to which we can expect to be able to predict how vegetation is affected by external events, including future climate change. The southern fringes of the South American landmass provide a rare opportunity to examine the development of moorland vegetation with sparse tree cover in a wet, cool temperate climate of the Southern Hemisphere. We present a record of changes in vegetation over the past 17,000 years, from a lake in extreme southern Chile (Isla Santa Inés, Magallanes region, 53°38.97S; 72°25.24W; Fontana, Bennett 2012: The Holocene), where human influence on vegetation is negligible. The western archipelago of Tierra del Fuego remained treeless for most of the Lateglacial period. Nothofagus may have survived the last glacial maximum at the eastern edge of the Magellan glaciers from where it spread southwestwards and established in the region at around 10,500 cal. yr BP. Nothofagus antarctica was likely the earlier colonizing tree in the western islands, followed shortly after by Nothofagus betuloides. At 9000 cal. yr BP moorland communities expanded at the expense of Nothofagus woodland. Simultaneously, Nothofagus species shifted to dominance of the evergreen Nothofagus betuloides and the Magellanic rain forest established in the region. Rapid and drastic vegetation changes occurred at 5200 cal. yr BP, after the Mt Burney MB2 eruption, including the expansion and establishment of Pilgerodendron uviferum and the development of mixed Nothofagus-Pilgerodendron-Drimys woodland. Scattered populations of Nothofagus, as they occur today in westernmost Tierra del Fuego may be a good analogue for Nothofagus populations during the Lateglacial in eastern sites. Climate, dispersal barriers and/or fire disturbance may have played a role controlling the postglacial spread of Nothofagus. Climate change during the Lateglacial and early Holocene was a prerequisite for the expansion of Nothofagus populations and may have controlled it at many sites in Tierra del Fuego. The delayed arrival at the site, with respect to the Holocene warming, may be due to dispersal barriers and/or fire disturbance at eastern sites, reducing the size of the source populations. The retreat of Nothofagus woodland after 9000 cal. yr BP may be due to competitive interactions with bog communities. Volcanic disturbance had a positive influence on the expansion of Pilgerodendron uviferum and facilitated the development of mixed Nothofagus-Pilgerodendron-Drimys woodland.
Biogeochemical interfaces shape microbial community function in soil. On the other hand microbial communities influence the properties of biogeochemical interfaces. Despite the importance of this interplay, basic understanding of the role of biogeochemical interfaces for microbial performance is still missing. We postulate that biogeochemical interfaces in soil are important for the formation of functional consortia of microorganisms, which are able to shape their own microenvironment and therefore influence the properties of interfaces in soil. Furthermore biogeochemical interfaces act as genetic memory of soils, as they can store DNA from dead microbes and protect it from degradation. We propose that for the formation of functional biogeochemical interfaces microbial dispersal (e.g. along fungal networks) in response to quality and quantity of bioavailable carbon and/or water availability plays a major role, as the development of functional guilds of microbes requires energy and depends on the redox state of the habitat.To address these questions, hexadecane degradation will be studied in differently developed artificial and natural soils. To answer the question on the role of carbon quantity and quality, experiments will be performed with and without litter material at different water contents of the soil. Experiments will be performed with intact soil columns as well as soil samples where the developed interface structure has been artificially destroyed. Molecular analysis of hexadecane degrading microbial communties will be done in vitro as well as in situ. The corresponding toolbox has been successfully developed in the first phase of the priority program including methods for genome, transcriptome and proteome analysis.
Forests play a relevant role in mitigation of climate change. A major issue, however, is the scientifically well founded, transparent and verifyable monitoring of achievements in forest carbon sequestration through reduction of deforestation and forest degradation, and through fostering sustainable forest management. Monitoring is particularly difficult in diverse and inaccessible humid tropical forest areas. The proposed research will contribute to the improvement of forest carbon monitoring under the challenging conditions of humid tropical forests. Sample based field observations and model based biomass predictions will be linked to area-wide satellite remote sensing imagery (RapidEye) and to strip samples of LiDAR imagery. Techniques of linking these data sources will be further developed and analysed with respect to (1) precision of carbon estimation and (2) accuracy of carbon regionalization. The proposed project implies research on methodological improvements of both sample based forest inventories (resampling techniques for biomass, imputation of non-response) and remote sensing application to forest monitoring (regionalization, sample based application of LiDAR data). At the core of this research is the analysis of the error variance components that each data source brings into the system. Such error analysis will allow identifying optimal resource allocation for the efficient improvement of forest carbon monitoring systems.
The dataset is composed of Neo HySpex (VNIR/SWIR) hyperspectral imagery acquired during airplane overflights on June 6th, 2015 covering the Omongwa Pan located in the South-West Kalahari, Namibia. The dataset includes three cloud-free flight lines with 408 spectral bands ranging from VNIR to SWIR wavelength regions (0.4-2.5 µm). The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). The overall goal of the campaign was to acquire imagery over the Omongwa Pan and use the spectral reflectance for the analyses of surface sediments, specifically the mineralogical composition of exposed surface evaporites / salts on the airborne and spaceborne scale. The data are highly novel and can be used to test estimation of surface sediment properties in a highly saline and dynamic environment.
The number one question in ecology is why certain organisms occur where they do, and what the traits are which make them successful. This project aims at arriving at a mechanistic rather than a correlative explanation of the climatic limits of major European broad leaved tree taxa. It will focus on and explore their temperature-related limits and aims at reviving Europe's traditional strength in physiology based ecology by training a group of young scientists to answer such questions. The project builds upon the PIs experience in mechanism-oriented ecology (e.g., synthesis in Körner 2003) and should help trading those rapidly disappearing skills to a next generation of experimental ecologists. The project adopts a three-step approach: (1) Assess the current extreme postions of tree taxa along thermal gradients, using existing data bases and site visits (data mining, biogeography). (2) Associate those patterns with bioclimatic information, both available and newly acquired (climatology). (3) Empirically test hypotheses of causes of growth limitation and stress survival, both in the field and in the laboratory (ecophysiology). The project will account for ecotypic differentiation by using the marginal and central (optimal) positions of taxa and will explore plant establishment as well as adult plant performance. It will use in situ measurements, transplant and common gardens as well as phytotron testing. Genotypic control of phenology, frost hardiness, thermal constraints for shoot and root growth and reproductive system (fitness) will play a central role. The results will, for the first time, offer a mechanistic (rather then correlative) explanation for broad leaf tree species distribution in Europe and thus, will provide a basis for improved parameterization and evaluation of species distribution models in a climate change context. The new European Research Council (ERC) has granted Prof. Körner one of the extremely rare 5 year 'advanced grants', which contrast any previous granting regime by being personal. The 2 Mio Swiss Francs will permit to explore where, why and how major European tree taxa find climatic range limits. A team of two PhD students and two postdocs plus a technician will be established for a period of four years each (overlapping). The project has various tasks, such as - Idendification of tree species range limits as precise as possible based on GIS and archive data, interviews and site visits - Climatology of those limits based on climate stations and climate data bases - Assess local climate by a large data logging programm with backward cross correlating - Assess marginal versus non marginal location dendrological responses - Assess seedling versus adult positions and viability of seeds - Common garden experiments across climatic gradients (recipical transplants) - Assess freezing resistance of key tissues at key phenophases and link with climatic extremes In a first phase starting 1st April 2009, we will focus on GIS and c
Water repellency (WR) plays a significant role in a large number of soils all over the world. In many regions global warming will lead to drier land surfaces and thus, increasing the likeliness of actual water repellency for such soils. The hydrological effects of WR (surface runoff, water erosion, preferential flow) have been relatively well investigated in the last decades. However, its effect on the energy balance between soil and atmosphere has not been studied yet. We postulate that global warming does not only lead to an increase in WR of soils, but WR has an impact on the energy balance and thus, will lead to a feedback on global warming. In order to test our hypothesis, we want to determine all components of the energy- and water balance between soil and atmosphere for a strongly water repellent soil. As a reference we want to repeat the same measurements for the same soil, at which the WR has been suspended by application of a surfactants. While the laboratory studies aim to give insight into more principle processes, the lysimeter (bare and with plants) and field scale studies shall give information about integrated complex natural processes. The gained knowledge shall be implemented into a numerical simulation tool for modeling water and energy balances in order to predict the effects of WR under different atmospheric conditions and physical soil properties.
Heat and carbon dioxide exchange between the atmosphere and ocean is a major control on Earths climate and increasing atmospheric carbon dioxide (CO2) and concomitant global warming stimulate uptake of both heat and CO2 by the ocean. The Southern Ocean south of 30 S, occupying just over 1/4 of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere. On average, the Southern Ocean absorbs 70Prozent of anthropogenic heat and 42Prozent of anthropogenic carbon in a new set of climate model simulations. This region thus plays a central role in determining the rate of climate change. However, the exact processes governing the magnitude and regional distribution of heat and carbon uptake remain poorly understood with models showing the largest disagreement in Southern Ocean anthropogenic air-sea heat and CO2 fluxes due to their widely divergent representation of physical circulation and atmosphere-ocean interactions. Indeed, the fraction of the simulated uptake within the Southern Ocean ranges between 30 to 160Prozent for excess heat and between 38 to 47Prozent for anthropogenic carbon. Natural unforced variability in models and observations further complicates the detection and attribution of changes. We will investigate anthropogenic ocean heat and carbon uptake with our main objectives being: (i) intercomparing ocean heat and carbon uptake in Earth System Model (ESM) simulations conducted for the Coupled Model Intercomparison Project Phase 5 (CMIP5), (ii) assessing the contribution of internal variability to model-model and model-data differences in anthropogenic heat and carbon uptake, and (iii) quantifying the contribution of differences in basic atmospheric forcing, model parameterizations, sea ice representation and model resolution to differences in heat and carbon uptake and distribution, and disagreements between models. This will be achieved through a series of process-perturbation experiments and ensemble simulations with an Earth System Model configured for transient climate change that help in attributing variations over the Southern Ocean. We will also contribute to the broader community goal in interpreting projections of IPCC AR5 coupled climate models. Ultimately, the project leads to a better understanding of Southern Ocean biogeochemical processes, thereby pinning down one of the greatest sources of uncertainty in predictions of the fate of anthropogenic carbon and of the climate.
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