64 research outputs found

    Costs and benefits of spatial data accuracy on comprehensive conservation planning assessments - A conceptual approach

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    The planning of protected habitat networks to safeguard global biodiversity requires substantial knowledge on exposure, services, and functions of ecosystems. Spatial-ecological datasets contain important information for the adequate assessment of spatial economic and ecologic interdependencies. However, these data are still lacking in many places. Comprehensive earth observation can play an important role in the provision of such data but it also involves costs. Cost-benefit analyses may answer the question whether the preparation of such comprehensive spatial data is worthwhile and may help to find the appropriate data resolution for conservation planning questions under consideration of costs. We compare several wetland data sets on global, national, and regional scale according to their spatial accuracy of wetland distribution and the costs of data survey, monitoring, and supply. The spatial data are integrated into bioeconomic land use models of different scales to assess benefits and uncertainties of increased data resolution and accuracy

    Uncertainties in global land cover data and its implications for climate change mitigation policies assessment

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    Land cover maps provide critical input data for global models of land use. Urgent questions exist, such as how much land is available for the expansion of agriculture to combat food insecurity, how high will be competition for land between food and bioenergy in the future as well as how much land is there available for afforestation projects? These questions can only be answered if reliable maps of land cover exist. We put this research in the framework of GEOSS, examine how modeling tools can be used for benefit assessment and design an assessment framework. We illustrate the importance of good quality global land cover maps by using cropland extend from the currently best global maps of land cover namely GLC-2000, MODIS, GlobCover and CropLikelyhood as input for the EPIC model (to model crop yields) and global economic land use model GLOBIOM. We use all of the 4 maps and create a maximum crop extend and map. Based on a baseline map and the maximum crop extend map e model effects of climate policies (e.g. the potentials of substitution of fossil fuels with biofuels)

    A stakeholders’ pathway towards a future land use and food system in Germany

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    Food systems contribute considerably to greenhouse gas (GHG) emissions and influence land use. In Germany, many strategies have been proposed by policy-makers to reduce negative impacts and make the food system more sustainable. It is unclear how close the suggested policies, when bundled, will bring the food and land use system towards the targeted goals; and what stakeholders from non-policy-making organizations consider realistic changes in the German food system. We thus surveyed different stakeholder groups on their opinions about realistic changes in the food and land use system in Germany up to 2050, developed four stakeholder pathways, and used an accounting tool to determine the effect of each pathway on indicators such as land use, GHG emissions, and biodiversity conservation potential. The assessment showed that GHG emissions from agricultural activities and land use are reduced from 66 to - 2-22 TgCO2e by 2050, while the area where natural processes predominate increases from 19 to 27-32%, and the resilience of the food system is not negatively influenced. The change is caused mainly by a diet-change-induced reduction of livestock production and agricultural area transformation into areas with higher carbon sequestration rates. If followed, the common stakeholder pathway (based on all stakeholder responses) would thus lead towards a sustainable food and land use system, but only if the underlying assumption of a drastic diet change towards more plant-based products comes true. Stakeholders from the academic and public sectors were more likely to assume that such a change was realistic than stakeholders from the private sector

    Water productivity and footprint of major Brazilian rainfed crops – A spatially explicit analysis of crop management scenarios

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    Green water is a central resource for global agricultural production. Understanding its role is fundamental to design strategies to increase global food and feed production while avoiding further land conversion, and obtaining more crop per drop. Brazil is a country with high water availability, and a major exporter of agricultural goods and virtual water. We assess here water use and water productivity in Brazil for four major rainfed crops: cotton, maize, soybeans, and wheat. For this, we use the EPIC crop model to perform a spatially explicit assessment of consumptive water use and water productivity under crop management scenarios in Brazil between 1990 and 2013. We investigate four different land-water interactions: (i) water use and productivity for different management scenarios, (ii) the potential of supplemental irrigation for productivity improvement, (iii) changes in green water use throughout the study period, and finally (iv) potential reduction of land and water demand related to agricultural intensification. The results show that, for the studied crops, green water is the main resource for biomass production, and intensification can lead to great improvements in green water productivity. The results also suggest that, despite achieving higher yields, irrigation-based intensification tends to lower overall water productivity, compared to fertilizer-based intensification strategies. This is, however, regionally and crop-specific. Furthermore, due to higher yields and water productivity, producing the same amount of crop output in irrigated or rainfed intensification scenarios would result in the reduction of resource demand, in the order of 34–58 % for cropland, and 29–52 % for water

    Testing the implications of a permanent or seasonal marine reserve on the population dynamics of Eastern Baltic cod under varying environmental conditions

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    A spatially disaggregated, discrete time, age-structured model for the Eastern Baltic cod (Gadus morhua callarias L.) stock was constructed, in order to test the implications of the establishment of a marine reserve in the Baltic Sea. Functional relationships for recruitment and predation mortality were developed by multiple regression analyses. The resultant model output compares well with observed data from the fishery. The model was then applied to simulate stock development over a 50 year time period using different management policies and a variety of environmental conditions. The investigated management policies reduce fishing mortality and range from a moratorium on the Eastern Baltic cod fishery via the establishment of a permanent or a seasonal marine reserve in ICES subdivision 25 to a fishing as usual scenario. The environmental conditions incorporated were based on the size of the reproductive volume (RV) and comprise a best case and a worst case of reproductive conditions, and two more realistic scenarios, where we assumed that a historic series of RV-sizes reoccurs over the simulation period. Our results show a strong dependence of stock dynamics on the environmental conditions. Under prevailing low RV, our model projects stock extinction by the year 2020, if fishing continues as usual. Under the restrictive scenarios, where fishing mortality is reduced either directly or by implementation of a marine reserve, the stock benefits from an increase in stock size and an improved age structure. A seasonal closure of subdivision (SD) 25 as opposed to a closure of the entire Baltic Sea appears to be sufficient to prevent the Eastern Baltic cod stock from failing below safe biological limits

    The Net Global Effects of Alternative U.S. Biofuel Mandates

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    One of the declared objectives of U.S. biofuel policy is the reduction of greenhouse gas (GHG) emissions from fossil fuel combustion, but many studies have questioned whether such a reduction would actually occur and, if so, how large it would be. This report describes the global market, land use, GHG emissions, and nitrogen use impacts of the U.S. Renewable Fuel Standard (RFS2) and several alternative biofuel policy designs, which differ in terms of mandate magnitude and feedstock composition, over the 2010-2030 period

    Saturn Atmospheric Structure and Dynamics

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    2 Saturn inhabits a dynamical regime of rapidly rotating, internally heated atmospheres similar to Jupiter. Zonal winds have remained fairly steady since the time of Voyager except in the equatorial zone and slightly stronger winds occur at deeper levels. Eddies supply energy to the jets at a rate somewhat less than on Jupiter and mix potential vorticity near westward jets. Convective clouds exist preferentially in cyclonic shear regions as on Jupiter but also near jets, including major outbreaks near 35°S associated with Saturn electrostatic discharges, and in sporadic giant equatorial storms perhaps generated from frequent events at depth. The implied meridional circulation at and below the visible cloud tops consists of upwelling (downwelling) at cyclonic (anti-cyclonic) shear latitudes. Thermal winds decay upward above the clouds, implying a reversal of the circulation there. Warm-core vortices with associated cyclonic circulations exist at both poles, including surrounding thick high clouds at the south pole. Disequilibrium gas concentrations in the tropical upper troposphere imply rising motion there. The radiative-convective boundary and tropopause occur at higher pressure in the southern (summer) hemisphere due to greater penetration of solar heating there. A temperature “knee ” of warm air below the tropopause, perhaps due to haze heating, is stronger in the summer hemisphere as well. Saturn’s south polar stratosphere is warmer than predicted by radiative models and enhanced in ethane, suggesting subsidence-driven adiabatic warming there. Recent modeling advances suggest that shallow weather laye
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