Browsing by Author "Hiederer, Roland"

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    The distribution of peatland in Europe.
    (Jointly by International Mire Conservation Group and International Peat Society, 2006) Montanarella, Luca; Jones, Robert J. A.; Hiederer, Roland
    This paper derives the distribution of peatland in Europe as the extent of peat and peat-topped soils indicated by soil databases. The data sources were the 1:1,000,000 European Soil Database (v1.0) and a data set of organic carbon content (%) for the topsoils of Europe at 1km x 1km resolution that was recently published in map form. The strong influences of vegetation and land use on soil organic carbon (OC) content were taken into account in computing the 1km (OC) data set, as was the influence of temperature. The areas of peat and peat-topped soils estimated from the European Soil Database are generally in close agreement with those obtained using the Map of OC in Topsoils of Europe. The results reveal a strong northern bias in the distribution of organic soils across Europe. Almost one-third of the peatland resource of Europe is in Finland, and more than a quarter is in Sweden. The remainder is in Poland, the UK, Norway, Germany, Ireland, Estonia, Latvia, The Netherlands and France. Small areas of peat and peat-topped soils also occur in Lithuania, Hungary, Denmark and the Czech Republic. For most European countries, the distribution of peat and peat-topped soils is probably more accurately portrayed by the Map of OC in Topsoils of Europe than by the European Soil Map and Database. Such baseline data are important for the conservation of peat and for making much more precise estimates of carbon stocks in topsoil than have been possible hitherto. The results are also relevant to the planning of effective soil protection measures at European level.
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    Estimating organic carbon in the soils of Europe for policy support.
    (Blackwell, 2005-10) Jones, Robert J. A.; Hiederer, Roland; Rusco, E.; Montanarella, Luca
    The estimation of soil carbon content is of pressing concern for soil protection and in mitigation strategies for global warming. This paper describes the methodology developed and the results obtained in a study aimed at estimating organic carbon contents (%) in topsoils across Europe. The information presented in map form provides policy-makers with estimates of current topsoil organic carbon contents for developing strategies for soil protection at regional level. Such baseline data are also of importance in global change modelling and may be used to estimate regional differences in soil organic carbon (SOC) stocks and projected changes therein, as required for example under the Kyoto Protocol to the United Nations Framework Convention on Climate Change, after having taken into account regional differences in bulk density.
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    Monitoring rangeland vegetation in the Sahel by Landsat MSS and NOAA AVHRR
    (Cranfield University, 1991-07) Hiederer, Roland; Taylor, John C.; D'Souza, G.
    Quantities of herbaceous vegetation of Sahelian rangelands in Niger and Mali were compared to vegetation indices (VI) derived from Landsat MSS and NOAA AVHRR LAC images. Field data was collected in 1985,1988 and 1989 in Niger and an appropriate sampling scheme for the study area was developed. Herbaceous vegetation could be estimated to within t 150 kgha 1 at an 80% confidence level up to 1300 kgha -1. Establishing site positions was found to be a primary obstacle when selecting suitable sampling areas. Suggested is the use of Landsat MSS image hard-copies in combination with a global positioning system. Landsat MSS and NOAA AVHRR LAC data were available for dates corresponding to field surveys of 1985 and 1988. While Landsat MSS scenes were geometrically corrected to maps, NOAA AVHRR images were registered to Landsat MSS with a simulated resolution of 1.1 km. Data from both satellites were radiometrically corrected and standardized to atmospheric conditions to the image with the highest relative scene contrast for each study area. These reference images were identified on the basis of bare soil spectral reflectance values and a binary decision tree. Five methods of resampling image data to represent field sites were applied. - The image data sampling methods were found to have a significant influence on spectral reflectance values attributed to a site and, consequently, on the relationship between ground and satellite VIs. Ratio, normalized difference and perpendicular VIs (RVI, NDVI and PVI) were computed for each step of pre-processing procedures. For Landsat MSS VIs were also derived from average spectral reflectance values of bands 3 and 4 to simulate NOAA AVHRR channel 2. VIs were compared for the same sensor, between sensors and related to field data by using linear and logarithmic regression analyses. RVIs and NDVIs achieved very similar results, while PVIs showed a more variable relationship to ground data. Overall, VIs from simulated NOAA AVHRR channel 2 values were found to be not superior to those derived from just band 4. NOAA AVHRR VIs could be related to Landsat MSS ratio VIs by a single regression line for 1985 and 1988 growing seasons for Niger and Mali survey sites. For the inter-calibration a simulation of the NOAA AVHRR pixel size was found to be better suited than the high resolution Landsat MSS data.
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    Projected changes in mineral soil carbon of European forests, 1990–2100
    (Agricultural Institute of Canada, 2006) Smith, Pete; Smith, Jo; Wattenbach, Martin; Meyer, Jeannette; Lindner, Marcus; Zaehle, Sönke; Hiederer, Roland; Jones, Robert J. A.; Montanarella, Luca; Rounsevell, Mark; Reginster, Isabelle; Kankaanpää, Susanna
    Forests are a major land use in Europe, and European forest soils contain about the same amount of carbon as is found in tree biomass. Changes in the size of the forest soil carbon pool could have significant impacts on the European carbon budget. We present the first assessment of future changes in European forest soil organic carbon (SOC) stocks using a dedicated process-based SOC model and state-of-the-art databases of driving variables. Soil carbon change was calculated for Europe using the Rothamsted Carbon model using climate data from four climate models, forced by four Intergovernmental Panel on Climate Change (IPCC) emissions scenarios (SRES). Changes in litter input to the soil due to forest management, projected changes in net primary production (NPP), forest age-class structure, and changes in forest area were taken into account. Results are presented for mineral soil only. Under some climate scenarios carbon in forest soils will increase slightly (0.1 to 4.6 Pg) in Europe over the 21st Century, whilst for one scenario, forest SOC stocks are predicted to decrease by 0.3 Pg. Different trends are seen in different regions. Climate change will tend to speed decomposition, whereas increases in litter input due to increasing NPP and changing age-class structure will slow the loss of SOC. Increases in forest area could further enhance the total soil carbon stock of European forests. Whilst climate change will be a key driver of change in forest soil carbon, changes in ageclass structure and land-use change are estimated to have greater effects.
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    Soil Profile Analytical Database for Europe (SPADE): Reconstruction and Validation of the Measured Data (SPADE/M)
    (Royal Danish Geographical Society, 2006) Hiederer, Roland; Jones, Robert J. A.; Daroussin, J.
    The Soil Profile Analytical Database of Europe of Measured profiles (SPADE/M) was created to provide a common structure for storing harmonized information on typical soil profile properties of European soils. The main difficulty encountered in constructing the database was the transfer of the source data from individual electronic spreadsheet pages to the more rigid structure of a relational database. The data in spreadsheet format had been collected more than 12 years earlier but pressure was mounting for the capability to link these data to the Soil Map of Europe. A semi-automatic process was implemented to transfer data from nominal positions on the spreadsheet page to an intermediate structure highlighting any deviations from expected values. Conflicting situations were solved by manual intervention and expert judgement. Data in the intermediate structure were subjected to a validation procedure with the aim of storing uniform data in the database. The validation checks cover format authentication, restricting entries to permissible values and those passing plausibility tests. In cases where a horizon property could not be represented consistently following the field specifications, the database structure was adapted to accommodate those conditions. The database model was extended to allow data from multiple samples taken at the same plot and from the analysis of samples from different laboratories to be stored.