Documents

Assessing Soil Processes and Function across an International Network of Critical Zone Observatories: Research Hypotheses and Experimental Design Banwart Steven, Bernasconi Stefano,......., Panagos Panos, ..........Zhang Bin. Assessing Soil Processes and Function across an International Network of Critical Zone Observatories: Research Hypotheses and Experimental Design (2011), VADOSE ZONE JOURNAL , Vol 10, No 3, pp. 974–987.

European Union policy on soil threats and soil protection has prioritised new research to address global soil threats. This research draws on the methodology of Critical Zone Observatories (CZOs) to focus a critical mass of international, multi-disciplinary expertise at specific field sites. These CZOs are selected as part of an experimental design to study soil processes and ecosystem function along a hypothesised soil life cycle; from incipient soil formation where new parent material is being deposited, to highly degraded soils that have experienced millennia of intensive land use. Further CZOs have been selected to broaden the range of soil environments and data sets to test soil process models that represent the stages of the soil life cycle. The scientific methodology for this research focuses on the central role of soil structure and soil aggregate formation and stability in soil processes. Research methods include detailed analysis and mathematical modelling of soil properties related to aggregate formation and their relation to key processes of reactive transport, nutrient transformation and carbon and food web dynamics in soil ecosystems. Within this programme of research, quantification of soil processes across an international network of CZOs is focussed on understanding soil ecosystem services including their quantitative monetary valuation within the soil life cycle.

Access the paper:
http://dx.doi.org/10.2136/vzj2010.0136

https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2389.2010.01249.x

Soil bulk density (ρ) is an important physical property, but its measurement is frequently lacking in soil surveys due to the time‐consuming nature of making the measurement. As a result pedotransfer functions (PTFs) have been developed to predict ρ from other more easily available soil properties. These functions are generally derived from regression methods that aim to fit a single model. In this study, we use a technique called Generalized Boosted Regression Modelling (GBM; Ridgeway, 2006) which combines two algorithms: regression trees and boosting. We built two models and compared their predictive performance with published PTFs. All the functions were fitted based on the French forest soil dataset for the European demonstration Biosoil project. The two GBM models were Model G3 which involved the three most frequent quantitative predictors used to estimate soil bulk density (organic carbon, clay and silt), and Model G10, which included ten qualitative and quantitative input variables such as parent material or tree species. Based on the full dataset, Models G3 and G10 gave R2 values of 0.45 and 0.86, respectively. Model G3 did not significantly outperform the best published model. Even when fitted from an external dataset, it explained only 29% of the variation of ρ with a root mean square error of 0.244 g/cm3. In contrast, the more complex Model G10 outperformed the other models during external validation, with a R2 of 0.67 and a predictive deviation of ±0.168 g/cm3. The variation in forest soil bulk densities was mainly explained by five input variables: organic carbon content, tree species, the coarse fragment content, parent material and sampling depth.

https://onlinelibrary.wiley.com/doi/full/10.1111/j.1475-2743.2010.00305.x

This study presents the results of a series of evaluations of a continent-wide soil database (EU/UN-ECE Level I) with the aim to estimate baseline soil carbon concentrations and stocks. The methodology included the biogeographic stratification of soil carbon measurements throughout Europe using climatic zones derived from the Soil Regions Map of Europe. The presented stock estimates range from 1.3 to 70.8 t C/ha for the O-layer, and from 11.3 to 126.3 t C/ha for the mineral soil 0–20 cm (Germany: 0–30 cm) (5 and 95 percentiles). Histosols were excluded because of methodological differences and data gaps. When looking at the median values of the strata investigated, relationships were found. For example, carbon stocks in the O-layer of sandy soils are distinctly higher than those of fine-textured soils. However, the variability is so high that some of these relationships disappear. For example in western and central Europe, the level of carbon stocks in the mineral soil between shallow soils (Leptosols) and more deeply developed soils (Podzols and Cambisols) do not differ very much. It was also found that just the investigation of topsoils is not sufficient to understand the regional pattern of organic matter in forest soils – unless the subsoil becomes included as well. It is hypothesized that for Europe, the impact of site factors such as climate, texture and relief are difficult to extract from such a database if the data are only stratified according to macro-climatic areas. It has to be considered that the effect of systematic error in the database is quite large (but cannot be identified on the level of the current data availability). In order to receive a first impression of the landscape-level distribution of carbon, a map of carbon concentrations in the topsoil was generated. The results support the relationships found between carbon stocks and site factors, such as climatic zones and soil type. Compared to the much lower carbon concentrations of agricultural soils, the results demonstrate clearly the importance of forest soils for the terrestrial carbon cycling in Europe.

https://www.sciencedirect.com/science/article/pii/S0378112710001787

https://pubs.rsc.org/en/content/articlelanding/2009/EM/b822931g

Soil organic carbon content indicators and web mapping applications. Panagos, P., Van Liedekerke, M., Montanarella, L. and Jones, R.A (2008). ENVIRONMENTAL MODELLING & SOFTWARE, Elsevier LTD, Volume 23· Issue 9: pp 1207-1209, DOI: 10.1016/j.envsoft.2008.02.010. Distributing geographic information via the Internet allows interoperability with similar information and real-time integration of data from around the world. The software developed allows the users to exchange, integrate, and analyze data in new ways. Users can combine various environmental indicators (Organic carbon con-tent) and information accessed via the Internet with their local data for display, query, and analysis. In order to guarantee interoperability, the developed services are based on international standards, as promoted by the INSPIRE initiative. Keywords: Web mapping services; Organic carbon; Environmental indicators; Interoperability; INSPIRE; European soil database. Access the paper

Northern Peatlands: their characteristics, development and sensitivity to climate change C. Tarnocai and V. Stolbovoy In the past two decades there has been considerable work on global climatic change and its effect on the ecosphere, as well as on local and global environmental changes triggered by human activities. Download the Introduction or contact the Author V. Stolbovoy for more information Full Access to the research paper: Elsevier Publisher, Petlands - Evolution and Records of Environmental and Climate Changes. (35 pp)

The distribution of peatland in Europe

L. Montanarella(1), R.J.A. Jones (2) and R. Hiederer (1) 

(1) Joint Research Centre of the European Commission, Institute for Environment and Sustainability, I-21020 Ispra (VA) - Italy,

(2) National Soil Resources Institute, Cranfield University, Silsoe, Bedford MK45 4DT, UK. © 2006 Published by Mires and Peat.

This paper derives the distribution of peatland in Europe as the extent of peat and peat-topped soils indicated by soil databases. 

Variability in regional wheat yields as a function of climate, soil and economic variables: Assessing the risk of confounding. BAKKER, M.M., GOVERS, G., Ewart, F., Roundsevell, Mark and JONES, Robert. (2005). Variability in regional wheat yields as a function of climate, soil and economic variables: Assessing the risk of confounding. Agriculture, Ecosystems & Environment, 110 (3-4), 195-209. Keywords: Wheat yields; Productivity; Climate; Soils; Economics; Regression analysis Look for the research paper: Elsevier Publisher

Modeling sediment yields in Italian catchments VAN ROMPAEY, A.J.J., BAZZOFFI, P., JONES, R.J.A. and MONTANARELLA, L.(2005). Modeling sediment yields in Italian catchments. Geomorphology 65 (2005) 157-169. Sediment yield observations, derived from 40 long-term sedimentation records in Italian reservoirs, were used to calibrate and validate the spatially distributed sediment delivery model WaTEM/SEDEM using the best data available at national scale Keywords: Sediment yield; Soil erosion; Reservoirs; Italy Look for the research paper: Elsevier Publisher
https://www.sciencedirect.com/science/article/pii/S0169555X04001710