Search

Surface water quality is particularly sensitive to land use practices and climatic events that affect its catchment. The relative influence of a set of watershed characteristics (climate, land use, morphology and pedology) and climatic variables on two key water quality parameters (turbidity and fecal coliforms (FC)) was examined in 24 eastern Canadian catchments at various spatial scales (1 km, 5 km, 10 km and the entire catchment). A regression analysis revealed that the entire catchment was a better predictor of water quality. Based on this information, linear mixed effect models for predicting turbidity and FC levels were developed. A set of land use and climate scenarios was considered and applied within the water quality models. Four land use scenarios (no change, same rate of variation, optimistic and pessimistic) and three climate change scenarios (B1, A1B and A2) were tested and variations for the near future (2025) were assessed and compared to the reference period (2000). Climate change impacts on water quality remained low annually for this time horizon (turbidity: +1.5%, FC: +1.6%, A2 scenario). On the other hand, the influence of land use changes appeared to predominate. Significant benefits for both parameters could be expected following the optimistic scenario (turbidity: -16.4%, FC: -6.3%; p0.05). However, pessimistic land use scenario led to significant increases on an annual basis (turbidity: +11.6%, FC: +15.2%; p0.05). Additional simulations conducted for the late 21st century (2090) revealed that climate change impacts could become equivalent to those modeled for land use for this horizon.

We applied a multi-level approach assessing the quality, toxicity and functioning of Pb, Zn and Cd contaminated/remediated soil from a vegetable garden in Meza Valley, Slovenia. Contaminated soil was extracted with EDTA and placed into field experimental plots equipped with lysimeters. Soil properties were assessed by standard pedological analysis. Fractionation and leachability of toxic metals were analyzed by sequential extraction and TCLP and metal bioaccessibility by UBM tests. Soil respiration and enzyme activities were measured as indicators of soil functioning. Remediation reduced the metal burden by 80, 28 and 72% for Pb, Zn and Cd respectively, with a limited impact on soil pedology. Toxic metals associated with labile soil fractions were largely removed. No shifts between labile and residual fractions were observed during the seven months of the experiment. Initial metal leaching measured through lysimeters eventually ceased. However, remediation significantly diminished potential soil enzyme activity and no trends were observed of the remediated soil recovering its biological properties. Soil washing successfully removed available forms of Pb, Zn and Cd and thus lowered the human and environmental hazards of the remediated soil; however, remediation also extracted the trace elements essential for soil biota. In addition to reduced water holding capacity, soil health was not completely restored.

The soil sampling guidelines used in European countries (ESSG), as kindly provided by the national institutions which participated in the project, have been recorded, studied, evaluated and presented in this paper. The aim has been to ascertain what soil sampling guidelines exist in Europe; to detect similarities and differences (comparable results), advantages and deficiencies; to identify incompatible strategies and evaluate how methodologies might affect data quality; to investigate sources of deviations or uncertainties; to improve comparability and representativeness of soil sampling; to investigate the need for harmonised sampling guidelines; and to develop suggestions for standard operating procedures (SOP). Soil sampling guidelines throughout Europe differ as to whether they are applied by law, or used throughout the country. In some countries these are ISO/DIS related or based (ISO 10381-1, 1995; ISO 10381-2, 1995), or are produced by a scientific society or a standardisation body. As far as sampling strategy is concerned, not all sampling guidelines clearly describe the sampling scale, the specifications for contamination risk precautions, the sampling plan and protocol structure and the pre-analysis treatment of the soil samples. The purpose for sampling, in descending order of frequency, is soil pollution, soil fertilisation, general soil monitoring, background risk assessment, or else it is not specified. The majority of countries do not sample the top organic matter separately. Sampling depth is either related to the morphogenetic horizon or to ad hoc sampling depth, which is not specified in all cases. They suggest mass- and volume-related soil sampling, while the sampling pattern is not presented in all national guidelines. The criteria for area, site, unit, sub-unit, and point selection are mainly based on pedology and land use, following the history and pre-screening information or geology, or is site related. Some guidelines suggest the division of sampling units into sub-units. The sampling pattern is mainly grid sampling, grid and random sampling, or not mentioned. Sampling density inside the sampling unit either varies greatly or it is not mentioned, while the size of the sampling unit varies widely. Most guidelines require the collection of composite instead of simple samples, while some prefer sampling soil profiles. In the European SSG many technical details and steps are either not defined or vary, while in the pre-analysis treatment quality assurance (QA) and quality control (QC) approaches are used either both in the lab and in the field, or only in the field, or are not mentioned. The common points and the points in which harmonisation could be started or achieved are discussed.

The biogeochemical and ecosystem functioning of the Amazon is of global concern given its size, uniqueness of its flora and fauna, extent to which it affects the Earth’s climate system, and its/our environmental vulnerability. Yet, because of the scale, magnitude and complexity of the underlying physical, chemical and biological processes, understanding the biogeochemical and ecosystem functioning is a daunting task for researchers and decision makers alike, while the implications of the findings inevitably resonate through to the geo-political level and environmentalism’s agendas. This book covers 479 pages of detailed information: 90 figures, 115 tables inserted in the text, appendix tables (69 p.), references (33 p.) and glossary of symbols (9 p.). It is a source book for researchers of the biogeochemistry of Amazon. Therefore, the method described is general and can be easily extended to small or large basins, in all climatic conditions This book examines a strategic component of the Amazon biogeochemical functioning of global significance, carbon and the water cycle. It follows from over twenty years of dedicated hydrogeochemical studies of intensive and extensive collaborations between Brazilian and French researchers and its style is very much like a monograph. The work encompasses an extensive database collected as part of the Camrex-Project in the early 1980s, with subsequent research development and the presentation of key findings (Tardy et al., 2005). Given the complexity of the hydrogeochemistry of the Amazon, there were many aspects that needed to be weaved together. This was done following an introduction as a series of themes dealing with issues of tropical soil genesis (Part 1: geomorphology, hydrology, climate, lithology), sources of aquatic species (Part 2: rock and mineral composition, sources of sulphur and carbon), chemical and mechanical erosion (Part 3: chemical weathering, ablation and mechanical erosion) and aquatic pedology (Part 4: physiology of the river system, hydrograph separation and the carbon cycle). The book culminates in a synthesis chapter dealing with the carbon cycle and climate modelling (Part 5: soil respiration, evaporation together with final balance of carbon fluxes and climate modelling) and a general conclusion. The authors are to be praised for their dedication to researching the Amazon over so many years and for bringing together high quality and leading datasets with a combination of approaches from flux inventories through to isotopic studies and classic as well as contemporary biogeochemical approaches. The book allows a much fuller examination and extension of the Tardy et al (2005) study and appears as a potential and much needed resource for independent research. The work flags the fundamental importance of the water cycle to the carbon cycle as the processes of carbon transport including carbon dioxide production, respiration and usage are intimately linked to rainfall, evaporation/transpiration and the drainage network.