Defining patch mosaic functional types to predict invasion patterns in a forest landscape.

Alien plant invasions contribute significantly to global changes by often affecting biodiversity and ecosystem processes. Operational methods for identifying landscape attributes that promote or constrain plant invasions are urgently needed to predict their future spread and manage them efficiently. We combined landscape and functional ecology concepts to define patch mosaic functional types (PMFTs) as groups of cells showing the same response to a plant invasion in a heterogeneous forest landscape. The invasion of a European temperate forest by the American black cherry (Prunus serotina) has been chosen as a case study. A set of variables was collected, mapped using a Geographic Information System, and analyzed with multivariate analyses to correlate landscape traits with Prunus serotina abundance in each cell of a grid overlaid on the forest. A risk index was derived and mapped for three invasion levels: seedling colonization, tree establishment, and ecosystem invasion. Five PMFTs were identified and characterized by a set of traits related to soil properties, land use, disturbance, and invasion history. Scots pine plantations on podzols were the most invasible, while cells dominated by hydromorphic or calcareous soils were the most resistant. Most colonized patch mosaics provided suitable conditions for future establishment and invasion. Being strongly spatially connected, suitable patches provide corridors for Prunus serotina to colonize new parts of the forest. Conversely, the most resistant PMFTs were spatially agglomerated in the south of the forest and could act as a barrier. Colonization, establishment, and invasion risk maps were finally obtained by combining partial risks associated with each landscape trait at the cell scale. Within a heterogeneous landscape, we defined and organized PMFTs into a hierarchy, according to their associated risk for colonization, establishment, or invasion by a given invasive species. Each hierarchical level should be associated with a management strategy aiming at reducing one or more partial risk. Monitoring safe areas, extending cutting rotations, harvesting recently colonized stands tree by tree, promoting a multilayered understory vegetation, cutting down reproducing alien trees, favoring shade-tolerant, fast-growing, native tree species, removing alien trees at the leading edge, and proposing soil enrichment or irrigation in heavily invaded areas are recommended.     

Examination of environmental quality of raw and composting de-inking paper sludge

Paper sludges were traditionally landfilled or burned. Over the years, the use of paper sludges on soils has increased, as well as the concerns about their environmental effects. Therefore, the chemical characterization of paper sludges and their young (immature) compost needed to be investigated, and over 150 inorganic and organic chemicals were analyzed in de-inking paper sludge (DPS). In general, nitrogen, phosphorus and potassium contents were low but variable in raw DPS and its young compost. The contents of arsenic, boron, cadmium, cobalt, chromium, manganese, mercury, molybdenum, nickel, lead, selenium, and zinc were also low and showed low variability. However, the copper contents were above the Canadian compost regulation for unrestricted use and required a follow-up. The fatty- and resin acids, and polycyclic aromatic hydrocarbons were the organic chemicals measured at the highest concentrations. For resinic acids, care should be taken to avoid that leachates reach aquatic life. For polycyclic aromatic hydrocarbons, naphthalene should be followed until soil content reaches 0.1 microg g(-1), the maximum allowed for soil use for agricultural purposes according to Canadian Environmental Quality Guidelines. In young compost, the concentration of these chemical families decreased over time and most compounds were below the detection limits after 24 weeks of composting. In raw DPS, among the phenol, halogenated and monoaromatic hydrocarbons, dioxin and furan, and polychlorinated biphenyl families, most compounds were below the detection limits. The raw DPS and its young compost do not represent a major threat for the environment but can require an environmental follow-up.     

常压非平衡态等离子体降解挥发性烃类污染物

采用无声放电产生的非平衡态等离子体,对含有易挥发性有机化合物正己烷、环己烷、苯和甲苯4种典型的烃类废气的空气进行了处理．结果表明,对于一个大气压下正己烷含量（体积分数）为0．26％、0．79％、13％的宁气,在12kV的电压下放电ls,正己烷的降解率分别为88％、81.8％、64．9％．含有环己洗、苯及甲苯浓度为0．26％的空气,在同样的条件下,放电ls后,环己烷、苯及甲苯降解率分别为87．4％、8l％和70．3％,其主要降解产物为CO₂和H₂O．还研究了污染物浓度与氧含量对非平衡态等离子体法降解挥发性烃类污染物的影响     

Growth,deforestation and the efficiency of the REDD mechanism

This paper assesses the long term impacts of an international transfer called the Reduced Emissions from Deforestation and Degradation (REDD) mechanism, which aims at preserving tropical forests of the recipient economy. This two-sector economy faces a dilemma between economic growth and deforestation. The rural sector can substitute reproducible capital for agricultural land whereas the manufacturing sector only requires capital. The model shows that the REDD mechanism has a non-monotonic effect on steady state welfares. For low transfer schemes, the agricultural output increases with the transfer even though less land is under cultivation. For high transfer schemes, the increase in the transfer may not offset the decrease in the agricultural output. The open-loop symmetric Nash equilibrium in a dynamic deforestation game predicts that redistributing the transfer among a finite number of producers is less efficient in reducing deforestation than in the social optimum.     

ICT applications in the research into environmental sustainability: a user preferences approach

Whether information and communication technology (ICT) constitutes a threat or a cure to environment??s deterioration is controversially discussed. Empirical evidence on the impacts of ICT is rare, so that generalizable lessons can hardly be drawn. This study provides empirical results on the role of ICT in research for environmental sustainability, but instead of ascertaining the impact of ICT on environmental protection, we conduct an analysis of the use of ICT in sustainability research. We assess the preferences of experts in different thematic sustainability fields for applying ICT tools, and we investigate ways to improve the application of these tools in order to augment their returns with respect to environmental protection research. This analysis is based on a set of surveys that were administered to international experts to evaluate the importance of ICT in environmental sustainability research and the research demands in key environmental sectors, such as climate change, natural resources, energy and biodiversity. The methodological framework is built on the analysis of users?? preferences for future developments in ICT tools using stated preferences techniques. Overall results suggest that ICT tools need to be developed in specific contexts, taking into account users?? needs and expectations. Our analysis shows that the use of ICT in environmental research is of great importance in the scientific community, but it can also play a crucial role in the policy context.     

Stakeholder Analysis and Social-Biophysical Interdependencies for Common Pool Resource Management: La Brava Wetland (Argentina) as a Case Study

This article gives an account of the implementation of a stakeholder analysis framework at La Brava Wetland Basin, Argentina, in a common-pool resource (CPR) management context. Firstly, the context in which the stakeholder framework was implemented is described. Secondly, a four-step methodology is applied: (1) stakeholder identification, (2) stakeholder differentiation-categorization, (3) investigation of stakeholders' relationships, and (4) analysis of social-biophysical interdependencies. This methodology classifies stakeholders according to their level of influence on the system and their potential in the conservation of natural resources. The main influential stakeholders are La Brava Village residents and tourism-related entrepreneurs who are empowered to make the more important decisions within the planning process of the ecosystem. While these key players are seen as facilitators of change, there are other groups (residents of the inner basin and fishermen) which are seen mainly as key blockers. The applied methodology for the Stakeholder Analysis and the evaluation of social-biophysical interdependencies carried out in this article can be seen as an encouraging example for other experts in natural sciences to learn and use these methods developed in social sciences. Major difficulties and some recommendations of applying this method in the practice by non-experts are discussed.     

Assessing Cd,Pb, Zn human bioaccessibility in smelter-contaminated agricultural topsoils (northern France)

The extractability of Cd, Pb, and Zn was investigated in contaminated agricultural topsoils located in an area highly affected by the past atmospheric emissions of two smelters in northern France in order to assess their mobility and human bioaccessibility. The determination of Cd, Pb, and Zn bioaccessibility (Unified Barge Method, in vitro test) was made to evaluate the absolute trace element (TE) bioavailability. The results highlighted differences in bioaccessibility between Cd, Pb, and Zn (Cd > Pb > Zn). The mean values of the bioaccessible fractions of Cd, Pb, and Zn during the gastric phase were 82, 55, and 33%, respectively, of the pseudototal concentrations, whereas during the gastrointestinal phase, the bioaccessible fractions of metals decreased to 45, 20, and 10%, respectively. Stepwise multiple regression analysis showed that human bioaccessibility was affected by various physicochemical parameters (i.e., sand, carbonates, organic matter, assimilated P, free Al oxides, and pseudototal Fe contents). Sequential extractions were performed as an indication of the TE availability in these soils. Cadmium occurred in the more available fractions, Pb was mostly present as bound by oxides, and a significant contribution to the pseudototal Zn concentration was defined as the unavailable residual form related to the crystalline structures of minerals. The concepts of bioavailability and bioaccessibility are important for quantifying the risks associated with exposure to environmental pollutants and providing more realistic information for human health.