Organic pollutants in compost and digestate. Part 2. Polychlorinated dibenzo-p-dioxins, and -furans, dioxin-like polychlorinated biphenyls, brominated flame retardants, perfluorinated alkyl substances, pesticides, and other compounds

Compost and digestate are important recycling fertilizers and have beneficial effects on soil parameters. However, they can contain significant amounts of organic pollutants. Here, the first comprehensive data set on dibenzo-p-dioxins and -furans (PCDD/F), dioxin-like polychlorinated biphenyls (DL-PCB), brominated flame retardants, perfluorinated alkyl substances (PFAS), pesticides, phthalates, nonylphenol and chlorinated paraffins (CP) in source-separated compost and digestate from Switzerland is presented (n = 3-18). The median summation 17PCDD/F and summation 12DL-PCB concentrations were at 3.2 ng I-TEQ kg(-1)dry weight (dw) and 3.0 ng WHO-TEQ kg(-1)dw, respectively. Brominated diphenyl ether 209 (BDE 209) accounted for 72% of the total polyBDE content (10 microg kg(-1)dw). Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) levels were at 100 and 0.51 microg kg(-1)dw, respectively. PFAS were identified for the first time in compost and digestate (median concentration 6.3 microg kg(-1)dw, summation 21compounds). Out of 269 pesticides analysed, 30 fungicides, 14 herbicides, eight insecticides and one acaricide were detected. Di-(2-ethylhexyl)phthalate (DEHP) median concentration accounted for 280 microg kg(-1)dw and nonylphenol was below the detection limit of 1 mg kg(-1)dw. The sum of short and medium chain CP was between 90 and 390 microg kg(-1)dw. The concentrations observed were at or above the levels found in background soils, which are the main recipient of compost and digestate. Where actually applied, compost can contribute considerably to the total input of organic pollutants to the soil. However, on a total Swiss agricultural area base, inputs seem to be limited.     

Effects of water temperature and mixed layer depth on zooplankton body size

Ecological consequences of global warming include shifts of species ranges toward higher altitudes and latitudes as well as temporal shifts in phenology and life-cycle events. Evidence is accumulating that increasing temperature is also linked to reduced body size of ectotherms. While temperature can act directly on body size, it may also act indirectly by affecting the timing of life-cycle events and the resulting population age and size structure, especially in seasonal environments. Population structure may, in turn, be influenced by temperature-driven changes in resource availability. In a field mesocosm experiment, we investigated how water temperature and mixed surface layer depth (a temperature-dependent determinant of light availability to phytoplankton) affected population dynamics, population age and size structure, and individual size at stage (size at first reproduction) of Daphnia hyalina during and after a phytoplankton spring bloom. Mixed layer depth was inversely related to the magnitudes of the phytoplankton spring bloom and the subsequent Daphnia peak, but had no effect on the body size of Daphnia. Conversely, temperature had no effects on abundance peaks but strongly affected the timing of these events. This resulted in at times positive, at other times negative, transient effects of temperature on mean body size, caused by asynchronous changes in population size structure in cold versus warm treatments. In contrast to mean body size, individual size at stage consistently decreased with increasing temperature. We suggest that size at stage could be used as an unbiased response parameter to temperature that is unaffected by transient, demographically driven changes in population size structure.     

Can preferential credit programs speed up the adoption of low-carbon agricultural systems in Mato Grosso,Brazil? Results from bioeconomic microsimulation

The need to balance agricultural production and environmental protection shifted the focus of Brazilian land-use policy toward sustainable agriculture. In 2010, Brazil established preferential credit lines to finance investments into low-carbon integrated agricultural systems of crop, livestock and forestry. This article presents a simulation-based empirical assessment of integrated system adoption in the state of Mato Grosso, where highly mechanized soybean–cotton and soybean–maize double-crop systems currently prevail. We employ bioeconomic modeling to explicitly capture the heterogeneity of farm-level costs and benefits of adoption. By parameterizing and validating our simulations with both empirical and experimental data, we evaluate the effectiveness of the ABC Integration credit through indicators such as land-use change, adoption rates and budgetary costs of credit provision. Alternative scenarios reveal that specific credit conditions might speed up the diffusion of low-carbon agricultural systems in Mato Grosso.

     

Using machine learning to disentangle homonyms in large text corpora

Systematic reviews are an increasingly popular decision‐making tool that provides an unbiased summary of evidence to support conservation action. These reviews bridge the gap between researchers and managers by presenting a comprehensive overview of all studies relating to a particular topic and identify specifically where and under which conditions an effect is present. However, several technical challenges can severely hinder the feasibility and applicability of systematic reviews, for example, homonyms (terms that share spelling but differ in meaning). Homonyms add noise to search results and cannot be easily identified or removed. We developed a semiautomated approach that can aid in the classification of homonyms among narratives. We used a combination of automated content analysis and artificial neural networks to quickly and accurately sift through large corpora of academic texts and classify them to distinct topics. As an example, we explored the use of the word reintroduction in academic texts. Reintroduction is used within the conservation context to indicate the release of organisms to their former native habitat; however, a Web of Science search for this word returned thousands of publications in which the term has other meanings and contexts. Using our method, we automatically classified a sample of 3000 of these publications with over 99% accuracy, relative to a manual classification. Our approach can be used easily with other homonyms and can greatly facilitate systematic reviews or similar work in which homonyms hinder the harnessing of large text corpora. Beyond homonyms we see great promise in combining automated content analysis and machine‐learning methods to handle and screen big data for relevant information in conservation science.     

Intraspecific physiological variability of the gastropod Littorina saxatilis related to the vertical shore gradient in the White and North Seas

 Physiological responses to desiccation and temperature stress as well as behavioural responses to fast and abrupt environmental changes were investigated in high- and low-shore Littorina saxatilis (Olivi) from several populations from the White and North Seas. Variations in evaporation rates, resistance to air exposure and to acute and chronic temperature stress between animals from different shore levels were similar in White and North Sea periwinkles, consistent with the adaptive nature of these variations. High-shore snails were found to be able to conserve body water reserves better, to resist higher temperatures and to survive longer under conditions of combined temperature and desiccation stress than their low-shore counterparts. In a temperature range of 25 to 35 °C, the rate of evaporative water loss was positively correlated with temperature in low-shore snails while being largely temperature-independent in high-shore snails. Median lethal time during air exposure in L. saxatilis was negatively but not linearly related to the temperature of exposure. In a temperature range of 30 to 38 °C, the resistance to heat exposure in air was only slightly dependent on the temperature, with Q ₁₀ = 1.4 for the median lethal time; the heat resistance dropped drastically at temperatures above 38 °C, with Q ₁₀ = 593.8. This suggests different mechanisms of temperature resistance in different parts of the studied temperature range. In contrast, behavioural response to extreme salinity fluctuations was not uniform in the high- and low-shore periwinkles from the White and North Seas, which may reflect specific environmental conditions at different shore levels in the two areas studied. Observed physiological and behavioural variations are discussed from the viewpoint of different adaptive strategies employed by eulittoral and eulittoral-fringe animals within populations of a single species. Received: 13 December 1999 / Accepted: 11 April 2000     

Identifying impediments to long‐distance mammal migrations

In much of the world, the persistence of long‐distance migrations by mammals is threatened by development. Even where human population density is relatively low, there are roads, fencing, and energy development that present barriers to animal movement. If we are to conserve species that rely on long‐distance migration, then it is critical that we identify existing migration impediments. To delineate stopover sites associated with anthropogenic development, we applied Brownian bridge movement models to high‐frequency locations of pronghorn (Antilocapra americana) in the Greater Yellowstone Ecosystem. We then used resource utilization functions to assess the threats to long‐distance migration of pronghorn that were due to fences and highways. Migrating pronghorn avoided dense developments of natural gas fields. Highways with relatively high volumes of traffic and woven‐wire sheep fence acted as complete barriers. At crossings with known migration bottlenecks, use of high?quality forage and shrub habitat by pronghorn as they approached the highway was lower than expected based on availability of those resources. In contrast, pronghorn consistently utilized high?quality forage close to the highway at crossings with no known migration bottlenecks. Our findings demonstrate the importance of minimizing development in migration corridors in the future and of mitigating existing pressure on migratory animals by removing barriers, reducing the development footprint, or installing crossing structures. Identificación de los Impedimentos para las Migraciones de Larga Distancia de Mamíferos     

The Influence of Agroforestry and Other Land-Use Types on the Persistence of a Sumatran Tiger (<Emphasis Type="Italic">Panthera tigris sumatrae</Emphasis>) Population: An Individual-Based Model Approach

The importance of preserving both protected areas and their surrounding landscapes as one of the major conservation strategies for tigers has received attention over recent decades. However, the mechanism of how land-use surrounding protected areas affects the dynamics of tiger populations is poorly understood. We developed Panthera Population Persistence (PPP)—an individual-based model—to investigate the potential mechanism of the Sumatran tiger population dynamics in a protected area and under different land-use scenarios surrounding the reserve. We tested three main landscape compositions (single, combined and real land-uses of Tesso-Nilo National Park and its surrounding area) on the probability of and time to extinction of the Sumatran tiger over 20 years in Central Sumatra. The model successfully explains the mechanisms behind the population response of tigers under different habitat landscape compositions. Feeding and mating behaviours of tigers are key factors, which determined population persistence in a heterogeneous landscape. All single land-use scenarios resulted in tiger extinction but had a different probability of extinction within 20 years. If tropical forest was combined with other land-use types, the probability of extinction was smaller. The presence of agroforesty and logging concessions adjacent to protected areas encouraged the survival of tiger populations. However, with the real land-use scenario of Tesso-Nilo National Park, tigers could not survive for more than 10 years. Promoting the practice of agroforestry systems surrounding the park is probably the most reasonable way to steer land-use surrounding the Tesso-Nilo National Park to support tiger conservation.     

Objective exposure to road traffic noise,noise annoyance and self-rated poor health – framing the relationship between noise and health as a matter of multiple stressors and resources in urban neighbourhoods

Borrowing from concepts of socio-environmental epidemiology and psychology, we conceived self-rated health as a function of multiple physical and psychosocial stressors and resources at the residential neighbourhood and individual level. In this model of multiple stressors, objective exposure to road traffic noise was specified as a physical stressor whose effect on health may be mediated and modified by residents’ subjective response to noise (serious noise annoyance). Self-reported hearing disability, recreational coping in green areas and residential neighbourhood satisfaction were examined as additional psychosocial stressors or resources, independently of socio-demographic and -economic factors. Results from our empirical analysis based on two studies and multivariable logistic regressions might support the idea that environmental planning should overcome sectoral boundaries and adopt an integrative approach including objective exposures, residents’ subjective responses, and perceived resources.