Fragmentation effects on an endangered species across a gradient from the interior to edge of its range

Understanding how habitat fragmentation affects individual species is complicated by challenges associated with quantifying species-specific habitat and spatial variability in fragmentation effects within a species’ range. We aggregated a 29-year breeding survey data set for the endangered marbled murrelet (Brachyramphus marmoratus) from >42,000 forest sites throughout the Pacific Northwest (Oregon, Washington, and northern California) of the United States. We built a species distribution model (SDM) in which occupied sites were linked with Landsat imagery to quantify murrelet-specific habitat and then used occupancy models to test the hypotheses that fragmentation negatively affects murrelet breeding distribution and that these effects are amplified with distance from the marine foraging habitat toward the edge of the species’ nesting range. Murrelet habitat declined in the Pacific Northwest by 20% since 1988, whereas the proportion of habitat comprising edges increased by 17%, indicating increased fragmentation. Furthermore, fragmentation of murrelet habitat at landscape scales (within 2 km of survey stations) negatively affected occupancy of potential breeding sites, and these effects were amplified near the range edge. On the coast, the odds of occupancy decreased by 37% (95% confidence interval [CI] –54 to 12) for each 10% increase in edge habitat (i.e., fragmentation), but at the range edge (88 km inland) these odds decreased by 99% (95% CI 98 to 99). Conversely, odds of murrelet occupancy increased by 31% (95% CI 14 to 52) for each 10% increase in local edge habitat (within 100 m of survey stations). Avoidance of fragmentation at broad scales but use of locally fragmented habitat with reduced quality may help explain the lack of murrelet population recovery. Further, our results emphasize that fragmentation effects can be nuanced, scale dependent, and geographically variable. Awareness of these nuances is critical for developing landscape-level conservation strategies for species experiencing broad-scale habitat loss and fragmentation.     

PM2.5 concentration declining saves health expenditure in China

● Monthly hospitalization expenses are sensitive to increases in PM_2.5 exposure. ● The increased PM_2.5 causes patients with CHD and LRI to stay longer in the hospital. ● The impact of PM_2.5 on total expenses for stroke is greater in southern China. ● Males may be more sensitive to air pollution than females. Air pollution has been a severe issue in China. Exposure to PM_2.5 has adverse health effects and causes economic losses. This study investigated the economic impact of exposure to PM_2.5 pollution using monthly city-level data covering 88.5 million urban employees in 2016 and 2017. This study mainly focused on three expenditure indicators to measure the economic impact considering lower respiratory infections (LRIs), coronary heart disease (CHD), and stroke. The results show that a 10 µg/m³ increase in PM_2.5 would cause total monthly expenses of LRIs, CHD, and stroke to increase by 0.226%, 0.237%, and 0.374%, respectively. We also found that LRI, CHD, and stroke hospital admissions increased significantly by 10%, 8.42%, and 5.64%, respectively. Furthermore, the total hospital stays of LRIs, CHDs, and strokes increased by 2.49%, 2. 51%, and 1.64%, respectively. Our findings also suggest heterogeneous impacts of PM_2.5 exposures by sex and across regions, but no statistical evidence shows significant differences between the older and younger adult subgroups. Our results provide several policy implications for reducing unequal public health expenditures in overpolluted countries.     

Transport and biodegradation of creosote compounds in clayey till, a field experiment

The transport and biodegradation of 12 organic compounds (toluene, phenol, o-cresol, 2,6-, 3,5-dimethylphenol, naphthalene, 1-methylnaphthalene, benzothiophene, dibenzofuran, indole, acridine, and quinoline) were studied at a field site located on the island of Funen, Denmark, where a clayey till 10–15 m deep overlies a sandy aquifer. The upper 4.8 m of till is highly fractured and the upper 2.5 m contains numerous root and worm holes. A 1.5–2 m thick sand lens is encountered within the till at a depth of 4.8 m. Sampling points were installed at depths of 2.5 m, 4 m, and in the sand lens (5.5 m) to monitor the downward migration of a chloride tracer and the organic compounds. Water containing organic compounds and chloride was infiltrated into a 4 m×4.8 m basin at a rate of 8.8 m³ day⁻¹ for 7 days. The mass of naphthalene relative to chloride was 0.39–0.98 for the sampling points located at a depth of 2.5 m, 0.11–0.61 for the sampling points located at a depth of 4 m, and 0–0.02 for the sampling points located in the sand lens. A similar pattern was observed for eight organic compounds for which reliable results were obtained (toluene, phenol, o-cresol, 2,6-, 3,5-dimethylphenol, 1-methylnaphthalene, benzothiophene, and quinoline). This shows that the organic compounds were attenuated during the downward migration through the till despite the high infiltration rate. The attenuation process may be attributed to biodegradation.     

Food web structure of a restored macroalgal bed in the eastern Korean peninsula determined by C and N stable isotope analyses

Loss of macroalgae habitats has been widespread on rocky marine coastlines of the eastern Korean peninsula, and efforts for restoration and creation of macroalgal beds have increasingly been made to mitigate these habitat losses. Deploying artificial reefs of concrete pyramids with kelps attached has been commonly used and applied in this study. As a part of an effort to evaluate structural and functional recovery of created and restored habitat, the macroalgal community and food web structure were studied about a year after the establishment of the artificial macroalgal bed, making comparisons with nearby natural counterparts and barren ground communities. Dominant species, total abundance, and community structure of macroalgal assemblage at the restored macroalgal bed recovered to the neighboring natural bed levels during the study period. The main primary producers (phytoplankton and macroalgae) were isotopically well separated. δ¹³C and δ¹⁵N values of consumers were very similar between restored and natural beds but varied greatly among functional feeding groups. The range of consumer δ¹³C was as wide as that of primary producers, indicating the trophic importance of both producers. There was a stepwise trophic enrichment in δ¹⁵N with increasing trophic level. A comparison of isotope signatures between primary producers and consumers showed that, while suspension feeders are highly dependent on pelagic sources, invertebrates of other feeding guilds and fishes mainly use macroalgae-derived organic matter as their ultimate nutritional sources in both macroalgal beds, emphasizing the high equivalency of trophic structure between both beds. Isotopic signatures of a few mollusks and sea urchins showed that they use different dietary items in macroalgal-barren grounds compared with macroalgal beds, probably reflecting their feeding plasticity according to the low macroalgal biomass. However, isotopic signatures of most of the consumers at the barren ground were consistent with those at the macroalgal beds, supporting the important trophic role of drifting algae. Our results revealed the recoveries of the macroalgal community and trophic structure at the restored habitat. Further studies on colonization of early settlers and the following succession progress are needed to better understand the process and recovery rate in the developing benthic community.     

Desorption characteristics of kaolin clay contaminated with zinc from electrokinetic soil processing

A number of bench scale laboratory column tests were carried out using a newly designed and developed electrokinetic cell to investigate the fundamental behavior of zinc-spiked kaolin clay subjected to an electric field. Laboratory investigations focused on (i) zinc migration by the combined effects of electromigration and electro-osmosis and (ii) the electrically induced desorption characteristics of zinc-contaminated kaolin that occurred during processing. The correlations of the applied voltage gradient, electro-osmotic flow rate, and the development of a pH gradient were examined and evaluated. The results showed that the removal efficiency was high during the early stage of processing due to rapid desorption by electrokinetic effects in the cathode region. However, the majority of zinc migrating from the anode was precipitated due to the high pH environment in the cathode region.     

The Impact of Perceptual and Situational Factors on Environmental Communication: A Study of Citizen Engagement in China

This study applied a situational approach to understanding an environmental problem: PM2.5 (its resulted haze and smog air pollution) in China. Based on a national sample of 374 citizens living in China, it tested a situational model of problem solving and extended it by adding citizens’ environmental engagement behaviour as an immediate consequence of their communicative action. Results of a structural equation modelling analysis supported all the causal links in the conceptual model. Moreover, communicative action significantly mediated the relationship between referent criterion and environmental engagement. Problem recognition, constraint recognition, and involvement recognition did not influence environmental engagement directly, but exerted their significant indirect impact via two key mediators in the model: situational motivation in problem solving and communicative action in problem solving. Theoretical and practical implications of the present study were discussed.     

The role of local governments before and during chemical accidents,focusing on changes in hazardous chemical management systems

ABSTRACT

Disaster management spans actions before, during, and after disaster events. Changes in the roles and functions of local governments before a disaster can influence other stages of disaster management. After a chemical spill in 2012, South Korean hazardous chemical management tasks were returned to the central government and local governments’ roles and functions were reduced. To identify associated issues and enhance the hazardous chemical management system, this study analyzed changes in laws and policies and conducted interviews with stakeholders. While the changes helped with centralization, reinforcement, and specification, some loopholes were discovered. The information and human resource capacities of local governments and intra – and intergovernmental relations issues have hindered their active participation before and during chemical disasters. These loopholes can be addressed through institutional enhancements for local governments, such as including them in monitoring hazardous chemical handling facilities, developing codes articulating the division of tasks among departments within them, and providing adequate incentives for them to increase their personnel. This study provides empirical data that informs ongoing debates about the centralization and devolution of disaster management by linking local governments’ ordinary management systems to their disaster management activities.     

Application of biochar in advanced oxidation processes: supportive,adsorptive, and catalytic role

Environmental Science and Pollution Research - The advanced oxidation processes (AOPs), especially sulphate radical (SO4•−)–based AOPs (SR-AOPs), have been considered more...     

Assessments of natural and anthropogenic influences on water chemistry in the upper Nakdong River,South Korea

Abstract

The purpose of this study is to evaluate what sources principally affect the chemical compositions in the catchment of the upper Nakdong River, South Korea where bedrock mostly consists of silicates as a natural factor. From October 7^th to 9^th, 2015, thirty-three water samples were collected, including samples from tributaries which run alongside mines. We analyzed the major anions, cations, trace elements and water isotopes of the samples and the analyzed data are divided into four groups by principle component analysis (PCA). We determined that most of the water samples are influenced by water-rock interactions when we consider the PCA results and the chemical weathering equation line. However, six samples have excess concentrations of sulfate and plot below the equation line. These samples were mostly from streams beside a zinc-cadmium smelter, which was also consistent with the PCA results. Samples near populated area could also be separated into a group via domestic pollution. Based on the PCA and chemical results, the chemical compositions of the river can be affected by two anthropogenic inputs: mine wastes and domestic contaminants.