Functional nonredundancy of elephants in a disturbed tropical forest

Conservation efforts are often motivated by the threat of global extinction. Yet if conservationists had more information suggesting that extirpation of individual species could lead to undesirable ecological effects, they might more frequently attempt to protect or restore such species across their ranges even if they were not globally endangered. Scientists have seldom measured or quantitatively predicted the functional consequences of species loss, even for large, extinction‐prone species that theory suggests should be functionally unique. We measured the contribution of Asian elephants (Elephas maximus) to the dispersal of 3 large‐fruited species in a disturbed tropical moist forest and predicted the extent to which alternative dispersers could compensate for elephants in their absence. We created an empirical probability model with data on frugivory and seed dispersal from Buxa Tiger Reserve, India. These data were used to estimate the proportion of seeds consumed by elephants and other frugivores that survive handling and density‐dependent processes (Janzen‐Connell effects and conspecific intradung competition) and germinate. Without compensation, the number of seeds dispersed and surviving density‐dependent effects decreased 26% (Artocarpus chaplasha), 42% (Careya arborea), and 72% (Dillenia indica) when elephants were absent from the ecosystem. Compensatory fruit removal by other animals substantially ameliorated these losses. For instance, reductions in successful dispersal of D. indica were as low as 23% when gaur (Bos gaurus) persisted, but median dispersal distance still declined from 30% (C. arborea) to 90% (A. chaplasha) without elephants. Our results support the theory that the largest animal species in an ecosystem have nonredundant ecological functionality and that their extirpation is likely to lead to the deterioration of ecosystem processes such as seed dispersal. This effect is likely accentuated by the overall defaunation of many tropical systems.     

Annual ambient atmospheric mercury speciation measurement from Longjing,a rural site in Taiwan

The main purpose of this study was to monitor ambient air particulates and mercury species [RGM, Hg(p), GEM and total mercury] concentrations and dry depositions over rural area at Longjing in central Taiwan during October 2014 to September 2015. In addition, passive air sampler and knife-edge surrogate surface samplers were used to collect the ambient air mercury species concentrations and dry depositions, respectively, in this study. Moreover, direct mercury analyzer was directly used to detect the mercury Hg(p) and RGM concentrations. The result indicated that: (1) The average highest RGM, Hg(p), GEM and total mercury concentrations, and dry depositions were observed in January, prevailing dust storm occurred in winter season was the possible major reason responsible for the above findings. (2) The highest average RGM, Hg(p), GEM and total mercury concentrations, dry depositions and velocities were occurred in winter. This is because that China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. (3) The results indicated that the total mercury ratios of Kaohsiung to that of this study were 5.61. This is because that Kaohsiung has the largest industry density (~60 %) in Taiwan. (4) the USA showed average lower mercury species concentrations when compared to those of the other world countries. The average ratios of China/USA values were 89, 76 and 160 for total mercury, RGM and Hg(p), respectively, during the years of 2000–2012.     

Understanding stewardship behaviour: factors facilitating and constraining private water well stewardship

Regulatory frameworks to ensure municipal drinking water safety exist in most North American jurisdictions. However, similar protection is rarely provided to people reliant on water provided from private wells. In Canada, approximately 4 million people depend on privately owned, domestic wells for their drinking water. Numerous studies have shown that people who rely on private wells for their water supplies are at risk from nitrate and bacterial contamination. Given the fact that regulations relating to private wells tend to be weak or poorly enforced, actions taken by well owners to protect their own drinking water safety are extremely important. Drawing on one of the largest and most comprehensive surveys of private well owners ever conducted in Canada or elsewhere, this paper explores factors that influence well owner stewardship behaviour. Key behaviours examined included annual testing of well water and inspection of wells, measures to protect water quality, and proper decommissioning of unused wells. A geographically-stratified survey, sent to 4950 well owners in Ontario, Canada, resulted in an effective response rate of 34% (n = 1567). Logistic regression analyses revealed that motivations for well stewardship behaviours included reassurance, the perception of problems, and knowledge of the environment. Knowing how to perform stewardship behaviours was an important antecedent to action. Barriers to stewardship included complacency, inconvenience, ignorance, cost, and privacy concerns. To promote stewardship, local initiatives, better educational materials, and enforcement through real estate laws are all required. Ultimately, drinking water safety for people reliant on private wells is shown to be a responsibility shared by governments and private well owners.     

Review of PSR framework and development of a DPSIR model to assess greenhouse effect in Taiwan

In dealing with the complex issues of greenhouse gas (GHG) emission and climate change mitigation, many interrelated factors such as cost, level of technology development, supply and demand of energy, structure of industry, and expenditures on research and development exist. Using indicators to monitor environmental impacts and evaluate the efficacies of policies and regulations has been practiced for a long time, and it can serve as a useful tool for decision making and for comparison between different countries. Although numerous indicators have been developed for relevant subjects, integrated approaches that consider individual changes, dynamic interaction, and multi-dimensions of indicators are scarce. This paper aimed to develop a Driving Force-Pressure-State-Impact-Response (DPSIR) framework to assess the problems. This DPSIR model is mainly related to energy consumption, environmental impacts, and policy responses. The objectives of the paper were: (1) conduct a literature review on the indicators that have been used in GHG-related studies; (2) develop a DPSIR model that incorporates GHG-related indicators and evaluate their relationships using a cause?Ceffect chain of GHG emission; and (3) develop a calculative method that can be used to explain the dynamic correlation among the interdependent indicators. Taiwan is a significant source of global GHG emissions. A case study, using the developed framework and Taiwan??s actual data of the past two decades, was conducted. The results indicate that regulatory strategies for pollution control are inadequate in terms of ensuring environmental quality, and the nature does not have the capability to revert the impacts from the existing level of pollution.     

Incorporating stakeholders’ preferences into a multi-criteria framework for planning large-scale Nature-Based Solutions

Hydro-meteorological risks are a growing issue for societies, economies and environments around the world. An effective, sustainable response to such risks and their future uncertainty requires a paradigm shift in our research and practical efforts. In this respect, Nature-Based Solutions (NBSs) offer the potential to achieve a more effective and flexible response to hydro-meteorological risks while also enhancing human well-being and biodiversity. The present paper describes a new methodology that incorporates stakeholders’ preferences into a multi-criteria analysis framework, as part of a tool for selecting risk mitigation measures. The methodology has been applied to Tamnava river basin in Serbia and Nangang river basin in Taiwan within the EC-funded RECONECT project. The results highlight the importance of involving stakeholders in the early stages of projects in order to achieve successful implementation of NBSs. The methodology can assist decision-makers in formulating desirable benefits and co-benefits and can enable a systematic and transparent NBSs planning process.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01419-4) contains supplementary material, which is available to authorized users.     

Using Landsat 8 imagery for remote monitoring of total phosphorus as a water quality parameter of irrigation ponds in Taiwan

Environmental Science and Pollution Research - Monitoring water body quality parameters with high spatial and temporal resolutions is crucial because mitigation of pollution is usually costlier...     

城市灾时大范围人员应急疏散探讨

人类面临着许多自然的和人为的灾害,比如最近发生的印度洋大海啸和2001年的美国"9·11"恐怖袭击事件等.当这类重大灾害性事件发生时,在短时间内安全地大范围疏散转移高密集人群,实施科学的应急救灾策略,是减轻灾害后果严重性的重要措施之一.探讨了如何建立一个综合性的疏散规划模型,为人员应急疏散管理提供决策支持.     

Decomposition of perfluorooctanoic acid by microwaveactivated persulfate: Effects of temperature, pH, and chloride ions

Microwave-hydrothermal treatment of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water with persulfate (S₂O₈²⁻) has been found effective. However, applications of this process to effectively remediate PFOA pollution require a better understanding on free-radical scavenging reactions that also take place. The objectives of this study were to investigate the effects of pH (pH = 2.5, 6.6, 8.8, and 10.5), chloride concentrations (0.01–0.15 mol·L⁻¹), and temperature (60°C, 90°C, and 130°C) on persulfate oxidation of PFOA under microwave irradiation. Maximum PFOA degradation occurred at pH 2.5, while little or no degradation at pH 10.5. Lowering system pH resulted in an increase in PFOA degradation rate. Both high pH and chloride concentrations would result in more scavenging of sulfate free radicals and slow down PFOA degradation. When chloride concentrations were less than 0.04 mol·L⁻¹ at 90°C and 0.06 mol·L⁻¹ at 60°C, presence of chloride ions had insignificant impacts on PFOA degradation. However, beyond these concentration levels, PFOA degradation rates reduced significantly with an increase in chloride concentrations, especially under the higher temperature.