Table of Content

    30 March 2020, Volume 11 Issue 2 Previous Issue    Next Issue
    Nitrogen Addition Decreases Soil Respiration without Changing the Temperature Sensitivity in a Semiarid Grassland
    DU Wei, LI Yue, HE Pei, ZHANG Jiaqi, JING Haichao, NIE Cheng, LIU Yinghui
    2020, 11 (2):  129-139.  doi: 10.5814/j.issn.1674-764x.2020.02.001
    Abstract ( 164 )   PDF (829KB) ( 57 )   Save
    The mechanisms underlying the response of soil respiration (Rs) to nitrogen (N) addition remain to be explored in semiarid ecosystems. This study was conducted to determine the effect of N addition on soil microbial composition, Rs and the temperature sensitivity of Rs (Q10). The N addition experiment was carried out in a semiarid grassland in China, with N fertilizer application rates of 0, 2, 4, 8, 16, or 32 g N m-2 yr-1. Microbial phospholipid fatty acids (PLFAs), Rs and Q10 were measured, and their relationships with soil properties were determined for three growing seasons. The results showed that N addition significantly increased the content of soil dissolved organic carbon (DOC) and inorganic nitrogen (IN), and decreased soil pH. With respect to soil microbes, N addition reduced soil PLFAs, reduced the fungi to bacteria ratio (F:B) and increased the gram-positive bacteria to gram-negative bacteria ratio (G+:G-). Rs under the N2, N4, N8, N16 and N32 treatments decreased by 2.58%, 14.86%, 22.62%, 23.97% and 19.87%, respectively, compared to the N0 (control) treatment. The results of structural equation models showed that N addition reduced Rs by lowering soil PLFAs and altering the microbial composition. However, N addition had no significant effect on either Q10, soil total organic carbon (TOC) or total nitrogen (TN), indicating that N addition alleviated soil carbon loss and was unlikely to change the potential for a bigger loss under global warming.
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    Coupling the Occurrence of Correlative Plant Species to Predict the Habitat Suitability for Lesser White-fronted Goose (Anser erythropus) under Climate Change: A Case Study in the Middle and Lower Reaches of the Yangtze River
    XIANG Ling, GAO Xiang, PENG Yuhui, LIANG Jie
    2020, 11 (2):  140-149.  doi: 10.5814/j.issn.1674-764x.2020.02.002
    Abstract ( 104 )   PDF (2300KB) ( 17 )   Save
    Climate change and human activities influence species biodiversity by altering their habitats. This paper quantitatively analyzed the effects of climate change on a migratory bird. The Lesser White-fronted Goose (LWfG), a species which migrates via the middle and lower reaches of the Yangtze River region, is an herbivorous species of high ecological value. It is an endangered species threatened by climate change and human activities, so comprehensive information about its distribution is required. To assess the effectiveness of conservation of the LWfG under climate change, both climate variables and human activities are often used to predict the potential changes in the distribution and habitat suitability for LWfG. In this work, the current scenario and the Global Circulation Models (GCMs) climate scenarios were used to simulate the future distribution of the species. However, besides climate change and human activities, the spatial pattern of plants surrounding the wetland is also known to be closely related to the distribution of LWfG. Therefore, the distribution model results of six plant species related to LWfG’s diet selection were used as environment variables to reflect the changes of suitable LWfG habitat. These environmental variables significantly improved the model’s performance for LWfG, since the birds were clearly influenced by the plant distribution factors. Meanwhile, the suitable habitat area decreases by 2070 in GCM models under two representative concentration pathways scenarios (RCP2.6 and RCP8.5). More appropriate management and conservation policies should be taken to adapt to future climate change. These adjustments include modifications of the size, shape and use of the conservation area for this species.
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    Effects of Grassland Restoration Approaches in Different Major Function-oriented Zones of the Headwater Region of the Yellow River in China
    WEI Yunjie, ZHEN Lin, DU Bingzhen
    2020, 11 (2):  150-158.  doi: 10.5814/j.issn.1674-764x.2020.02.003
    Abstract ( 90 )   PDF (560KB) ( 17 )   Save
    Given the high alpine grassland coverage and intensive animal grazing activity, the ecosystem and livelihood of the herders are extremely vulnerable in the headwater region of the Yellow River. A series of programs have been implemented by the Chinese government to restore degraded grasslands in this region, and major function-oriented zones (MFOZs) applied in 2014, have divided the region into three zones, i.e., the development prioritized, restricted, and prohibited zones, based on environmental carrying capacity, as well as the utilization intensity of grassland. This study identified various restoration approaches adopted in different MFOZs, and assessed the effects of the approaches in order to determine the most effective approaches. We collected 195 questionnaires from herders to analyze the effects of the various restoration approaches, and additional remote sensing and statistical data were also used for the analysis. Four distinct differences in the ecological and socioeconomic characteristics were found in three MFOZs. (1) Five technologies were applied in the study areas. (2) The grassland recovery rate was higher in development prioritized zones than in restricted and prohibited zones during 2000 and 2016, and especially high and very high coverage grasslands increased in the areas where crop-forage cultivation and grass seeding dominated in the prioritized zones. (3) The net income of households in the development prioritized zone was the best of all three zones. (4) The degree of awareness and willingness of herders to restore grassland was more positive in development prioritized zones than in restricted zones, where more herders adopted approaches with a combination of enclosure + deratization + crop-forage cultivation + warm shed. Based on these findings, it is recommended that decision-makers need to increase their efforts to narrow the gap of willingness and behavior between herders and other stakeholders, such as researchers and grassland administrators, in order to ensure grassland sustainability in the MFOZs. It is also beneficial to understand the effects of restoration on the ecological carrying capacities in different zones depending on the different development goals.
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    Effects of Vegetation Cover, Grazing and Season on Herbage Species Composition and Biomass: A Case Study of Yabello Rangeland, Southern Ethiopia
    Yeneayehu FENETAHUN, XU Xinwen, YOU Yuan, WANG Yongdong
    2020, 11 (2):  159-170.  doi: 10.5814/j.issn.1674-764x.2020.02.004
    Abstract ( 84 )   PDF (821KB) ( 5 )   Save
    The Yabello rangeland is a semi-arid area in Borana, Ethiopia that is facing great degradation challenges. Increasing infestation of vegetation cover, over grazing and high seasonal variation have significantly affected the herbage composition and biomass in the Yabello rangeland. This study focused on assessing the effect of vegetation cover, grazing and season on both herbage composition and biomass in the Yabello rangeland. An experiment was conducted using randomized plots of 1 m × 1 m. Sites were selected based on vegetation cover type and grazing variation, and seasonal impacts were also assessed. Data on herbage composition, height and mass with respect to those parameters were analyzed using SAS statistical software version 9.1 (SAS Institute, 2001) and Microsoft Excel. A total of 26 grass species were recorded and Chloris roxburghiana Chrysopogon aucheri and Chrysopogon aucheri grass species showed the highest average single species cover height and biomass production, for all the sites among all parameters. As a result, those grass species are highly recommended for the rehabilitation of degraded rangeland in the study area. This study also showed that vegetation cover type grazing and seasonal variation were the key factors in determining herbage species composition, height and biomass production. Finally, we recommended that sustainable management which controls bush vegetation cover and balances grazing levels is essential for sustainable herbage production and biodiversity conservation in the area.
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    A Case Study of Allocasuarina robusta Recovery Using History and Biogeography to Identify Future Priorities
    MATTHEW W Pearson
    2020, 11 (2):  171-181.  doi: 10.5814/j.issn.1674-764x.2020.02.005
    Abstract ( 70 )   PDF (1776KB) ( 5 )   Save
    Identifying the cause of a threatened species can aid in how best to formulate recovery actions. Recovery can be based on broad concepts and may not reflect a specific community or species requirements. Urban sprawl and intensification of land are known as threatening processes. How a threatening process interacts with a threatened species can aid in the recovery efforts. In South Australia, the species Allocasuarina robusta provides an opportunity to understand how past land usage may direct recovery efforts. Information on past land usage can involve identifying and using data from multiple repositories. The investigation focused on the relationship between changes in land use and herbarium data to understand a relationship between a common and threatened species. As a species evolves and adapts, the conservation practices used, including the methods used for identifying future actions, needs to be reflective of a changing environment. A changing environment can have consequences to biodiversity, creating several issues for a land manager. Traditional species recovery techniques can slow the threatening process down. Sometimes these threats may be visible like grazing from fauna (native and introduced). The threat to Allocasuarina robusta is a change in land use originating from anthropogenic activities. Supplementary planting with tube stock is a well-grounded practice, but the implications from this practice may need further investigation. Natural regeneration is crucial for long term population survival, but in Allocasuarina robusta, this is not occurring. The Allocasuarina robusta investigation aims to explore the relationships between herbarium data and land-use histories to guide future recovery efforts.
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    A Study of China’s Air Pollution Prevention and Control Policy Framework from a Policy Instrument Perspective
    QIN Qin, SUN Youhai
    2020, 11 (2):  182-190.  doi: 10.5814/j.issn.1674-764x.2020.02.006
    Abstract ( 107 )   PDF (585KB) ( 17 )   Save
    Environmental pollution caused by rapid economic development like that seen in China over the past twenty years poses various threats to human health. People have started to place much more of an emphasis on environmental security, working to find a balance between sustainability and economic growth. In recent years, air pollution has emerged as a highly discussed topic of social and environmental relevance in China, due in part to persistent smog that affects everyday life and causes serious harm to human health. Although air pollution is normally associated with human activity, is can be caused by natural processes such as eruptions and forest fires, but is always characterized by the release of certain substances into the atmosphere which, when present in certain concentrations or for given durations, can harm human health, daily life, productivity, and other aspects. In humans, it mainly affects the respiratory system, notably the lungs, as well as the immune system. A series of studies both in China and overseas have shown, in certain cases, even low concentrations of air pollution can pose a great threat to human health. In this study, we conducted an analysis of air quality policies, focusing on the 2018 revision of the People’s Republic of China’s Law on the Prevention and Control of Air Pollution (LPCAP). We utilized the content analysis method and Strauss and Corbin’s grounded theory to construct a policy framework, demarcate analysis units, code and classify policy texts, determine descriptive statistics, and analyze dimensional interactions. We used two dimensions (basic policy instruments classified as demand-, supply-, and environment-side; and air carrying capacity) to quantify and analyze the LPCAP, which enabled us to analyze the deficiencies and conflicts within policy instruments. The results show a higher utilization frequency of environment-side policy instruments, particularly regulation management and strategic measures. This reflects efforts by the government to create a favorable environment for improving air quality. Additionally, supply-side policy instruments are used far less frequently than environment-side policy instruments. Air quality legal policies and pollution control measures mainly consist of environment-side policy instruments; ecological thinking and air quality policies that are based mainly on supply-side and environment-side policy instruments; and social coordination policies that mainly use environment-side policy instruments. Based on the results of this study, we recommend an increase in the number of supply- and demand-side policy instruments, particularly the latter which includes promoting ecological thinking amongst citizens, to optimize and improve air pollution prevention and control policies.
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    Spatial Distribution Pattern of the Catering Industry in A Tourist City: Taking Lhasa City as A Case
    LI Yunyun, LIU Haiyang, WANG Ling-en
    2020, 11 (2):  191-205.  doi: 10.5814/j.issn.1674-764x.2020.02.007
    Abstract ( 147 )   PDF (1036KB) ( 9 )   Save
    Affected by factors such as the city’s functional orientation and tourism consumption, the spatial layout of the catering industry in a tourism city has its own distinctive characteristics. The spatial distribution characteristics of the catering industry and the factors impacting it (from the perspectives of transportation, tourism resources and population) in the main city area of Lhasa, Tibet were analysed through point of interest data mining, average nearest neighbour analysis, a standard deviational ellipse, kernel density estimation, and buffer analysis in ArcGIS software. As a result, the spatial distribution pattern showed catering providers are mainly aggregated in the vicinity of areas with either developed transportation or rich tourism resources. The resident population has an important but inconclusive influence on the distribution, while the distribution of its concentration is highly consistent with that of the instant population. Considering the spatial structure, functional orientation, and tourism development of the area, measures are proposed for optimizing the spatial layout of the catering industry in this tourism-heavy plateau city.
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    The Threshold Effect of Rationalization of Industrial Structure on Air Quality in Shanxi Province
    ZHU Meifeng, WU Qinglong, ZHANG Huaming, CHEN Zhanbo
    2020, 11 (2):  206-212.  doi: 10.5814/j.issn.1674-764x.2020.02.008
    Abstract ( 63 )   PDF (363KB) ( 4 )   Save
    Shanxi Province is a typical resource-based region. After years of economic transformation, the air quality has been at a low level for a long time. The rationalization of industrial structure can measure the effect of economic transformation and whether it has an important impact on air quality. Therefore, it is necessary to study the non-linear impact that the rationalization of industrial structure has had on air quality at different stages, which is of positive significance for the continuing transformation and upgrading of resource-based regions. This study constructs a threshold regression model based on the panel data of 11 provincial cities in Shanxi Province from 2004 to 2016. The results show that the rationalization of industrial structure had a double threshold effect on air quality under different threshold variables. On the whole, optimizing the rationalization of industrial structure in Shanxi Province can improve air quality, and the improvement effect dropped first, and then began to rise. As a result, the current energy transformation and upgrading process should focus on the rationalization of industrial structure to solve the conflict between air quality and economic development.
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    Optimum Solution for the Safe Drinking Water Crisis in Tala Upazila, Bangladesh
    Sajidur RAHMAN, ZHAO Junkai
    2020, 11 (2):  213-222.  doi: 10.5814/j.issn.1674-764x.2020.02.009
    Abstract ( 92 )   PDF (5238KB) ( 16 )   Save
    Coastal areas of Bangladesh are especially vulnerable due to their physiographic location and exposure to natural calamities. Around 35 million people living in coastal areas have no access or limited access to safe drinking water. Contamination of water sources by salinity, arsenic or iron are the principal causes of water scarcity. Rising sea levels and unevenness of climatic events due to climate change will exacerbate the situation in coastal areas, especially in the southwestern coastal zone. This study examines one of the vulnerable coastal upazila Tala at Satkhira (an “upazila” is a medium level administrative unit in Bangladesh) in the southwestern zone of Bangladesh to understand the gravity of the problems. The study develops a GIS based multi-criteria analysis to identify suitable options and locations of fresh water as part of a current and future solution to the problems and further deterioration. To fulfill the objectives, a questionnaire-based GPS guided field survey was conducted to collect details of field level conditions in order to find a suitable solution. Because aquifers are considered the primary source of drinking water, field data have been analyzed for two distinct aquifers, one relatively shallow and one deeper, to understand aquifer quality. Potentiality of different water sources the socioeconomic status of communities, types of water use and corresponding sources and water demand are also evaluated. The analysis finds that alternative water sources that are safe are difficult to find, because both surface and groundwater-based sources are already contaminated, and there are no nearby, easily accessible safe sources. Groundwater-based sources are contaminated by arsenic, iron or salinity, and surface water-based sources are not in use due to maintenance and management issues. In some cases, surface water sources are polluted by flash flooding of high saline water during storm surges or seepage from saline water-based aquacultures. Multiple limitations identified during field observations and field data analysis were considered as an analytical parameter A GIS based multi-criteria analysis incorporated field data, including Geo-spatial and socioeconomic information for road networks, settlement locations, number of households, quality and quantity of existing water sources, water demand and business opportunities. The analysis found some potential options in distributed locations which are consistent with community demand. Suggested options made use of technologies that are already understood and commonly used by communities, like deep tubewells, PSFs (Pond Sand Filter) and WTPs (Water Treatment Plant). In the study area, PSF is the most commonly used method and to make this surface water-based technology sustainable some precautionary measurements are suggested.
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    Change in the Distribution of National Bird (Himalayan Monal) Habitat in Gandaki River Basin, Central Himalayas
    Raju RAI, Basanta PAUDEL, GU Changjun, Narendra Raj KHANAL
    2020, 11 (2):  223-231.  doi: 10.5814/j.issn.1674-764x.2020.02.010
    Abstract ( 98 )   PDF (5933KB) ( 7 )   Save
    Gandaki River Basin (GRB) is part of the central Himalayan region, which provides habitat for numerous wild species. However, due to changes in climate and land cover, the habitats of many protected species are at risk. Based on the maximum entropy (MaxEnt) model, coupled with bioclimatic layers, land cover and DEM data, the impacts of environmental factors on habitat suitability of Himalayan Monal (Lophophorus impejanus), a national bird of Nepal, was quantified. This study further assessed the present and future habitat and distribution of the Himalayan Monal in the context of climate and land cover changes. The results of this study show that the highly suitable habitat of Himalayan Monal presently occupies around 749 km2 within the northern, eastern and western parts, particularly protected areas such as Langtang National Park, Manaslu Conservation Area and Annapurna Conservation Area, while it is likely to decrease to 561 km2 by 2050, primarily in the northern and northwestern parts (i.e., Chhyo, Tatopani, Humde and Chame). These expected changes indicate increasing risk for Himalayan Monal due to a decline in its suitable habitat area.
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    Spatial Analysis and Biogeochemical Cycles: A Comparative Study of Kashin-Beck Disease Villages and Non-disease Villages in Linzhou County, Tibet
    TIAN Yuan, ZHA Xinjie, GAO Xing, DAI Erfu, YU Chengqun
    2020, 11 (2):  232-246.  doi: 10.5814/j.issn.1674-764x.2020.02.011
    Abstract ( 70 )   PDF (4628KB) ( 2 )   Save
    This study investigated Linzhou County in Tibet, which currently hosts the most serious outbreak of Kashin-Beck disease (KBD) in China. This study uses the geographical detector (GeoDetector) algorithm to measure the influences that several risk factors have on KBD prevalence and validates the spatial analysis results with environmental chemistry. Based on a comprehensive examination of 10 potentially related spatial factors and an environmental chemistry analysis of the soil-water-grain-human biogeochemical cycle in the local KBD and non-KBD villages, four main conclusions are drawn. (1) KBD in Linzhou County is a consequence of multiple interrelated environmental factors, of which the most important controlling factor is the stratum factor. (2) The concentrations of selenium (Se) in all environmental media (soil, water, and food) and human tissue in the KBD villages in Linzhou County are lower than those of the non-KBD villages. (3) The intake of Se and chromium (Cr) by local residents is seriously insufficient, especially the average daily dose by ingestion (ADD) for Se in the KBD village, which is only about 4% of the World Health Organization (WHO) recommended lower limit for adult elemental intake. (4) We speculate that the main cause for the local KBD outbreak is a lack of Se in the stratum. This absence leads to a serious Se deficiency in the local population through ecosystem migration and transformation, which will eventually lead to an endemic biogeochemical Se deficiency.
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