Shikui Dong - Academia.edu (original) (raw)
Papers by Shikui Dong
Current Research in Agricultural Sciences, 2020
Contribution/Originality: This study is one of the few studies that investigate plant diversity, ... more Contribution/Originality: This study is one of the few studies that investigate plant diversity, regeneration and soil properties across PAs in Sierra Leone. The research contributes to the existing literatures in PAs and their ecosystem characteristics. The article concludes that; PAs in Sierra Leone plant diversity and richness and regeneration ability is low.
New Zealand Journal of Agricultural Research, 2005
In the alpine region of the Tibetan Plateau, five perennial grass cultivars, Bromus inermis (B), ... more In the alpine region of the Tibetan Plateau, five perennial grass cultivars, Bromus inermis (B), Elymus nutans (E), Clinelymus nutans (C), Agropyron cristatum (A), and Poa crymophila (P) were combined into nine communities with different compositions and ratios,
PloS one, 2013
The deterioration of alpine grassland has great impact on ecosystem services in the alpine region... more The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassl...
International Journal of Mining Science (IJMS)
Sierra Leone is endowed with abundant natural resources that have potential to transform the liv... more Sierra Leone is endowed with abundant natural resources that have potential to transform the lives of its citizens if sustainably utilized. Although the blueprint of mining in Sierra Leone is characterized
by environmental degradation, but the sector also has positive impact on society. Since 1930, mineral extraction incomes have been helping to forge socio-economic development in the small nation although
critics argue that the impact is barely felt or seen. Over the years, mineral resources have been the main source of export and direct foreign exchange earning for Sierra Leone. Artisanal and large-scale mining
have provided jobs for thousands of people of Sierra Leone over the past decades. Income from mining especially in rural community’s support livelihood and regulate the local economy in mining communities.
Revenues generated from mining in the form of taxes, exploration fees, environmental impact assessment and monitoring fees, surface rent, license fees and customs taxes among others have help the government in undertaking massive infrastructural development across the country. Mining companies over the years have built schools, clinics, police stations, community centers, bridges, engaged in road maintenance, provide scholarship for outstanding student within the mining communities, support agribusiness ventures, support sporting activities and provided loan to local for business startups as part of their corporate social responsibilities. Nonetheless, improper reporting, corruption, civil war, weak mining policies, inadequate reporting of revenue collected from and lack of transparency prompted public mistrust on benefits of mining in Sierra Leone. It is recommended that revenue generated by mining companies be made public and
corporate social responsibilities (CSR) undertaken be published regularly.
The Rangeland Journal, 2015
This special issue covers a wide range of topics on the protection and sustainable management of ... more This special issue covers a wide range of topics on the protection and sustainable management of alpine rangelands on the Qinghai-Tibetan Plateau (QTP), including Indigenous knowledge of sustainable rangeland management, science-policy interface for alpine rangeland biodiversity conservation, adaptations of local people to social and environmental changes and policy design for managing coupled human-natural systems of alpine rangelands.
Sustainability , 2020
Grassland ecosystems on the Qinghai-Tibet Plateau (QTP) provide numerous ecosystem services and f... more Grassland ecosystems on the Qinghai-Tibet Plateau (QTP) provide numerous ecosystem services and functions to both local communities and the populations living downstream through the provision of water, habitat, food, herbal medicines, and shelter. This review examined the current ecological status, degradation causes, and impacts of the various grassland degradation mitigation measures employed and their effects on grassland health and growth in the QTP. Our findings revealed that QTP grasslands are continually being degraded as a result of complex biotic and abiotic drivers and processes. The biotic and abiotic actions have resulted in soil erosion, plant biomass loss, soil organic carbon loss, a reduction in grazing and carrying capacity, the emergence of pioneer plant species, loss of soil nutrients, and an increase in soil pH. A combination of factors such as overgrazing, land-use changes, invasive species encroachment, mining activities, rodent burrowing activities, road and dam constructions, tourism, migration, urbanization, and climate change have caused the degradation of grasslands on the QTP. A conceptual framework on the way forward in tackling grassland degradation on the QTP is presented together with other appropriate measures needed to amicably combat grassland degradation on the QTP. It is recommended that a comprehensive and detailed survey be carried out across the QTP to determine the percentage of degraded grasslands and hence, support a sound policy intervention.
EURASIAN JOURNAL OF SOIL SCIENCE, 2015, 4(1): 22-29, Jan 1, 2015
Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam wer... more Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam were studied to demonstrate the spatial distribution of heavy metals in the sediments and to assess their risk. Correlation analysis showed that the spatial distribution of Cd, Zn and Mg were significantly affected by dam construction. PCA analysis demonstrate that Cd and Zn were both controlled by Ca, As, Pb, organic matter and clay. Mg was controlled by silt, Al, P and K. The risk assessment demonstrated that the pollution of Cd, As, Zn were more serious than other heavy metals. Fine-grained sediments with higher risk level were found in the section near the upstream of dam, while coarse-grained ones with lower risk level were found in the section far away from the downstream of dam. The sections in tributary were lower in risk than those in the main stream. Heavy metal concentrations in the mainstream sediments were influenced by dam construction and those in tributary were influenced by both dam construction and human activities in locality. Unusual high concentrations of Cd, As, and Zn in both sections implied that more pollution prevention measures are needed in the Manwan Dam in order to prevent increased heavy metal pollutions in the Lancang-Mekong River.
Stochastic Environmental Research and Risk Assessment, 2013
ABSTRACT Regional ecological degradation induced by hydroelectric project construction (HPC) is o... more ABSTRACT Regional ecological degradation induced by hydroelectric project construction (HPC) is of great concern in the field of landscape ecology research. Using GIS-based spatial analysis, we predicted and assessed the impacts of HPC on the ecological integrity of the Nuozhadu Nature Reserve (NNR). The results show that, after Nuozhadu HPC, the naturality of the NNR will be modified due to changes in the landscape composition such that larger areas covered by vegetation will be occupied by construction land and flooded by water areas. Meanwhile, landscape diversity will increase due to the additional landscape types of construction land and submerged areas, while landscape stability will decrease because of the splitting and contagion of the landscape after Nuozhadu HPC. The human disturbance index shows that the HPC will contribute to increasing the disturbance of the ecosystem. From buffer analyses, we conclude that the impacts of HPC will mainly occur in buffer zones over the distance of 800 m from the Lancang River in the NNR, and tend to be moderate in the 800–5,000 m buffer zone. Therefore, within the 800 m buffer zone, taking the naturality, diversity and stability of the ecosystem as well as anthropogenic interference as evaluation indicators, we calculated the ecological integrity index; the results indicate that the ecological integrity of the NNR will decrease by 7.6 % after project construction.
Inoculated with compost from methane oxidation habitats, the differences of methane oxidation cap... more Inoculated with compost from methane oxidation habitats, the differences of methane oxidation capacity were compared and investigated after suspended-growth process and attached-growth process. The result showed that the ceramsite-compost matrix was formed in short time (3d) under the suspended growth condition and its methane oxidation capacity increased remarkably. The peak methane oxidation rate was 52.7g CH4·m-3·h-1 after suspended-growth process. However,
Chemosphere, 2015
We detected the longitudinal variability of phosphorus speciations and its relation to metals and... more We detected the longitudinal variability of phosphorus speciations and its relation to metals and grain size distribution of sediments in three cascade canyon reservoirs (Xiaowan, Manwan and Dachaoshan) along Lancang River, China. Five phosphorus speciations including loosely bound P (ex-P), reductant soluble P (BD-P), metal oxide-bound P (NaOH-P) calcium-bound P (HCl-P) and residual-P were extracted and quantified. Results showed that in Manwan Reservoir HCl-P accounted for the largest part of total phosphorus (TP) (49.69%), while in Xiaowan and Dachaoshan reservoirs, NaOH-P was the most abundant speciation which accounted for 57.21% and 55.19% of total phosphorus respectively. Higher contents of bio-available phosphorus in Xiaowan and Dachaoshan reservoirs suggested a high rate of P releasing from sediments. Results also showed ex-P and HCl-P had positive correlation with Ca. Total phosphorus was positively correlated with Fe. The silt/clay contents of the sediments had close relationship with ex-P (r=0.413, p<0.05), NaOH-P (r=0.428, p<0.05) and BAP (r=0.458, p<0.05). The concentration of Ca, Mn and silt/clay speciation in the sediments explained 40%, 10% and 4% of the spatial variation of phosphorus speciations, respectively.
International journal of nanomedicine, 2014
Water Resources Management, 2009
Along with the sequent completion of Manwan and Dachaoshan Dam, the river continuum of the middle... more Along with the sequent completion of Manwan and Dachaoshan Dam, the river continuum of the middle and lower reaches of the Lancang River was separated into three types of segments: reservoir, below-dam segment and downstream flowing segment. The long-term series of water quality and river flow data over 20 years were analyzed in order to study the impact of dam construction and operation on water quality and water self-purification capacity of these different river segments. From pre-dam period to the first 7 years after Manwan Dam had been accomplished, the water quality of Manwan Reservoir became worse due to the accumulation of pollutants, and then to the next 5 years the water quality became better in virtue of the water self-purification of the reservoir. The cooperative operation of Manwan and Dachaoshan Dam had cumulatively positive impacts on water quality of their below-dam segment but no impacts on that of downstream flowing segment. From pre-dam period to the first 7 years after the closure of Manwan Dam, the water self-purification capacity of Xiaowan–Manwan segment for BOD5, CODMn and NH3–N decreased. Also, the water self-purification capacity of Manwan–Dachaoshan segment for BOD5 and CODMn decreased but for NH3–N increased. However, the water self-purification capacity of Jinghong–Ganlanba segment changed contrary to Manwan–Dachaoshan segment. In general, the construction of Manwan Dam negatively affected the water self-purification capacity of reservoir and below-dam segment but impose little impact on that of downstream flowing segment. This study suggested that it is necessary to pay attention to the effect of complicated temporal and spatial characteristics of dam on aquatic ecosystem.
![Research paper thumbnail of Corrigendum to “Characterizing the “fragmentation–barrier” effect of road networks on landscape connectivity: A case study in Xishuangbanna, Southwest China” [Landscape Urban Plan. 95 (3) (2010) 122–129]](https://attachments.academia-assets.com/46554694/thumbnails/1.jpg)
](Landscape and Urban Planning, 2010
Landscape and Urban Planning, 2010
The “fragmentation–barrier” effect of road network expansion on landscape function draws attentio... more The “fragmentation–barrier” effect of road network expansion on landscape function draws attention throughout the world. Presently, there is a lack of quantitative analysis to integrate different ecological effects of road networks at landscape scale to depict, compare and evaluate landscape changes. In this study, the “Probability of Connectivity (PC)” index was used to evaluate the effects of road networks on landscape connectivity for an area in Xishuangbanna, Southwest China. The results indicate that the fragmentation effect of road networks decreased in PC value by 15.81%, the barrier effect of road networks decreased in PC value by 11.73% and the combination of the two effects decreased PC value by 32.78%. In conclusion, the combined fragmentation and barrier effects of road networks considerably degraded landscape connectivity more than either individual effect. In addition, the fragmentation effect influenced connectivity to a greater degree for ecological processes having low movement abilities. The barrier effect influenced connectivity to a greater degree for medium to high movement abilities. The combined effects influenced connectivity for those ecological processes of low movement ability within the study area.
Procedia Environmental Sciences, 2010
Selecting Manwan Dam as a study case, we studied the spatial-temporal change of land use during 1... more Selecting Manwan Dam as a study case, we studied the spatial-temporal change of land use during 1974, 1991 and 2004 based on the application of RS interpretation and GIS buffer analysis. Land use indices within three buffer distances from dam centre were calculated to quantify the effects of dam construction. The results showed that land use structure changed greatly during and after dam construction. Forestland and grassland were two main types of land use, which occupied over 79.70% of total area in 10000 m buffer. The main conversion of land use types took place from forest land to grass and farm land between 1974 and 1991, and that was almost consistent between 1991 and 2004 . During 1974 -1991, spatial dynamics of grass, farm and construction land were much larger than water body and forest land, and had an increasing tendency and the balanced state decreased with the increased off-dam distances which indicated that conversion of input and output were frequently between the three land use types. During 1991During -2004, water body had the largest value of R ss , in a state of extreme non-balanced with its P s reached 0.96, 0.96 and 0.99 in 10000, 5000 and 1000 m buffer, respectively. Further studies showed that direct effect was limited in the 1000 m buffer region based on the land use indices including temporal dynamics of land use change (R s ), spatial dynamics of land use change (R ss ,) and tendency and state index (P s ). Generally, three indices of each land use type decreased with the increased off-dam distances.
Transportation Research Part D: Transport and Environment, 2011
The paper presents the results of a case study carried out in Xishuangbanna, Southwest China, to ... more The paper presents the results of a case study carried out in Xishuangbanna, Southwest China, to examine the relationship between vegetation dynamics and road network extension. We find that lower level roads had more effects on vegetation patches. Minor roads, including Class IV and Class V roads, contributed most to regional landscape fragmentation while high level roads had larger effect
PLoS ONE, 2013
Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increas... more Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increases the release rate of internal phosphorus (P) loading. This study investigated the longitudinal variability of phosphorus fractions in sediments and the relationship between the contents of phosphorus fractions and its influencing factors of the Manwan Reservoir, Lancang River, Yunnan Province, China. Five sedimentary phosphorus fractions were quantified separately: loosely bound P (ex-P); reductant soluble P (BD-P); metal oxide-bound P (NaOH-P); calcium-bound P (HCl-P), and residual-P. The results showed that the total phosphorus contents ranged from 623 to 899 mg/g and were correlated positively with iron content in the sediments of the reservoir. The rank order of P fractions in sediments of the mainstream was HCl-P.NaOH-P.residual-P.BD-P.ex-P, while it was residual-P.HCl-P.NaOH-P.BD-P.ex-P in those of the tributaries. The contents of bio-available phosphorus in the tributaries, including ex-P, BD-P and NaOH-P, were significantly lower than those in the mainstream. The contents of ex-P, BD-P, NaOH-P showed a similar increasing trend from the tail to the head of the Manwan Reservoir, which contributed to the relatively higher content of bio-available phosphorus, and represents a high bioavailable phosphorus releasing risk within a distance of 10 km from Manwan Dam. Correlation and redundancy analyses showed that distance to Manwan Dam and the silt/clay fraction of sediments were related closely to the spatial variation of bio-available phosphorus.
… monitoring and assessment, 2009
The disturbance of highway construction upon surrounding vulnerable ecosystems is a common threat... more The disturbance of highway construction upon surrounding vulnerable ecosystems is a common threat in the Longitudinal Range Gorge Region of southwestern China. We evaluated the disturbance of highway on plant species richness and diversity and soil nutrients from adjacent to the highway to 300 m upslope and 100 m downslope in forests and grasslands by setting 12 belt transects in forests and grasslands (six belt transects and six control belt transects, respectively). The results showed that there were some significant variances in belt transects with respective control belt transects for species richness and diversity in both forests and grasslands. Species richness and diversity of trees were lower within a 50-m distance from the highway and more noticeable on the downslope portion. Species richness and diversity of shrubs and herbs appeared higher near highway edge. Both species richness and diversity of herbs were similar in forests. In addition, exotic species, such as Eupatorium adenophorum, were further from the road and more widely dispersed in grasslands. Soil nutrients except total potassium (TK) were lower in the downslope area adjacent to highway edge and showed a significant increase with increasing distance from the highway in both forests and grasslands. This indicates that grasslands acted as microhabitats for exotic species and are more easily to be invaded than forests, especially if disturbed. Once destroyed, plant species and soil nutrients will require a significant amount of time to be restored to control levels. This work illustrates that the effects extend considerably to distances upslope and downslope from the construction site. Given that these changes occurred relatively quickly, the study suggests that the environmental "footprint" grows far beyond the road and adjacent zone of disruption.
Journal of environmental …, 2009
Rangelands represent one of the most important natural resources in mountainous regions of northe... more Rangelands represent one of the most important natural resources in mountainous regions of northern Nepal. However, a poor understanding of the social dimensions of rangeland use has limited their proper management and sustainable development, which represent major challenges for Nepal's resource managers. Institutional development is thought to be a viable solution to this problem and may ultimately lead to improved rangeland management in Nepal. Based on this hypothesis, a study was conduced in the Rasuwa district of northern Nepal to examine the effectiveness of institutional development at the local and national levels in mitigating the problems facing sustainable rangeland management by using an institutional analysis and development (IAD) framework. The information and data were mainly collected from different stakeholders, farmers, professionals and practitioners using a toolkit of participatory rural appraisal (PRA), workshops and literature review. It can be concluded from this case study that a number of institutional development efforts are needed to promote sustainable rangeland management in this region. First, local herders represent a repository of rich indigenous knowledge essential to sustaining sound rangeland management practices; hence, indigenous practices need to be integrated into modern technologies. Second, public services and technical support are currently unavailable or inaccessible to local herders; hence, research, development and extension interventions need to be initiated for marginalized pastoral communities. Third, rangeland institutions are incomplete and illorganized, so institutional development of various organizations is necessary for promoting sustainable rangeland management. Fourth, the policies and governance necessary for promoting rangeland management are not well-designed; hence, governance reform and policy development need to be formulated through internal and external agencies and organizations.
Procedia Environmental Sciences, 2010
Road ecologists have dedicated their efforts in analyzing the interactions between road networks ... more Road ecologists have dedicated their efforts in analyzing the interactions between road networks and the surrounding landscape ever since the establishment of Road Ecology. The understanding of the interactions has been promoted by the proposed quantification parameters of road networks' impacts such as road density, buffer zone and so on. Using these parameters, we analyzed the road network's disturbance effect on the landscape pattern with the newly proposed index-RV (Roadless Volume) in the study. Based on the sampling of square quads all over the Longitudinal Range-Gorge Region (LRGR) during 1980-2000, the changes of the different patches such as forest, grassland, cropland and urban land under different disturbance degrees of road networks classified by RV value have been examined. The results showed that: the decreased area and number of forest and arable patches changed with the disturbance degree of road networks' logarithmically; The area and number of grassland decreased at the highest disturbance level but increased in some lower disturbance level; The area of urban land increased at the high disturbance level which followed the logarithmical trend with the disturbance level. These results imply that the road networks generally transformed the landscape pattern from the forest and cropland to large patch of urban land surrounding roads.
Current Research in Agricultural Sciences, 2020
Contribution/Originality: This study is one of the few studies that investigate plant diversity, ... more Contribution/Originality: This study is one of the few studies that investigate plant diversity, regeneration and soil properties across PAs in Sierra Leone. The research contributes to the existing literatures in PAs and their ecosystem characteristics. The article concludes that; PAs in Sierra Leone plant diversity and richness and regeneration ability is low.
New Zealand Journal of Agricultural Research, 2005
In the alpine region of the Tibetan Plateau, five perennial grass cultivars, Bromus inermis (B), ... more In the alpine region of the Tibetan Plateau, five perennial grass cultivars, Bromus inermis (B), Elymus nutans (E), Clinelymus nutans (C), Agropyron cristatum (A), and Poa crymophila (P) were combined into nine communities with different compositions and ratios,
PloS one, 2013
The deterioration of alpine grassland has great impact on ecosystem services in the alpine region... more The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassl...
International Journal of Mining Science (IJMS)
Sierra Leone is endowed with abundant natural resources that have potential to transform the liv... more Sierra Leone is endowed with abundant natural resources that have potential to transform the lives of its citizens if sustainably utilized. Although the blueprint of mining in Sierra Leone is characterized
by environmental degradation, but the sector also has positive impact on society. Since 1930, mineral extraction incomes have been helping to forge socio-economic development in the small nation although
critics argue that the impact is barely felt or seen. Over the years, mineral resources have been the main source of export and direct foreign exchange earning for Sierra Leone. Artisanal and large-scale mining
have provided jobs for thousands of people of Sierra Leone over the past decades. Income from mining especially in rural community’s support livelihood and regulate the local economy in mining communities.
Revenues generated from mining in the form of taxes, exploration fees, environmental impact assessment and monitoring fees, surface rent, license fees and customs taxes among others have help the government in undertaking massive infrastructural development across the country. Mining companies over the years have built schools, clinics, police stations, community centers, bridges, engaged in road maintenance, provide scholarship for outstanding student within the mining communities, support agribusiness ventures, support sporting activities and provided loan to local for business startups as part of their corporate social responsibilities. Nonetheless, improper reporting, corruption, civil war, weak mining policies, inadequate reporting of revenue collected from and lack of transparency prompted public mistrust on benefits of mining in Sierra Leone. It is recommended that revenue generated by mining companies be made public and
corporate social responsibilities (CSR) undertaken be published regularly.
The Rangeland Journal, 2015
This special issue covers a wide range of topics on the protection and sustainable management of ... more This special issue covers a wide range of topics on the protection and sustainable management of alpine rangelands on the Qinghai-Tibetan Plateau (QTP), including Indigenous knowledge of sustainable rangeland management, science-policy interface for alpine rangeland biodiversity conservation, adaptations of local people to social and environmental changes and policy design for managing coupled human-natural systems of alpine rangelands.
Sustainability , 2020
Grassland ecosystems on the Qinghai-Tibet Plateau (QTP) provide numerous ecosystem services and f... more Grassland ecosystems on the Qinghai-Tibet Plateau (QTP) provide numerous ecosystem services and functions to both local communities and the populations living downstream through the provision of water, habitat, food, herbal medicines, and shelter. This review examined the current ecological status, degradation causes, and impacts of the various grassland degradation mitigation measures employed and their effects on grassland health and growth in the QTP. Our findings revealed that QTP grasslands are continually being degraded as a result of complex biotic and abiotic drivers and processes. The biotic and abiotic actions have resulted in soil erosion, plant biomass loss, soil organic carbon loss, a reduction in grazing and carrying capacity, the emergence of pioneer plant species, loss of soil nutrients, and an increase in soil pH. A combination of factors such as overgrazing, land-use changes, invasive species encroachment, mining activities, rodent burrowing activities, road and dam constructions, tourism, migration, urbanization, and climate change have caused the degradation of grasslands on the QTP. A conceptual framework on the way forward in tackling grassland degradation on the QTP is presented together with other appropriate measures needed to amicably combat grassland degradation on the QTP. It is recommended that a comprehensive and detailed survey be carried out across the QTP to determine the percentage of degraded grasslands and hence, support a sound policy intervention.
EURASIAN JOURNAL OF SOIL SCIENCE, 2015, 4(1): 22-29, Jan 1, 2015
Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam wer... more Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam were studied to demonstrate the spatial distribution of heavy metals in the sediments and to assess their risk. Correlation analysis showed that the spatial distribution of Cd, Zn and Mg were significantly affected by dam construction. PCA analysis demonstrate that Cd and Zn were both controlled by Ca, As, Pb, organic matter and clay. Mg was controlled by silt, Al, P and K. The risk assessment demonstrated that the pollution of Cd, As, Zn were more serious than other heavy metals. Fine-grained sediments with higher risk level were found in the section near the upstream of dam, while coarse-grained ones with lower risk level were found in the section far away from the downstream of dam. The sections in tributary were lower in risk than those in the main stream. Heavy metal concentrations in the mainstream sediments were influenced by dam construction and those in tributary were influenced by both dam construction and human activities in locality. Unusual high concentrations of Cd, As, and Zn in both sections implied that more pollution prevention measures are needed in the Manwan Dam in order to prevent increased heavy metal pollutions in the Lancang-Mekong River.
Stochastic Environmental Research and Risk Assessment, 2013
ABSTRACT Regional ecological degradation induced by hydroelectric project construction (HPC) is o... more ABSTRACT Regional ecological degradation induced by hydroelectric project construction (HPC) is of great concern in the field of landscape ecology research. Using GIS-based spatial analysis, we predicted and assessed the impacts of HPC on the ecological integrity of the Nuozhadu Nature Reserve (NNR). The results show that, after Nuozhadu HPC, the naturality of the NNR will be modified due to changes in the landscape composition such that larger areas covered by vegetation will be occupied by construction land and flooded by water areas. Meanwhile, landscape diversity will increase due to the additional landscape types of construction land and submerged areas, while landscape stability will decrease because of the splitting and contagion of the landscape after Nuozhadu HPC. The human disturbance index shows that the HPC will contribute to increasing the disturbance of the ecosystem. From buffer analyses, we conclude that the impacts of HPC will mainly occur in buffer zones over the distance of 800 m from the Lancang River in the NNR, and tend to be moderate in the 800–5,000 m buffer zone. Therefore, within the 800 m buffer zone, taking the naturality, diversity and stability of the ecosystem as well as anthropogenic interference as evaluation indicators, we calculated the ecological integrity index; the results indicate that the ecological integrity of the NNR will decrease by 7.6 % after project construction.
Inoculated with compost from methane oxidation habitats, the differences of methane oxidation cap... more Inoculated with compost from methane oxidation habitats, the differences of methane oxidation capacity were compared and investigated after suspended-growth process and attached-growth process. The result showed that the ceramsite-compost matrix was formed in short time (3d) under the suspended growth condition and its methane oxidation capacity increased remarkably. The peak methane oxidation rate was 52.7g CH4·m-3·h-1 after suspended-growth process. However,
Chemosphere, 2015
We detected the longitudinal variability of phosphorus speciations and its relation to metals and... more We detected the longitudinal variability of phosphorus speciations and its relation to metals and grain size distribution of sediments in three cascade canyon reservoirs (Xiaowan, Manwan and Dachaoshan) along Lancang River, China. Five phosphorus speciations including loosely bound P (ex-P), reductant soluble P (BD-P), metal oxide-bound P (NaOH-P) calcium-bound P (HCl-P) and residual-P were extracted and quantified. Results showed that in Manwan Reservoir HCl-P accounted for the largest part of total phosphorus (TP) (49.69%), while in Xiaowan and Dachaoshan reservoirs, NaOH-P was the most abundant speciation which accounted for 57.21% and 55.19% of total phosphorus respectively. Higher contents of bio-available phosphorus in Xiaowan and Dachaoshan reservoirs suggested a high rate of P releasing from sediments. Results also showed ex-P and HCl-P had positive correlation with Ca. Total phosphorus was positively correlated with Fe. The silt/clay contents of the sediments had close relationship with ex-P (r=0.413, p<0.05), NaOH-P (r=0.428, p<0.05) and BAP (r=0.458, p<0.05). The concentration of Ca, Mn and silt/clay speciation in the sediments explained 40%, 10% and 4% of the spatial variation of phosphorus speciations, respectively.
International journal of nanomedicine, 2014
Water Resources Management, 2009
Along with the sequent completion of Manwan and Dachaoshan Dam, the river continuum of the middle... more Along with the sequent completion of Manwan and Dachaoshan Dam, the river continuum of the middle and lower reaches of the Lancang River was separated into three types of segments: reservoir, below-dam segment and downstream flowing segment. The long-term series of water quality and river flow data over 20 years were analyzed in order to study the impact of dam construction and operation on water quality and water self-purification capacity of these different river segments. From pre-dam period to the first 7 years after Manwan Dam had been accomplished, the water quality of Manwan Reservoir became worse due to the accumulation of pollutants, and then to the next 5 years the water quality became better in virtue of the water self-purification of the reservoir. The cooperative operation of Manwan and Dachaoshan Dam had cumulatively positive impacts on water quality of their below-dam segment but no impacts on that of downstream flowing segment. From pre-dam period to the first 7 years after the closure of Manwan Dam, the water self-purification capacity of Xiaowan–Manwan segment for BOD5, CODMn and NH3–N decreased. Also, the water self-purification capacity of Manwan–Dachaoshan segment for BOD5 and CODMn decreased but for NH3–N increased. However, the water self-purification capacity of Jinghong–Ganlanba segment changed contrary to Manwan–Dachaoshan segment. In general, the construction of Manwan Dam negatively affected the water self-purification capacity of reservoir and below-dam segment but impose little impact on that of downstream flowing segment. This study suggested that it is necessary to pay attention to the effect of complicated temporal and spatial characteristics of dam on aquatic ecosystem.
Landscape and Urban Planning, 2010
Landscape and Urban Planning, 2010
The “fragmentation–barrier” effect of road network expansion on landscape function draws attentio... more The “fragmentation–barrier” effect of road network expansion on landscape function draws attention throughout the world. Presently, there is a lack of quantitative analysis to integrate different ecological effects of road networks at landscape scale to depict, compare and evaluate landscape changes. In this study, the “Probability of Connectivity (PC)” index was used to evaluate the effects of road networks on landscape connectivity for an area in Xishuangbanna, Southwest China. The results indicate that the fragmentation effect of road networks decreased in PC value by 15.81%, the barrier effect of road networks decreased in PC value by 11.73% and the combination of the two effects decreased PC value by 32.78%. In conclusion, the combined fragmentation and barrier effects of road networks considerably degraded landscape connectivity more than either individual effect. In addition, the fragmentation effect influenced connectivity to a greater degree for ecological processes having low movement abilities. The barrier effect influenced connectivity to a greater degree for medium to high movement abilities. The combined effects influenced connectivity for those ecological processes of low movement ability within the study area.
Procedia Environmental Sciences, 2010
Selecting Manwan Dam as a study case, we studied the spatial-temporal change of land use during 1... more Selecting Manwan Dam as a study case, we studied the spatial-temporal change of land use during 1974, 1991 and 2004 based on the application of RS interpretation and GIS buffer analysis. Land use indices within three buffer distances from dam centre were calculated to quantify the effects of dam construction. The results showed that land use structure changed greatly during and after dam construction. Forestland and grassland were two main types of land use, which occupied over 79.70% of total area in 10000 m buffer. The main conversion of land use types took place from forest land to grass and farm land between 1974 and 1991, and that was almost consistent between 1991 and 2004 . During 1974 -1991, spatial dynamics of grass, farm and construction land were much larger than water body and forest land, and had an increasing tendency and the balanced state decreased with the increased off-dam distances which indicated that conversion of input and output were frequently between the three land use types. During 1991During -2004, water body had the largest value of R ss , in a state of extreme non-balanced with its P s reached 0.96, 0.96 and 0.99 in 10000, 5000 and 1000 m buffer, respectively. Further studies showed that direct effect was limited in the 1000 m buffer region based on the land use indices including temporal dynamics of land use change (R s ), spatial dynamics of land use change (R ss ,) and tendency and state index (P s ). Generally, three indices of each land use type decreased with the increased off-dam distances.
Transportation Research Part D: Transport and Environment, 2011
The paper presents the results of a case study carried out in Xishuangbanna, Southwest China, to ... more The paper presents the results of a case study carried out in Xishuangbanna, Southwest China, to examine the relationship between vegetation dynamics and road network extension. We find that lower level roads had more effects on vegetation patches. Minor roads, including Class IV and Class V roads, contributed most to regional landscape fragmentation while high level roads had larger effect
PLoS ONE, 2013
Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increas... more Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increases the release rate of internal phosphorus (P) loading. This study investigated the longitudinal variability of phosphorus fractions in sediments and the relationship between the contents of phosphorus fractions and its influencing factors of the Manwan Reservoir, Lancang River, Yunnan Province, China. Five sedimentary phosphorus fractions were quantified separately: loosely bound P (ex-P); reductant soluble P (BD-P); metal oxide-bound P (NaOH-P); calcium-bound P (HCl-P), and residual-P. The results showed that the total phosphorus contents ranged from 623 to 899 mg/g and were correlated positively with iron content in the sediments of the reservoir. The rank order of P fractions in sediments of the mainstream was HCl-P.NaOH-P.residual-P.BD-P.ex-P, while it was residual-P.HCl-P.NaOH-P.BD-P.ex-P in those of the tributaries. The contents of bio-available phosphorus in the tributaries, including ex-P, BD-P and NaOH-P, were significantly lower than those in the mainstream. The contents of ex-P, BD-P, NaOH-P showed a similar increasing trend from the tail to the head of the Manwan Reservoir, which contributed to the relatively higher content of bio-available phosphorus, and represents a high bioavailable phosphorus releasing risk within a distance of 10 km from Manwan Dam. Correlation and redundancy analyses showed that distance to Manwan Dam and the silt/clay fraction of sediments were related closely to the spatial variation of bio-available phosphorus.
… monitoring and assessment, 2009
The disturbance of highway construction upon surrounding vulnerable ecosystems is a common threat... more The disturbance of highway construction upon surrounding vulnerable ecosystems is a common threat in the Longitudinal Range Gorge Region of southwestern China. We evaluated the disturbance of highway on plant species richness and diversity and soil nutrients from adjacent to the highway to 300 m upslope and 100 m downslope in forests and grasslands by setting 12 belt transects in forests and grasslands (six belt transects and six control belt transects, respectively). The results showed that there were some significant variances in belt transects with respective control belt transects for species richness and diversity in both forests and grasslands. Species richness and diversity of trees were lower within a 50-m distance from the highway and more noticeable on the downslope portion. Species richness and diversity of shrubs and herbs appeared higher near highway edge. Both species richness and diversity of herbs were similar in forests. In addition, exotic species, such as Eupatorium adenophorum, were further from the road and more widely dispersed in grasslands. Soil nutrients except total potassium (TK) were lower in the downslope area adjacent to highway edge and showed a significant increase with increasing distance from the highway in both forests and grasslands. This indicates that grasslands acted as microhabitats for exotic species and are more easily to be invaded than forests, especially if disturbed. Once destroyed, plant species and soil nutrients will require a significant amount of time to be restored to control levels. This work illustrates that the effects extend considerably to distances upslope and downslope from the construction site. Given that these changes occurred relatively quickly, the study suggests that the environmental "footprint" grows far beyond the road and adjacent zone of disruption.
Journal of environmental …, 2009
Rangelands represent one of the most important natural resources in mountainous regions of northe... more Rangelands represent one of the most important natural resources in mountainous regions of northern Nepal. However, a poor understanding of the social dimensions of rangeland use has limited their proper management and sustainable development, which represent major challenges for Nepal's resource managers. Institutional development is thought to be a viable solution to this problem and may ultimately lead to improved rangeland management in Nepal. Based on this hypothesis, a study was conduced in the Rasuwa district of northern Nepal to examine the effectiveness of institutional development at the local and national levels in mitigating the problems facing sustainable rangeland management by using an institutional analysis and development (IAD) framework. The information and data were mainly collected from different stakeholders, farmers, professionals and practitioners using a toolkit of participatory rural appraisal (PRA), workshops and literature review. It can be concluded from this case study that a number of institutional development efforts are needed to promote sustainable rangeland management in this region. First, local herders represent a repository of rich indigenous knowledge essential to sustaining sound rangeland management practices; hence, indigenous practices need to be integrated into modern technologies. Second, public services and technical support are currently unavailable or inaccessible to local herders; hence, research, development and extension interventions need to be initiated for marginalized pastoral communities. Third, rangeland institutions are incomplete and illorganized, so institutional development of various organizations is necessary for promoting sustainable rangeland management. Fourth, the policies and governance necessary for promoting rangeland management are not well-designed; hence, governance reform and policy development need to be formulated through internal and external agencies and organizations.
Procedia Environmental Sciences, 2010
Road ecologists have dedicated their efforts in analyzing the interactions between road networks ... more Road ecologists have dedicated their efforts in analyzing the interactions between road networks and the surrounding landscape ever since the establishment of Road Ecology. The understanding of the interactions has been promoted by the proposed quantification parameters of road networks' impacts such as road density, buffer zone and so on. Using these parameters, we analyzed the road network's disturbance effect on the landscape pattern with the newly proposed index-RV (Roadless Volume) in the study. Based on the sampling of square quads all over the Longitudinal Range-Gorge Region (LRGR) during 1980-2000, the changes of the different patches such as forest, grassland, cropland and urban land under different disturbance degrees of road networks classified by RV value have been examined. The results showed that: the decreased area and number of forest and arable patches changed with the disturbance degree of road networks' logarithmically; The area and number of grassland decreased at the highest disturbance level but increased in some lower disturbance level; The area of urban land increased at the high disturbance level which followed the logarithmical trend with the disturbance level. These results imply that the road networks generally transformed the landscape pattern from the forest and cropland to large patch of urban land surrounding roads.