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Reconstruction of debris-flow activity in a temperate mountain forest catchment of central Mexico

Journal of Mountain Science 2019年第9期16卷 2096-2109页

作者： Osvaldo FRANCO-RAMOS Markus STOFFEL Juan Antonio BALLESTEROS-CANOVAS Instituto de Geografia. Universidad NacionalAutonoma de Mexico Ciudad Universitaria Coyoacan 04510 Mexico Dendrolab.ch Department of Earth Sciences University of Geneva 13 rue des Maraichers CH-1205 Geneva Switzerland Climate Change Impacts and Risks in the Anthropocene (C-CIA) Institute for Environmental Sciences University of Geneva 66 Boulevard Carl-Vogt CH-1205 Geneva Switzerland Department F.-A. Forelfor environmental and Aquatic sciences University of Geneva 66 Boulevard Carl-Vogt CH- 1205 Geneva Switzerland

The use of dendrochronology to study and date geomorphic processes in volcanic environments is still incipient, even more so on the volcanic slopes covered by temperate forests in central Mexico. Mass movements, such as debris flows, often impact forest stands where they cause damage to individual trees, thereby generating growth disturbances(GD) in the tree-ring records. The identification and dating of GD enables reconstruction of the age of trees colonizing bare surfaces after major events, but also allows the assessment of the frequency or spatial distribution of past geomorphic process activity. Here we used increment cores from 65 Pinus leiophylla, Abies religiosa, and Alnus jorullensis trees growing in the Axal gorge, on the southern slopes of La Malinche volcano, to unravel past debris-flow activity both temporally and spatially. Based on the combination of GD records, a weighted tree response index(Wit), field evidence and hydrometeorological records, we reconstructed 23 debris flows since ***, almost two-thirds of the reconstructed years with debris-flow activity in Axal gorge match with events recorded in Axaltzintle gorge located on the NE slopes of La Malinche. These findings suggest a regional triggering mechanism, most likely related to the occurrence of hurricanes. This research could be useful for disaster risk management of the La Malinche National Park.

关键词： Debris flows La Malinche volcano Dendrogeomorphology Temperate forest Hydrometeorological phenomena

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Traditional farming in the mountainous region of Bangladesh and its modifications

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Journal of Mountain Science 2016年第8期13卷 1489-1502页

作者： MISBAHUZZAMAN Khaled institute of Forestry and environmental sciences Chittagong University

Shifting cultivation is a traditional farming system practiced in the tropical mountainous areas. Although it has been widely perceived as an economically inefficient and environmentally harmful agricultural production system, recent science reviews, however, indicate that the deleterious impacts of shifting cultivation on environment may have been overestimated. Despite the pressures of agricultural intensification in areas where shifting cultivation occurs, farmers across the tropics still maintain this traditional farming system. The objective of this study was to explore existing traditional shifting cultivation practices and their various modifications including the innovative farming techniques developed by farmers in the Chittagong Hill Tracts(CHTs), the mountainous region of Bangladesh, and examine their importance with respect to recent socio-economic and environmental changes. The study revealed that shifting cultivation still exists as the most dominant farming method which supports livelihoods and culture of the hill ethnic people. However, demand for more food and household income to meet livelihood needs of an increasing population combined with a rapid deterioration of soil and water quality over decades contributed to development of innovative farming practices through fallow land farming, crop substitution, agroforestry and homestead gardening in the CHTs. Through these farming techniques farmers maintain a strong relationship with traditional knowledge system embedded in the ageold shifting cultivation practices. Today state policies and market forces act in favor of replacement of traditional farming with intensive cash crop agriculture. It seems that disappearance of traditional farming practices from the hills may threaten local biodiversity and food security. It may be recommended that shifting cultivation should be encouraged in areas where they have potential for contributing to preservation of native biodiversity and ecosystem services, and

关键词： Shifting cultivation Chittagong HillTracts Agroforestry Food security

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Diversity and structural composition of species in dipterocarp forests:a study from Fasiakhali Wildlife Sanctuary, Bangladesh

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Journal of Forestry Research 2018年第5期29卷 1241-1249页

作者： S.C.Das M.S.Alam M.A.Hossain institute of Forestry and environmental sciences University of Chittagong

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）*** present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 *** forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance *** turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value *** firmum and Tectona grandis followed in terms of *** structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas *** was the only species that dominated most of the growth *** stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and *** study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of *** will also contribute to identifying threatened plants to undertake *** based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.

关键词： Species diversity Structural composition Protected area Importance value index Cluster analysis

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The effects of teak monoculture on forest soils: a case study in Bangladesh

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Journal of Forestry Research 2018年第4期29卷 1100-1109页

作者： Md.Abdullah Al Mahmud Mohammad Mahfuzur Rahman Mohammed Kamal Hossain institute of Forestry and environmental sciences University of Chittagong

Teak plantations date back to 1871 in Bangladesh. This study was designed to assess how teak monoculture has impacted the soil properties in Bangladesh. Multiple linear regression and correlation matrices were estimated to evaluate these impacts. The means of soil physicochemical properties were compared across various attributes of the plantations. Older plantations accumulated more organic carbon in the soils than the younger plantations. Excessive removal of litter from the forest floor resulted in reduced levels of N, P, K, and other nutrients in the soils. Since bulk density was continuously decreasing deeper into the soil, the penetration of mineral nutrients into the soil was low. Furthermore, moisture content in the topsoil was significantly lower than that in the bottom layers due to the exposed and dry condition of the forest floor under teak plantations. For improving depleted teak plantation soils, teak could be planted with other tree species rather than just in monocultures. In addition, the forest floor could be enriched with leguminous herbs and shrubs to improve soil health in these plantations.

关键词： CHTs Monoculture. Organic carbon Soilnutrients Teak plantation

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Pre-sowing treatments for improved germination and growth of two rare native species of Bangladesh

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Journal of Forestry Research 2018年第5期29卷 1277-1282页

作者： M.A.Hossain K.S.Islam N.Rajasree M.K.Hossain M.S.Alam institute of Forestry and environmental sciences University of Chittagong

Pre-sowing treatments are expected to increase seed *** evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata *** Vitex glabrata *** hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid（H_2SO_4）.Results indicate that *** showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail *** with sand paper was the best pre-sowing treatment for ***,resulting a 80% germination rate and 30% germination *** and *** seedlings from seeds soaked 24h in water resulted in maximum heights and collar *** were significantly higher（at p〈0.05） than those of other *** results indicate that scarification or nicking of seeds may have some negative impacts on seedling ***,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth.

关键词： Germination Early seedling growth Height Native species Garuga pinnata Vitex glabrata

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Cache-Based Aggregate Query Shipping:An Efficient Scheme of Distributed OLAP Query Processing

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Journal of Computer Science & Technology 2008年第6期23卷 905-915页

作者：廖华明裴国顺 Research Center for grid and Service Computing Institute of Computing TechnologyChinese Academy of Sciences

Our study introduces a novel distributed query plan refinement phase in an enhanced architecture of distributed query processing engine （DQPE）. Query plan refinement generates potentially efficient distributed query plan by reusable aggregate query shipping （RAQS） approach. The approach improves response time at the cost of pre-processing time. If the overheads could not be compensated by query results reusage, RAQS is no more favorable. Therefore a globM cost estimation model is employed to get proper operators： RR_Agg, R_Agg, or R_Scan. For the purpose of reusing results of queries with aggregate function in distributed query processing, a multi-level hybrid view caching （HVC） scheme is introduced. The scheme retains the advantages of partial match and aggregate query results caching. By our solution, evaluations with distributed TPC-H queries show significant improvement on average response time.

关键词： distributed system query optimization reusability query shipping hybrid view caching

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Modeling soil conservation, water conservation and their tradeoffs: A case study in Beijing

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Journal of environmental sciences 2012年第3期24卷 419-426页

作者： Yang Bai Zhiyun Ouyang Hua Zheng Xiaoma Li Changwei Zhuang Bo Jiang State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China institute of Applied Ecology Shanghai Academy of Environmental SciencesShanghai 200233China Nanjing institute of environmental sciences Ministry of Environmental ProtectionNanjing 210042China

Natural ecosystems provide society with important goods and services. With the rapid increase in human populations and excessive utilization of natural resources, humans frequently enhance the production of some services at the expense of the others. Although the need for tradeoffs between conservation and development is urgent, the lack of efficient methods to assess such tradeoffs has impeded progress. Three land use strategy scenarios （development scenario, plan trend scenario and conservation scenario） were created to forecast potential changes in ecosystem services from 2007 to 2050 in Beijing, China. GIS-based techniques were used to map spatial and temporal distribution and changes in ecosystem services for each scenario. The provision of ecosystem services differed spatially, with significant changes being associated with different scenarios. Scenario analysis of water yield （as average annual yield） and soil retention （as retention rate per unit area） for the period 2007 to 2050 indicated that the highest values for these parameters were predicted for the forest habitat under all three scenarios. Annual yield/retention of forest, shrub, and grassland ranked the highest in the conservation scenario. Total water yield and soil retention increased in the conservation scenario and declined dramatically in the other two scenarios, especially the development scenario. The conservation scenario was the optimal land use strategy, resulting in the highest soil retention and water yield. Our study suggests that the evaluation and visualization of ecosystem services can effectively assist in understanding the tradeoffs between conservation and development. Results of this study have implications for planning and monitoring future management of natural capital and ecosystem services, which can be integrated into land use decision-making.

关键词： ecosystem services tradeoffs scenario management

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Tale of mitochondria and mitochondria-associated ER membrane in patient-derived neuronal models of Wolfram syndrome

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Neural Regeneration Research 2025年第9期20卷 2587-2588页

作者： Laetitia Aubry Timothy Barrett Sovan Sarkar I-STEM CECSCorbeil-EssonnesFrance UniversitéParis-Saclay Universitéd’EvryINSERMI-STEMUMR861Corbeil-EssonnesFrance institute of Cancer and Genomic sciences Institute of Biomedical ResearchCollege of Medical and Dental SciencesUniversity of BirminghamEdgbastonBirminghamUK Department of Endocrinology Birmingham Women’s and Children’s HospitalSteelhouse LaneBirminghamUK

Mitochondria and mitochondria-associated endoplasmic reticulum membrane in neurodegenerative diseases:Mitochondria generate most of the chemical energy needed to power the biochemical reactions of cells,and thus are often referred to as the"powerhouse"of the ***,this organelle is also involved in a pleth,ora of different cellular functions such as calcium(Ca^(2+))homeostasis,apoptosis,oxidative stress,and several metabolic pathways including oxidative phosphorylation,tricarboxylic acid cycle,andβ-oxidation of fatty acids.

关键词： oxidative cycle carboxylic

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Impact of livelihood diversification of rural households on their ecological footprint in agro-pastoral areas of northern China

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Journal of Arid Land 2015年第5期7卷 653-664页

作者： HAO Haiguang ZHANG Jiping LI Xiubin ZHANG Huiyuan ZHANG Qiang Chinese Research Academy of environmental sciences Beijing Municipal Research institute of environmental Protection institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences

Human-environment relationship is a focus of academic researches and an understanding of the rela- tionship is important for making effective policies and decisions. In this study, based on rural household survey data of Taibus Banner, Duolun county and Zhengxiangbai Banner in the Inner Mongolia autonomous region of China, we identified the impact of livelihood diversification on ecosystems in these agro-pastoral areas by using the ecological footprint theory and methodology together with the one-way analysis of variance （ANOVA） and correlation analysis methods. In 2011, the total ecological footprint of consumption （EFC） was 0.665 g hm2, and the total ecological footprint of production （EFP） was 2.045 g hm2, which was more than three times the EFC. The ecological footprint of arable land consumption （EFAC） accounted for a large proportion of the EFC, and the ecological footprint of grassland production （EFGP） occupied a large proportion of the EFP. Both the ecological footprint of grassland consumption （EFGC） and EFGP had a significant positive correlation with the income, indicating that income was mainly depended on livestock production and the households with higher incomes consumed more livestock prod- ucts. The full-time farming households （FTFHs） had the highest EFP, ecological footprint of arable land production （EFAP）, EFGP and EFGC, followed by the part-time farming households （PTFHs） and non-farming households （NFHs）, which indicated that part-time farming and non-farming employment reduced the occupancy and con- sumption of rural households on local ecosystems and natural resources to some extent. When farming households engaged in livestock rearing, both the EFAP and EFAC became smaller, while the EFP, EFC, EFGC and EFGP increased significantly. The differences in ecological footprints among different household groups should be taken into account when making ecosystem conservation policies. Encouraging the laborers who have the advantages of participati

关键词： ecological footprint livelihood diversification livestock rearing non-farming employment rural households agro-pastoral area

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The levels, sources and reactivity of volatile organic compounds in a typical urban area of Northeast China

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Journal of environmental sciences 2019年第5期31卷 121-134页

作者： Zhuobiao Ma Chengtang Liu Chenglong Zhang Pengfei Liu Can Ye Chaoyang Xue Di Zhao Jichen Sun Yiming Du Fahe Chai Yujing Mu Research Center for Eco-environmental sciences Chinese Academy of Sciences University of Chinese Academy of sciences Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Shenyang Academy of environmental sciences Shenyang environmental Monitoring Centre Chinese Research Academy of environmental sciences

Air concentrations of volatile organic compounds(VOCs) were continually measured at a monitoring site in Shenyang from 20 August to 16 September 2017. The average concentrations of alkanes, alkenes, aromatics and carbonyls were 28.54, 6.30, 5.59 and9.78 ppbv, respectively. Seven sources were identified by the Positive Matrix Factorization model based on the measurement data of VOCs and CO. Vehicle exhaust contributed the most(36.15%) to the total propene-equivalent concentration of the measured VOCs,followed by combustion emission(16.92%), vegetation emission and secondary formation(14.33%), solvent usage(10.59%), petrochemical industry emission(9.89%), petrol evaporation(6.28%), and liquefied petroleum gas(LPG) usage(5.84%). Vehicle exhaust, solvent usage and combustion emission were found to be the top three VOC sources for O_3 formation potential, accounting for 34.52%, 16.55% and 11.94%, respectively. The diurnal variation of the total VOCs from each source could be well explained by their emission characteristics,e.g., the two peaks of VOC concentrations from LPG usage were in line with the cooking times for breakfast and lunch. Wind rose plots of the VOCs from each source could reveal the possible distribution of the sources around the monitoring site. The O_3 pollution episodes during the measurement period were found to be coincident with the elevation of VOCs, which was mainly due to the air parcel from the southeast direction where petrochemical industry emission was found to be dominant, suggesting that the petrochemical industry emission from the southeast was probably a significant cause of O_3 pollution in Shenyang.

关键词： Volatile organic compounds Source apportionment Photochemical ozone formation Field measurement

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