907 research outputs found

    Climate change impacts on central China and adaptation measures

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    Abstract In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within the study area, and with the harmful effects far more prevalent. Under the scenario A1B, it is reported that temperature, precipitation, days of heat waves and extreme precipitation intensity will increase at respective rates of 0.38 ā€¢ C per decade, 12.6 mm per decade, 6.4 d and 47 mm per decade in the 21st century. It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems, water resources, wetland ecosystem, forest ecosystem, human health, energy sectors and other sensitive fields in Central China. Due to the limited scientific knowledge and researches, there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results. Therefore, it is urgent and essential to increase the studies of the regional climate change adaptation, extend the research fields, and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments

    Nutrient Cycling in Forest Ecosystems

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    The long-term productivity of forest ecosystems depends on the cycling of nutrients. The effect of carbon dioxide fertilization on forest productivity may ultimately be limited by the rate of nutrient cycling. Contemporary and future disturbances such as climatic warming, N-deposition, deforestation, short rotation sylviculture, fire (both wild and controlled), and the invasion of exotic species all place strains on the integrity of ecosystem nutrient cycling. Global differences in climate, soils, and species make it difficult to extrapolate even a single important study worldwide. Despite advances in the understanding of nutrient cycling and carbon production in forests, many questions remain. The chapters in this volume reflect many contemporary research priorities. The thirteen studies in this volume are arranged in the following subject groups: ā€¢ N and P resorption from foliage worldwide, along chronosequences and along elevation gradients; ā€¢ Litter production and decomposition; ā€¢ N and P stoichiometry as affected by N deposition, geographic gradients, species changes, and ecosystem restoration; ā€¢ Effects of N and P addition on understory biomass, litter, and soil; ā€¢ Effects of burning on soil nutrients; ā€¢ Effects of N addition on soil fauna

    Early ā€œNeolithicsā€ of China: Variation and Evolutionary Implications

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    The growth and significance of scientific research into the origins of agriculture in China calls for fresh examination at scales large enough to facilitate explanation of cultural evolutionary processes. The Paleolithic to Neolithic transition (PNT) is not yet well-understood because most archaeological research on early agriculture cites data from the more conspicuous and common early Neolithic sites. In this, the first of two papers, we synthesize a broad range of early Neolithic archaeological data, including diagnostic artifacts, settlement patterns, site structure, and biological remains, to consider agriculture as a system-level adaptive phenomenon. Although farming by this period was already well-established in much of North China and the middle Yangtze River basin, echoes of the foraging past can be found in the persistence of hunting-related artifacts in North Chinaā€™s Loess Plateau and aquatic-based intensification and vegeculture in South China. Our analysis of the growing body of Chinese data and projections using Binfordā€™s hunting and gathering database indicate that agriculture was differentially developed, adopted, or resisted by foragers according to measurable, predictable initial conditions of habitat that influenced diet breadth. In a subsequent paper (Journal of Anthropological Research 73(3), 2017, doi: 10.1086/692660), we will use these findings as a platform for a deeper consideration of the emerging archaeological record of the PNT, and to develop hypotheses for the last foraging and first farming adaptations in China

    Remote sensing technology applications in forestry and REDD+

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    Advances in close-range and remote sensing technologies are driving innovations in forest resource assessments and monitoring on varying scales. Data acquired with airborne and spaceborne platforms provide high(er) spatial resolution, more frequent coverage, and more spectral information. Recent developments in ground-based sensors have advanced 3D measurements, low-cost permanent systems, and community-based monitoring of forests. The UNFCCC REDD+ mechanism has advanced the remote sensing community and the development of forest geospatial products that can be used by countries for the international reporting and national forest monitoring. However, an urgent need remains to better understand the options and limitations of remote and close-range sensing techniques in the field of forest degradation and forest change. Therefore, we invite scientists working on remote sensing technologies, close-range sensing, and field data to contribute to this Special Issue. Topics of interest include: (1) novel remote sensing applications that can meet the needs of forest resource information and REDD+ MRV, (2) case studies of applying remote sensing data for REDD+ MRV, (3) timeseries algorithms and methodologies for forest resource assessment on different spatial scales varying from the tree to the national level, and (4) novel close-range sensing applications that can support sustainable forestry and REDD+ MRV. We particularly welcome submissions on data fusion

    A regional chemical transport modeling to identify the influences of biomass burning during 2006 BASE-ASIA

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    To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA\u27s 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27ā€“28 March and 13ā€“14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to CO, O3 and PM2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 Ī¼g/m3, respectively. The perturbations with and without biomass burning of the above three species were in the range of 10 to 60%, 10 to 20% and 30 to 70%, respectively. The impact due to long-range transport could spread over the southeastern parts of East Asia and could reach about 160 to 360 ppbv, 8 to 18 ppbv and 8 to 64 Ī¼g/m3 on CO, O3 and PM2.5, respectively; the percentage impact could reach 20 to 50% on CO, 10 to 30% on O3, and as high as 70% on PM2.5. An impact pattern can be found in April, while the impact becomes slightly broader and goes up to Yangtze River Delta. Two cross-sections at 15Ā° N and 20Ā° N were used to compare the vertical flux of biomass burning. In the source region (Southeast Asia), CO, O3 and PM2.5 concentrations had a strong upward tendency from surface to high altitudes. The eastward transport becomes strong from 2 to 8 km in the free troposphere. The subsidence contributed 60 to 70%, 20 to 50%, and 80% on CO, O3 and PM2.5, respectively to surface in the downwind area. The study reveals the significant impact of Southeastern Asia biomass burning on the air quality in both local and downwind areas, particularly during biomass burning episodes. This modeling study might provide constraints of lower limit. An additional study is underway for an active biomass burning year to obtain an upper limit and climate effects. doi:10.5194/acpd-11-3071-201

    Temporal and spatial dynamics in emission of water-soluble ions in fine particulate matter during forest fires in Southwest China

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    Aims: The aim of this study was to analyze changes in emission of water-soluble ions in fine particulate matter over time and in different southwest forest areas in China based on China's Forestry Statistical Yearbook and MODIS satellite fire point data.Methods: We took 6 dominant tree species samples in the southwestern forest region of China and simulated combustion using controllable biomass combustion devices. Based on the spatial analysis method of ArcGIS, combining satellite fire point data and official statistical yearbooks, we analyzed the spatial and temporal dynamics of emissions of water-soluble ions in PM2.5 released by forest fires in southwestern forest areas from 2004 to 2021.Results: The total amount of forest biomass combusted in southwest forest areas was 64.43 kt. Among the different forest types, the proportion of burnt subtropical evergreen broad-leaved forest was the largest (60.49%) followed by subtropical mixed coniferous and broad-leaved forest (22.78%) and subtropical evergreen coniferous forest (16.72%). During the study period, 61.19 t of water-soluble ions were released in PM2.5 from forest fires, and the emissions of Li+, Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, Br-, NO3-, PO43- and SO42- were 0.48 t, 11.54 t, 2.51 t, 19.44 t, 2.12 t, 2.92 t, 1.94 t, 12.70 t, 1.12 t, 1.18 t, 1.17 t and 4.07 t, respectively. Yunnan was the province with the highest emissions of water-soluble ions in PM2.5 in the southwest forest areas, and the concentration K+ was the highest. Emission of water-soluble ions in Yunnan and Sichuan all showed a significant downward trend, while the overall decrease in Tibet, Chongqing and Guizhou was not significant. The peak emission of water-soluble ions in PM2.5 during forest fires appeared in spring and winter, which accounted for 87.66% of the total emission.Discussion: This study reveals the spatiotemporal changes in water-soluble ion emissions from forest fires, by studying the spatiotemporal dynamics of water-soluble ions in PM2.5, we can better understand the sources, distribution, and change patterns of these ions, as well as their impact on the atmospheric environment, ecosystems, and climate change. This information is crucial for predicting and managing air pollution, as well as developing effective forest management and environmental protection policies to respond to fires; and hence concerted fire prevention efforts should be made in each province, taking into account the season with higher probability of fire occurrence to reduce the potential impact of fire-related pollutions

    A regional chemical transport modeling to identify the influences of biomass burning during 2006 BASE-ASIA

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    To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA\u27s 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27ā€“28 March and 13ā€“14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to CO, O3 and PM2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 Ī¼g/m3, respectively. The perturbations with and without biomass burning of the above three species were in the range of 10 to 60%, 10 to 20% and 30 to 70%, respectively. The impact due to long-range transport could spread over the southeastern parts of East Asia and could reach about 160 to 360 ppbv, 8 to 18 ppbv and 8 to 64 Ī¼g/m3 on CO, O3 and PM2.5, respectively; the percentage impact could reach 20 to 50% on CO, 10 to 30% on O3, and as high as 70% on PM2.5. An impact pattern can be found in April, while the impact becomes slightly broader and goes up to Yangtze River Delta. Two cross-sections at 15Ā° N and 20Ā° N were used to compare the vertical flux of biomass burning. In the source region (Southeast Asia), CO, O3 and PM2.5 concentrations had a strong upward tendency from surface to high altitudes. The eastward transport becomes strong from 2 to 8 km in the free troposphere. The subsidence contributed 60 to 70%, 20 to 50%, and 80% on CO, O3 and PM2.5, respectively to surface in the downwind area. The study reveals the significant impact of Southeastern Asia biomass burning on the air quality in both local and downwind areas, particularly during biomass burning episodes. This modeling study might provide constraints of lower limit. An additional study is underway for an active biomass burning year to obtain an upper limit and climate effects. doi:10.5194/acpd-11-3071-201

    The Case for Adaptive Evolution: The Dong Village of Dimen, Guizhou Province, China

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    Despite the fact that over 90 % of the Chinese nationals are Han ethnicity, China is considered a multiethnic country. There are many ethnic minority groups living in various parts of China, and their culture blends with and affects the Han culture to create the amazing mixture and diverse Chinese culture. However, this diversity has gradually lost its magic under the influence of rapid economic growth which encourages uniformity and efficiency rather than diversity and traditional identity. As a result, the architectures and languages of many ethnic minorities are gradually assimilated by the mainstream Han culture. Therefore, the research and preservation of ethnic minoritiesā€™ settlements have become a crucial topic. As one of the representative ethnic minority, the Dong people and their settlements contain enormous historical, artistic and cultural values. Most importantly, its utilization of space is the foundation of its sustainability and development. As a living heritage, the maintenance of public space is crucial to the development of Dong village since the traditional function of its space makes up a major part of its cultural heritage. However, the younger Dong peopleā€™s changing social practices and life-style have resulted in the alteration of their public space. Despite the difficulties in keeping its traditional living space, Dimen Dong village still plays a positive role in maintaining its ethnic culture. The support and protection of ethnic villages like Dimen should thus be evaluated and taken into serious consideration. This paper mainly focuses on analyze the relationships between the villageā€™s public space and the residentsā€™ behaviors, aesthetic experience and the culture. It also reveals the formation mechanism of public space to provide theoretical guidance for the future design of Dong village. By referring to existing documents, scholarship, on-site surveys and photography to support my case studies of various Dong settlements, I will also provide suggestions on possible sustainable development of local tourism and heritage conservations of the Dong area. The Dimen village in Liping County of Guizhou province in China is the main case study of this research. I will discuss the formation mechanism of its public space and trace back the historical configuration and adjustment of its spatial components. The case studies of Gaoding village of Guangxi province and Zhaoxing village of Guizhou Province also offer me some new ideas on the improvement of Dimen village. This paper also tries to reveal that the different ideologies and attitudes of the villagers and the local government towards cultural protection and sustainable development. In the ending chapter, I propose a plan that may give some suggestions on how to improve the living environment for local villagers. This proposal includes reformation of the current layout of the Dimen village and renovation suggestions of the buildings. It also aims to improve the functionality of the public space as well as the infrastructures of the village for future development of tourism and economy

    A culture of conservation: How an ancient forest plantation turned into an old-growth forest reserve ā€“ The story of the Wamulin forest

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    The global expansion of forest plantations at the expense of natural forests, especially old-growth forests, raises concerns about habitat loss and a decline in ecosystem services. Natural regeneration of second-growth forests with minimal human assistance has been suggested as a cost-effective way to restore forests and increase forest ecosystem service potential. However, it is unclear whether natural regeneration will lead to the development of second-growth forests similar to natural forests because most naturally regenerated second-growth forests are still young. We present a case study of a very old second-growth forest in southeastern China in which a forest plantation established approximately six centuries ago has now developed into an old forest with extraordinary high biodiversity levels, an immense carbon pool, and a rich culture. The forest was established in the 14th century because of a charitable contribution, became protected under the Chinese cultural norm of ā€˜unity between humans and the natureā€™, and was conserved because of the belief that the prosperity of people is closely linked to the prosperity of trees. The recent designation of the forest as a nature reserve further protects it from development despite competing land-use demands related to recent economic growth. This case illustrates that, although human activity is the main cause for the disappearance and degradation of many forests, when human interests and cultural values align second-growth restoration and subsequent forest conservation can lead to the successional development of old-growth forests. Because this development takes multiple centuries, the protection of current second-growth forests within conservation easements (e.g. nature reserves) and the reformation of culture values for the linkage of forests to human well-being are key aspects of the continued conservation-aided succession of second-growth forests. A free Plain Language Summary can be found within the Supporting Information of this article
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