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1.
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2.
Human activities have diverse and profound impacts on ecosystem carbon cycles. The Piedmont ecoregion in the eastern United States has undergone significant land use and land cover change in the past few decades. The purpose of this study was to use newly available land use and land cover change data to quantify carbon changes within the ecoregion. Land use and land cover change data (60-m spatial resolution) derived from sequential remotely sensed Landsat imagery were used to generate 960-m resolution land cover change maps for the Piedmont ecoregion. These maps were used in the Integrated Biosphere Simulator (IBIS) to simulate ecosystem carbon stock and flux changes from 1971 to 2010. Results show that land use change, especially urbanization and forest harvest had significant impacts on carbon sources and sinks. From 1971 to 2010, forest ecosystems sequestered 0.25 Mg C ha?1 yr?1, while agricultural ecosystems sequestered 0.03 Mg C ha?1 yr?1. The total ecosystem C stock increased from 2271 Tg C in 1971 to 2402 Tg C in 2010, with an annual average increase of 3.3 Tg C yr?1. Terrestrial lands in the Piedmont ecoregion were estimated to be weak net carbon sink during the study period. The major factors contributing to the carbon sink were forest growth and afforestation; the major factors contributing to terrestrial emissions were human induced land cover change, especially urbanization and forest harvest. An additional amount of carbon continues to be stored in harvested wood products. If this pool were included the carbon sink would be stronger.  相似文献   

3.
In the tropical mountains of Southeast Asia, slash-and-burn (S/B) agriculture is a widely practiced and important food production system. The ecosystem carbon stock in this land-use is linked not only to the carbon exchange with the atmosphere but also with food and resource security. The objective of this study was to provide quantitative information on the land-use and ecosystem carbon stock in the region as well as to infer the impacts of alternative land-use and ecosystem management scenarios on the carbon sequestration potential at a regional scale. The study area was selected in a typical slash-and-burn region in the northern part of Laos. The chrono-sequential changes of land-use such as the relative areas of community age and cropping (C) + fallow (F) patterns were derived from the analysis of time-series satellite images. The chrono-sequential analysis showed that a consistent increase of S/B area during the past three decades and a rapid increase after 1990. Approximately 37% of the whole area was with the community age of 1–5 years, whereas 10% for 6–10 years in 2004. The ecosystem carbon stock at a regional scale was estimated by synthesizing the land-use patterns and semi-empirical carbon stock model derived from in situ measurements where the community age was used as a clue to the linkage. The ecosystem carbon stock in the region was strongly affected by the land-use patterns; the temporal average of carbon stock in 1C + 10F cycles, for example, was greater by 33 MgC ha−1 compared to that in 1C + 2F land-use pattern. The amount of carbon lost from the regional ecosystems during 1990–2004 periods was estimated to be 42 MgC ha−1. The study approach proved to be useful especially in such regions with low data-availability and accessibility. This study revealed the dynamic change of land-use and ecosystem carbon stock in the tropical mountain of Laos as affected by land-use. Results suggest the significant potential of carbon sequestration through changing land-use and ecosystem management scenarios. These quantitative estimates would be useful to better understand and manage the land-use and ecosystem carbon stock towards higher sustainability and food security in similar ecosystems.  相似文献   

4.
It is important to ensure the efficient supply of land ecosystem services when the competition for land is increasing. In this paper we simulated the ecosystem services function under two scenarios, including carbon sequestration, agricultural production, water and soil conservation, and analyzed the tradeoffs among these ecosystem services in Guanzhong-Tianshui region from 2000 to 2050. Then the productive efficiency of ecosystem services was assessed under two scenarios and compared their production possibility frontiers (PPFs). Through the simulation analysis of their optimum allocation, we also provide the scientific evidence to the development of ecosystem. The natural rules were revealed that if these trade-offs emphasize the potential to sequester carbon in the landscape, along with very little loss of agricultural production, much more water is used. It could be identified to adhere to combine the exploitation and utilization, remediation and protection for land to promote the effective circulation of land eco-system, and meet the society’s preferences for land ecosystem service function by adjusting the use of multiple eco-services.  相似文献   

5.
Recently there have been reports of forest regrowth occurring in different regions across the world. There is also a growing recognition of the potential beneficial impact that secondary forests may have on the global environment: providing crucial ecosystem services such as soil conservation, stabilization of hydrological cycles, carbon sequestration, and support for forest dependent communities. Consequently, there is a growing awareness of the need to recognize that landscapes are complex shifting mosaics wherein forest clearing and reforestation take place. In this study, the rates of reforestation, deforestation, forest regrowth and degradation were measured using multi-temporal Landsat images of Danjiangkou, China. Landsat data from 1990, 1999 and 2007 were (1) classified as dense forest, open forest and non-forest areas and (2) compared between years to identify forest cutting, regeneration and degradation. The results showed that there was a net gain of 29,315 ha of forest area (including dense and open forest) from 1990 to 2007, showing a clear trend of reforestation in the study area. Forest modification (degradation and regrowth) and change categories (deforestation and reforestation) occurred simultaneously during the observation time period. Socioeconomic data from public statistics and environmental attributes allowed the assessment of the socioeconomic factors and the environmental conditions that caused these changes using non-metric multidimensional scaling (NMDS). The research showed that the socioeconomic factors due to different policies were major driving forces of forest transition, whereas environmental attributes of the underlying landscape constrained forest cover changes. These findings have led to a better understanding of forest transition at a local scale in our study region. Comprehensive knowledge of these relationships may be useful to reconstruct past forest transitions and predict future changes, and may help to enhance sustainable management practices aimed at preserving essential ecological functions.  相似文献   

6.
Terrestrial ecosystems play a significant role in global carbon and water cycles because of the substantial amount of carbon assimilated through net primary production and large amount of water loss through evapotranspiration (ET). Using a process-based ecosystem model, we investigate the potential effects of climate change and rising atmospheric CO2 concentration on global terrestrial ecosystem water use efficiency (WUE) during the twenty-first century. Future climate change would reduce global WUE by 16.3% under high-emission climate change scenario (A2) and 2.2% under low-emission climate scenario (B1) during 2010–2099. However, the combination of rising atmospheric CO2 concentration and climate change would increase global WUE by 7.9% and 9.4% under A2 and B1 climate scenarios, respectively. This suggests that rising atmospheric CO2 concentration could ameliorate climate change-induced WUE decline. Future WUE would increase significantly at the high-latitude regions but decrease at the low-latitude regions under combined changes in climate and atmospheric CO2. The largest increase of WUE would occur in tundra and boreal needleleaf deciduous forest under the combined A2 climate and atmospheric CO2 scenario. More accurate prediction of WUE requires deeper understanding on the responses of ET to rising atmospheric CO2 concentrations and its interactions with climate.  相似文献   

7.
Net primary production (NPP) is a crucial feature of ecosystem function and structure. Furthermore, precipitation use efficiency (PUE) is a critical indicator for exploring NPP in grassland ecosystem responses to variations in precipitation and temperature. In this study, we examined the spatial patterns of NPP and PUE in China’s grasslands from 2000 to 2010 and explored the effects of environmental factors on NPP and PUE at different scales. The results showed first that the spatial distribution of NPP and PUE decreased from the northeast to southwest. NPP increased in most places across China’s grasslands; however, there was no obvious change in PUE during 2000–2010. Second, in most regions across China’s grasslands, positive and negative correlations existed between precipitation and NPP and PUE, respectively. The spatial distribution of the relationship between temperature and NPP and PUE was consistent with the relationship between precipitation with NPP and PUE. Finally, for the gradients of the various environmental factors in different regional grassland ecosystems, on the Tibetan Plateau, there were unimodal correlations between precipitation with NPP and PUE and aridity with NPP and PUE, but a positive linear correlation existed for temperature with NPP and PUE. However, in the Inner Mongolian Plateau, there were positive correlations between precipitation and NPP, temperature and NPP, and aridity and both NPP and PUE and negative correlations between precipitations and PUE and temperature and PUE. Our findings improve understanding of grassland ecosystem responses to global climate change and provide a basis for the protection of grassland ecosystems in arid and semi-arid regions.  相似文献   

8.

Background

A large proportion of the world’s tropical peatlands occur in Indonesia where rapid conversion and associated losses of carbon, biodiversity and ecosystem services have brought peatland management to the forefront of Indonesia’s climate mitigation efforts. We evaluated peat volume from two commonly referenced maps of peat distribution and depth published by Wetlands International (WI) and the Indonesian Ministry of Agriculture (MoA), and used regionally specific values of carbon density to calculate carbon stocks.

Results

Peatland extent and volume published in the MoA maps are lower than those in the WI maps, resulting in lower estimates of carbon storage. We estimate Indonesia’s total peat carbon store to be within 13.6 GtC (the low MoA map estimate) and 40.5 GtC (the high WI map estimate) with a best estimate of 28.1 GtC: the midpoint of medium carbon stock estimates derived from WI (30.8 GtC) and MoA (25.3 GtC) maps. This estimate is about half of previous assessments which used an assumed average value of peat thickness for all Indonesian peatlands, and revises the current global tropical peat carbon pool to 75 GtC. Yet, these results do not diminish the significance of Indonesia’s peatlands, which store an estimated 30% more carbon than the biomass of all Indonesian forests. The largest discrepancy between maps is for the Papua province, which accounts for 62–71% of the overall differences in peat area, volume and carbon storage. According to the MoA map, 80% of Indonesian peatlands are <300 cm thick and thus vulnerable to conversion outside of protected areas according to environmental regulations. The carbon contained in these shallower peatlands is conservatively estimated to be 10.6 GtC, equivalent to 42% of Indonesia’s total peat carbon and about 12 years of global emissions from land use change at current rates.

Conclusions

Considering the high uncertainties in peatland extent, volume and carbon storage revealed in this assessment of current maps, a systematic revision of Indonesia’s peat maps to produce a single geospatial reference that is universally accepted would improve national peat carbon storage estimates and greatly benefit carbon cycle research, land use management and spatial planning.
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9.
Droughts are projected to occur more frequently with future climate change of rising temperature and low precipitation. However, its impact on regional and global vegetation production is not well understood, which in turn contributes to uncertainties to model carbon sequestration under drought scenarios. Using long-term continuous eddy covariance measurements (168 site-year), we present an analysis of the influences of interannual summer drought on vegetation production across 29 sites representing diverse ecoregions and plant functional types in North America. Results showed that interannual summer drought, which was evaluated by the increase in summer temperature or decrease in soil moisture, would cause reductions of both summer gross primary production (GPP) and net ecosystem production (NEP) in non-forest sites (e.g., grasslands and crops). On the contrary, forest ecosystems presented a very different pattern. For evergreen forests, lower summer soil moisture decreased both GPP and NEP; however, higher summer temperature only reduced NEP with no apparent impacts on GPP. Furthermore, summer drought did not show evident impacts on either summer GPP or NEP in deciduous forests, suggesting a better potential of deciduous forests in resisting summer drought and accumulating carbon from atmosphere. These observations imply diverse responses of vegetation production to interannual summer drought and such features would be useful to improve the strengths and weaknesses of ecosystem models to better comprehend the impacts of summer drought with future climate change.  相似文献   

10.
Among the most productive ecosystems around the world, wetlands support a wide range of biodiversity such as waterfowl, fish, amphibians, plants and many other species. They also provide ecosystem services that play important roles in relation to nutrient cycling, climate mitigation and adaptation, as well as food security. In this research, we examined and projected the spatiotemporal trends of change in open wetlands by coupling logistic regression, Markov chain methods and a multi-objective land allocation model into a hybrid geosimulation model. To study the changes in open wetlands we used multi-temporal land cover information interpreted from LANDSAT images (1985, 1995, and 2005). We predicted future spatial distributions of open wetlands in the administrative region of Abitibi-Témiscamingue, Quebec, Canada for 2015, 2025, 2035, 2045 and 2055. A comparison and assessment of the model’s outcomes were performed using map-comparison techniques as well as landscape metrics. Change analysis between 1985 and 2005 showed an increase of about 63% in open wetlands, while simulation results indicated that this tendency would persist into 2055 with a continuous augmentation of open wetlands in the region. The spatial distribution of predicted trends in open wetlands could provide support to local biodiversity assessments, management and conservation planning of the open wetlands in Quebec, Canada.  相似文献   

11.
刘一良  张景  王丝丝  苗晨  李晗  宋婉娟  张松梅 《遥感学报》2022,26(10):2106-2120
持续开展生态环境遥感监测对于认识和评估全球生态系统可持续性和人类生存环境状况具有重要的科学意义,是面向“推进生态文明建设”和“构建地球生命共同体”等目标和愿景,提升综合地球观测能力和应对全球生态环境挑战的务实行动。为此,中华人民共和国科学技术部国家遥感中心聚焦可持续发展、气候变化、防灾减灾和韧性城市等优先事项,通过政府部门、科研机构、国际组织和社会公众的协同,连续十年（2012年—2021年）发布和共享了“全球生态环境遥感监测年度报告”共29个专题报告和100余个遥感数据集。此项工作取得的成果包括：在遥感技术方法创新方面,基于国产高分辨率卫星和多源遥感影像,针对生态系统状况和人类活动痕迹的高精度遥感监测取得了一批具有自主知识产权的算法模型和数据产品;在人类生存环境认知方面,显著提升了公众对粮食安全、气候变化、城市扩展、土地退化和自然灾害风险等全球生态环境热点问题的科学认知;在生态环境重点区域方面,对“一带一路”、南极、非洲、东盟等典型区域开展精细化监测和评估。该项工作是中国作为地球观测组织GEO（Group on Earth Observations）联合主席国对国际社会的实质贡献,为相关机构和部门决策制定提供了重要的信息参考。本论文在此项工作开展十周年之际,系统阐述和总结了全球生态环境遥感监测年度报告的主要内容和亮点成果,并对未来发展提出展望。  相似文献   

12.
开展土地利用总体规划生态环境影响评价实证研究,能够为不同城市的土地利用总体规划修编和生态环境保护提供依据。本文从土地利用结构和布局的角度,以格网为评价单元,运用生态系统服务功能价值评估法,对土地利用总体规划的结构调整所带来的生态服务价值的变化做了空间上的定量预测;并运用生态环境敏感性评价和GIS叠置法从土地利用布局上评价建设用地布局的生态合理性。以鄂城区为例,划分了702个格网,规划实施后生态系统服务功能总价值减少了414.54万元;建设用地布局具有较好的生态适宜性,只有0.23%分布在高度敏感区内。因此,鄂城区土地利用总体规划从生态环境保护角度是可行的,但还应注重对森林和水域等重要生态用地的保护。  相似文献   

13.
Biodiversity Conservation in the REDD   总被引：1，自引：0，他引：1  

Background

Forests occur across diverse biomes, each of which shows a specific composition of plant communities associated with the particular climate regimes. Predicted future climate change will have impacts on the vulnerability and productivity of forests; in some regions higher temperatures will extend the growing season and thus improve forest productivity, while changed annual precipitation patterns may show disadvantageous effects in areas, where water availability is restricted. While adaptation of forests to predicted future climate scenarios has been intensively studied, less attention was paid to mitigation strategies such as the introduction of tree species well adapted to changing environmental conditions.

Results

We simulated the development of managed forest ecosystems in Germany for the time period between 2000 and 2100 under different forest management regimes and climate change scenarios. The management regimes reflect different rotation periods, harvesting intensities and species selection for reforestations. The climate change scenarios were taken from the IPCC's Special Report on Emission Scenarios (SRES). We used the scenarios A1B (rapid and successful economic development) and B1 (high level of environmental and social consciousness combined with a globally coherent approach to a more sustainable development). Our results indicate that the effects of different climate change scenarios on the future productivity and species composition of German forests are minor compared to the effects of forest management.

Conclusions

The inherent natural adaptive capacity of forest ecosystems to changing environmental conditions is limited by the long life time of trees. Planting of adapted species and forest management will reduce the impact of predicted future climate change on forests.  相似文献   

14.
地下水是水资源的重要组成部份,地下水污染危害人的健康,影响人们的生产和生活,查明某一地区地下水容易受污染的可能性即地下水脆弱性,能为管理决策部门提供合理开发地下水资源,防治地下水污染的科学规划和管理依据。在脆弱性评价工作中,应用当前国际上最先进的地理信息系统平台ArcGIS,并结合地统计分析原理,完成地下水系统脆弱性编...  相似文献   

15.
Land use regulations are an important but often underrated legal domain. In densely populated regions such as the Netherlands, spatial plans have a profound impact on both (local) governments and citizens. This article describes our work on a ‘Legal Atlas’. Using Semantic Web technology we combine distributed geospatial data, textual data and controlled vocabularies to support users in answering questions such as: “What activity is allowed here?” Spatial norms are represented using OWL 2 in a way that enables intuitive visualisation of their effects: map‐based legal case assessment. Users can represent a (simple) case by selecting or drawing an area on the map. Given a designation for that area, the system can assess whether this is allowed or not. The same solution also enables the comparison of two or more sets of spatial norms that govern the same region. We discuss the advantages and drawbacks of a number of alternative solutions for representing and integrating metadata of spatial plans, and the representation of normative conflicts and exceptions between norms.  相似文献   

16.
采用静态情景模拟与基于GIS的淹没分析相结合的情景分析方法和指标体系方法综合的脆弱性分析方法开展研究,重点探讨了中国沿海地区典型区域在全球气候变化背景下的脆弱性情况。从危险性、暴露性、敏感性和恢复性等方面开展脆弱性分析,探讨了指标间的权重分配方法,并将脆弱性评估结果划分为低、中、高、极高4个等级,从而为区域的防灾降险提供决策依据。  相似文献   

17.
This study investigates urbanization and its potential environmental consequences in Shanghai and Stockholm metropolitan areas over two decades. Changes in land use/land cover are estimated from support vector machine classifications of Landsat mosaics with grey-level co-occurrence matrix features. Landscape metrics are used to investigate changes in landscape composition and configuration and to draw preliminary conclusions about environmental impacts. Speed and magnitude of urbanization is calculated by urbanization indices and the resulting impacts on the environment are quantified by ecosystem services. Growth of urban areas and urban green spaces occurred at the expense of cropland in both regions. Alongside a decrease in natural land cover, urban areas increased by approximately 120% in Shanghai, nearly ten times as much as in Stockholm, where the most significant land cover change was a 12% urban expansion that mostly replaced agricultural areas. From the landscape metrics results, it appears that fragmentation in both study regions occurred mainly due to the growth of high density built-up areas in previously more natural/agricultural environments, while the expansion of low density built-up areas was for the most part in conjunction with pre-existing patches. Urban growth resulted in ecosystem service value losses of approximately 445 million US dollars in Shanghai, mostly due to the decrease in natural coastal wetlands while in Stockholm the value of ecosystem services changed very little. Total urban growth in Shanghai was 1768 km2 and 100 km2 in Stockholm. The developed methodology is considered a straight-forward low-cost globally applicable approach to quantitatively and qualitatively evaluate urban growth patterns that could help to address spatial, economic and ecological questions in urban and regional planning.  相似文献   

18.
在分析鄂州市生态环境矛盾和生态服务需求的基础上,根据生态红线原理和目标,提出较为完整的生态红线划定方法,保障生态系统完整性及连续性,维护区域生态系统安全。从生态环境敏感性评价、生态服务功能重要性评价、生态灾害危险评价等3方面构建生态适宜性评价体系,展开生态适宜性分析。在GIS与RS支持下,创建了鄂州市网格空间属性数据库,采用层次分析法确定指标权重,运用叠加分析、空间分析等技术方法最终完成生态适宜性评价,将鄂州市划分为红线、黄线、蓝线、绿线等4个区域,同时,叠加整合已有的重要生态功能区,并将红线区划分为一级管控区和二级管控区,明确重点保护方向,确定生态红线管控体系。  相似文献   

19.
Abstract

Mangrove ecosystems play a very important ecological role on land–ocean interfaces in tropical regions. These ecosystems comprise of various tree species and aquatic animals, protecting the environment and providing a habitat that supports many living organisms including humans. The identification of image regions in mangrove ecosystems plays a significant role in ecosystem monitoring and conservation. Recent studies have suggested oversegmentation of colour images using superpixels as a solution to the segmentation of image regions. This study used the SLIC superpixel algorithm and k-means clustering to segment images taken from a camera mounted on a drone from a mangrove ecosystem in Fiji. The SLIC superpixel algorithm performed well to demarcate image regions with similar colour and texture information into patches and to use k-means for the segmentation of the whole image. These results lend support to the use of superpixel algorithms for the segmentation of mangrove ecosystems. Understanding how superpixels can be used for the segmentation of drone images will assist conservation efforts in mangrove ecosystems.  相似文献   

20.
Ecosystem based approach (EBA) for resource management is a concerted, environmentally tuned and an integrated framework that holistically addresses the ecological character of the natural resource, its societal benefit spectrum and its environmental functions. In this paper, the EBA concept is closely linked with the emerging concept of multiple use systems (MUS) while taking account of environmental, economic, and social factors that govern the ecosystems services and benefits. We elucidate a multi-scalar approach and multiple case studies to understand EBA particularly in context of a wetlandscape. At the global scale, Ramsar sites of international importance are geospatially analyzed with reference to their agro-ecology and biodiversity. At regional scale, the agrarian use of inland wetlands in India was re-evaluated taking account of database from a recent inland wetland inventory. At the local scale, drawing on the landscape characterization and the ecological economics for fresh water Lake Kolleru in India and the Muthurajawela Marsh-Negombo Lagoon coastal marsh in Sri Lanka, we illustrate some of the practical challenges in balancing wetland conservation, development needs and the overall well-being of local people. We also discuss how variability in the scale, geophysical characteristics of the site and the data availability confines the ability to simplify a single complete approach to address issues in complex ecosystem such as wetlands. All levels of the study are supported by a variety of earth observation data and the geographical information system (GIS) tools. The site level analysis also draws on socio-economic assessment tools.  相似文献   

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