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1.
基于RS和GIS的西双版纳土地覆被动态变化   总被引:9,自引:0,他引:9  
人口增加、经济发展导致滇南热带地区西双版纳土地利用/土地覆被发生显著变化,这些变化对该区的生态环境及生物多样性保护有着重要影响。基于RS和GIS方法,通过对1976、1988和2003年三个时期遥感影像解译分析,试图了解西双版纳近27 a间土地利用/土地覆被时空变化特征及影响因素。结果表明,近27 a间有林地在西双版纳分布最广、占绝对优势,其中以亚热带常绿阔叶林面积最大;但在研究时段内,有林地面积不断减少、呈现破碎化,尤其是热带季节雨林、山地雨林面积减少最为明显和破碎化最为严重。相应,橡胶园、灌木林面积不断扩大并聚集成片,其中橡胶园在1988~2003年间是面积增长最快、最多的地类,其面积扩张主要来源于对热带季节雨林的砍伐。轮歇地面积在1976~1988年是所有地类中增长最快、最多的,在1988~2003年由于向橡胶园转变而大幅度减小。粗放式的刀耕火种和橡胶种植园的不断扩大是主导本区土地利用/土地覆被变化的主要因素,土地利用变化导致了本区生态环境的退化和生物多样性的丢失。  相似文献   

2.
喀拉峻-库尔德宁区域是新疆天山自然遗产地的重要组成部分,其生态健康状况将影响该自然遗产地的突出普遍价值。目前从景观生态学角度,通过景观格局动态演化过程反映自然遗产地生态健康研究较少。本研究以喀拉峻-库尔德宁区域为例,基于多源遥感影像,提取景观信息进行定性与定量分析,并结合景观格局指数,从景观动态特征、类型水平和景观水平分析景观格局演化特征,评价景观健康状况,形成自然遗产地景观数据的获取方法,探索景观格局与生态过程的关系,为相关研究提供借鉴。结果显示:裸地增加,冰雪、针阔混交林等景观减少;类型水平上,针阔混交林受人为干扰严重,中和低覆盖度草地呈破碎化;景观水平上,景观聚集度、连通性、分形状况稳定,景观多样性提升后维持稳定;总体景观生态健康,突出普遍价值(OUV)维持稳定,但对针阔混交林需要进行重点保护。结果可为研究区综合管理和生态健康分析提供有效数据。  相似文献   

3.
Tropical forests play a major role in storing large carbon stocks and regulating energy, and water fluxes, but such forest cover is decreasing rapidly in spite of the policy attention on reducing deforestation. High-resolution spatiotemporal maps are unavailable for the forests in majority of the tropical regions in Asia because of the persistent cloud cover and haze cover. Recent advances in radar remote sensing have provided weather-independent data of earth surface, thus offering an opportunity to monitor tropical forest change processes with relatively high spatiotemporal resolutions. In this research, we aim to examine the tropical deforestation process and develop a spatial model to simulate future forest patterns under various scenarios. Riau Province from central Sumatra of Indonesia is selected as the study area; this province has received much attention worldwide because the highest CO2 emission resulting from tropical deforestation has been recorded. Annual time series PALSAR data from 2007 to 2010 were analyzed for forest mapping and detecting land cover changes. A spatial model was calibrated using the Bayesian method. Modeling parameters were customized for the local subregions that allocate deforestation on the basis of their empirical relationships to physical and socioeconomic drivers. The model generated landscape spatial patterns mirrored the possible locations and extent of deforested areas by 2030 and provided time-series crucial information on forest landscape under various scenarios for future landscape management projects. The results suggested that the current deforestation process is in a critical stage where some subregions may face unprecedented stress on primary forest costing rivers and forest ecosystems by the end of 2020. The perspective views of Riau Province generated by the model highlighted the need for forest/environmental planning controls for the conservation of environmentally sensitive areas.  相似文献   

4.
5.
Analyzing temporal changes in forest amount and configuration is paramount to better design future forest management interventions. Such analyses are especially required for tropical biomes, which are usually subject to dynamic and heterogeneous land uses. Recent studies have suggested that many tropical biomes are passing through the process of “forest transition”, i.e. an overall change from forest loss to forest gain. However, this hypothesis remains scarcely tested, due to the difficulty of obtaining detailed, quantitative historical records of forest cover. In this study, we investigate 38 years of land use change in Brazil's Atlantic Forest, a biodiversity hotspot, from 1976 to 2014, using multitemporal datasets from aerial photographs and satellite images. We classified the historical series to produce land use maps and calculated a set of landscape metrics, including total forest cover, patch size, patch shape and patch connectivity. Our results indicated non-linear changes through time in forest loss and gain and also in landscape structure, which can be classified into two distinct periods. The first period (1976–1996) was marked by expressive forest loss and fragmentation, whereas the second (1996–2014) was characterized by a much less intense forest dynamics, with little deforestation being balanced by forest regeneration. We attribute the forest dynamics observed to temporal changes in socioeconomic factors, such as increasing human settlements and changes in environmental protection policies. Our results show that current forests are a heterogeneous mosaic of forests with different ages, and support the hypothesis that forest transition is occurring in Atlantic Forest landscapes.  相似文献   

6.
In spite of widely documented studies of deforestation rates and land use/cover changes in tropical dry forests in Mexico, relatively little is known about fragmentation patterns in such forests. This study defines the spatial distribution of landforms and land use/cover types the lower Papagayo River basin and examines their influence on fragmentation patterns and biological diversity in a tropical dry forest in that southern Pacific region. The land use/cover map was constructed from aerial photographs, Landsat TM imagery (2000) and fieldwork. Landform units were defined based on altitude, slope, lithology and morphology. Landscape fragmentation parameters were obtained using FRAGSTATS (version 3.3) considering the numbers of patches, mean, minimum and maximum patch size, edge density, total edge and connectivity. Results show tropical dry forest to be remnant vegetation (~11 per cent), characterized by isolation and low connectivity. Land use/cover types have different effects on fragmentation patterns. Agriculture and cattle raising produce similar numbers of patches, but with a different mean size; and human settlements have a scattered distribution pattern. The abandonment of rural agricultural livelihoods has favoured the expansion of secondary tropical dry forest characterized by continuity and high connectivity, which suggests a high regeneration potential from land abandonment. It can be concluded that tropical dry forest fragmentation and recovery at regional scales depend on such landscape attributes as lithology, slope, geomorphology and management.  相似文献   

7.
景观类型分析在土地覆被变化中的作用   总被引:1,自引:1,他引:0  
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8.
Swidden agriculture is often deemed responsible for deforestation and forest degradation in tropical regions, yet swidden landscapes are commonly not visible on land cover/use maps, making it difficult to prove this assertion. For a future REDD+ scheme, the correct identification of deforestation and forest degradation and linking these processes to land use is crucial. However, it is a key challenge to distinguish degradation and deforestation from temporal vegetation dynamics inherent to swiddening. In this article we present an approach for spatial delineation of swidden systems based on landscape mosaics. Furthermore we introduce a classification for change processes based on the change matrix of these landscape mosaics. Our approach is illustrated by a case study in Viengkham district in northern Laos. Over a 30-year time period the swidden landscapes have increased in extent and they have degraded, shifting from long crop-fallow cycles to short cycles. From 2007 to 2009 degradation within the swidden system accounted for half of all the landscape mosaics change processes. Pioneering shifting cultivation did not prevail. The landscape mosaics approach could be used in a swidden compatible monitoring, reporting and verification (MRV) system of a future REDD+ framework.  相似文献   

9.
南沙群岛景观分5种类型:礁丘热带海洋生物繁生景观,环礁带海洋生物繁生景观,灰沙岛热带常绿刮灌林磷积石灰土景观,大陆架热带海海海洋生物繁生景观,深海热带大洋性和深海性海洋生物景观,这5种景观归纳为两类,一类为热带海洋景观,包括浅海和深海;另一类为热带珊瑚礁景观,下分礁丘,环礁和灰沙岛3种,南沙群岛景观类型分布和演化与古地理和现代化环境条件有关。  相似文献   

10.
A comprehensive understanding of the patterns that occur as human processes transform landscapes is necessary for sustainable development. We provide new evidence on how landscapes change by analysing the spatial patterns of human processes in three forest landscapes in southern Chile at different states of alteration (40%-90% of old-growth forest loss). Three phases of landscape alteration are distinguished. In Phase I (40%-65% of old-growth forest loss), deforestation rates are < 1% yr−1, forests are increasingly degraded, and clearance for pastureland is concentrated on deeper soils. In Phase II (65%-80%), deforestation reaches its maximum rate of 1-1.5% yr−1, with clearance for pastureland being the main human process, creating a landscape dominated by disturbed forest and shrubland. In this phase, clearance for pastureland is the primary driver of change, with pastures expanding onto poorer soils in more spatially aggregated patterns. In Phase III (80%-90%), deforestation rates are again relatively low (<1% yr−1) and forest regrowth is observed on marginal lands. During this phase, clearance is the dominant process and pastureland is the main land cover. As a forest landscape is transformed, the extent and intensity of human processes vary according to the existing state of landscape alteration, resulting in distinctive landscape patterns in each phase. A relationship between spatial patterns of land cover and human-related processes has been identified along the gradient of landscape alteration. This integrative framework can potentially provide insights into the patterns and processes of dynamic landscapes in other areas subjected to intensifying human use.  相似文献   

11.
广西岩溶植被自然分布规律及对岩溶生态恢复重建的意义   总被引:29,自引:0,他引:29  
广西的岩溶植被类型和物种多样性丰富,分为5个植被型组8个植被型共96个群系,广西岩溶植被纬度分布由南至北为季节性雨林→含热带成份的常绿落叶阔叶混交林→常绿落叶阔叶混交林,生态结构复杂,特有成分突出,形成特殊的热带亚热带岩溶植物区系。岩溶区生态建设与植被恢复过程中,需遵循植被地带性分布规律,参照区域性顶极植物群落,进行人工群落的重建设计,选择优良乡土树种尤其是速生常绿阔叶树种,模拟天然植被构建先锋植物群落,乔灌藤草优化配置,针对生境异质性的主导因子,强化岩溶山地造林与封育管理技术,有效提高生物生产效率和植被覆盖率,开发特有适生的名特优产品,带动经济发展、促进生态环境尽快改善。  相似文献   

12.
根据森林旅游资源具有生命周期的特点,引入环境评价中的生命周期评价方法与步骤,并利用生命周期矩阵的半定量方法,对森林景观进行生命力评价。结果表明:(1)各个景观所表现出的生命力,在森林景观自身的功能基础上,取决于生命周期的各个阶段的旅游魅力,生命力评价指数和常绿阔叶林景观的相关性,说明了常绿阔叶林景观的旅游魅力;(2)森林景观应按照年龄结构进行合理的空间格局配置,以提高旅游吸引力;(3)提高森林景观的旅游生命力,必须调整资源类型结构,尽量扩大高质量的森林景观种类比例,优化树种结构。  相似文献   

13.
基于景观格局定量分析的流域治理--以文峪河流域为例   总被引:6,自引:0,他引:6  
以航片、森林资源调查资料和林相图为基础资料,在地理信息系统软件及数据库管理系统的支持下,应用景观多样性指数、景观要素优势度指数、类斑形状指数、景观要素斑块分数维等景观格局分析指标,对流域景观空间总体分布、景观组成结构、景观要素斑块形状特征进行分析,揭示了山西文峪河流域植被景观的总体格局。基于分析成果,针对目前文峪河流域植被景观格局存在的问题,建议在今后的流域管理和建设中应开展的工作,即上游及中高海拔带重点进行寒温性针叶林保护;中下游山地积极增加阔叶林,营造混交林;河谷重点开展河岸植被和河岸林规划设计和建设。  相似文献   

14.
Maintaining forest landscape connectivity is one of the most effective ways to alleviate natural forest fragmentation and biodiversity loss problems. Recently, graph theory based metrics have been used as powerful tools in the assessment of landscape connectivity. However, the functional features of landscape units at different structure levels, based on which outcomes can be enriched and advice can be given for practical applications, have been overlooked. In this study, a series of graph-based connectivity indices was calculated to 1) evaluate the optimal threshold distance, 2) identify the key landscape units at the component and patch levels, and 3) classify the functional types of components and patches and analyze functional patterns at different structural levels. The relationship between patch size and patch functional performance in maintaining landscape connectivity was discussed. With a natural forest area in Minqing County of China as the study area, recommendations regarding forest conservation and connectivity enhancement were provided based on the research conclusions. This study provides a way to comprehensively analyze habitat fragmentation and functional patterns for local forest conservation.  相似文献   

15.
To protect the richness, diversity and uniqueness of China's ecosystems and landscapes, more than 150 national parks (named "National scenic and historic interest areas" in China), 85 national geoparks and 230 national nature reserves have been delimited nationwide. In addition, a total of 30 world heritage sites (4 mixed, 4 natural, 22 cultural), 24 biosphere reserves and 8 world geoparks have been ratified for China in a short time by the UNESCO. Unfortunately, most of these national and…  相似文献   

16.
林地是维护生态安全,实现区域可持续发展的根本基础资源。林地变化可能导致一些生态环境问题,包括土壤侵蚀,水资源短缺,干旱加剧以及生物多样性的丧失。本文以景观生态学和逻辑回归模型为基础,探讨了京津冀地区1985-2000期间林地变化的时空格局及其影响因素。格局分析结果表明,林地景观破碎化正在下降和林地形状变得越来越规则。通过建立Logistic回归模型,这项研究旨在探讨这一区域1985-2000期间林地变化的重要变量。对于京津冀地区1985-2000期间林地变化而言,土壤有机质含量,坡度(5°),到最近村庄的距离以及人均国内生产总值是最重要的解释变量。研究表明,空间异质性会影响到林地变化的逻辑回归模型的可预测性。  相似文献   

17.
生态脆弱区的生态重建与景观规划   总被引:31,自引:10,他引:21  
肖笃宁 《中国沙漠》2003,23(1):6-11
通过对生态脆弱区生态建设目标和内涵的分析,提出生态建设尺度性的概念,从理论上总结了景观生态建设的目标、内容和设计指导原则。并以沙地田、草、林体系,三北农田防护林网络体系,黄土高原农、草、林立体镶嵌模式为例,论述了这类景观尺度上的生态建设乃是以景观单元空间结构的调整和重新构建为基本手段,通过增加景观异质性的办法创建新的景观格局;在原有的生态平衡中引进新的负反馈环,实行多种经营、综合发展以增加系统的稳定性,取得了超过自然生态系统的生产力,并且保持了生态环境的可持续性。这是一种具有中国特色的农村景观规划思路,可与20世纪90年代以来国际上流行的持续农业发展研究相接轨。  相似文献   

18.
About 70% of its land area as mountains and plateaus, China is the largest mountain country in the world. Thanks to its vast territory (9.6 million km2), outstanding relief and varied climates, China boasts extremely plenty of ecosystems and landscapes. From south to north, it traverses almost all the temporal zones from tropical rainforest in the southernmost to frigid-temperate needle-leaved forest in the northernmost; from east to west, it sees a gradual transition fro humid forest landscape to extremely arid desert landscape; vertical change of landscapes is most striking owing to the existence of many high mountains (above 6000–7000 m, e.g., the Himalayas, the Kunlun, the Tianshan, the Hengduan, etc.) and plateaus, especially the immense Tibetan Plateau (averagely 4500 m above sea level). All of this give rise to the richness and diversity of ecosystems and landscape in China. Some of the ecosystems are endemic to China, e.g., alpine desert and alpine steppe in the Tibetan Plateau. As a result, China bears a great responsibility in the protection of global ecosystems and landscape.  相似文献   

19.
Non-crop habitats have been suggested to impact local biodiversity significantly in agricultural landscapes. However, there have been few studies of the effects of less-focused non-crop habitats(orchard, wetland, pit and ditch) on variation of spider abundance. In this study, spiders in 30 woodlands were captured using pitfall traps in Fengqiu County, China, and the effects of local and landscape variations at different scales(50 m, 100 m, 200 m, 350 m and 500 m) on spider abundance were analysed. The most important variation that influenced spider abundance at the 500 m scale was the less-focused non-crop habitat(LNH) cover, and 10% was an appropriate proportion of LNH cover to sustain high level of spider diversity in the investigated landscape. Non-metric multidimensional scaling analyses revealed that there were significant differences in the spider composition among the high, medium and low LNH coverage. Based on indicator species analysis, different spider species were associated with landscapes with different levels of LNH cover. Lycosidae, which accounted for 48% of the total specimens, preferred woodland habitats neighbouring areas with high LNH cover. Compared with woodland habitats, LNH provided more diverse food sources and habitat to sustain more spider species in the study area. Furthermore, linear elements composed of vegetation, such as pits and ditches, may prevent agricultural intensification by enhancing landscape connectivity and providing habitats for different spiders. Our findings may provide a theoretical basis for biodiversity conservation in agro-ecosystems and top-down control of pests.  相似文献   

20.
While a number of studies have applied public participation GIS (PPGIS) approaches to the spatial assessment of ecosystem services, few have considered the associations between the spatial distribution of ecosystem services and the context-specific nature of self-reported well-being. In this study, we engage the general public to identify and map a range of ecosystem services that originate in place-based, local knowledge and explore the context-dependent nature of subjective well-being. We conducted a PPGIS survey with 219 local residents in a Spanish agroforestry (dehesa) landscapes and analysed the spatial patterns of mapped ecosystem services, their relation to land cover, protected area and common land patterns. In addition, we explored the landscape values contributing to people’s well-being; and the relationships between ecosystem services in different land covers, landscape values and socio-demographic characteristics. A mosaic of landscape types (i.e., the landscape) provided more ecosystem services (especially cultural and provisioning) to people compared with the individual land system of agroforestry. However, land tenure and public access significantly guided the spatial practices and values of the people beyond the preferred landscape types. The contribution of the landscape to well-being is largely related to values based on interactions among people and the landscape, as tranquillity/relaxation and people-people interactions such as being with family and friends. We discuss the specific contribution of agroforestry landscapes to the provision of ecosystem services and human well-being. We conclude that the integration of the applied methods of social-cultural assessment on the one hand links to ecosystem services frameworks but on the other hand represents a more holistic conceptualisation of people’s benefits from landscapes.  相似文献   

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