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1.
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   

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.
Topographic maps are powerful tools for the purpose of identifying land use and cover change (LUCC) as they are among the most reliable representations of past landscapes for the time prior to the existence of aerial photography. In light of the increased availability of historical maps, we argue that there is a need for a standardized process to assess map comparability in a systematic way in order to avoid, or at least minimize, the detection of spurious landscape changes due to incompatible map series. A full understanding of map quality, background and error distributions is fundamental to attain reliable LUCC results. The conceptual framework presented in this study considers the context, distortion and cartographic generalization of topographic maps. Furthermore, it includes an approach to homogenize the level of generalization of landscape elements (e.g. forests) from maps with different scales. To demonstrate its application, we assessed the comparability of seven topographic maps from Canton Zurich covering a time span of 336 years (1664–2000). Overall, for the maps of Canton Zurich, a wall-to-wall comparison of forest cover based on the topographic maps presented here can be problematic for the oldest map from 1664. Based on the results, a wall-to-wall comparison with the later maps is not recommended, due to its substantial distortion. Yet, after re-generalization of natural landscape elements, such as forests, a comparison based on landscape indices is possible, even for the oldest map. Furthermore, our results demonstrate that maps from the mid-19th century onward possess an acceptable level of accuracy. This framework can be applied to a wide range of maps at regional, national, or global levels, providing the opportunity to look at land cover history over multiple centuries.  相似文献   

4.
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   

5.
This study explores the potential of historical maps to detect, measure and monitor changes of trees outside forests. The main goal is to assess local-level changes of scattered trees and orchards and their land-use determinants in two areas in Southern Germany between 1901/1905 and 2009. Firstly, overall landscape changes are recorded. Secondly, the spatial-temporal trajectories of scattered trees and their land-use determinants are identified. Thirdly, changes in quantity and fragmentation patterns of traditional orchards are analyzed in their relationship to overall land-cover change. The results confirm major losses in scattered trees, mainly due to urbanization, agricultural intensification, and land abandonment. They further reveal that, while orchards have persisted in total area, they have undergone critical changes toward a simplified landscape structure and loss of the traditional land-use mosaic, which is a characterizing feature of high nature value landscapes. Multi-temporal assessment showed that most trends have been continuous and did not change directions over time, but rather accelerated during periods of rapid change (most dramatically in the 1950-1990 period). The case of orchards and scattered trees illustrates a major problem of cultural landscapes in Europe: Semi-natural landscape features of high nature value are threatened by both intensification and abandonment of land uses. This makes their conservation a potentially costly enterprise, as both opportunity costs for lost alternative land uses and for conservation management costs arise.  相似文献   

6.
Traditional land use systems are threatened by land use intensification and resulting land cover transitions in northern areas. This article examines cumulative land cover changes and their impacts on reindeer grazing grounds in the Kyrö reindeer herding district in northern Finland. Land cover transitions were studied using Landsat TM and OLI images and topographic maps. The results showed that the herding district has experienced notable land cover changes during the past decades, and most of these changes were directly related to forestry. The proportion of continuous coniferous forests of the total forest cover declined from 92% to 78% between 1987 and 2013. Approximately one third of the forests outside current conservation areas were disturbed by forest management by 2013, and remaining forests were notably more fragmented than forests within conservation areas. The extent of the road and path networks expanded considerably between 1960s and 2010 as a result of increasing logging and tourism. Accumulation of disturbances gradually results in loss of key resources and declined quality of the landscape mosaic from the reindeer herding perspective, which can pose a serious threat to long-term sustainability of the livelihood. Rapid land cover changes in non-protected areas highlight an increasingly important role of conservation areas in maintaining resources for reindeer husbandry in the face of intensifying land use. Sustainable management of resources outside conservation areas requires careful participatory planning and efficient cumulative impact assessment of different land use activities.  相似文献   

7.
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8.
The Atlantic Forest biome has only 13 percent of its pristine vegetation cover left. This article analyzes the consequences of land changes on forest cover in the Paraíba Valley, São Paulo state, Brazil, from 1985 to 2011. Multitemporal satellite image classifications were carried out to map eight land use and land cover classes. The forest cover increased from 2,696 km2 in 1985 to 4,704 km2 in 2011, mostly over areas of degraded pastures. The highest rates of afforestation were observed within protected areas around eucalyptus plantations. On the other hand, deforestation processes were concentrated on areas covered by secondary forests. Socioeconomic changes taking place in particular Brazilian settings, such as industrialization and agricultural modernization, allied to the Paraíba Valley's natural biophysical constraints for agricultural production, have led the region to experience a remarkable case of forest transition.  相似文献   

9.
三江平原别拉洪河流域湿地农田化过程研究   总被引：10，自引：6，他引：10  
自20世纪50年代以来,三江平原的别拉洪河流域在经历了3次大规模开荒后,大面积的湿地被农田所替代,耕地面积迅速增加,湿地农田化过程干扰和破坏了原有的湿地环境。在遥感和地理信息系统技术支持下,应用景观生态学方法,利用1954年、1976年、1986年、2000年和2005年的土地利用数据,分析了研究区近50 a来的湿地农田化过程。结果显示,湿地农田化过程中大面积的湿地斑块被农田斑块所取代,破碎化的小耕地斑块又逐渐合并为大的耕地斑块,并导致斑块形状复杂度指数逐渐增大,景观均匀度指数呈现波动变化;耕地面积在1954~1986年期间增长幅度较大,特别是在20世纪70年代末和80年代初的改革开放初期,研究区景观动态度为0.201,远高于其它时期;目前,农田景观已成为主要景观类型,农田面积占研究区总面积的63.69%,湿地面积占研究区总面积的比例由1954年的64.83%减小到2005年的19.44%。质心模型的分析结果显示,近50 a来研究区耕地景观质心平移幅度明显大于湿地景观,湿地景观质心不断地向东北方向移动,偏移了约20.5 km,而农田景观质心逐渐向东平移,平移了约44.7 km。农业开垦是研究区湿地大面积消退的主要原因。  相似文献   

10.
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11.
The urban development of Banda Aceh, Indonesia was very rapid after the tsunami in 2004, posing critical challenges in planning for its future sustainable development. Scientifically-derived information about its land change patterns and the driving factors of its rapid urbanization might provide vital information. However, the spatio–temporal patterns of its urban land use/cover (LUC) changes have not been examined. Hence, this study aims to: (1) detect and analyze the spatio–temporal changes in the urban LUC of Banda Aceh between 2005 and 2009; and (2) examine the driving factors that influence urban growth. The 2005 and 2009 LUC maps were derived from remote sensing satellite images using a supervised classification method (maximum likelihood). Both LUC maps contained four categories, namely built-up area, vegetation, water body, and wet land. The 2005 LUC map had an overall accuracy of 77.8%, while the 2009 LUC map had 89.4%. The two LUC maps were re-classed into two categories (i.e. built-up area and non built-up area) to facilitate logistic regression analysis. A total of seven variables or potential driving factors of urban growth were identified and examined, including two socio-economic factors (population density and distance to central business district) and five biophysical factors (distances to green open space, historical area, river, highway, and coastal area). The results showed that the LUC of Banda Aceh has changed drastically between 2005 and 2009, particularly its built-up area, which increased by 90.8% (1016.0 ha) at the expense of the other LUC categories. The socio-economic factors showed positive influence to the growth of the city, whereas the biophysical factors showed negative effect, except the distance to coastal areas. The importance of the findings for future landscape and urban planning for Banda Aceh is discussed.  相似文献   

12.
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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13.
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   

14.
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   

15.
湿地景观变化过程与累积环境效应研究进展   总被引：47，自引：5，他引：42  
湿地在流域中处于水陆交错的特殊过渡区域,是地表重要的景观覆盖类型和生态系统。湿地具有独特的水文、土壤和植被特征,在维护区域/流域生态平衡和环境稳定方面发挥巨大作用。湿地景观变化过程主要表现为景观格局和过程在时间和空间尺度上的相互作用过程。该过程对系统的能量流动、物质循环以及物种迁移产生作用,对地理环境也产生巨大环境效应。湿地景观变化与土地利用/覆盖变化紧密相关,与人类活动影响息息相联。至今,人类已把天然的湿地景观格局改变为受人类支配的土地利用格局。自然湿地景观格局的变化过程对湿地生态系统以及其他系统的生物多样性、初级生产力产生显著影响,对局地、区域及全球气候环境、水文环境、生物多样性等方面产生显著而深刻的影响。湿地景观变化是全球变化研究的重要内容,尤其对认识全球气候变化、土地利用/覆盖变化和生物多样性变化的区域响应具有重大意义。  相似文献   

16.
This study answers the following research questions: 1) What are the change trajectories of woody vegetation elements at the landscape level? 2) What are the differences in change trajectories amongst the various categories of forest, non-forest and reclamation woody vegetation? 3) How do the change trajectories differ in mining and non-mining landscapes? The study area, measuring 209.6 km2, is located in the north-western part of the Czech Republic and may be broken down into 76.8 km2 of mining landscape and 132.8 km2 of non-mining landscape. Brown coal mining began in this region during the second half of the 18th century and led to the radical transformation of the landscape, including woodlands, during the second half of the 20th century. The source data for this study was obtained from the original stable cadastre maps (1842) and the landscape field mapping performed in 2010. The various woody vegetation elements (forest, non-forest, and reclamation woody plants) and land use/cover (LULC) categories were identified. The GIS symmetrical difference tool was subsequently used to perform an overlay analysis for the individual woody vegetation elements in order to study the change trajectories and to obtain information about the woodlands that have remained unchanged (continuous), the ones that have disappeared (extinct), and the ones that have newly appeared in the landscape (recent). In the case of the non-mining landscape, the total proportion of woodlands has increased (from 17 to 32%), but there has been a decline in the overall volume of forest woody plants found in these areas (from 93 to 74%). As far as the mining landscape is concerned, there has also been an increase in the area covered by woodlands (from 10 to 20%), however, the proportion of forest woody plants has decreased to a much greater extent (from 90 to 31%). From the perspective of extinct woody vegetation, 23.3% of all types of woodlands in the mining landscape may be classified as such, as compared to 10.8% in the non-mining landscape. The primary causes of this decline are mining activities and newly built-up areas. More continuous woody vegetation may be found in the non-mining landscape (42.1%) as compared to the mining landscape (15.4%). Recent woody vegetation, which has primarily replaced grasslands and partially arable land, prevails in both the mining (61.3%) as well as the non-mining (47.1%) landscapes. Different categories of woodlands (forest, non-forest, and reclamation woody vegetation elements) exhibit various change dynamics due to their different structure and the functions they serve. At the most basic level, there has been an overall increase in the occurrence of woodlands in the studied areas. However, once GIS spatial analysis is applied it is possible to see more complex processes in the development of woodland areas as characterised by gains and losses, and it is possible to identify mining and agricultural extensification as the two most significant factors behind the historical changes. Mining leads to a direct decrease in the area of woodlands; conversely, the spontaneous succession of vegetation resulting from agricultural extensification and forest reclamation facilitates woodland recovery. Forest reclamation and reforestation are essential on order to ensure the time continuity of woodlands in both types of landscape, i.e. mining and non-mining. The study presented in this paper proves that it is relevant to analyse the changes occurring in different woodland categories separately. The same methodology may be applied when studying the change dynamics of other important landscape elements, such as wood pastures and wetlands.  相似文献   

17.
湿地景观格局变化研究进展   总被引：45，自引：1，他引：44  
湿地是自然界最富生物多样性的生态景观,具有重要的生态功能。湿地景观格局是各种生态过程综合作用的结果,具有高度的景观异质性,对景观的功能和过程有着显著的影响。湿地生态系统是世界上受威胁最为严重的生态系统之一,在自然因素和人类活动的影响下发生了大面积的转化或丧失。本文从湿地景观格局研究方法、面积变化、景观类型转化、驱动力以及动态模型、湿地景观格局指数以及湿地景观格局与气候变化之间的关系等方面综述了湿地景观格局变化的研究进展,指出湿地景观格局变化及其生态效应和高原湿地景观格局变化与气候变化之间的关系是未来研究的重点领域。  相似文献   

18.
Cash crop cultivation has been a critical driver of land use change in many countries around the world. However, few efforts have been made to quantify the relationships between cash crop expansion and the subsequent landscape pattern changes. This paper characterized the process of cash crop expansion across Tiaoxi watershed (China) from 1985 to 2009 using multi-sensor and multi-temporal remotely sensed imageries. Correlations were identified between indicators of cash crop expansion (total area and total production of cash crops) and a family of landscape fragmentation metrics (patch density, edge density, landscape division index, effective mesh size, splitting index, Shannon's diversity index, and aggregation index). Results showed that Tiaoxi watershed experienced profound cash crop expansion and progressive landscape fragmentation. The cash crops spread in accessible and productive areas at the expense of paddy and forests. Social drivers of cash crop expansion included population growth, labor structure changes and market incentives. Indicators of cash crop expansion presented linear relationships with landscape fragmentation metrics. These findings evidenced that cash crop cultivation would significantly fragment landscapes. Our study contributed to understanding on the enlarging cultivation of cash crops and the associated modifications of landscape patterns in subtropical regions.  相似文献   

19.
景观格局在沙漠化研究中的作用   总被引：27，自引：5，他引：22  
常学礼  赵爱芬 《中国沙漠》1998,18(3):210-214
应用景观生态学中格局分析的一些方法对４种典型沙漠化土地景观进行了分析,研究结果表明：景观和景观中斑块的格局通过影响边界长度和组合状况,进而影响沙漠化过程中的各种生物学和生态学过程。其中,分维数的变化可以反映景观和斑块格局的变化,分维数越大格局越复杂,两者关系呈正相关;修改分维数可以反映景观格局的多样性和景观中斑块之间的相邻性,两者关系也呈正相关;沙漠化土地景观格局的数量化分析和描述,为研究沙漠化过程和景观格局的相互关系奠定了基础。同时还指出了景观格局在沙漠化危害程度判定中有重要作用。  相似文献   

20.
We developed a new approach combining statistical and graphical methods to build a hierarchically networked structure for understanding spatial characteristics of urban landscapes at multiple scales. Natural breaks optimization algorithm is applied to determine the optimal number of urban land hierarchies and assign discrete patches into ordered sub-groups according to a selected geometric or functional attribute. Patches contained in a sub-group are linked to the patches in the next sub-group according to the spatial relationships between the patch centroids and Voronoi cells. The conceptual foundations and technical details of this approach are elaborated in the case study of building a hierarchically networked structure of urban built-up patches in Beijing. This approach can be applied to quantify landscape patterns of other land uses to facilitate assessments of interconnection between various types of land uses at varied hierarchical levels (spatial scales) and to evaluate ecological service functions of urban built infrastructures.  相似文献   

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