Review of forest landscape models: Types, methods, development and applications

Forest landscape models simulate forest change through time using spatially referenced data across a broad spatial scale (i.e. landscape scale) generally larger than a single forest stand. Spatial interactions between forest stands are a key component of such models. These models can incorporate other spatio-temporal processes such as natural disturbances (e.g. wildfires, hurricanes, outbreaks of native and exotic invasive pests and diseases) and human influences (e.g. harvesting and commercial thinning, planting, fire suppression). The models are increasingly used as tools for studying forest management, ecological assessment, restoration planning, and climate change. In this paper, we define forest landscape models and discuss development, components, and types of the models. We also review commonly used methods and approaches of modeling forest landscapes, their application, and their strengths and weaknesses. New developments in computer sciences, geographic information systems (GIS), remote sensing technologies, decision-support systems, and geo-spatial statistics have provided opportunities for developing a new generation of forest landscape models that are increasingly valuable for ecological research, restoration planning and resource management.     

面向生态系统服务的森林生态系统经营:现状、挑战与展望

森林生态系统是地球陆地生态系统的主体,它具有很高的生物生产力和生物量以及丰富的生物多样性,对全球生态系统和人类经济社会发展起着至关重要和无可替代的作用。伴随着人口的不断增长和经济社会的迅猛发展,对森林资源和森林生态系统服务的需求不断高涨,而且人类对森林资源价值的认识也发生了很大程度的改变。推进森林资源可持续经营,增加森林总量、提高森林质量、增强生态功能,已成为中国林业可持续发展乃至推进中国生态文明建设和建设美丽中国的战略任务。本文全面综述了森林生态系统经营发展历程,分析了森林生态系统经营的现状和存在问题,在此基础上,提出整合基于生态系统管理与满足现代人类福祉对森林多重需求的新的森林生态系统经营理念,面向生态系统服务的森林生态系统经营理念是未来的发展趋势。森林经营发展战略表现为:1)从单纯的森林面积数量扩张,转变到提高单位面积的森林生产力和森林质量;2)从单一追求木材生产逐步转变为多目标经营,将森林林产品单一的经营目标转变为广泛的生态、经济和社会等多目标经营;3)森林经营重点从林分水平转变为森林景观的经营,强调森林景观的时空异质性和动态变化,权衡和协同多种生态系统的服务功能,倡导森林景观的多样性和连通性,提高森林与其它土地利用模式镶嵌构成的复合景观的可持续性和稳定性,增强森林生态系统对气候变化影响的适应能力;4)森林生态系统经营将从依赖传统经验的主观决策转变为信息化、数字化和智能化的决策,发展森林生态系统经营决策支持系统和森林景观恢复与空间经营规划系统。     

基于生态恢复和文化回归的梯田景观格局重建--以菲律宾科迪勒拉高山水稻梯田景观复兴为例

基于菲律宾科迪勒拉梯田景观遭到严重破坏、世界文化遗产受到威胁的现状,通过分析先人建立的"水源涵养林-木涌-聚落-梯田-水系"结构体系以及传统文化对梯田景观格局稳定性的保护和控制,剖析隐含在高山水稻梯田景观背后的生态技术和文化格局,了解和借鉴先人智慧,结合现状生态、社会问题和地区特征,分析梯田景观恢复的需求和挑战,运用景观生态学技术手段和对传统文化的唤醒,进行采伐迹地恢复、梯田景观恢复、灌溉体系修复、对抗外来物种入侵,借鉴传统管理模式建立适应新形势的社区管理和合理的旅游规划体系,重建"森林-木涌-聚落-梯田-水系"的景观生态格局,促进传统文化回归,实现高山梯田景观复兴与世界文化遗产保护。     

气候变化、林火和营林措施对寒温带典型森林生态弹性的影响

生态弹性是森林生态系统在遭受外在扰动后恢复到稳定状态的能力,是森林资源可持续发展的重要目标之一,且森林生态弹性对诸如气候变化、林火和营林措施等外部因子的影响较为敏感.探究这些外部因子对森林生态弹性的影响在未来森林生态系统管理方面有重要意义.本研究首先从森林组成、结构和功能等方面选取指标因子并估算了森林生态弹性值,然后运用LANDIS PRO模型,模拟气候变化、林火干扰和营林措施等对寒温带典型森林生态弹性的影响,并探讨了当前抚育采伐方案在未来气候下的可持续性.结果表明: 模型初始化的2000年林分密度和胸高断面积与2000年真实景观较为吻合,模拟的2010年森林景观与野外调查数据无明显差异,基于当前林火干扰状况的模拟结果与火烧迹地调查数据基本匹配,说明林火模块能很好地模拟当前研究区林火发生状况.林火干扰增加30%将会使该区模拟期内景观水平上森林生态弹性提高15.7%～40.8%,而林火干扰增加200%则会降低该区4.4%～24.6%的森林生态弹性.短期和中期林火干扰增加对森林生态弹性的影响大于气候变化的影响.与当前预案相比,B1气候(林火增加30%预案)和A2气候(林火增加200%预案)对整个模拟阶段景观尺度森林生态弹性的影响分别处于-15.9%～38.9%和-60.4%～34.8%范围内.与无采伐预案相比,B1和A2气候下在整个模拟时期内若继续实施当前抚育采伐方案,将不利于景观水平森林生态弹性的提高.在B1气候(林火增加30%预案)下,在各模拟时期内无需实施任何营林措施;而在A2气候(林火增加200%预案)下,建议实施中、高强度种植的营林措施以提升景观水平森林生态弹性.     

Lakes in the era of global change: moving beyond single-lake thinking in maintaining biodiversity and ecosystem services

The Anthropocene presents formidable threats to freshwater ecosystems. Lakes are especially vulnerable and important at the same time. They cover only a small area worldwide but harbour high levels of biodiversity and contribute disproportionately to ecosystem services. Lakes differ with respect to their general type (e.g. land-locked, drainage, floodplain and large lakes) and position in the landscape (e.g. highland versus lowland lakes), which contribute to the dynamics of these systems. Lakes should be generally viewed as ‘meta-systems’, whereby biodiversity is strongly affected by species dispersal, and ecosystem dynamics are contributed by the flow of matter and substances among locations in a broader waterscape context. Lake connectivity in the waterscape and position in the landscape determine the degree to which a lake is prone to invasion by non-native species and accumulation of harmful substances. Highly connected lakes low in the landscape accumulate nutrients and pollutants originating from ecosystems higher in the landscape. The monitoring and restoration of lake biodiversity and ecosystem services should consider the fact that a high degree of dynamism is present at local, regional and global scales. However, local and regional monitoring may be plagued by the unpredictability of ecological phenomena, hindering adaptive management of lakes. Although monitoring data are increasingly becoming available to study responses of lakes to global change, we still lack suitable integration of models for entire waterscapes. Research across disciplinary boundaries is needed to address the challenges that lakes face in the Anthropocene because they may play an increasingly important role in harbouring unique aquatic biota as well as providing ecosystem goods and services in the future.     

Natural regeneration in the context of large‐scale forest and landscape restoration in the tropics

Large‐scale and long‐term restoration efforts are urgently needed to reverse historical global trends of deforestation and forest degradation in the tropics. Restoration of forests within landscapes offers multiple social, economic, and environmental benefits that enhance lives of local people, mitigate effects of climate change, increase food security, and safeguard soil and water resources. Despite rapidly growing knowledge regarding the extent and feasibility of natural regeneration and the environmental and economic benefits of naturally regenerating forests in the tropics, tree planting remains the major focus of restoration programs. Natural regeneration is often ignored as a viable land‐use option. Here, we assemble a set of 16 original papers that provide an overview of the ecological, economic, and social dimensions of forest and landscape restoration (FLR), a relatively new approach to forest restoration that aims to regain ecological integrity and enhance human well‐being in deforested or degraded forest landscapes. The papers describe how spontaneous (passive) and assisted natural regeneration can contribute to achieving multiple social and ecological benefits. Forest and landscape restoration is centered on the people who live and work in the landscape and whose livelihoods will benefit and diversify through restoration activities inside and outside of farms. Given the scale of degraded forestland and the need to mitigate climate change and meet human development needs in the tropics, harnessing the potential of natural regeneration will play an essential role in achieving the ambitious goals that motivate global restoration initiatives.     

Landscape Pattern Dynamics and Mechanisms during Vegetation Restoration: A Multiscale,Hierarchical Patch Dynamics Approach

The spatial pattern of vegetation changes during ecological restoration, and these changes are affected by the process of restoration. The objective of this study was to integrate the pattern and mechanism of forest restoration in the Dinghushan Nature Reserve (DNR), Guangdong, China, based on data from remote sensing and long‐term field observations. We studied the pattern dynamics of three main forest types and their underlying mechanisms during restoration following a multiscale, hierarchical patch dynamics framework that integrates population, community, and landscape processes. Remote sensing data were used to determine the changes in landscape pattern during different periods of forest restoration from 1978 to 2006. At the landscape scale, the number, area, and perimeter of the needle/broad‐leaved mixed forest (MF) and the evergreen broad‐leaved forest (BF) increased, whereas those of the tropical needle‐leaved forest (NF) decreased during succession. Our analysis based on long‐term field observations indicated that the change rate of NF was lower than that of MF during 1981–1996, but became much higher during 1996–2007. The rate of change in landscape pattern and the progression of succession stages were consistent with each other. Our results also showed that species regeneration and community succession are the biological basis of forest landscape dynamics during vegetation restoration. Landscape pattern analysis allowed us to show “what” happened during vegetation restoration and “where,” and population and community analysis indicated “why” and “how” it happened.     

Comparing Bioenergy Production Sites in the Southeastern US Regarding Ecosystem Service Supply and Demand

Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance tools used to ensure comparable sustainability standards for biomass produced in countries with variable or absent legal frameworks for landscape planning.     

“山水林田湖草沙生命共同体”耦合框架、模型与展望

“山水林田湖草沙生命共同体”系统保护与修复是我国生态文明建设的重要内容。明确生命共同体的耦合机制，是科学地进行生态保护和修复工作的关键。针对当前生命共同体耦合机制不清、理论和方法不健全的问题，从耦合的视角出发，在小流域尺度上单一生态系统内部生态要素的耦合、流域尺度上不同生态系统之间的耦合、区域尺度上人与自然的耦合三个方面进行整合，在此基础上探讨了多尺度山水林田湖草沙耦合理论，提出了一般性的山水林田湖草沙耦合理论框架。梳理并比较了当前主要的生态系统模型、景观模型、统计学模型以及复合生态系统的多模型耦合方法，综合提出了一个适用于"山水林田湖草沙生命共同体"耦合研究方法。对进一步完善山水林田湖草沙一体化保护修复提出了建议，包括：一是构建多源信息数据库，推进定量化耦合机制研究；二是开展全生命周期监测与评估，探索适应性治理路径；三是强化多元主体参与，完善协同保护机制。     

Ecological restoration in coastal areas in the Netherlands: concepts,dilemmas and some examples

This chapter gives an overview of attempts in the Netherlands to restore coastal ecosystems and habitats, and explains how scientific and non-scientific information has been used to meet the goals. Indications for successes and failures of management measures taken so far, as well as dilemmas to cope with, are given. Up to now only small scale restoration projects have been executed, while large scale projects generally are not further then the thinking or planning phase. A special type of `restoration projects' are the large civil engineering works, particularly in the south-west of the Netherlands. Although these works were not planned and executed as restoration projects, but designed for safety against flooding from the sea, they have led to significant changes in the boundary conditions of the systems concerned. For restoration projects yet to be executed one can learn very much from these developments, particularly regarding the sensitivity of coastal systems for changes in boundary conditions and about the (im)possibilities to `steer' ecological developments. Physical, chemical and biological processes form the basis of restoration measures of coastal habitats, and this means that a thorough knowledge of these processes is essential. Coastal ecosystems are the result of complex interactions of large-scale and small-scale processes, implying a holistic approach in scientific investigations. Consequently, restoration of these systems primarily has to be realised by influencing the basic processes. This is the only way to preserve or regain in a sustainable way ecological values, such as species composition. Focusing only at one particular species (e.g. breeding terns) or a specific habitat (e.g. a salt marsh) may easily ignore the underlying processes. In general, coastal restoration should focus on the redirection of processes towards a desired status by stimulating certain process parameters. Monitoring of the results and, if necessary, gradual readjustment of the governing factors, is an essential part of this approach.     

基于GIS、景观格局和网络分析法的厦门本岛生态网络规划

 以厦门本岛2000年Landsat-TM卫星影像解译的土地利用现状图、绿地系统现状图与规划图为基础资料,在地理信息系统（GIS）支持下,运用景观格局分析方法,选用多种景观指数,评价了厦门本岛绿地系统的现状与已有规划。在此基础上,应用网络分析法构建了旨在优化生态网络的不同新方案。通过α指数、β指数、γ指数等网络结构指数,进行不同方案的比较,从中选出最优的规划方案。将选出的生态网络E的廊道宽度设为50 m,叠加到厦门市绿地系统规划图上,并应用景观指数,定量评价了该优化方案对厦门本岛绿地系统的改善情况。其结果表明：该优化方案能使景观的破碎化程度得到改善,绿地斑块形状的复杂性程度进一步增加,景观连接度得到提高,说明优化方案生态网络E可进一步明显改善厦门本岛现有绿地系统的数量和质量。我们的研究结果也表明：应用景观指数和网络分析法相结合的方法,不仅可以定量评价城市绿地系统现状以及规划的合理性,而且可以优化城市生态网络的方案,使其更符合城市生态网络建设的整合性、和谐性、流通性、安全性、多样性和持续性原则。     

Multiple successional pathways in human‐modified tropical landscapes: new insights from forest succession,forest fragmentation and landscape ecology research

Old‐growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human‐modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio‐economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land‐use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio‐temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well‐preserved biodiversity‐rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i) succession must be examined using more comprehensive explanatory models, providing information about the forces affecting not only the presence but also the persistence of species and ecological groups, particularly of those taxa expected to be extirpated from HMTLs; (ii) SS research should integrate new aspects from forest fragmentation and landscape ecology research to address accurately the potential of secondary forests to serve as biodiversity repositories; and (iii) secondary forest stands, as a dynamic component of HMTLs, must be incorporated as key elements of conservation planning; i.e. secondary forest stands must be actively managed (e.g. using assisted forest restoration) according to conservation goals at broad spatial scales.     

Why experiment with success? Opportunities and risks in applying assessment and adaptive management to the Emiquon floodplain restoration project

The Nature Conservancy’s wetland restoration at the Emiquon Preserve has been a success to date, but there are warning signs of undesirable change if left unmanaged. A water control structure built in 2016 will increase management capabilities, but periodic connection to the river, which has experienced human alterations typical of rivers in eastern North America and Europe, also introduces risks. The Conservancy’s planning process has identified (1) management targets (e.g., diverse native fish populations); (2) Key Ecological Attributes (KEAs) that maintain the targets (e.g., relatively deep over-wintering habitats for fishes); (3) measurable indicators for the KEAs (e.g., depth in winter); and (4) desirable ranges for the indicators (e.g., 10% of the aquatic area has depths of 2–3 m and dissolved oxygen levels of 4–6 mg/l). Assessments and experiments completed to date have focused on documenting the restoration, evaluating effects of the record flood of 2013, and predicting outcomes of management actions. Simulation models of hydrology, hydraulics, and vegetation response developed during the planning process allayed some concerns of stakeholders, but not all outcomes are predictable from either current theory or management experience. Therefore, each action can be considered not only as an adaptive management experiment focused on sustaining targets, but also contributing to ecological theory and restoration practice on a broader scale.     

区域生态建设与景观生态学的使命

区域和景观尺度上的生态建设是指一定地域、跨生态系统、适用于特定景观类型的生态建设,即实行科学的生态系统管理和优化环境的建设工程．近年来国家实施了一系列重大的生态工程项目,如天然林保护工程、部分地区退耕还林还草、内陆河流域的生态调水等,取得了显著的效果．加强区域生态建设,维护国土安全已成为国家的战略需求．依据不同类型区的特点应实行不同的生态建设战略,如生态敏感区、脆弱区和高人口密度的生态压力区,可分别实施以生态安全保障、生态负荷调整和生态秩序重建为重点的生态建设战略,调控人类活动,实行有序开发,统筹人与自然的和谐发展．面对转型期的国家需求,我国景观生态学的发展迎来了挑战与机遇并存的重要契机．研究的关键议题包括：景观生态安全格局;土地利用与生态过程;人类活动胁迫下的景观变化;区域开发人类活动生态影响的定量评价;区域生态安全评价与预警;景观生态建设的模式设计与优化组合．     

Re-establishing and assessing ecological integrity in riverine landscapes

1. River–floodplain systems are among the most diverse and complex ecosystems. The lack of detailed information about functional relationships and processes at the landscape and catchment scale currently hampers assessment of their ecological status.
2. Intensive use and alteration of riverine landscapes by humans have led to severe degradation of river–floodplain systems, especially in highly industrialised countries. Recent water-related regulations and legislation focussing on high standards of ecological integrity back efforts to restore or rehabilitate these systems.
3. Most restoration projects in the past have suffered from a range of deficits, which pertain to project design, the planning process, the integration of associated disciplines, scaling issues and monitoring.
4. The so-called `Leitbild' (i.e. a target vision) assumes a key role in river restoration and the assessment of ecological integrity in general. The development of such a Leitbild requires a multistep approach. Including explicitly the first step that defines the natural, type-specific reference condition (i.e. a visionary as opposed to an operational Leitbild), has great practical advantages for restoration efforts, primarily because it provides an objective benchmark, as is required by the European Water Framework Directive and other legal documents.
5. Clearly defined assessment criteria are crucial for evaluating ecological integrity, especially in the pre- and postrestoration monitoring phases. Criteria that reflect processes and functions should play a primary role in future assessments, so as to preserve and restore functional integrity as a fundamental component of ecological integrity.
6. Case studies on the Kissimmee River (U.S.A.), the Rhine River (Netherlands and Germany), and the Drau River (Austria) are used to illustrate the fundamental principles underlying successful restoration projects of river–floodplain systems.     

Mapping Restoration Opportunity for Collaborating with Land Managers in a Carbon Credit‐Funded Restoration Program in the Makana Municipality,Eastern Cape,South Africa

Spatial prioritization techniques are commonly used in conservation planning, but are relatively new for planning restoration programs. Typically, ecological data, and more recently data on economic costs and vulnerability of sites, are used. However, the effectiveness of restoration action ultimately relies on a combination of the appropriate ecological restoration techniques and the human and social dynamics of social‐ecological systems. Surveys were conducted with 29 land managers within the Makana Municipality of the Eastern Cape, South Africa, to identify a range of human and social factors hypothesized to define the potential effectiveness of restoration action. Land managers with similar characteristics were grouped using a cluster analysis, and the groups ranked and mapped in geographical information system (GIS) to provide a spatial representation of restoration opportunity. The total number of questions were reduced by 35.6%, a step toward developing a rapid assessment approach for assessing land managers' potential participation in restoration initiatives. Identifying and incorporating human and social factors that directly influence restoration prioritization should promote efficient and effective implementation of restoration actions by the Working for Woodlands programme, who are looking to funding landscape‐scale restoration through carbon trading.     

Landscape size affects the relative importance of habitat amount,habitat fragmentation,and matrix quality on forest birds

It is important to understand the relative effects of landscape habitat loss, habitat fragmentation, and matrix quality on biodiversity, so that potential management options can be appropriately ranked. However, their effects and relative importance may change with the size of the landscape considered because the multiple (and potentially conflicting) ecological processes that are influenced by landscape structure occur at different spatial scales (e.g. dispersal, predation, foraging). We estimated the relative effects of habitat loss, habitat fragmentation, and matrix quality (measured as the amount of forest, the proportion of forest area contained in large core forests, and the density of roads respectively) on fragmentation‐sensitive forest birds in southern Ontario, Canada using a range of landscape sizes (0.8–310 km²). We used three complementary statistical approaches to estimate relative effects of these correlated landscape factors – 1) multiple regression, 2) information theoretic (AIC) estimates of the most parsimonious model, and 3) multi‐model inference to average effects across all supported models. We controlled for spatial autocorrelation, local habitat, roadside sampling bias, time of day, season, habitat heterogeneity, and the interaction between the effects of habitat amount and fragmentation. We found that relative effects of habitat amount and fragmentation were scale dependent; habitat amount had a consistently positive effect that was consistent over more than two orders of magnitude in landscape area (~1–300 km²). In contrast, the effects of habitat fragmentation depended on the size of the landscape considered. Indeed, for veery Catharus fuscescens, habitat fragmentation had positive effects at one scale and negative effects at another. The effects of matrix quality were generally weak and changed little with scale. For the number of fragmentation sensitive species and the presence of veery, habitat amount was most important in large landscapes and habitat fragmentation in small landscapes but for the presence of ovenbird Seiurus aurocapilla, habitat amount was most important at all scales.     

Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States

We live in an era of unprecedented ecological change in which ecologists and natural resource managers are increasingly challenged to anticipate and prepare for the ecological effects of future global change. In this study, we investigated the potential effect of winter climate change upon salt marsh and mangrove forest foundation species in the southeastern United States. Our research addresses the following three questions: (1) What is the relationship between winter climate and the presence and abundance of mangrove forests relative to salt marshes; (2) How vulnerable are salt marshes to winter climate change‐induced mangrove forest range expansion; and (3) What is the potential future distribution and relative abundance of mangrove forests under alternative winter climate change scenarios? We developed simple winter climate‐based models to predict mangrove forest distribution and relative abundance using observed winter temperature data (1970–2000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marsh–mangrove forest interactions and highlight coastal areas in the southeastern United States (e.g., Texas, Louisiana, and parts of Florida) where relatively small changes in the intensity and frequency of extreme winter events could cause relatively dramatic landscape‐scale ecosystem structural and functional change in the form of poleward mangrove forest migration and salt marsh displacement. The ecological implications of these marsh‐to‐mangrove forest conversions are poorly understood, but would likely include changes for associated fish and wildlife populations and for the supply of some ecosystem goods and services.     

道路对林地景观连接度的影响——以巩义市为例

基于景观连接度原理,借用景观连接度指数,在地理信息系统支持下,探讨了巩义市山区林地景观在不同距离阈值下连接度的变化,定量分析了道路对林地景观连接度的影响。结果显示,随着景观距离阈值的增大,无论是否有道路,林地景观整体可能连通性指数值都表现为逐渐增大;对林地景观连接度起"非常高"和"高"作用的林地斑块数量都比较少,但占林地总面积比例较大,面积大的林地斑块在提高景观连接度中起的作用较大;道路的分割使得林地斑块重要值降低,就单一斑块而言,随着景观距离阈值的增大,分割成的小斑块的重要值降低程度在逐渐减小。