Farmers' involvement in landscape activities: an analysis of the relationship between farm location, farm characteristics and landscape changes in two study areas in Jutland, Denmark

Farmers are important agents in rural landscape management as they modify landscape elements to suit their needs. The purpose of this study is to investigate if patterns of landscape activities undertaken by farmers are related to certain farm characteristics and if landscape activities vary from one location to another. With this purpose, we investigated the differences between the level of farmers' involvement in landscape activities in two study areas in central Jutland, Denmark. Particular attention was given to the analysis of the type and extent of landscape activities and their relationship with farm characteristics. In both study areas, landscape activities leading to a more extensive type of land use predominate. However, a multivariate analysis implemented on the set of landscape activity data reveals significant differences between the two study areas. Hedgerow planting and removal is more common in S?nder Omme, while pond digging and cultivation of permanent grass lands are characteristic activities in Gadbjerg-Givskud. Moreover, the proportion of farmers involved and the area affected by different landscape activities is larger in S?nder Omme than in Gadbjerg-Givskud. The farms of the two areas are different in terms of production type, size and socio-economic characteristics. These characteristics represent significant relationships with landscape activities. However, they are not sufficient to explain the differences between landscape activities undertaken in the two areas. The differences are caused by unique cultural and biophysical environment, which influence and modify the relationship between farm characteristics and landscape activities in a distinct manner for each study area.     

岷江流域三江交汇区景观格局变化研究

本文以生态景观理论为基础,地理信息与遥感技术为支撑,对岷江流域三江交汇区三期遥感数据,1990年TM、2002年TM、2014年ETM+数据进行图像分类、景观指数提取、空间分析,同时采用面积转移矩阵统计各景观面积的转移情况,分析景观格局变化的影响因素,研究结果表明:(1)1990—2014年三江交汇区景观类型面积排序为:农田林地草地水域居民地裸地。优势景观为耕地,所占比例由72.83%下降到63.32%,面积减少了3480hm2。草地所占比例呈现波动变化,总体增加了2.81%。林地比例由15.98%上升到18.79%,增加了700hm2。居民地所占比例升高了4.1%;(2)1990年研究区内草地景观易受到外部干扰,其分布形状复杂。林地景观整体聚合度较高同时具有较低的异质性,分布通透性好、规模连续。农田分布较为分散且斑块较小。2002年农田斑块分布复杂化,同时具有聚集度高的特点。2014年研究区内农田优势地位下降。此时农田分布比较破碎并且呈现集中的态势。草地分布规模性较好、分布较为完整,但是内部存在一定的破碎性;(3)三江交汇区景观类型相互转化的主要原因:一是,退耕还林、还草政策实施,海拔超过500m的丘陵山地区域,建立生态保护区。二是,成绵乐铁路和高速路网的完善,使得三江交汇区的土地类型向建设用地转化加快,主要集中在乐山市中区和周围城镇。     

Landscape Changes in the Mullica River Basin of the Pinelands National Reserve,New Jersey,USA

In 1979, the Pinelands Commission was established as a regional land-use planning and regulatory agency charged with the implementation of a Comprehensive Management Plan (CMP) for the Pinelands National Reserve (New Jersey, USA). The CMP was created to balance land preservation and development interests in the Reserve. Because water-quality degradation from developed and agricultural landscapes is associated with changes in the composition of biological communities, monitoring landscape changes provides one of the most direct measures of the impact of land-use policies on the Pinelands ecosystem. In this study, we prepared detailed, land-cover maps within randomly selected aerial-photograph plots for a major watershed in the Reserve. We used these land-cover maps to quantify changes in landscape composition and structure (i.e., patch size, patch area, and number of patches) and characterize land-cover transitions in the basin between 1979 and 1991. Because the study period represented the first 12 years of the regional-planning effort in the Reserve, we evaluated the relationship between land-cover transitions and Commission management-area designations which permit different land-use intensities. Although the landscape composition was similar in 1979 and 1991, we found an increase in the total area and number of developed-land, managed-grassland, and barren-land patches. An increase in the number of patches and a decrease in the total area and median and third-quartile patch sizes for forest land and for all patches regardless of cover type indicated that fragmentation of forest land and the landscape as a whole occurred during the study period. The major land-cover transitions that occurred during the period were the loss of forest land to development and associated cover types and the conversion of one agricultural type to another. Overall, land-cover transitions during the period were found to be consistent with the Commission management-area designations, which indicated that the regional-planning effort has been successful in directing human activities to appropriate areas of the basin.     

Analysis of Changes in Farm Pond Network Connectivity in the Peri-Urban Landscape of the Taoyuan Area,Taiwan

The farm pond system for irrigation is the most prominent feature in the Taoyuan area, Taiwan, giving the region a unique landscape and hydrological character. Although this area had more than 3,290 ponds in the 1970s, fewer than 1,800 now remain. This study analyzes changes in irrigation farm ponds and the canal network landscape in the Taoyuan area. The spatial and temporal changes to ponds and the canal network on the Taoyuan plain were examined graphically for each spatial unit (2,765 m × 2,525 m) using aerial photographs for 1979 and 2005. Landscape metrics were calculated to analyze landscape change associated with increased urbanization. Landscape indices of connectivity and circuitry were utilized to describe changes in the configuration of ponds and canal networks. The total length of canals and total number of ponds in the study area decreased significantly during 1979-2005. The average values of connectivity indices (γ- and α-index) also decreased during 1979-2005, reflecting degradation of canal networks due to urban sprawl. A multivariate technique was applied to portion the study area into three zones according to changes to land cover, ponds, and canal networks. The effects of urban sprawl on the spatial pattern of ponds and canal networks are discussed.     

Integrating Landscape Ecology and Geoinformatics to Decipher Landscape Dynamics for Regional Planning

We used remote sensing and GIS in conjunction with multivariate statistical methods to: (i) quantify landscape composition (land cover types) and configuration (patch density, diversity, fractal dimension, contagion) for five coastal watersheds of Kalloni gulf, Lesvos Island, Greece, in 1945, 1960, 1971, 1990 and 2002/2003, (ii) evaluate the relative importance of physical (slope, geologic substrate, stream order) and human (road network, population density) variables on landscape composition and configuration, and (iii) characterize processes that led to land cover changes through land cover transitions between these five successive periods in time. Distributions of land cover types did not differ among the five time periods at the five watersheds studied because the largest cumulative changes between 1945 and 2002/2003 did not take place at dominant land cover types. Landscape composition related primarily to the physical attributes of the landscape. Nevertheless, increase in population density and the road network were found to increase heterogeneity of the landscape mosaic (patchiness), complexity of patch shape (fractal dimension), and patch disaggregation (contagion). Increase in road network was also found to increase landscape diversity due to the creation of new patches. The main processes involved in land cover changes were plough-land abandonment and ecological succession. Landscape dynamics during the last 50 years corroborate the ecotouristic-agrotouristic model for regional development to reverse trends in agricultural land abandonment and human population decline and when combined with hypothetical regulatory approaches could predict how this landscape could develop in the future, thus, providing a valuable tool to regional planning.     

Impacts of changes in land use and fragmentation patterns on Atlantic coastal forests in northern Spain

Changes in forested landscapes may have important consequences for ecosystem services and biodiversity conservation. In northern Spain, major changes in land use occurred during the second half of the 20th century, but their impacts on forests have not been quantified. We evaluated the dynamics of landscape and forest distribution patterns between 1957 and 2003 in Fragas do Eume Natural Park (northwestern Spain). We used orthoimages and a set of standard landscape metrics to determine transitions between land cover classes and to examine forest distribution patterns. Eucalypt plantations showed the greatest increase in area (197%) over time. Furthermore, transitions to eucalypt plantations were found in all major land cover classes. Forest showed a net decline of 20% in total area and represented 30% of the landscape area in 2003. Forest losses were mainly due to eucalypt plantations and the building of a water reservoir, while forest gains were due to increases in shrubland, meadows and cultivated fields which had been recolonised. Forest patch size and core area decreased, and edge length increased over time. In turn, increases were obtained in mean distance between forest patches, and in adjacency to eucalypt plantations and to a water reservoir. These results suggest an increase in forest fragmentation from 1957 to 2003, as well as a change in the nature of the habitat surrounding forest patches. This study shows that land use changes, mostly from eucalypt plantation intensification, negatively affected forested habitats, although some regeneration was ongoing through ecological succession from land abandonment.     

Spatial and temporal dynamics of hedgerows in three agricultural landscapes of southern Quebec,Canada

Noncrop areas such as hedgerows in agricultural landscapes can perform several ecological and agronomic functions (e.g., habitat, movement corridors, windbreak, etc.), but their dynamics and drivers of changes are often poorly known. We conducted a study in three agricultural landscapes of southern Quebec, Canada, to assess and compare the spatial and temporal (1958–1997) dynamics of three hedgerow networks in relation to geomorphic conditions (marine, glacial, and mixed deposit) and land-use changes. Hedgerow networks were mapped and described in terms of their structure (density, degree of connectivity, and presence of trees or shrubs) and their relationship to other components of the landscape (connection to woodland). Relationships were assessed in time and space using nonparametric correlation, Mantel test, and principal components analysis (PCA). Results show significant differences between hedgerow structure for the three landscapes and distinct temporal and spatial dynamics that can be related to changes in management practices and agricultural policies. On marine deposits, increases in hedgerow density did not always correspond to an increase in their degree of connectivity, suggesting a possible reduction in network quality. On glacial deposits, hedgerow density declined following abandonment of agricultural land, but rather than disappearing, these linear structures were integrated into adjacent brush or forested areas. Our analysis reveals the complex spatial and temporal dynamics of the hedgerow networks and highlights the need to take into account spatial attributes such as connectivity and connection to woodland to evaluate more accurately overall network quality.     

Linking socio-economic factors, environment and land cover in the German Highlands, 1945-1999

Land-cover changes are caused by human activities and natural ecological processes. Thus, our study uses an interdisciplinary approach to research land-cover changes. We present a method to (i) link socio-economic/environmental factors and land-cover changes, (ii) identify indicators of land-cover changes, and (iii) distinguish between socio-economic and environmental indicators associated with local types of overall land-cover changes. The study was conducted in the Lahn-Dill Highlands, Germany, a typical marginal rural landscape. In this region, we investigated land-cover changes occurring over the period 1945-1999. Land-cover data were derived from multi-temporal aerial photographs. Types of overall land-cover changes characterising the districts within the study area were differentiated. With the help of redundancy analysis (RDA), we analysed the relationships between land-cover changes and widely available socio-economic/environmental factors. The results reveal that both individual land-cover changes at patch level and types of overall land-cover changes characterising districts are correlated with socio-economic and environmental factors. Whereas the stable environmental factors are drivers of land-cover changes in our rural study area, socio-economic factors introduced into the analysis mostly result from land-cover changes. We identified correlative socio-economic indicators that cannot explain land-cover changes, but that in combination with the environmental factors can be used to greatly facilitate the reconstruction of past land-cover changes and thus lead to a better knowledge of land-cover history. Based on the types of overall land-cover changes, the results of the study can be adopted for the study of land-cover changes in other regions.     

基于3S技术的矿产资源开发景观格局动态变化研究——以木里县梭罗沟金矿改扩建工程为例

本文在阐述3S技术特点的基础上,以四川省木里县梭罗沟金矿改扩建工程所在地的梭罗沟和如米沟为研究区,介绍了3S技术在景观格局信息提取的技术要求、数据收集和工作流程,并对研究区景观格局的提取结果进行了动态变化预测与分析。实例研究证明,3S技术是景观生态学研究的重要技术工具,应用3S技术开展矿产资源开发景观格局动态评价,可以准确、快速地提取景观格局的主要特征指标,掌握景观格局现状、预测其动态变化特征、揭示其变化规律,满足区域景观格局研究的要求。本研究方法适用于生态类建设项目或区域开发规划的景观格局中短期动态预测研究,不宜用于景观格局长期的动态预测。     

Modeling the Potential of the Northern China Forest Shelterbelt in Improving Hydroclimate Conditions1

Abstract: The forest shelterbelt (afforestation) project in northern China is the most significant ecosystem project initiated in China during the past three decades. It aims to improve and conserve the ecological environment in the project areas. The tree belt stands along the southern edge of the sandy lands, nearly paralleling to the Great Wall. This study used a regional climate model to simulate the potential of improving regional hydroclimate conditions resulting from the afforestation project. Two simulations with preafforestation and postafforestation land cover were performed over East Asia from January 1987 to February 1988. The model resolution is 60 km. The differences between the two simulations suggest that the northern China forest shelterbelt project is likely to improve overall hydroclimate conditions by increasing precipitation, relative humidity, and soil moisture, and by reducing prevailing winds and air temperature. The effects are more significant in spring and summer than fall and winter. Changes in many hydrologic properties (e.g., evapotranspiration, soil moisture, and water yield), however, differ between the dry Northeast China and the moist Northeast China. The hydroclimate effects are also found in the surrounding areas, featured by noticeably moister conditions in the area south of the afforestation project. The results imply that the shelterbelt project would reduce water yield in afforested Northwest and North China during spring, but increase water yield in the afforested Northeast China as well as in the southern surrounding area, offset some greenhouse effects, and reduce the severity of dust storms. Possible improvements of this study by using actual afforestation data, modeling with higher resolution, longer integration and more detailed processes, and analyzing the physical mechanisms are discussed.     

An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed

Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its ecosystem services.     

Effect of Land-Use Patterns on Total Nitrogen Concentration in the Upstream Regions of the Haihe River Basin, China

Nutrient loading into rivers is generally increased by human-induced land-use changes and can lead to increased surface water pollution. Understanding the extent to which land-use patterns influence nutrient loading is critical to the development of best-management practices aimed at water-quality improvement. In this study, we investigated total nitrogen (total N) concentration as a function of land-use patterns and compared the relative significance of the identified land-use variables for 26 upstream watersheds of the Haihe River basin. Seven land-use intensity and nine landscape complexity variables were selected to form the land-use pattern metrics on the landscape scale. After analyzing the significance of the land-use pattern metrics, we obtained five dominant principal components: human-induced land-use intensity, landscape patch-area complexity, area-weighted landscape patch-shape complexity, forest and grassland area, and landscape patch-shape complexity. A linear regression model with a stepwise selection protocol was used to identify an optimal set of land-use pattern predictors. The resulting contributions to the total N concentration were 50% (human-induced land-use intensity), 23.13% (landscape patch-shape complexity), 14.38% (forest and grassland area), and 12.50% (landscape patch-area complexity), respectively. The regression model using land-use measurements can explain 87% of total N variability in the upstream regions of Haihe River. The results indicated that human-related land-use factors, such as residential areas, population, and road density, had the most significant effect on N concentration. The agricultural area (30.1% of the study region) was not found to be significantly correlated with total N concentration due to little irrigative farmland and rainfall. Results of the study could help us understand the implications of potential land-use changes that often occur as a result of the rapid development in China.     

Land Use and Land Cover Change Analysis and Prediction in the Upper Reaches of the Minjiang River,China

Scientists have aimed at exploring land use and land cover change (LUCC) and modeling future landscape pattern in order to improve our understanding of the causes and consequences of these phenomena. This study addresses LUCC in the upper reaches of Minjiang River, China, from 1974 to 2000. Based on remotely sensed images, LUCC and landscape pattern change were assessed using cross-tabulation and landscape metrics. Then, using the CLUE-S model, changes in area of four types of land cover were predicted for two scenarios considering forest polices over the next 20 years. Results showed that forestland decreased from 1974 to 2000 due to continuous deforestation, while grassland and shrubland increased correspondingly. At the same time, the farmland and settlement land increased dramatically. Landscape fragmentation in the study area accompanied these changes. Forestland, grassland, and farmland take opposite trajectories in the two scenarios, as does landscape fragmentation. LUCC has led to ecological consequences, such as biodiversity loss and lowering of ecological carrying capacity.     

The Influence of Landscape Patterns on the Bird Diversity of Four Urban Parks

In our study, we aimed to investigate the influence of landscape patterns on the diversity of birds in four urban parks. The parks are located in a region that has a high value of regional biodiversity and is also highly urbanized (Jundiai, state of São Paulo [SP], in Southeastern Brazil). Using a set of aerial photos, the surrounding landscape was divided into two regions (rings) and corresponding landscape metrics were calculated. The presence of bird species was recorded monthly over a one‐year period and classified according to selected ecological criteria. The land cover of the areas surrounding each park was primarily buildings and residences. Bird diversity was significantly correlated with the presence/proximity of water bodies. We state that the potential of the parks to harbor bird species is not negligible. Managing the area surrounding a park to increase the percentage of forested area and the size of forest fragments is as crucial as managing the core park area, especially for improving its attractiveness for new bird species.     

Effects of Increasing Urbanization on the Ecological Integrity of Open Space Preserves

This article analyzes the effects of increasing urbanization on open space preserves within the metropolitan area of Phoenix, Arizona, USA. Time series analysis is used in 10-year increments over 40 years to study urban landscape change. Three landscape metrics—(1) matrix utility (measures intensity of adjacent land uses), (2) isolation (measures distances to other open space patches), and (3) connectivity (measures physical links to other open space patches and corridors)—are used to assess changes in landscape patterns and serve as indicators of urban ecological integrity of the open space preserves. Results show that in the case of both open space preserves, general decline in indicators of urban ecological integrity was evident. The matrix utility analysis demonstrated that increasing intensity of land uses adjacent to preserve is likely to increase edge effects, reducing the habitat value of interior or core habitat areas. Isolation analysis showed that both preserves have experienced increasing isolation from other open space elements over time. Also, connectivity analysis indicated that terrestrial connections to other open space elements have also deteriorated. Conclusions of this research demonstrate that while preservation of natural areas as open space is important in an urban context, intense development of surrounding areas reduces the urban ecological integrity significantly.     

EFFECTS OF PRESCRIPTIVE RIPARIAN BUFFERS ON LANDSCAPE CHARACTERISTICS IN NORTHERN MINNESOTA,USA1

ABSTRACT: Forest buffers adjacent to water bodies are widely prescribed in forest management to protect ecological functions of riparian systems. To date, buffers have been applied on the landscape uniformly without quantifying their effectiveness or the effects they have on landscape characteristics. Our objective was to quantify landscape characteristics (amount of edge and interior forest) when buffers were applied to water bodies in a 100 by 100 km area of northern Minnesota. We used a Landsat classified image in a geographic information system platform to apply two buffer widths ?28.5 m and 57 m — to water bodies, including nonforested wetlands, intermittent or perennial streams, and lakes. A total of 107,141 ha (18.3 percent) of the forest area was adjacent to and within 28.5 m of these water bodies, while 201,457 ha of forest was within 57 m, representing 34.4 percent of the total forest area. Imposing a 28.5 m buffer on water bodies increased the amount of edge and interior forest in the study area. When water bodies were buffered with a 57 m forest strip, we found a slight increase in forest edge from the current condition, and this buffer width resulted in the largest amount of interior forest. Interior forest increased with the 57 m buffer due to the density of water bodies in this region; adjacent water bodies coalesced when buffers were applied and formed isolated forest islands that contained forest interior habitat. Instead of wholesale application of set width riparian buffers, we suggest that ecological conditions of riparian areas be evaluated on a site level and that areas that currently provide important riparian conditions be maintained on the landscape with appropriate management practices.     

A landscape ecological approach to address scaling problems in conservation management and monitoring

Management of many African game reserves is today often still an art based on experience and intuition, rather than a science. Decision-making is based on an informal integration of accumulated individual knowledge and keen field observations. Data are generally poorly captured and curated. Until fairly recently, denominators of biological parameters (such as the unit of land or unit of plant production used as measurement) have generally been treated as being homogenous. The patchiness of landscapes and the issue of ecological scaling were ignored, often because of a lack of appropriate technical tools. The ecological data available on the 49,000-ha Songimvelo Game Reserve (SGR) result from a number of discrete survey and monitoring projects undertaken by different researchers, with different objectives, at different spatial and temporal scales. A landscape ecological approach towards research and monitoring is appropriate for an area of the size and diversity of the SGR. A combination of a database approach and spatial representation was used to consolidate and integrate data across temporal and spatial scales. Herbivore spatial and temporal distribution patterns were explored across three spatial scales. An understanding was achieved of the importance of landscape patchiness in controlling resource availability for herbivores. This insight is important in guiding management and monitoring of the SGR by placing perceived patch overutilization in its proper landscape context. The landscape ecological approach bridges the traditional scale-independent view to a more contemporary scale-related understanding of ecosystem diversity and functioning.     

An Application of Remote Sensing Data in Mapping Landscape-Level Forest Biomass for Monitoring the Effectiveness of Forest Policies in Northeastern China

Monitoring the dynamics of forest biomass at various spatial scales is important for better understanding the terrestrial carbon cycle as well as improving the effectiveness of forest policies and forest management activities. In this article, field data and Landsat image data acquired in 1999 and 2007 were utilized to quantify spatiotemporal changes of forest biomass for Dongsheng Forestry Farm in Changbai Mountain region of northeastern China. We found that Landsat TM band 4 and Difference Vegetation Index with a 3 × 3 window size were the best predictors associated with forest biomass estimations in the study area. The inverse regression model with Landsat TM band 4 predictor was found to be the best model. The total forest biomass in the study area decreased slightly from 2.77 × 10⁶ Mg in 1999 to 2.73 × 10⁶ Mg in 2007, which agreed closely with field-based model estimates. The area of forested land increased from 17.9 × 10³ ha in 1999 to 18.1 × 10³ ha in 2007. The stabilization of forest biomass and the slight increase of forested land occurred in the period following implementations of national forest policies in China in 1999. The pattern of changes in both forest biomass and biomass density was altered due to different management regimes adopted in light of those policies. This study reveals the usefulness of the remote sensing-based approach for detecting and monitoring quantitative changes in forest biomass at a landscape scale.     

成都龙泉山地区建设用地生态适宜性评价

随着景观格局与生态过程之间的关系日益受到重视,传统的评价方法已经不能满足生态适宜性评价的发展需要。本文以成都市龙泉山地区为例,从景观类型、生态功能、生态价值、土壤侵蚀敏感性和地质灾害敏感性5个方面建立评价指标体系,分别采用最小累积阻力模型和模糊综合评判法描述水平生态过程和垂直生态过程下的生态适宜性,综合两种评价结果进行建设用地的生态适宜性评价。研究结果表明,模型机理的差异使评价结果有着很大的区别,两种方法的综合应用可以有效弥补彼此的不足,本文将研究区的生态适宜性评价结果划分为禁止开发区、严格限建区、一般限建区、重点开发区和优化开发区5个分区,各区的面积分别为259．70km^2、793．89km2、1220．35km2、739．68km2和490．42km2。以往的生态适宜性评价方法往往单一地考虑水平或者垂直生态过程,本文构建的这种综合水平和垂直生态过程的评价方法为生态适宜性评价的方法研究提供了有益的尝试和补充。