Detecting dominant landscape objects through multiple scales: An integration of object-specific methods and watershed segmentation

Complex systems, such as landscapes, are composed of different critical levels of organization where interactions are stronger within levels than among levels, and where each level operates at relatively distinct time and spatial scales. To detect significant features occurring at specific levels of organization in a landscape, two steps are required. First, a multiscale dataset must be generated from which these features can emerge. Second, a procedure must be developed to delineate individual image-objects and identify them as they change through scale. In this paper, we introduce a framework for the automatic definition of multiscale landscape features using object-specific techniques and marker-controlled watershed segmentation. By applying this framework to a high-resolution satellite scene, image-objects of varying size and shape can be delineated and studied individually at their characteristic scale of expression. This framework involves three main steps: 1) multiscale dataset generation using an object-specific analysis and upscaling technique, 2) marker-controlled watershed transformation to automatically delineate individual image-objects as they evolve through scale, and 3) landscape feature identification to assess the significance of these image-objects in terms of meaningful landscape features. This study was conducted on an agro-forested region in southwest Quebec, Canada, using IKONOS satellite data. Results show that image-objects tend to persist within one or two scale domains, and then suddenly disappear at the next, while new image-objects emerge at coarser scale domains. We suggest that these patterns are associated to sudden shifts in the entire image structure at certain scale domains, which may correspond to critical landscape thresholds.This revised version was published online in May 2005 with corrections to the Cover Date.     

Combining holding-level economic goals with spatial landscape-level goals in the planning of multiple ownership forestry

In Finland, management of biological diversity at the landscape level is complicated by the relatively small size of the holdings. To alleviate this problem, this study presents a hierarchical planning model that aims at combining spatial landscape-level ecological goals with holding-level owner-specific goals. The influence of ecological objectives extends across holding borders, but their impact is greatest in areas where they are least in conflict with the owners goals. This feature, which results in minimum losses to individual landowners, can be called ecological efficiency. In the case study, the ecological objective was to cluster the breeding and foraging areas of flying squirrel (Pteromys volans). Other sets of objectives were related to individual holdings according to the various preferences of the forest owners. The forest plan produced by the presented planning model was compared with two other forest plans: 1) a combination of independent forest holding level plans, which were assumed to represent the outcome of the current planning tradition, and 2) an area-level plan, where the holding borders and holding-specific objectives were not taken into account. The same objective variables and objective weights were used in all plans. All the plans were produced for six planning areas (ranging from 404.6 to 984.9 ha) and 110 forest holdings (ranging from 0.6 to 449.8 ha) within these areas. The case-study results were promising: with the model presented here, the spatial structure of flying squirrel breeding and foraging areas could be improved with only minor losses in holding-level objectives. The spatial structure of the landscape after the 60-year planning period was very close to the area-level plan. This outcome was made possible by synchronizing the treatment proposals across forest-holding borders. The outcome of the model seems promising also from the practical standpoint: because the variation in the objectives of forest owners is efficiently taken into account in optimization, only rarely do the solutions suggest that the holding-level targets be compromised.This revised version was published online in May 2005 with corrections to the Cover Date.     

安仁县山塘生态观光果园总体规划

通过对安仁县山塘生态观光果园的指导思想、规划理念、功能分区及其总体规划进行介绍,力求将景观元素与农业生产有机结合,使园区的建设集生态观光、原野休闲、科教示范于一体。     

江西大富生态农业观光园总体规划

通过对大富生态农业观光园的指导思想、规划目标、功能分区、绿化配置诸方面,对其总体规划进行了介绍,力求将景观元素与农业生产相结合,使园区建设集观光、旅游、休闲、教育、生产、示范于一体.     

Balancing water supply and old-growth forest conservation in the lowlands of south-central Chile through adaptive co-management

Ecosystem management is a conservation strategy, but there is not a standard protocol for implementation. In theory, ecosystem management will utilize the best available science to sustain social-ecological systems in the landscape by maximizing multiple ecosystem services expected from the stakeholders’ of those systems. Llancahue is a watershed (1,270 ha) that provides fresh water to the city of Valdivia (130,000 inhabitants) and protects >700 ha of old-growth forest within a severely disturbed landscape in the lowlands of south-central Chile. The native vegetation of this landscape is the threatened Valdivian Temperate Rainforests. Management of the watershed by the Universidad Austral de Chile needs to both provide timber and work to the neighboring campesinos (small poor rural land owners) who were illegally logging the forest and improve the conservation of the old-growth forests and the quantity and quality of water provided by the watershed. This paper demonstrates how adaptive management has utilized a multi-step process to improve management of the watershed. This process has included (1) understanding stakeholders’ views towards the project, (2) developing an ecosystem management plan for the watershed that balanced multiple societal demands and ecosystem functions from the watershed, and (3) monitoring the Llancahue forest and streams to ensure activities provided desired results. This paper reports results after 4 years of implementation and provides perspectives on the ecosystem management approach.     

Landscape Ecology – towards a unified discipline?

Contemporary landscape ecology is not unified at all.There are historical, geographical and biological reasons for the lack of unification, as well as differences between science and application. The search for a unified theory of landscape ecology should consider previous concepts such as ‘landscape diagnosis’ and ‘landscape functions’ which were elaborated in Central Europe. Because of the various aspects in a landscape (components, processes, relations), landscape ecology should be regarded as a multidisciplinary, better a transdisciplinary, science where different views and approaches are involved in a holistic manner. The principle of complementarity is helpful to understand and describe the landscape. As a crucial step, the transformation of natural science categories to categories of the human society is brought out. This is realized by land(scape) evaluation and by the elaboration of goals (visions) of landscape development.This revised version was published online in May 2005 with corrections to the Cover Date.     

Maintenance of flying squirrel habitat and timber harvest: a site-specific spatial model in forest planning calculations

Spatial and temporal continuity of resources often benefits both ecological and economic goals in landscape management. Consideration of multiple and conflicting goals is also needed to view the future production possibilities of forests in successful forest management. Our aim was to estimate the production potential of a planning area in Finland by examining different forest management strategies from ecological and economic perspectives using long-term forest planning calculations. Economic objectives referred to timber production, whereas ecological objectives were based on suitable habitats for arboreal Siberian flying squirrel (Pteromys volans). Suitable habitats were defined using an empirical site-specific model, which includes a spatial variable reflecting the availability of habitat within an individual’s activity area. Five alternative forest plans were worked out with different objectives for flying squirrel habitat and timber production. The alternative plans were compared with respect to values of objective variables at the end of the planning period of 60 years and against a production possibility frontier among net present value and flying squirrel habitat. Varying objective values in our analyses resulted from different utilization of production possibilities, and the changes were in line with the objectives used. The formation of flying squirrel habitat clusters in the landscape was enhanced, and it did not always incur severe reductions in harvestable timber volume. Possibilities to combine ecological and economic goals, both spatial and aspatial, in the planning process seems to be an encouraging alternative for the long-term forest management in the future.     

The appearance of ecological systems as a matter of policy

Environmental policy should explicitly address the appearance of the landscape because people make inferences about ecological quality from the look of the land. Where appearances are misleading, failing to portray ecological degradation or ecological health, public opinion may be ill-informed, with consequences for environmental policy. This paper argues that while ecology is a scientific concept, landscape perception is a social process. If we do not recognize this difference, we have problems with the appearance of ecological systems. Three influential problems are discussed: 1) the problem of the false identity of ecological systems, 2) the problem of design and planning as deceit about ecological systems, and 3) the problem of invisible ecological systems. These problems for environmental policy may be resolved in part if landscape planners and policy-makers use socially-recognized signs to display human intentions for ecological systems. Specifically, planning and policy can include socially-recognized signs of beauty and stewardship to display human care for ecological systems. An example in United States federal agricultural policy is described.     

Comparison and development of new graph-based landscape connectivity indices: towards the priorization of habitat patches and corridors for conservation

The loss of connectivity of natural areas is a major threat for wildlife dispersal and survival and for the conservation of biodiversity in general. Thus, there is an increasing interest in considering connectivity in landscape planning and habitat conservation. In this context, graph structures have been shown to be a powerful and effective way of both representing the landscape pattern as a network and performing complex analysis regarding landscape connectivity. Many indices have been used for connectivity analyses so far but comparatively very little efforts have been made to understand their behaviour and sensitivity to spatial changes, which seriously undermines their adequate interpretation and usefulness. We systematically compare a set of ten graph-based connectivity indices, evaluating their reaction to different types of change that can occur in the landscape (habitat patches loss, corridors loss, etc.) and their effectiveness for identifying which landscape elements are more critical for habitat conservation. Many of the available indices were found to present serious limitations that make them inadequate as a basis for conservation planning. We present a new index (IIC) that achieves all the properties of an ideal index according to our analysis. We suggest that the connectivity problem should be considered within the wider concept of habitat availability, which considers a habitat patch itself as a space where connectivity exists, integrating habitat amount and connectivity between habitat patches in a single measure.     

Landscape planning for a rural ecosystem: case study of a resettlement area for residents from land submerged by the Three Gorges Reservoir,China

The goals of landscape planning are multiple for rural ecosystems of the resettlement area in the Hubei Province of China. They relate to the types, diversity and patterns of the ecosystems, and to the conservation of ecosystem functions and biodiversity. We were interested in the improvement of socio-economic conditions, and the promotion of the development of farmland ecosystems and natural forest ecosystems. The landscape planning took into account the conservation and the restoration of forestlands, and the reconstructions of farmlands, towns and villages. The areas of towns and villages were assigned by trade-off analysis balancing ecological, economic and social benefits. The spatial pattern of used lands was designed by a multi-criteria optimal spatial planning, resulting in the strengthening of some primary ecosystem functions. In the resettlement area forests will expand to a matrix, and cropland patches together with tree fences will form patch-corridor systems. Significant ecological, economic and social benefits can be derived from this landscape pattern.This revised version was published online in May 2005 with corrections to the Cover Date.     

Residential landscapes—Garden design,urban planning and social formation in Belgium

This paper aims at providing a historical understanding of the role of gardens and green spaces in urbanization and urban planning, as well as in processes of social formation and social mobility that took place on the background of a changing spatial, socio-economical and political context in Belgium in the period 1889–1940. The research is based on a number of case studies, which represent different stages and themes in the evolution of garden design, urban planning and society: 1) vernacular versus designed gardens and landscapes; 2) the popularization of the garden and the development of a new framework for urban planning; 3) the garden city versus private arcadia and 4) modern garden design and the rise of the middle class (1930–1940). Through an analysis of designs and discourses of, amongst others, leading landscape architects/urban planners Louis Van der Swaelmen, Jules Buyssens and Jean Canneel-Claes, the paper exposes a number of ambiguities and tensions, for example between the ‘vernacular garden’ and the ‘garden of the establishment’ and between the deep-rooted dream of a privately owned house and garden, and attempts to create new social and spatial frameworks that surpass the individual lot. The paper concludes that these tensions can still be traced in the context in which landscape designers and urban planners work today. This historical awareness, however, can help them to set out strategic goals for the contemporary garden as a place of both production and consumption, and as a place where social identity is shaped.     

关于公园绿地的道路规划问题的思考

城市公园中的道路把园林内的景区联成整体,是园林绿地中的重要组成部分,贯穿于主园各景区的景点之间,蜿蜒起伏的曲线,丰富的寓意,精美的图案,都给人以美的享受。因此,园路的规划,直接影响到园林绿地各功能空间划分的合理与否,人流交通是否通畅,景观组织是否合理,对园林绿地的整体规划的合理性起着举足轻重的作用。本文通过大量收集与查阅资料、文献,从理论上详细论证与探讨园路在规划中应遵循的原则,以及应注意的问题等,为园林绿地景观的规划提供可靠的理论依据。     

Placing the pieces: Reconstructing the original property mosaic in a warrant and patent watershed

Recent research shows that land use history is an important determinant of current ecosystem function. In the United States, characterization of land use change following European settlement requires reconstruction of the original property mosaic. However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed (Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as ‘metes and bounds’). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas, the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property mosaic in heavily urbanized/suburbanized areas is generally ‘reset.’ Further, trends in surveying technique, parcel size, and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape. This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of landscape structure on nest predation in roadsides of a midwestern agroecosystem: a multiscale analysis

Nest predation is an important cause of mortality for many bird species, especially in grassland ecosystems where generalist predators have responded positively to human disturbance and landscape fragmentation. Our study evaluated the influence of the composition and configuration of the surrounding landscape on nest predation. Transects consisting of 10 artificial ground nests each were set up in 136 roadsides in six watersheds in south-central Iowa. Nest predation on individual roadside transects ranged from 0 to 100% and averaged 23%. The relationship of landscape structure within spatially-nested landscapes surrounding each roadside transect (within 200, 400, 800, 1200, and 1600 m of the transect line) to nest predation was evaluated by using multiple regression and canonical correlation analyses. The results of this multiscale landscape analysis demonstrated that predation on ground nests was affected by the surrounding landscape mosaic and that nest predators with different-sized home ranges and habitat affinities responded to landscapes in different ways. In general, wooded habitats were associated with greater nest predation, whereas herbaceous habitats (except alfalfa/pasture) either were associated with less nest predation or were not important. Different landscape variables were important at different spatial scales. Whereas some block-cover habitats such as woodland were important at all scales, others such as rowcrops and alfalfa/pasture were important at large scales. Some strip-cover habitats such as gravel roads and paved roads were important at small scales, but others such as wooded roadsides were important at all all scales. Most landscape metrics (e.g., mean patch size and edge density) were important at large scales. Our study demonstrated that the relationships between landscape structure and predator assemblages are complex, thus making efforts to enhance avian productivity in agricultural landscapes a difficult management goal.     

Placing the pieces: Reconstructing the original property mosaic in a warrant and patent watershed

Recent research shows that land use history is an important determinant of current ecosystem function. In the United States, characterization of land use change following European settlement requires reconstruction of the original property mosaic. However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed (Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as ‘metes and bounds’). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas, the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property mosaic in heavily urbanized/suburbanized areas is generally ‘reset.’ Further, trends in surveying technique, parcel size, and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape. This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States. This revised version was published online in July 2006 with corrections to the Cover Date.     

Landscape Diagnosis on Different Space and Time Scales – A Challenge for Landscape Planning

Landscape diagnosis provides a bridge between scientific knowledge and socio-economic issues that is needed to meet the demands of sophisticated landscape planning and management. The diagnostic assessment of landscape functions (capacities, goods and services supported by the landscape) at different spatio-temporal scales is a valuable tool that can solve the transformation problem. A variety of landscape classification systems – including biophysical and landscape units – can be applied as a spatial reference system. Examples are described from the multitude of approaches to assess landscape functions that can be employed in landscape diagnosis. The theoretical and methodological aspects of the approach are illustrated using examples both from Germany and the Czech Republic. The examples focus on landscape functions such as groundwater recharge, regulation of water balance, and resistance to wind erosion. In addition, the rarity of and threats to landscape types, landscape aesthetic values, and the landscape character and landscape persistence are discussed.     

Resilience, experimentation, and scale mismatches in social-ecological landscapes

Growing a resilient landscape depends heavily on finding an appropriate match between the scales of demands on ecosystems by human societies and the scales at which ecosystems are capable of meeting these demands. While the dynamics of environmental change and ecosystem service provision form the basis of many landscape ecology studies, enhancing landscape resilience is, in many ways, a problem of establishing relevant institutions that act at appropriate scales to modify and moderate demand for ecosystem services and the resulting exploitation of ecosystems. It is also of central importance for landscape sustainability that institutions are flexible enough to adapt to changes in the external environment. The model provided by natural ecosystems suggests that it is only by encouraging and testing a diversity of approaches that we will be able to build landscapes that are resilient to future change. We advocate an approach to landscape planning that involves growing learning institutions on the one hand, and on the other, developing solutions to current problems through deliberate experimentation coupled with social learning processes.     

Landscape change with agricultural intensification in a rural watershed,southwestern Ohio,U.S.A.

Specialized cash grain production, emergent in the midwestern United States during the post-WWII era, typifies the Upper Four Mile Creek watershed in southwestern Ohio. This style of agriculture intensifies cropland use, with consequent increases in soil erosion and stream sedimentation - a serious problem in the lower reservoir, Acton Lake. Agricultural statistics and aerial photographs compiled between 1934 and 1984 were used to quantify agricultural dynamics and landscape change in the watershed, including land-use apportionment, diversity, and the structural configuration of forest, woodland, and old-field/brushland patches and corridors. A questionnaire sent to all land owners in the basin documented farm-level characteristics and factors that influence management decisions. Crop diversity (H) in Preble County, Ohio decreased from 1.42 in 1934 to 1.17 in 1982, as corn and soybeans dominated the landscape mosaic. Yields rose, but net profits were reduced by declining prices per bushel and increases in fertilizer and petroleum-based subsidies. Landuse diversity in the county also declined (H = 1.37 in 1934 tot 0.80 in 1982) in response to cropland expansion, whereas forest land in the watershed increased from 1605 to 2603 ha. Fragmentation declined and the landscape became polarized after 1956, with a concentration of agricultural patches in the upper watershed and forest-patch coalescence in stream gullies and state park land in the lower watershed. The questionnaire (~ 29% return) further supported, at the farm-level, observed regional trends toward expansion (farm coalescence and lease contracts) and specialization (conversion toward corn and soybeans). The most important factors influencing farm size and management were better equipment and family traditions. Thus, cultural and technological factors that operate at the farm-level, coupled with meso-scale variation in the physical conditions of a catchment basin, tend to influence landscape-level patterns more than regional socioeconomics and governmental policies.     

Relationships between watershed Stressors and sediment contamination in Chesapeake Bay estuaries

Three methods for assessing the relationships between estuarine sediment contaminant levels and watershed Stressors for 25 Chesapeake Bay sub-estuaries were compared. A geographic information system (GIS) was used to delineate watersheds for each sub-estuary and analyze land use pattern (area and location of developed, herbaceous and forested land) and point source pollution (annual outflow and contaminant loading) using three landscape analysis methods: (1) a watershed approach using the watershed of the estuary containing the sampling station. (2) a partial watershed approach using the area of the watershed within a 10 km radius of the sampling station and (3) a weighted partial watershed approach where Stressors within the partial watershed were weighted by the inverse of their linear distance from the sampling station. Nine sediment metals, 16 sediment organics and seven metals loading variables were each reduced to one principal component for statistical analyses. Relationships between the first principal components for sediment metals and organics concentrations and watershed stressor variables were analyzed using rank correlation and stepwise multiple regression techniques. For both metals and organics, the watershed method yieldedR ² values considerably lower than the partial and weighted partial watershed analysis methods. Regression models using Stressor data generated by the weighted partial watershed landscape analysis method explained 76% and 47% of the variation in the first principal component for sediment metals and organics concentrations, respectively. Results suggest that the area of developed land located in the watershed within 10 km of the sediment sampling station is a major contributing factor in the sediment concentrations of both metals and organics.     

Wetland effects on lake water quality in the Minneapolis/St. Paul metropolitan area

A method developed to evaluate the cumulative effect of wetland mosaics on water quality was applied to 33 lake watersheds in the seven-county region surrounding Minneapolis-St. Paul, Minnesota. A geographic information system (GIS) was used to record and measure landscape variables derived from aerial photos. Twenty-seven watershed land-use and land-cover variables were reduced to eight principal components which described 85% of the variance among watersheds. Relationships between lake water quality variables and the first six principal components plus an index of lake mixis were analyzed through stepwise multiple regression analysis. A combination of three landscape components (wetland/watershed area, agriculture/wetlands, and forest/soils components) explained 49% of the variance in a trophic state index, even though most of the lakes examined were already highly eutrophic, and thus were influenced by internal loading. The regression equations explained a range of 14 to 76% of the variation in individual water quality variables. Forested land-use was associated with lower lake trophic state, chloride, and lead. High lake trophic state was associated with agricultural land-use and with wetland distance from the lake of interest. The extent of wetlands was associated with low total lead and high color in lakes downstream. Wet meadows or herbaceous, seasonally-flooded wetlands contributed more to lake water color than did cattail marshes.