Collaborative landscape research in Reunion Island: Using spatial modelling and simulation to support territorial foresight and urban planning

This paper reflects on collaborative landscape research conducted in Reunion Island, an outermost region of the European Union. On this 2,500 km² tropical island also considered a major international biodiversity hotspot, land-use planners must address important challenges, especially growing population densities and urban sprawl that cause important pressure on agricultural land and natural ecosystems. While progress has been made towards land-use zoning and planning at the island scale, entrenched interests and a lack of communication between the agricultural, urban and environmental sectors continue to hinder the design and implementation of integrated land-use plans at the local level. This paper presents an approach to territorial foresight where urban development scenarios and spatial models were co-constructed with a collective of institutional actors in order to facilitate dialogue on future urbanization patterns and impacts on landscapes. It describes how spatially explicit models and simulations of urban development, first used as demonstrators, have raised individual interests and expectations and facilitated the structuring of a collaborative research network. Models and scenarios were then questioned, redesigned collectively and used as boundary objects to facilitate a shift away from statistical and sectorial readings towards more territorialized and integrated perspectives. Analysing inputs, reactions and feedback from the actors involved in the research, this paper discusses the role and potential value of landscape modelling and simulation in mediating debates among planning stakeholders and creating social learning situations.     

Land changes in Slovakia: Past processes and future directions

The aim of this study is to bring a unique overview of past, current and plausible future land use development in Slovakia. The study assessed land change processes and their spatial determinants related to the most significant socio-political periods that have shaped the former socialist country over the past 30 years, namely, socialism (1980–1990), postsocialism (1990–2000), EU accession (2000–2006), EU membership (2006–2012). Using boosted regression trees, the impact of different biophysical, socioeconomic, policy and distance-based factors was evaluated on land transitions, categorised as urbanisation, agricultural intensification and extensification, afforestation, deforestation and forest disturbance (natural and management-induced). Results show significant shifts in the landscape management associated with the institutional changes, especially in the postsocialist period.Agricultural intensification, which dominated the socialist period, was in subsequent periods substituted by afforestation and agricultural extensification. High relative annual rates of forest disturbance have dominated land-use change over the past 30 years, while deforestation was a minor land-use change during the late socialist period. Urbanisation has played a significant role and changed considerably through the studied periods: high urbanisation rates under socialism, a massive decline in the postsocialism and EU accession periods and increasingly high urbanisation rates during the EU membership period.Taking into account national and international (EU related) demands, we assessed land use development for 2040 within five different future land use scenarios. These scenarios were characterised as either extensions of current development trends, or as developments along axes that target globalisation or regionalisation, and more or less intervention. Results show that afforestation is by far the land-change process that will have the greatest impact on future Slovakian landscapes, mostly in rural areas. Among changes in agriculture, all scenarios uniformly suggest that extensification will exceed intensification mostly at the cost of arable land. In addition, urban areas will expand at the expense of arable land, particularly in the accessible city hinterlands.     

Comparison of input data with different spatial resolution in landscape pattern analysis – A case study from northern Latvia

A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern metrics in four landscapes at scales 1:10 000, 1:50 000 and 1:100 000. The aim was to determine the applicability of three data sources for thematic models in landscape pattern analyses in the Eastern Baltic region. We found that the utility of CORINE Land Cover data for comprehensive structural assessment in mosaic-type landscapes was very limited, as the level of cartographic generalization excluded many small and linear landscape structure elements with potentially high importance for landscape functioning, such as habitat continuity. We also found that actual area harvested using clearcuts was considerably higher than shown in CORINE data, due to clearcuts size being much smaller than the minimum mapping unit. In the light of this, we suggest using data with spatial resolution corresponding to a cartographic scale of at least 1:50 000, in cases when spatial patches have size up to 25 ha.     

Time series evaluation of landscape dynamics using annual Landsat imagery and spatial statistical modeling: Evidence from the Phoenix metropolitan region

Urbanization is a natural and social process involving simultaneous changes to the Earth’s land systems, energy flow, demographics, and the economy. Understanding the spatiotemporal pattern of urbanization is increasingly important for policy formulation, decision making, and natural resource management. A combination of satellite remote sensing and patch-based models has been widely adopted to characterize landscape changes at various spatial and temporal scales. Nevertheless, the validity of this type of framework in identifying long-term changes, especially subtle or gradual land modifications is seriously challenged. In this paper, we integrate annual image time series, continuous spatial indices, and non-parametric trend analysis into a spatiotemporal study of landscape dynamics over the Phoenix metropolitan area from 1991 to 2010. We harness local indicators of spatial dependence and modified Mann-Kendall test to describe the monotonic trends in the quantity and spatial arrangement of two important land use land cover types: vegetation and built-up areas. Results suggest that declines in vegetation and increases in built-up areas are the two prevalent types of changes across the region. Vegetation increases mostly occur at the outskirts where new residential areas are developed from natural desert. A sizable proportion of vegetation declines and built-up increases are seen in the central and southeast part. Extensive land conversion from agricultural fields into urban land use is one important driver of vegetation declines. The xeriscaping practice also contributes to part of vegetation loss and an increasingly heterogeneous landscape. The quantitative framework proposed in this study provides a pathway to effective landscape mapping and change monitoring from a spatial statistical perspective.     

Structural attributes of individual trees for identifying homogeneous patches in a tropical rainforest

Mapping and monitoring tropical rainforests and quantifying their carbon stocks are important, both for devising strategies for their conservation and mitigating the effects of climate change. Airborne Laser Scanning (ALS) has advantages over other remote sensing techniques for describing the three-dimensional structure of forests. This study identifies forest patches using ALS-based structural attributes in a tropical rainforest in Sumatra, Indonesia. A method to group trees with similar attributes into forest patches based on Thiessen polygons and k-medoids clustering is developed, combining the advantages of both raster and individual tree–based methods. The structural composition of the patches could be an indicator of habitat type and quality. The patches could also be a basis for developing allometric models for more accurate estimation of carbon stock than is currently possible with generalised models.     

Performance evaluation of land change simulation models using landscape metrics

This study proposes a landscape metrics-based method for model performance evaluation of land change simulation models. To quantify model performance at both landscape and class levels, a set of composition- and configuration-based metrics including number of patches, class area, landscape shape index, mean patch area and mean Euclidean nearest neighbour distance were employed. These landscape metrics provided detailed information on simulation success of a cellular automata-Markov chain (CA-Markov) model standpoint of spatial arrangement of the simulated map versus the corresponding reference layer. As a measure of model simulation success, mean relative error (MRE) of the metrics was calculated. At both landscape and class levels, the MRE values were accounted for 22.73 and 10.2%, respectively, which are further categorised into qualitative measurements of model simulation performance for simple and quick comparison of the results. Findings of the present study depict a hierarchical and multi spatial level assessment of model performance.     

The conversion of natural riparian forests into agricultural land affects ecological processes in Atlantic forest streams

Agricultural practices affect the integrity of riparian areas of small streams. In this study we tested the hypothesis that the increase of agricultural activities influences negatively the functional conditions of the low order streams in the Atlantic forest of southern Brazil. Litter bags with leaves of Nectandra megapotamica (Spreng.) Mez were located in eight streams with different amounts of woody vegetation and agriculture land uses in their riparian zones. After 7, 15 and 30 days, the litter bags were removed for identification of associated invertebrates and determination of decomposition rate. Decomposition rates were negatively influenced by agriculture in the riparian zone while primary production was positively influenced. On the other hand, the decomposition mediated by microorganisms did not vary along the degradation gradient. The abundance of collectors increased in streams adjacent to agricultural land while the abundance of shredders was decreased. Our results showed that algae biomass and leaf decomposition were sensitive to the replacement of native vegetation by agricultural use. However, the trophic structure of invertebrates was moderately sensitive to agricultural land use.     

The effectiveness of richness,diversity and dominance textural indices when applied on digital ground photographs using a GIS for landscape visual analysis purposes

This study aims to investigate the effectiveness of three main textural indices for the automatic evaluation and classification of landscape scenic quality using digital ground photographs. Based on the textural indices that are commonly used in landscape ecology, the richness, diversity and dominance indices were selected to be examined, and the results from the application of these indices to a sample of ground photographs are described in this paper. The application of the textural indices to the sample of photographs takes place in two different ways, using a geographic information system (GIS) that aims to describe the general and partial heterogeneity of the landscape appearing in each photograph. Furthermore, we investigate the effectiveness of the indices selected as to the classification of the landscape's scenic quality, with the results being compared to other results derived from a research programme of the National Technical University of Athens. Comments and suggestions are presented for further investigation. The main conclusion of the investigation is that the texture indices are sensitized in the landscape's scenic quality, a fact that is positive and encourages the pursuit of further research.     

Farm size and landscape composition in relation to landscape changes in Denmark

Geografisk Tidsskrift, Danish Journal of Geography 106(2): 45–59, 2006

This paper explores relationships between farm size and landscape composition in terms of densities of uncultivated landscape elements and sizes of agricultural fields. The study is based on national agricultural registers for Denmark and on aerial photo interpretation of three study areas, representing different Danish landscape types. Results indicate significantly smaller fields and significantly higher densities of uncultivated landscape elements on small farms (<25 ha). At national level, current differences between small and large farms are to some extent caused by landscape changes between 1998 and 2004. Analyses of the study areas indicate that current differences between small and large farms mainly evolved between 1982 and 2002, while the influences of changes between 1954 and 1982 are limited. Relationships between farms size and landscape composition are independent of spatial variations in soil type and slope conditions. Consequently, attention must be paid to other parameters linked to farm size. In particular, the effects on landscape composition of part-time and hobby farming, as well as production type, must be considered.     

Guiding rural landscape change: Current policy approaches and potentials of landscape strategy making as a policy integrating approach

Public policy interventions concerning rural landscapes have grown significantly in recent decades in many developed countries and internationally, in response to a range of imperatives. These include concern for declining biodiversity, heritage and social wellbeing in the face of urbanisation, and structural change in rural economies involving both agricultural intensification and extensification. The public policy response has been a fragmented array of measures, both horizontally (across policy sectors) and vertically (across political-administrative-organisational levels). Against this background, rural landscape policy approaches are analysed in respect to their instrumentality and spatial logic, informed by Hägerstrand's concepts of territorial and spatial competence. A framework for local policy making and policy integration inspired by landscape strategy making approaches is presented and illustrated through four Danish experiments in rural landscapes of various scale and with different policy issues. Results suggest that landscape strategy making represents a promising way to improve policy integration in rural contexts but research is needed to find suitable ways to engage large scale intensive farming with the community based process.