New concepts and methods to describe model and quantify ecosystem services on different and multiple spatial and temporal scales (Part 1) Roberta Aretano robertaaretano@alice.it Ecosystem services are the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life (Daily 1997). Ecosystems like forests, grasslands, mangroves, and urban areas provide different goods and services that are of value to people. These include provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services, such as nutrient cycling, that maintain the conditions for life on Earth (MEA, 2003). Ecosystem services affect human well-being and all its components, including basic material needs such as food and shelter, individual health, security, good social relations, and freedom of choice and action (MEA, 2005). Ecosystem services are provided at various spatial and temporal scales. Scale refers to the physical dimension, in space or time, of phenomena or observations (O’Neill and King, 1998) and is expressed in physical units, such as meters or years. Some ecosystem services are local (provision of pollinators), others are regional (flood control or water purification), and still others are global (climate regulation). Traditionally, ecologists have estimated ecological variables without much regard for location and to date, there has been relatively little elaboration of the various spatial and temporal scales at which ecosystem services are supplied (MEA 2003, Turner et al. 2003). Hence, there is a need to examine the various scales at which ecosystem services are generated and used. The ecosystem services listed in Costanza et al. (1997) can be collected into five categories according to their spatial characteristics (Costanza, 2008): 1) Global non-proximal (they do not depend on proximity): Climate regulation, Carbon sequestration (NEP), Carbon storage, Cultural/existence value; 2) Local proximal (depends on proximity): Disturbance regulation/ storm protection, Waste treatment, Pollination, Biological control, Habitat/refugia; 3) Directional flow related: flow from point of production to point of use: Water regulation/flood protection, Water supply, Sediment regulation/erosion control, Nutrient regulation; 4) In situ (point of use): Soil formation, Food production/non-timber forest products, Raw materials; 5) User movement related: flow of people to unique natural features: Genetic resources, Recreation potential, Cultural/aesthetic. The ecosystem services, as the ecosystems they are provided by, can be also classified according to their temporal characteristics: Cycling with high/low frequency; Predictability; Trend vs. Constant provision/use; Way of change (continuous/threshold) (Levin, 2006). In assessing ecosystem services, scale matters for many reasons. First, ecological and social systems and processes operate at a wide variety of scales—from very small and short to very large and long—and between scales they can change in their nature and sensitivity to various driving forces. It cannot be assumed that results obtained at one scale are automatically valid at another (Kremen et al. 2000). The application of the same approach at different spatial scales can be seen in the context of “scale transformation” that has been criticized both for technical and for conceptual reasons (Milne and Cohen, 1999). Scale transformation is problematic because the spatial structure and the corresponding geostatistical properties of a scene change with scale (Openshaw, 1984). Model calibrations developed at one scale are not readily applied at others (O’Neill and Rust, 1979; O’Neill et al., 1996); they may be further complicated if many variables are of interest (Levin, 1992; Pierce and Running, 1995). Second, cross-scale interactions exert a crucial influence on outcomes at a given scale and focusing solely on a single scale can miss these interactions. In addition real-space models are needed to represent the relationships between sources and sinks that affect fluxes of ecosystem services, as identified by Milne and Cohen (1999) for fluxes of nutrients. Moreover, analyzing scales is important in order to reveal the interests of different stakeholders in ecosystem management. Starting in the late 1960s, there has been a growing interest in the analysis and valuation of the multiple benefits provided by ecosystems. This interest was triggered by an increasing awareness that the benefits provided by natural and semi-natural ecosystems were often underestimated in decision making (Odum and Odum, 1972). Since then, economic valuation of ecosystems has received much attention in scientific literature and several studies have provided frameworks for the valuation of ecosystem services (Costanza et al., 1997; Turner et al., 2000; De Groot et al., 2002; MEA, 2005). While much attention has focused on the economic theory and practice of environmental value transfer itself, the spatial and temporal dimension to economic valuation has barely been investigated (Eade and Moran, 1996). Ecosystem services are supplied to the economic system at a range of spatial and temporal scales, varying from the short-term, site level (e.g., amenity services) to the long-term, global level (e.g., carbon sequestration) (Turner et al., 2000; Limburg et al., 2002;). Time changes the value of things therefore the supply of ecosystem services will often be variable over time, and, where relevant, both actual and potential future supplies of services have to be included in the valuation (Barbier, 2000). Landscape Science can contribute to develop ES valuation in terms of incorporating scale and evaluating spatial temporal variability. Ecosystem services are generated at different, sometimes overlapping, ecological scales and furthermore exploited at multiple social scales, with possible scale-mismatching and cross-scale interactions (Petrosillo et al. 2008). Recognizing that ESs are characterized by spatial cross-scale interactions, the moving window algorithm can be used to measure composition (amount) and spatial configuration (contagion) of ecosystem services along a continuum of scales (Petrosillo et al., 2008 (Salzau). This is a way to approach landscape complexity from the perspective of ‘‘content and context’’, giving the same importance to the amount and spatial configuration of ecosystem services, with the aim to investigate causes, processes and possible consequences of driving forces, i.e. land use, and decision making at various scales (Zurlini et al., 2007). The use of a multiscale approach that simultaneously uses larger- and smaller-scale assessments can help identify important dynamics of the system that might otherwise be overlooked. Trends that occur at much larger scales, although expressed locally, may go unnoticed in purely local-scale assessments. Geographic information system (GIS) is probably the most effective instrument for introducing a spatial dimension into the economic valuation, through the use of “spatial economic valuation” methodology and production of economic value maps. The adoption of a spatial approach to economic valuation is desirable in terms of producing more accurate economic valuation figures, for use as a repository for benefits estimates, examining spatial sustainability, and facilitating the introduction of natural capital concepts into environmental decision-making processes. The use of GIS to map and model natural capital adds a new dimension to environmental economics and is worthy of further investigation. The multi scale integrated model of ecosystem services (MIMES) stretches the edge of technical achievement in GIS data and display, in modeling environments, and in interface development. MIMES is a project useful to assess the value of ecosystem services in a sophisticated and transferable system to allow ecosystem managers to quickly understand the dynamics of ecosystem services, how their services are linked to human welfare, how their function and value might change under various management scenarios (Nadrowski et al., 2008 (Salzau). It will facilitate understanding ofthe context of spatial patterns of land use, they dynamics of value, and the scale at which information is available for estimating ecosystem services at various scales (e.g. watershed, national and global). MIMES will provide economic arguments for land use managers to approach conservation of ecosystems as a form of economic development. The remote sensing is also a useful technology to assess spatial and temporal variability in the condition of landscapes. For example the use of satellite imagery to provide remotely sensed indicators that account for continuous variation in vegetation structure may be more appropriate to measure ecosystem condition and their ability to provide services (Price et al., 2008 (Salzau). The index NDVI (Normalized Difference Vegetation Index) provides a spatially continuous measure of vegetation structure and photosynthetic activity that represents a supporting services, from which all the other services depend on. It can act as an alternative to metrics derived from the discrete patch model of landscape structure. NDVI can be easily derived from readily available Landsat imagery at a variety of spatial extents and temporal resolutions. MODIS monthly NDVI dynamics show that Ecosystem Services values for certain services may fluctuate during “small” intervals, too (Zaccarelli et al., 2008 (Salzau). To promote researches at multiple scales, new techniques are certainly needed. 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