Assessing, valuing, and mapping ecosystem services in Alpine forests

Highlights

• Biophysical assessment, economic valuation, and GIS mapping was performed.

• Forest ecosystem services in Fiemme and Fassa Valleys (Italy) were assessed.

• Mapping ecosystem services resulted useful in identifying priority areas.

• Trade-offs and synergies between different ecosystem services were found.

• The Total Economic Value of the investigated services was calculated.

Abstract

Forests support human economy and well-being with multiple ecosystem services. In this paper, the ecosystem services generated in a mountainous forest area in North Italy were assessed in biophysical and monetary units. GIS was used to analyze and visualize the distribution and provision of different services. The assessment of ecosystem services in biophysical units was an important step to investigate ecosystem functions and actual service flows supporting socio-ecological systems. The Total Economic Value (TEV) of all the investigated ecosystem services was about 33 M€/yr, corresponding to 820 €/ha/yr. The provisioning services represented 40% of the TEV while the regulating and cultural services were 49% and 11%. The service of hydrogeological protection, particularly important in areas characterized by a high risk of avalanches and landslides, showed a major importance among the regulating services (81%) and within the TEV (40%). Results from mapping ecosystem services were useful in identifying and visualizing priority areas for different services, as well as exploring trade-offs and synergies between services. Finally, we argue that while a biophysical perspective can ensure a solid accounting base, a comprehensive economic valuation of all categories of forest ecosystem services can facilitate communication of their importance to policy makers.

Introduction

Connecting biophysical aspects of ecosystems and human well-being through the notions of natural capital and ecosystem services has been an essential step to recognize the dependence of human societies on natural ecosystems (Braat and de Groot, 2012; Daily, 1997, Folke et al., 2011, MA (Millennium Ecosystem Assessment), 2005). To account for the benefits provided by ecosystems, several assessment and valuation methods have been developed, some using different biophysical approaches while others highlighting the importance of economic values of ecosystem services (Burkhard et al., 2012, Costanza et al., 1997, Farber et al., 2002, Häyhä and Franzese, 2014, Jørgensen, 2010, Seppelt et al., 2012, Ulgiati et al., 2011). Integrating ecosystem services into policy and decision-making also depends on the availability of spatially explicit information on ecosystem service supply and demand (Burkhard et al., 2013, Maes et al., 2012, Schägner et al., 2013). To map ecosystem services, biophysical measures (Burkhard et al., 2012, García-Nieto et al., 2013, Remme et al., 2014, Schröter et al., 2014, Vihervaara et al., 2010), as well as monetary values (Costanza et al., 1997, Kubiszewski et al., 2013, La Notte et al., 2012, van Berkel and Verburg, 2014) have been used.

Monetary valuation has been proposed as a necessary tool to raise awareness and communicate the importance of ecosystems and biodiversity to policy makers. This is because decisions in resource management are mostly affected by ecosystem services for which it is possible to define a market price, while non-marketed ecosystem services are frequently disregarded (Balmford et al., 2002, Costanza et al., 2014, de Groot et al., 2012, TEEB, 2010). In fact, market failures in relation to ecosystem services that are often free public goods can lead to higher exploitation levels providing short-term economic benefits to some stakeholders at the expense of long-term well-being of many others (de Groot et al., 2010, Hardin, 1968). Yet, it should be regarded that economic values of ecosystem services are sensitive to the chosen valuation method and subjective assumptions, whereas considering possible use in decision-making, a limitation is that economic instruments do not address issues of social fairness and equity in ecosystem use (Spangenberg and Settele, 2010).

Ecosystems are complex adaptive systems characterized by non-linearity (Müller, 2005). When reaching a certain threshold, ecosystems can switch into a new equilibrium state, possibly leading to irreversible loss of critical natural capital, after which the ecosystem does not provide ecosystem goods and services (Folke, 2006, Burkhard et al., 2011, Holling, 1973). For instance, removing too much forest cover can lead to severe soil erosion driving the forest ecosystem towards a radical change such as desertification. As discussed by Limburg et al. (2002) and Farley, 2008, Farley, 2012, monetary valuation could assist allocation decisions between conservation and conversion when the stocks of critical natural capital or flows ecosystem services are healthy and resilient. Instead, in the vicinity of thresholds, a small decrease in the physical quantity of ecosystem services can cause a large increase in their marginal economic value, making monetary analysis inappropriate, whereas information about biophysical quantities and quality of ecosystem structure is more relevant.

Forests provide human economy and well-being with a wide range of ecosystem services, from timber and non-wood products to carbon sequestration, watershed protection, and recreation (de Groot et al., 2002, MA (Millennium Ecosystem Assessment), 2005). Concerns about greenhouse gas emissions as well as future shortage and rising prices of fossil fuels and natural resources are leading to a growing interest in wood biomass as renewable material and energy source (Buonocore et al., 2012, Buonocore et al., 2014). On the other hand, forests are intended to play an important role in carbon storage while also meeting the needs of biodiversity conservation and ecotourism. Moreover, forests in mountain areas are especially important for the protection of human activities against natural hazards such as avalanches, rock falls, and landslides (Dorren et al., 2004). Since ecosystem services are typically highly interlinked, the optimization of one typology of services can affect other services (Bennett et al., 2009), which is why all forest management choices entail trade-offs.

Former studies on forest ecosystem functions and services have focused on a single or few services: timber and bioenergy production in relation to carbon sequestration (Canadell and Raupach, 2008, Seely et al., 2002, Seidl et al., 2007), outdoor recreation (Zandersen and Tol, 2009), and protection against natural hazards (Olschewski et al., 2012, Teich and Bebi, 2009), whereas other authors have studied forest ecosystems by considering multiple services (Croitoru, 2007, Fürst et al., 2013, Grêt-Regamey et al., 2008, Grêt-Regamey et al., 2013, Grêt-Regamey and Kytzia, 2007, Matero and Saastamoinen, 2007, Pearce, 2001, Olschewski et al., 2010, Viglia et al., 2013). With specific reference to the Alpine context of North Italy, Gios et al. (2006) estimated the benefits gained from natural resources focusing on tourism, while Goio et al. (2008) compared standard accounting, green accounting, and total economic value to evaluate the benefits produced by forests in the Province of Trento. In the same region, Notaro et al. (2008) illustrated the economic values of a series of productive and non-productive forest functions, while Notaro and Paletto (2012) performed an economic valuation of the protective function of forest against natural hazards. In addition, Grilli et al. (2014) discussed the importance of Alpine forests for recreation.

In this study, we integrated biophysical assessment and economic valuation to investigate multiple forest ecosystem services in Fiemme and Fassa Valleys (Province of Trento, North Italy). The main services were identified, quantified in their biophysical units, and valued in economic terms, estimating also the Total Economic Value (TEV) of the investigated services. A Geographic Information System (GIS) was used to perform a spatial assessment and map the distribution of selected ecosystem services in the study area. Finally, the spatial information was also used to assess trade-off and synergies between different ecosystem services.