Assessing the distribution of forest ecosystem services in a highly populated Mediterranean region

Abstract

Forest ecosystems provide a wide range of goods and services to society and host high levels of biodiversity. Nevertheless, forest ecosystem services (ES) are often quantified and assessed using simplified methodologies (e.g., proxy methods based exclusively on Land Use Land Cover maps) that introduce substantial uncertainty in the analysis by ignoring, for instance, the species composition and spatial configuration of the ecosystems studied. In this work we defined and calculated a set of 12 indicators of several ES for the forests of the highly populated region of Catalonia (North-eastern Iberian Peninsula). The indicators combined different sources of information such as forest surveys, ecological model predictions and official statistics, but also included additional land cover information. All ES indicators were aggregated at the municipality level to compare their values and distribution patterns. We assessed spatial trade-offs and synergies among ES, as well as their relationships with a set of socioeconomic, climatic and biodiversity variables using correlation analyses and mixed-effects models. The results suggest a clustering of provisioning and regulating ES in mountainous zones towards the North of the study area. These two types of services showed a high degree of spatial similarity and presented high positive correlations. In contrast, cultural ES showed a more scattered pattern, which included lower elevation areas in the South of the study region. Climatic conditions were the main determinants of the spatial variability in the supply of the different ES, with most indicators being positively associated with precipitation and negatively associated with temperature. In addition, biodiversity (particularly woody species richness) showed positive relations with most of these ES, while socioeconomic indicators (such as population density and the percentage employment in agriculture) showed negative associations with most of them. The combination of information from different data sources (including primary data) allowed for a detailed analysis of forest ES, likely removing some of the problems derived from approaches based only on proxy methods. In addition, the use of municipalities as study unit makes results directly relevant to management and planning strategies operating at this scale (e.g., forest management and planning).

The spatial level of analysis affects the patterns of forest ecosystem services supply and their relationships

“…We also assessed two biodiversity indicators and a measure of forest cover. All these indicators are described briefly in the following paragraphs; more detailed information can be found elsewhere (Roces-Díaz et al, 2017b). Mushroom production (P1, food provision, Provisioning ES) was estimated for each SNFI plot using the models developed by de-Miguel et al (2014) for the study area.…”

“…These results appear logical considering the scale-dependency of the ecological processes underlying ES provision (Hein et al, 2006) and are consistent with previous findings showing the influence of spatial data characteristics (e.g., spatial, temporal or thematic resolution) on ES patterns (Konarska et al, 2002;Kandziora et al, 2013;Gret-Regamey et al, 2014), including indicators of the supply, demand and flow of ES (e.g., Bagstad et al, 2014;Wolff et al, 2015). Although it is known that the spatial level of analysis may influence ES assessments (Geijzendorffer et al, 2015), the number of works assessing the importance of this effect is still limited (e.g., Raudssep-Hearne and Peterson, 2016) and most ES assessments are based on the use of administrative (or similar) boundaries including municipalities, counties or larger levels (referred generically as NUTS (Nomenclature of territorial units for statistics) Rodriguez-Loinaz et al, 2015;Roces-Díaz et al, 2017b;Schulp et al, 2014). In our study, the level with finest resolution (local) was based on 1-km 2 cells, and provides a similar level of detail to previous works that assessed similar sets of ES for comparable study areas (e.g., Anderson et al, 2009;Eigenbrod et al, 2010;Locatelli et al, 2013).…”

Integrating erosion risk into forest management in Catalonia, Spain

“…Soil protection as an ES has been defined as forests growing on slopes steeper than 30% (e.g. Roces-Díaz et al 2018). In other cases, assessment of soil protection ES is based on potential soil loss calculation using the USLE (e.g.…”

“…However, the topic has gained importance recently, and some surveys of forest ES including soil protection have been undertaken (e.g. Roces-Díaz et al 2018) where the erosion protection has been defined as constant if forest cover exists on slopes steeper than 30%. In this thesis, the erosion risk was related to the stand structural variables and influence of the slope, which made it possible to integrate erosion protection as one forest ES into forest management using simulations and optimisation.…”

A Multifactorial Approach to Value Supporting Ecosystem Services in Spanish Forests and Its Implications in a Warming World

“…Other ecosystem services and functions related to forest systems might also be critical for climate change mitigation, for example, the conservation of biodiversity as it promotes multifunctionality and ecosystem resilience [20]. However, little knowledge is available to quantify multiple services and it is usually not covered by national and continental assessments (but see References [21,22]). Furthermore, the provision of multiple ecosystem services can have certain trade-offs where some ecosystem functions can be promoted (e.g., biomass of actively restored forests ( [23])).…”