The case study area is located in Central Bulgaria and covers the central part of the Balkan Mountains (Stara Planina in Bulgarian) and the surrounding areas (Fig. 2). The spatial coverage is outlined by following both natural and administrative criteria including all the municipalities that have parts of their areas included in the Central Balkan National Park. In total, the area covers 299894 ha (2998.9 km²) where 73536.5 ha or 24% of the case study area is designated as protected (37 areas in total). The most important protected area is the Central Balkan National Park (71825.5 ha) which encompasses nine other protected areas within its borders. The average altitude is 913 m ranging from 265 m in the Karlovo Plain to 2376 m at the Botev Peak (the highest summit in the Balkan Mountains). Although the study area is relatively small, its nature is quite diverse, due to the influence of the Balkan Mountain Range. This leads to the formation of different hydro-climatic conditions in the higher altitudes and in the northern and southern parts of the mountain. There are three types of climate: temperate continental in the north, transitional to Mediterranean in the south and mountainous in the central part and in the areas above 1000 m. The average annual temperatures vary from south to north from 11.1^oC (in the Town of Karlovo) to 10.0^oC in the Town of Troyan and decrease to 0.7^oC at Botev Peak. The south part of the area is drier than the north part. The mean annual precipitation changes from 550 to 800 mm and the quantities rise to 1100 mm with the increase in altitude. The vegetation is characterised by typical altitudinal zoning. In the lower parts, the vegetation is presented by Oak and Oak-Hornbeam forests, followed by beech forests in the areas above 800 m and mountain grasslands at the highest parts of the mountain.

Figure 2.  

Central Balkan case study area.

The study area covers partially the territory of the following nine municipalities – Teteven, Anton, Pirdop, Karlovo, Sopot, Sevlievo, Apriltsi, Troyan and Pavel Banya. Only two of them - Karlovo (103911 ha) and Sopot (5630 ha) are situated entirely within the case study area. There are 82 settlements with a total population of 128626 residents while 58% of the population (74205 inhabitants) lives in urban areas. The most populated towns are Karlovo (25715 inhabitants) and Troyan (23623 inhabitants). The population of Karlovo Municipality is estimated at 50650 residents with a decreasing trend, due to the negative growth rate.

The Central Balkan National Park occupies the higher parts of the mountain and varies in altitude from 550 m to 2376 m. The park is part of the PAN Parks network and is one of the largest and the most valuable protected areas in Europe, ranked at category 2 by IUCN. It performs the functions of a significant ecological corridor in Eastern Europe, as well as a nexus for genetic exchange between the southern Balkans and the Asia Minor Peninsula. The Central Balkan National Park belongs to the Rhodope montane mixed forests terrestrial ecoregion of the Palearctic temperate broadleaf and mixed forest and is home of rare and endangered wildlife species and communities. The flora is represented by 2340 species and subspecies of plants. Forests occupy 56% of the total area. There are 59 species of mammals, 224 species of birds, 14 species of reptiles, 8 species of amphibian and 6 species of fish, as well as 2387 species of invertebrates. The National Park includes nine nature reserves that cover 28% of its territory. Since 2017, the Central Balkan National Park has formed the core and the buffer zone of the new Central Balkan Biosphere Reserve (Fig. 3). Different parts of the case study area were used as smaller scale case studies in order to demonstrate the application of the multi-tiered approach at different levels of scale. Municipality level (Karlovo municipality) was used to present the application of economic valuation at tier 2, watershed level (Vidima watershed) and town level (Karlovo) were used to present the application of biophysical methods at tier 3.

Figure 3.  

Central Balkan biosphere reserve (source: project "Linking nature protection and sustainable rural development").

The studies in the area of Central Balkan include flood hazard assessment and mapping of flood regulation in the upper part of the Yantra basin, natural capital assessment and application of the contingent valuation method in the Apriltsi and Kalofer municipalities (Borisova et al. 2015, Assenov and Borisova 2016), ES valuation of the forests in Central Balkan National Park (Dimitrova et al. 2015), mapping of carbon storage capacity in the Beklemeto area (Zhiyanski et al. 2016) and urban ecosystem assessment in the Karlovo Municipality - a pilot study in the national MAES-related activity (Nedkov et al. 2017). Most of these investigations have been conducted with the active support of the municipal and National Park administrations, which strengthens the policy context of the conducted research. The Central Balkan study area encompasses a part of a mountain region which suffers from a range of natural and socio-economic disadvantages (e.g. demographic loss, remote and limited access areas, higher climate change vulnerability), but it also provides key resources and ES to people and societies (water, renewable energy, protection against natural hazards, opportunities for tourism, natural and cultural diversity etc.). Central Balkan and the protected areas in it are ‘hotspots of biodiversity’, containing many ecosystems with rather low anthropogenic influence, particularly at higher altitudes, often in protected areas. Mountain ecosystems are particularly fragile and subject to both natural and human drivers of change, which implies the need forbetter knowledge of their specificities to produce sufficient conservation measures.

The application of the Ecosystem Services (ES) concept to the Central Balkan case study facilitate the adoption and/or further establishment of a number of policy instruments for a science-based, sustainable territorial governance, amongst which: the need for regular monitoring, immediate, free and open access to data, information and know-how; integration of scientific knowledge in civic affairs governance practice; continuous planning process with in-built policy alternatives coupled with respective impact assessments; continuous education, proper motivation and constant involvement of the stakeholders and the public (Burkhard et al. 2010, Primmer and Furman 2012, Rosenthal et al. 2014, Koulov et al. 2017, Guerry et al. 2015). The research activities related to sustainable development and mapping and assessment of ES have proven able to smooth out some of the tensions that often arise between the protection and conservation functions of the protected areas in mountain regions and the municipal administrations, which are usually more focused on securing local economic opportunities and short-term improvement of social wellbeing. In the days when the Central Balkan National Park (NP) was in its infancy, municipalities often used to hold it responsible for missed economic opportunities, which ultimately resulted in their opposition to certain Park-related projects. At this time, after experiencing some of the positive impacts of nature protection policies, municipalities have gradually started to cooperate.

The overall territorial impact of the Central Balkan NP, category II in the IUCN classification, on the development of its region, however, still presents significant challenges to comprehensive assessment, due to a number of factors, amongst which the sheer number and the diverse and multi-scale character of the institutions and actors involved. The Park itself is managed by the 1998 Protected Territories Act (Suppl. 1, Art. 8.1, Amen. SG 28/2000, Amen. SG 77/2002) and administered by the Ministry of Environment and Waters and its National Nature Protection Service. The Service is responsible for development of protection and conservation strategies, programmes, plans and other regulatory documents. Thus, the direct impacts on the Park are strongly related to the implementation of the national conservation policy.

Simultaneously, Central Balkan is the second largest national park in Bulgaria and its territory is included in four NUTS 2 economic planning regions, five NUTS 3 administrative regions (oblast) and nine LAU 1 self-governing administrative regions (obshtina) with thirty settlements, including seven towns. Their strategic and short term planning and policy documentation does not always coincide in time period, territorial scope, quality or level of implementation. For example, most municipal development plans (Troyan, Karlovo, Sevlievo, Pavel Banya, Anton) provide a strategic framework and programme for their development for the 2014-2020 programming period, while the Pavel Banya Municipal Plan still refers to the previous 2007-2013 planning period. The comparative analysis of the basic local development planning instruments – the municipal development plans – shows generally weak intra-regional and inter-sectoral connection and even less cooperation. Overall, some of the plans’ objectives are nature conservation-orientated and focus on the preservation of natural resources and natural heritage. They espouse implementation of international conventions and national conservation guidelines, e.g. Natura 2000, CBD, UNESCO MaB Programme and Seville Strategy, National Priority Framework for Action in Natura 2000 Areas. However, the EU level, national and regional development documents all focus on the population settlements and, particularly, the urban centres and do not directly connect their wellbeing to the Central Balkan NP, which is the legal responsibility of other ministries and agencies.

The local economic policy context in the Central Balkan NP region almost uniformly promotes development of sustainable tourism and ecotourism, nature and cultural tourism IN particular, are viewed as the key potential. This and most other envisioned economic activities (e.g. measures to support the shift to organic farming, local livestock breeding and silvi-culture bio-products, sustainable energy production) indicate a strong thematic link to the eco-potential of the National Park. Municipal plans provide ample evidence that, at the expert level at least, an increasing understanding has been shaping for the need for valorisation of a number of concrete ecosystem services, including in the forestry and water sectors and natural hazards control (i.e. forest fires, soil erosion, avalanches, floods and climate regulation. The main challenge in terms of regional territorial strategies and policies is to successfully combine the protection of natural assets and landscapes with valuation of ecosystem services and sustainable development.

This review of the ES studies in the Central Balkan area gains further significance in light of the latest developments in its ecological status. As a result of the implementation of the Seville Strategy for Biosphere Reserves (UNESCO 1996), which targets the "harmonious coexistence" between Man and Nature through integration of good policies and practices in biodiversity conservation and sustainable development of local communities, at its June 2017 meeting in Paris, UNESCO's Council of the Man and the Biosphere Programme endorsed the creation of a Central Balkan Biosphere Reserve. In fact, this distinction provides further stimuli for economic and socio-cultural development not only of the local municipalities, but of the region as a whole.

The geographic structure of the new Biosphere Reserve consists of three functional zones:

1. a core area, which comprises the nine reserves of the existing Central Balkan National Park;
2. a buffer zone, which includes the rest of the National Park’s territory; and
3. a specially created "development zone", which encompasses 80% of the area of the "Central Balkan Biosphere Reserve" and acts as a transition area between the National Park as a whole and the ecologically unregulated parts of the local municipalities (Fig. 3).

The Biosphere Reserve’s development zone is made up of territories from the following municipalities: Karlovo, Troyan, Sevlievo, Pavel Banya and Anton. It is an area of geospatial integration of the ecological (conservation and protection) functions of the National Park with the economic opportunities that the Park creates for the population in the region, including particular types of tourism and recreation services and a number of forest- and mountain-related ES.

According to the Lima Action Plan (2016-2025), a key role for the efficiency of biosphere reserves is their recognition as a source of ecosystem services and the provision of a long-term vision for the protection of these services (LAP 2016). On this basis, this work endorses the opinion of Tomova and Borisova 2018 that identification, evaluation and mapping of ES contribute for:

1. Enlargement of the environmental information base and its decision-making support functions, which go beyond the Natural Resources concept;
2. Deepening the role of the financial mechanisms in environmental policy and natural resources management;
3. Raising the value of spatial and sectoral planning analyses and increasing their sensitivity to landscape versatility.

Comprehensive identification and consideration of the dependence of the local population on the ES in the nearby areas makes valuation of the ES an important factor in sustainable landscape planning and territorial integration policy-making (Borisova 2013). As Grêt-Regamey et al. 2008 point out, appropriate selection and valuation of ES in a spatially explicit form facilitates the identification of the most beneficial locations for new development.

The studies above target the area of the following Natura 2000 zones: "Central Balkan" BG0000494, "Central Balkan buffer" BG0001493 and BG0002128 and the municipalities of Karlovo and Troyan. A series of activities, related to schemes for payments for ES (restoration and maintenance of a locally characteristic gene pool in protected areas - rare local animal breeds), support for organic livestock breeding (in ecosystems of high conservation value), as well as co-financing of economic activities, where the revenues are used to protect biodiversity, have been formally approved within the scope of the territory under investigation. These activities are part of the successful project of six Bulgarian NGOs, four Swiss organisations and the Ministry of Agriculture, Foods and Forests through the Executive Agency for Selection and Reproduction in Animal Breeding, named "For the Balkans and the Humans" (2012-2016), that won an European Commission "NATURA 2000" award in the "Socio-Economic Benefits" category (BBF 2016).

Mapping of ecosystems and their services depends to a very large extent on the availability of spatial data. The requirements to the data quantity and quality are strongly influenced by the scale of mapping. Larger scale mapping requires more detailed spatial data with higher accuracy. Some sources of data for the Central Balkan meet these requirements but none of them covers the whole study area. The data generated by the projects, which implemented the methodology for mapping and assessment, are organised in spatial datasets representing the ecosystems at the third level of the MAES typology. They correspond to scale 1:25000 and have aminimum mapping unit of 0.25 ha. There are actually nine different datasets, one for each main ecosystem type, which are not fully compatible. Furthermore, they do not cover the NATURA 2000 zones, which cover a significant part of the study area. More detailed datasets exist at municipality, city and watershed level which have been used for mapping and assessment of the selected ecosystem services. For instance, the results of the hydrologic modelling of the Vidima Watershed (Boyanova et al. 2016) has been used for assessment of the flood regulation ecosystem service and the carbon storage data for the urban ecosystems in Town of Karlovo (Nedkov et al. 2017) has been used for assessment of the global climate regulation.

The CORINE land cover dataset is the only one available that covers the whole study area. While it is too coarse for municipality or city level mapping and assessment, it is sufficient for a general overview of the ecosystems in the area and identification of relevant ecosystem services. The tiered approach has been used to organise the mapping exercises in the study area, in order to meet the needs for integrated ecosystem assessment and overcome the limitations of data availability. At tier 1, the studies perform identification and initial ES mapping for the whole case study area using CORINE land cover data for ecosystems delineation and expert-based assessment of the ecosystem services. At tier 2, it applies economic valuation for the Municipality of Karlovo by using statistical data and the contingent valuation method. At tier 3, the investigation applies more complex modelling methods to assess two different ecosystem services on a larger scale. Quantification of carbon storage for the assessment of global climate regulation is applied in the Karlovo Town and assessment of flood regulation based on GIS-based hydrological modelling is applied in the Vidima Watershed.

The tiered approach applied at different scales in frames of one and the same territorial unit illustrate very well the spatial integration of the assessed ecosystem services at different scales using different methods (Table 1).

The first step in the mapping and assessment procedure is to identify the ecosystem types and the relevant ecosystem services in the case study area. For this purpose, the studies use the spreadsheet method for ecosystem services assessment which is based on land cover/ES matrix approach (Burkhard et al. 2014, Burkhard et al. 2009, Burkhard et al. 2012). The matrix links ecosystem services to CORINE land cover classes and, at the intersections, the ES capacities are assessed on a 0 to 5 relative scale. There are 20 land cover classes in the Central Balkan case study area which are arranged on the y-axis of the matrix (see Figure 5 in the next section). The relevant ecosystem services for the case study area were selected using the CICES classification by the authors of this study and they were placed at the x-axis of the matrix. The scores for combination of land cover class and ES were made by team of experts during a fieldwork campaign in the study area. The team consisted of 14 researchers and PhD students from different fields including forestry, ecology, hydrology, climatology, landscape ecology, economical geography, regional planning, tourism and civil engineering. They were involved in a PhD seminar in the Central Balkan case study area in July 2016, organised under the project “The Mountain - Models of Socio-economic and Cultural Development: Regional Challenges and Transborder Cooperation” of the Center of Excellence in the Humanities - Sofia University ”St. Kliment Ohridski”. After the fieldwork, they filled the matrix and their scores were collected in separate spreadsheets. The scores for each land cover/ES combination were calculated as an average of the all 14 spreadsheets.

Availability of data for the purposes of ES valuation at the municipal level is a problem significantly more serious than at the higher levels. National level statistics and Eurostat are better equipped with data for provisioning ES assessment; however, thematic limitations and information deficits do exist. Eurostat’s coverage of the local (LAU) scale is generally quite scant, so the demand is currently satisfied by data transfer methods which utilise the regional and national scales (NSI 2015a, NSI 2015b, NSI 2016, MAF 2014). At times, even global statistics are utilised through a procedure which greatly lowers the degree of valuation relevance and hampers its validation (Koulov et al. 2017).

ES research in Bulgaria can partially rely on local business activity data, such as tangible fixed assets, number of active enterprises and short-term business initiatives, as well as inputs and outputs data. In some instances, data are obtained from the internal statistics of individual business entities, state institutions and associations or previously conducted research projects (as is the case with the Central Balkan National Park Directorate and the investigation of Dimitrova et al. 2015 under the OP "Environment 2007-2013").

The contingent valuation method, using a survey of 12 questions, has also been used in the Apriltsi Municipality and the Kalofer Mayorality. It is primarily orientated towards determining the local population’s knowledge, preferences and dependences regarding ecosystem services.

Database optimisation involves results obtained by assessment of the ecological status and, respectively, the potential of ecosystems to provide services. It is based on analysis of information from: the assessment of the state of the habitat types represented in NATURA 2000 protected sites within the CLC Classes at the respective municipality (with respect to the criteria: biodiversity, typology, natural character, rarity, size, vulnerability and stability/instability), validated by field observation data.

To summarise, the employed system of valuation methods, some of which are used indirectly, includes: Contingent Valuation, Market Price, Value Transfer, Replacement Cost and Net Financial Contribution (NFCu). The selection of concrete methods depends mostly on the possibility and practicality of transferring data or using generalisation methods, as well as the spatial variations of ES under evaluation. The total economic value (TEV, €/ha/yr) of the selected services, which form the current and future basis of the local economy and the welfare of the population, on the territory of the Karlovo Municipality (Koulov et al. 2017) is calculated as a sum (Formula 1 - Fig. 4)

Figure 4.  

Formula 1.

where: TEV is total economic value of ecosystem services; n=11 is the number of the raster layers; ESVj is the economic value of ES class type j; and m is the number of ecosystem services class types in layer i. The fact that the actual provision of one ES is dynamically linked to the provision of other services has been accounted for in the analytical process, which accompanies the valuation. Additionally, the study above ventures to analyse the impact of existing dysergies on the ES flows and attempts to incorporate their financial value. Thus, an intermediate step has been included, where necessary, in the course of the valuation, which assesses the complex and dynamic character of ecosystem interactions and their mutual interdependencies.

For mapping purposes, the investigations interpret the CORINE Land Cover 2012 classes (NRC 2014) as geospatial units for identification of ecosystem types, classes and sub-classes (Maes et al. 2013) and next - for valuation of the ES classes and class types (CICES v4.3).

Flood regulation mapping and assessment

Flood regulation has been assessed in the Vidima Watershed which is located in the northern part of the Central Balkan case study area. Vidima River is the left tributary of Rositsa River which is the main tributary of Yantra River (see Fig. 1). The Vidima Watershed, upstream of the Town of Apriltsi covers an area of 7677.9 ha with an elevation ranging from 505 to 2375 m. A flood regulation ecosystem service can have preventing or mitigating functions. In the first case, the ecosystems (i.e. forests) redirect or absorb parts of the incoming water (from rainfall), reducing in such a way the surface runoff and, consequently, the amount of river discharge. This ecosystem service plays its role before flood occurrence and, in some cases, it can even prevent it. However, the flood mitigation function comes into effect when the flood has already taken place. The ecosystems (i.e. floodplains and wetlands) provide retention space for the water surplus to spill, thus reducing the flood's destructive power (Nedkov and Burkhard 2012). In a mountainous watershed with limited or no floodplains, such as Vidima, the prevention function is dominant. Therefore, the assessment should be directed to define the capacity of ecosystems in the watershed to retain part of the rainfall water.

The approach relies on GIS based hydrological modelling performed through the extension ArcGIS AGWA2. It incorporates the KINEROS model, which is suitable for application in relatively small (up to 100 km²) watersheds with predominantly surface runoff. The model simulates water balance parameters within the watershed, which are used to quantify the regulation function for the different ecosystems. The outputs of the model used as indicators for flood regulation are infiltration, surface runoff and peak flow. The transformation of the model results to land cover classes has been carried out following the approach proposed by Nedkov and Burkhard 2012. The capacities of the land cover classes were assessed on a relative scale ranging from 0 to 5 (after Burkhard et al. 2009).

Carbon storage mapping in urban ecosystems

Carbon storage is one of the most common indicators for assessing global climate regulation. It is defined as the amount of carbon stored in the vegetation and soil measured in tC/ha. For calculation and mapping of carbon storage of urban ecosystems in Bulgaria, Nedkov et al. 2017 developed an approach based on an integrated index of spatial structure of the urban ecosystems. It combines data from different ecosystem parameters in the GIS environment to build a spatial proxy model that allows calculation of carbon storage in high resolution at city level (Nedkov et al. 2017). For the town of Karlovo, the study uses the urban ecosystems database developed through TUNESinURB project. The amount of carbon for each polygon of the urban ecosystems database is calculated through an algorithm of six main steps. First, the green area of each polygon is calculated using vegetation cover index (percent) and the area of the polygon (in ha). Next, the green area is differentiated into grass, scrub and tree parts using the data from the land cover part of the integrated index. At the third step, the amount of carbon in grass, shrubs and trees is calculated using reference values from literature sources. At the next step, soil carbon is calculated using data from a digital soil map and reference values from literature sources (Koynov et al. 1998, Zhiyanski et al. 2013, Zhiyanski et al. 2015). The fifth step is calculation of the amount of carbon in tC per polygon and, at the final step, the amount of carbon per hectare (tC/ha) is calculated for each polygon of the database. More details of the calculation procedure are provided in Nedkov et al. 2017.

The results of hydrological modelling have been used to estimate the flood regulation capacities of land cover classes, according to the following three indicators: infiltration, peak flow and surface runoff (Table 2). For peak flow and surface runoff, lower water quantities mean higher capacity because more water has been retained by the landscape and less water goes to the surface runoff, respectively to river discharge. For infiltration, the relation is opposite, higher quantity means higher capacity as the water, which is infiltrated into the soil, does not go directly to the river discharge.

The capacity for flood regulation defined on the basis of modelling results has been calculated for the land cover classes in the studied watershed using a GIS-based procedure (Nedkov and Burkhard 2012). The overall relevant capacities of the land cover classes have been defined as average values between the capacities estimated on the basis of the three indicators presented in Table 3. The results show that very high capacity for flood regulation is calculated for coniferous and mixed forests (Table 3). Broad-leaved forests have high capacity while the Urban and the Bare rock classes have no capacity. In general, the land cover classes with higher vegetation cover exhibit higher capacities. This is due to their higher ability to “catch” and retain a larger share of the incoming precipitation water. The land cover classes with almost no vegetation cover (i.e. urban, bare rocks) have no relevant capacity.

The map of flood regulation supply capacities (Fig. 9) shows that the watershed of Vidima River has relatively high capacities for flood regulation. Areas of high and very high relevant capacities cover about 38% of the study area. They are located predominantly in the areas with higher elevation in the southern and central parts of the watershed. This is mainly due to

Figure 9.  

Flood regulation supply capacity in Vidima watershed (after Boyanova et al. 2014).

the relatively high share of forest land cover types in this area. The areas with low and no relevant capacities comprise about 15% of the watershed. They are located mainly in the northern part of the watershed where the river valley is wide and relatively flat which allows for more and larger urban and agricultural areas.

The urban ecosystems in the town of Karlovo have been identified and mapped according to the typology of the urban ecosystems developed by Zhiyanski et al. 2017. Seven, out of a total of ten, urban ecosystem subtypes were identified in the study area: J1 – Residential and public areas of cities and towns, J3 - Residential and public low density areas; J5 – Urban green areas (including sport and leisure facilities), J6 – Industrial cities (including commercial sites), J7 –Transport network and other constructed hard surfaced sites), J9 – Waste deposits, J10 – Highly artificial man-made water basins and associated structures. The last subtype is represented by only one small patch which is not representative and, therefore, has been excluded from the assessment calculations. The carbon storage capacity and its spatial distribution are almost exclusively determined by the land cover of the respective ecosystem and its area. The carbon storage (in C t/ha) has been calculated for each polygon of the urban ecosystems dataset using the approach based on an integrated index of spatial structure (Nedkov et al. 2017). For the town of Karlovo, the figures vary from 0 to 83.64 C t/ha. The polygons with 0 values have been defined as having no capacity for carbon storage. The other values have been distributed in five intervals from 1 (low capacity) to 5 (very high capacity) using the statistical method of the Natural Breaks (Table 4).

The results from Table 5 have been used to produce a map of carbon storage capacity in the town of Karlovo (Fig. 10). Very high capacity is determined for the urban parks with predominant tree vegetation, such as the “Apostolova gora” Park located in the north-western part of the town. The other parks in the central area with more grassland and the suburban areas with scattered buildings have high carbon storage capacity. The residential areas, located around the town centre, have low capacity. They are characterised by relatively compact mid-rise buildings and low vegetation cover (20-30%). The other residential areas, characterised by open low-rise buildings and moderate vegetation cover (40-60%) have relevant capacity (class 2). No capacity is defined for some of the transport network areas.

Figure 10.  

Map of carbon storage capacity in Karlovo.

The results of the calculation per polygons have been used to summarise the carbon storage in the different ecosystem subtypes, in the elements of the vegetation and soils, as well as in the town as a whole (Table 5). The overall amount of carbon in Karlovo is estimated at 49622 t. More than 70% of this amount is in the soil and the rest is in the tree vegetation. The amount of carbon in grass and shrubs is very low. The highest overall amount of carbon is in the residential and public low density areas (J3) and is due to their large area. The highest average amount of C t/h is in the green area (65.2) while the lowest is in the transport networks (10.7).