INSIGHT INTO CULTURAL ECOSYSTEM SERVICES: COMPREHENSIVE REVIEW THROUGH CLUSTER ANALYSIS

The nature of an ecosystem shapes human culture, heritage, values, social interactions and knowledge systems as well as amenity services (i.e. aesthetic, tourism and recreation, artistic, spiritual and intellectual development) considerably; thus, any changes in an ecosystem can have significant impacts on cultural services for societies. In light of this, this paper presents the outcome of a comprehensive review of literature focusing on the current status of cultural ecosystem services (CES) and the various conceptual, ideological and methodological approaches developed and used in this context. The literature on CES covering the 2009-2016 period was screened with the aid of a structured questionnaire which was developed, pre-rested and modified to fit the purpose. An Agglomerative Hierarchical Cluster Analysis characterised by Binary Squared Euclidian distance with Centroid Clustering method was employed to analyse the responses to the questionnaire, and the result was further supported and interpreted by way of qualitative discussion. The review, as a whole, identified the importance of CES and acknowledged its contribution to wellbeing as peripherals to a bundle of services. It recognised that most studies on this phenomenon were not limited to a specific region and/or on a specific system and were rarely quantified. Further, it was remarked that those studies did not value the ecosystems very often in monetary terms, but tended towards areas like mapping and cultural landscape.

CES have been similarly defined as contributions to the nonmaterial benefits that arise from human ecosystem relationships (Chan, et al., 2012a) as well as the services that contribute to human wellbeing because of the existence of a particular interpretive 'lens' that has its roots in cultural background (Baulcomb, et al., 2015). These services demonstrate a significant relationship between ecosystem structures and functions specified in the biophysical domain and the satisfaction of human needs and wants (Daniel, et al., 2012). As an approach to define the 'culture in ecosystems, cultural heritage refers to complex activities of life, including those beliefs, values, customs and traditions that are embodied in folklore and ethnography or communal creations such as dances, songs, myths and designs (Tolentino, 2007). Furthermore, cultural services are recognised as the strongest incentives for developed communities to become involved in environmental conservation (Schaich, et al., 2010;Morcillo, et al., 2013;Chan, et al., 2012a).
Alternatively CES were addressed in the concept of natural capital as a metaphor to elicit values of nature which are not directly quantifiable in monetary terms i.e. amenity, health, education, symbolic meanings (Chiesura & Groot, 2003). These belong to the ethical, spiritual and affective realm of human beings, which reflect the intangible dimensions of their relation with nature. The importance of cultural services has consistently been recognised, but infrequently assessed due to its inherent characteristics. Those are intangible, subjective, invisible and nonmarket goods, which are difficult to quantify in biophysical or monetary terms. (Daniel, et al., 2012;Lopez, et al., 2009;Baulcomb, et al., 2015;Pleasant, et al., 2014).
The analysis of global values of ecosystems (Groot, et al., 2012) gives an overview of the value of ecosystem services of 10 main biomes (or subsystems). The study (Groot, et al., 2012) provides the values in monetary units. There are 665 value estimates on provisioning, regulating, habitat and cultural services (145 estimates) described as follows (Table 1). Source: (Groot, et al., 2012).
Among the 145 estimates, the majority found were for recreation (84%). The estimates were derived through contingent valuation (35%), direct market (33%), travel cost (16%), other (6%), Hedonic (2%) and group valuation (0.6%) methods. Table 2 shows a summary of the monetary values for each sub cultural service per biome which are presented as 'averages'. The highest economic values were recorded in coastal reefs, inland wetlands, coastal wetland and fresh water systems.
Thus the cultural service has a substantial contribution in total value of a particular ecosystem. But the intangible nature of cultural services hinders its value from the total ecosystem value. Therefore it is worthwhile to review, the literature on CES, rather than a general review of ecosystem services. Therefore this review explores the current status of CES in terms of conceptual frameworks and methodologies in literature, which allow to identify the conceptual, ideological and methodological approaches that has not been explored yet. Source: (Groot, et al., 2012).

METHODOLOGY
This study is a primary review of the publications which explicitly deal with CES. A comprehensive search was performed using Google Scholar to search peer-reviewed journal papers and publications that studied CES (search term: cultural ecosystem services). We confined the study to items published between January 2009 and January 2016, irrelevant to a particular journal or region. Further the study was limited to the articles that contained 'CES' in its title or among their keywords. The recreation and ecotourism service is often considered, but classified as a provisioning service rather than a cultural service. Therefore the articles that describe some of the subcategories of CES (i.e. tourism, recreation and landscape) but do not recognise them as cultural services, or studies that do not use cultural services in their terminology are excluded from the study. As the final point, 45 papers were subject to in-depth analysis. Those publications that explicitly deal with CES were taken as the study sample, and the contents of each were perused in line with a questionnaire designed to gather structured information on the literature reviewed. The questionnaire classified cultural services under ten categories as established in the Millennium Ecosystem Assessment. To gain a deeper understanding, the questions were developed to identify ecosystem services bundling, mapping, subcategories of CES, and subsystems in ecosystems, conceptual frameworks and different valuation approaches. It was difficult to individually contemplate all 45 articles. Therefore seven characteristic questions were used in an agglomerative hierarchical cluster analysis through Binary, Squared Euclidian distance with Centroid clustering method. Those seven characteristic questions that were best addressed to identify the ideology and methodology of the publication were accounted for as the variables of the study. The measures of the characteristics were taken as Binary solutions (if present 1; if absent 0). Best fit cutting points of the clusters were designated to minimise the variance within a group and to maximise the variance between groups. Similar groups that were identified through cluster analysis were interpreted and supported by qualitative discussions.

Figure 2: Cultural Service Studies on Ecosystems
Approximately half of the studies discuss cultural services in general, although these services should be articulated according to the specific type of ecosystems. There are systems (coastal, urban, forest) with significant levels of cultural diversity that are under threat from humans: a situation which should be addressed with vigour.
According to the review more than one fourth of the studies were not based in a specific region, while a majority of the studies (n=19) was based in Europe ( Figure 3). There is a lack of attention towards regions with significant levels of cultural diversity (Asia and Africa) that are at present under threat from humans and that need to be treated separately.
Twenty six publications discussed specific drivers promoting change of CES, either directly or indirectly. Seventeen publications presented ways to map CES (Tenerelli, et al., 2016;Berkel & Verburg, 2014;Giannecchini, et al., 2009;Plieninger, et al., 2013a;Groot, et al., 2010) and 22 acknowledged the contribution of CES to wellbeing. One third of publications (n=30) were assessed by accounting CES as a sole category and only 15 publications have made an attempt to figure out subservices as a discrete service bundle of CES ( Figure 4). Thus in literature, CES and their drivers of change have been sufficiently acknowledged, but its sub services have not been critically assessed. Further there are only a few studies with methods to map CES, which result in a huge gap in identifying those services. Recreation and ecotourism subcategories together with aesthetic were investigated more frequently in literature. The subservices, namely knowledge systems, education, sense of place, social relation, cultural and heritage values were not found in any article. Fourteen studies had no empirical method in either qualitative or quantitative form. There were qualitative (n=15), quantitative (n=14) as well as mixed (n=2) methodologies used across the sample.
There were seven publications that have derived an economic value for cultural services in relation to the recreation and ecotourism values that were derived through the revealed preference methods. The cultural landscape seems to be an area of research which is rapidly growing, with more than half of all studies surveyed dealing with the concept (Tenerelli, et al., 2016;Schaich, et al., 2010;Tengberg, et al., 2012;Hartel, et al., 2014;Berkel & Verburg, 2014;López-Santiago, et al., 2014;Plieninger, et al., 2014;Groot, et al., 2010;Pleasant, et al., 2014;Turner, et al., 2014 ). There were only five tradeoff analyses with in-depth discussions, often in relation to the tradeoffs among the ecosystem services but with very rare incidents of tradeoff among cultural services or stakeholders.

Cluster Analysis
Six meaningful clusters were developed to minimise the variance within the cluster and to maximise the variance between clusters ( Figure 5). The clusters are as follows: (a) Meta studies; (b) Conceptual studies; (c) Descriptive studies; (d) Qualitative studies; (e) Noneconomic studies and; (f) Economic studies. They will each be described in order.

a. Meta Studies
Meta studies are those with no conceptual framework or model which describe the large number of studies in literature using either qualitative, quantitative or semi-quantitative methods. These studies are a comprehensive review of literature and the smallest cluster consists of only three publications (Milcu, et al., 2013;Morcillo, et al., 2013;Schaich, et al., 2010). Milcu et al. (2013) is a comprehensive review of literature of CES studies. The study included service providers, geographical distribution, CES subcategories, methods, and drivers of change. The numbers of publications in each category are relatively higher in comparison with the numbers that we derived in our study. This is due to the fact that our search term is restricted only to the CES (the study was limited to articles that contained 'CES' in its title or among its keywords).  Morcillo et al. (2013) is an empirical meta-study of cultural ecosystem service indicators that intends to investigate the current state of cultural services by accounting and appraising existing indicators. The review builds on scientifically recognised frameworks (Roche, 1999) to develop a holistic understanding of how cultural services indicators are conceived within ecosystem services research. The selected relevant indicators in accordance with the ecosystem services classification framework are summarised in Table 3. Further the study contains the 10 indicators which obtained the best ratings in quality assessment (Table 4). Schaich et al. (2010) is a qualitative empirical meta-study of cultural landscape, which is a top indicator and a growing research area in CES. The study includes a broad discussion and a comparison of the objectives, approaches, and methodologies adopted by ecosystem services research and cultural landscape research. The term 'cultural landscape' is defined and supported through many references as the interface between nature and culture, tangible and intangible heritage, biological and cultural diversity that can be understood as a social-ecological system, where the social, economic, and environmental components are closely interlinked. The study compares two types of categories: (a) publications that contain ecosystem services as a keyword; and (b) publications that contains cultural landscape as the keyword. Cultural landscape was found to be documented 50 years before ecosystem services was documented, but was still behind in terms of the total number of publications as well as the mean number of citations per paper.

b. Conceptual Studies
There were two conceptual studies that outlines a framework to address cultural services within the ecosystem framework (Daniel, et al., 2012;Chan, et al., 2012a). Daniel et al. (2012) provide a foundation for merging ecological and social science epistemologies to define and integrate cultural services better within the broader ES framework ( Figure 6). This presents the cultural service categories in terms of the relevance of ecological structures and functions for their formation. There were three assessment methods i.e. (a) monetary assessments (b) quantitative (nonmonetary) assessments, and (c) comprehensive studies of the human nature interaction that was based on scope and may extend beyond the other classes.  (Morcillo, et al., 2013).  (Ceperley, et al., 2010) Cultural landscape Sacred sites b. (Wang, et al., 2010) Recreation and ecotourism Travel costs c. (Jim, 2006) Landscape Intrinsic tree attributes and related tree-condition d. (Ingold & Zimmermann, 2010) Recreation and ecotourism Infrastructure facilities e. (Wang, et al., 2010) Education and knowledge systems

Figure 6: Ecological and Social Science Epistemologies in CES
Source: (Daniel, et al., 2012). Fish et al. (2016) specifically discuss a conceptual framework for understanding CES and related benefits in terms of the environmental spaces and cultural practices that arise from interactions between humans and ecosystems ( Figure 9). The overall argument is that environmental spaces and cultural practices should be considered as mutually reinforcing CES through which cultural benefits to wellbeing accrue. Those elements (culture, spaces, practices, benefits, cultural values) shape and reflect CES, and provide researchers and decision makers with a framework by which to understand the cultural significance of ecosystems.
Two studies outline the relationship between the cultural services and landscape planning (Tengberg, et al., 2012;Groot, et al., 2012). Tengberg et al. (2012) aim to provide a conceptual analysis of CES and how they are linked to the concepts of landscape, heritage and identity ( Figure 10). De Groot et al. (2010) provide a framework for integrated ecosystem services and values in landscape planning, management and decision making (Figure 11).

Figure 7: Conceptual Framework to derive Values of CES
Source: (Chan, et al., 2012a). Christopher et al. (2014) evaluate two contrasting paradigms for the assessment of social values: (a) instrumental paradigm -an objective assessment of the distribution, type or intensity of values that individuals assign; and (b) deliberative paradigm -the exploration of desired end states through group discussion (Raymond, et al., 2014).

Decision
Clarify who is making the decision and why?

Consent
Obtain and maintain a license to operate

Benefits, Ecosystem Services and Values
Identify the benefits associated with ecosystems; how they are produced through socio-ecological interactions; and why and how much they matter to people (values)

Sociological Context
Describe the biophysical, social and socio-ecological context of the decision

Influence Diagram
Characterise the connections between possible decisions, sociological components, ecosystem services, and values

B. Cultural Landscape
Heritage Landscape memory/identity

A. Cultural Ecosystem Services (CES)
Heritage values Identity

D. Spatial & Physical Planning
Implementation of MEAs

c. Descriptive Studies
Descriptive studies (n=7) contained neither quantitative nor qualitative methods in the form of empirical study. The studies in this group explain some of the phenomena in CES and are frequently backed by many references. They often include discussions on challenges in incorporating cultural services in ecosystem and environmental assessments and ways of doing so (Satz, et al., 2013), limitations in such incorporation (H. Winthrop, 2014) and CES as an approach to sustainable planning as well as development (Andersson, et al., 2015;Plieninger, et al., 2015;Ghermandi, et al., 2009).

d. Qualitative Studies
This is the largest cluster of publications (n=12), and in these, the empirical studies dealt with localised outcomes of advanced qualitative arguments documented on CES.

CONCLUSIONS
In literature, ecosystem services have often been examined and the pluralities of those values have been tiered in recognising, demonstrating, and capturing the ecosystem services in policy making. CES as an ecosystem service is a relatively new field that has not been specifically acknowledged in literature and has mostly been treated in general. The objective of this study was to examine literature to identify the current status of CES in terms of conceptual frameworks and methodologies which allow us to identify the conceptual, ideological and methodological approaches that have not been explored in literature.
According to the review most studies were not specific to a region or system, although there were some regions (Asia and Africa) and systems (urban, coastal, forest) with significant levels of cultural diversity that were under threat from humans and which therefore needed to be treated separately. CES were searched as peripherals in bundle of services and most of the methodologically and theoretically important facets has not been explored yet. CES cannot be split into discrete units for marginal valuation and is difficult to measure. Therefore most of the studies are qualitative studies which acknowledged a contribution to wellbeing but rarely quantified it. Further the most frequently quantified subcultural services were the most easily quantifiable (recreation, tourism and aesthetic), but not those which matter to people. There is an occasional incidence of economic valuation, often in relation to recreation and tourism services. Cultural landscape seems to be an increasing research area that can be incorporated into the field of CES research. Review provides many principles that can be used in developing an economic valuation framework for CES.