Reaching the end of the European Union (EU) Biodiversity Strategy to 2020 [1
], and seven years after the publication of the multi-cited master document for Mapping and Assessment of Ecosystem and their Services (MAES) in the EU [2
], many EU Member States (MS) have developed methods (e.g., References [3
]) and conducted case studies (e.g., References [8
]) towards the implementation of Action 5 of Target 2 of the EU Biodiversity Strategy. From 2015 to 2018, the Horizon 2020 Coordination and Support Action, ESMERALDA (Enhancing ecoSysteM sERvices mApping for poLicy and Decision mAking), aimed at developing guidance and a flexible methodology to support the EU member states in the MAES implementation; more specifically, the main objective of ESMERALDA was to provide guidance for integrated mapping and assessment of ecosystem services (ES) that can be used for sustainable decision-making in policy, business, society, practice and science at EU, national and regional levels [11
]. In parallel, a collection of papers by Burkhard and Maes [13
] provides a comprehensive guidance for MAES implementation and in combination with the ever-updating MAES Explorer online [14
], that supports ecosystem ES research and proposes systematic ways of assessment, mapping and reporting for biophysical, economic and social aspects of ES applications (as well as for their possible wider integration). Furthermore, an operational framework for integrated MAES, developed by Burkhard et al. [16
], builds on the MAES common assessment framework [2
] and re-organizes it on the basis of specific, practical steps needed to be followed to ensure an integrated result, at EU and national levels.
For graphical representation and mapping of ES, a tiered approach is proposed by Grêt-Regamey et al. [17
], and updated in Burkhard and Maes [13
] (Chapter 5.6.1), to support MAES studies at standardized scales of detail and data availability. Thus, it is obvious that the methods and tools available for operationalizing Action 5 of Target 2 of the EU Biodiversity across and within MS should be urgently elaborated. However, Albert et al. [18
] highlighted that even with this guidance, national implementation of MAES requires the development of adapted sets of indicators that are most applicable to each respective context [19
]. Due to this need, a debate on national indicators [20
] and how they can be incorporated into policy, planning and management [22
] is still ongoing.
Indicators are also fundamental elements for ES monetary valuation and Natural Capital (NC) accounting. Some have continued to argue that monetary valuation of ES and NC is inappropriate, and we should preserve and protect nature strictly ‘for its own sake’, for its ‘intrinsic values’ [26
]. Costanza et al. [28
] point out that this perspective is itself an implicit valuation: it is simply arguing that nature is more valuable than any possible alternative. While in many cases this may be true, society has made decisions implying that this is not always the case [29
]. Through our historical and current interactions with the environment, in order to develop infrastructure and produce the goods necessary for contemporary life and well-being, we exploit ecosystems and impact NC. Thus, being more explicit about the value of ES and NC can help society make better decisions in the many cases in which trade-offs and complex conflicts exist [30
Simultaneously, everything in applied science, management and decision-making is data-dependent, as well as in need of interpretation. Throughout the relevant literature (e.g., References [7
]), it is highlighted that the crucial step for a successful MAES implementation is the identification, selection, elaboration and/or development of the appropriate indicators which capture in space and time ecosystems’ performance regarding their condition and the multitude of services and benefits they provide. Selecting the appropriate indicators is identified as one of the fundamental steps of the operational framework as proposed by Burkhard et al. [16
] and comprises a selection of (a) indicators for ecosystem condition (EC) and (b) indicators for ES.
The purpose of indicators is to measure and ascribe a value to the various dimensions [35
] of the complex ES concept [37
]. Simultaneously, the indicator and indicandum (i.e., the phenomenon of interest reflected by the indicator) should be correlated with one another and the variance should be low [33
]. It is clear that a common set of indicators cannot be applied across all the different ecosystem types; however, a standardized way of reporting ecosystem condition and ecosystem services at local, regional and national levels is important to support decision-making and strategic planning at MS and EU levels [2
]. MAES indicators should have specific characteristics in order to support robust ES studies and should be applicable for policy-relevant interpretation, with the capacity to inform a broad array of policies related to the use, conservation and preservation of natural resources [38
During the past five years, various studies guided by the MAES conceptual framework [2
] have been conducted in Greece, providing information for different types of ecosystems and applying different methodologies and tools for mapping and assessing ES at local (e.g., Reference [39
]), regional [40
] and national levels [41
]. In 2017, a group of scientists who believed in the importance of the MAES implementation (forming the Hellenic Ecosystem Partnership—HESP [45
]) drafted the National Agenda for the MAES implementation in Greece [34
] and set an Action Plan to 2020, including short- and mid-term objectives. Development and testing of a national set of indicators, by the end of 2020, is one of the mid-term objectives of the Agenda’s Action Plan needed to be accomplished for further MAES implementation in Greece. The Life Integrated Project with the acronym “LIFE-IP 4 Natura” [46
], led by the Hellenic Ministry of Environment and Energy, incorporates MAES implementation Actions at national, as well as at local (case-study) levels. These important developments towards standardizing MAES applications will also support NC accounting based on the System of Environmental Economic Accounting (SEEA)—Experimental Ecosystem Accounting [47
This work aims to (a) collect and review all available data from national, regional and local authorities, which can be used to identify, assess and map ES at the national scale, (b) evaluate the potential usability of these data directly, after sorting and processing, or consider part of them as inappropriate for further use, and (c) identify ES data hot-spots and data-scarce areas in Greece. The final goal of the study is to provide a pre-defined National Set of Indicators for the MAES implementation at the national level. This set of Indicators will form the official, national basis on which future studies will be conducted for MAES, reporting towards supporting the targets of the National and the EU biodiversity Strategy.
Inventory, classification and standardized description of ES is the basis for any effort to measure, map or value them, and it is also the basis of being transparent regarding our methods and findings, so that we may effectively communicate and critique results [66
]. However, the sheer number of ES and the correspondingly high number of indicators and large amounts of data needed for their assessment and valuation requires a pragmatic approach, such as the one proposed in the MAES indicators report, which focuses on using indicators supported by the available data [33
]. At the same time, other criteria, such as validity and policy relevance, also need to be fulfilled regardless of data availability: ignore these and the usefulness of the indicators is seriously compromised [37
]. Heink et al. [33
] claim that (a) it is essential to show how indicators are related to goals and to conceptual frameworks and (b) the validity and relevance of indicators is just as important as data availability, as well as to the extent that the policy makers understand them.
The present study complies with the above-mentioned requirements and follows the CSLF (Credibility, Salience, Legitimacy, Feasibility) approach, which provides criteria for developing ecosystem service indicators [69
]. Feasibility is of high importance in national ES assessments, since MS should (a) rapidly proceed with the baseline MAES status in their territory, (b) identify issues of importance regarding data gaps, management practices, trade-offs and/or sector policy conflicts and (c) move forward to detailed management-oriented and applied studies. Using available and feasible indicators and identifying data gaps avoids “paralysis by analysis” situations; taking such initiatives to apply indicators in practice also requires studying data gaps, risks, cultural idiosyncrasies and possible dysfunctions involved [70
Our proposed MAES indicator framework does have some limitations since we are at the beginning of its state-wide development in Greece. Some of the available data are based on an uneven sampling distribution, and there are data-scarcity and data-consistency issues in many areas [34
]; for example, higher quality information is available for some high-profile protected areas relative to the smaller and newer ones (e.g., Reference [72
]), and this is broadly evident in our ecosystem bundles analysis (Figure 4
). Moreover, work in the marine sector cannot at this time be fully integrated in this assessment framework since heterogeneity in data requirements, wide knowledge gaps and methodological limitations exist [34
]. Although there are numerous challenges in applying policy-relevant ecosystems services with standardized methods in marine ecosystems, these problems are actively being explored [74
]. Especially, in the Mediterranean MS, assessment approaches require careful considerations due to the diversity and intricacy of natural variability and cultural complexities [77
]. A particular challenge among the ES types are Cultural Ecosystem Services, especially their streamlined assessment at the national and regional scales [78
]. In our proposed MAES application, these are treated primarily within recreational values since it is difficult to survey other cultural services with any consistency on a state-wide scale (e.g., Reference [21
]). CES are important in providing various methods to engage stakeholder and local applications (where conflict areas may also be identified) (e.g., References [80
]). Obviously, we do not mean to degrade or denigrate other types of cultural ecosystem services [82
], and important aspects such as landscape quality, including aesthetics and other landscape-scale attributes, are being actively investigated (e.g., References [84
]). Many new methods and tools for landscape-scale analyses (e.g., References [87
]) and approaches incorporating assessments of non-material benefits to societal well-being are being developed and new indicators should be incorporated in our adaptive national framework in the near future.
Despite some limitations, based on the results of the study, we consider that the available data in Greece are appropriate for national scale MAES studies (tier 3 and tier 2) and are sufficiently informative to support decision-making for many forms of natural resources management. Especially within the Natura 2000 sites (27.5% of the terrestrial territory), data availability, administrative support and human resources are considered as of high capacity and the potential is high to prioritize the implementation of MAES studies within protected areas in the near future. In the frame of the LIFE-IP 4 Natura Project, detailed MAES studies will be implemented in selected sites, and the proposed indicators can be modified or altered to comply with local-level needs [89
]. Also, due to a variety of recently applied policy-relevant monitoring programs promoted in Greece, such as water body ecological quality monitoring applications [90
], the quality and quantity of perpetually updated data should rapidly increase. The drafted set of indicators and their spatial representation within an adaptive framework provide an adequate guide to support case-study sites’ selection and future ameliorations of assessment accuracy and precision.
Moreover, it was considered important to develop a standardized reporting methodology to EU authorities based on the 10 × 10 km EEA reference grid. Indicators’ thematic maps on ES, data gaps and compliance with policy-related requirements produced in this study serve as an appropriate way of reporting the MS status on ES. Using the common ES coding provided by the CICES system, relevant maps at the EU level can be produced and in this way, we can identify ES bundles and hotspot areas across EU territory.
The next steps should be to conduct a nation-wide field assessment of ES and EC, using a web-based platform that has been developed by the University of Patras, for the LIFE-IP 4 NATURA project [92
]. Plots within each EAA reference grid cell and for each ecosystem type are collected and this plots’ dataset will: (a) support data validation and update, (b) thematic representation of ES actual and potential supply, based on field data (c) spatial trim literature ES supply and demand data and (d) assist the identification of ecosystems in degraded condition. This action, combined with the National Set of Indicators assessments, is expected to provide the best available knowledge for ecosystem types and their services in Greece and thus support decision- and policy-making with robust scientific information. Elaborated trade-off analysis is also needed and highlighted as a next step for the LIFE-IP 4 NATURA project, at least at the national scale. Fully developed trade-off analyses at this preliminary stage of MAES applications should proceed with extra care, since some types of ES, such as cultural services, may not be adequately represented by the current indicator set in all ecosystem types. However, displaying ES indicators makes trade-offs explicit and this may help facilitate management plans and project planning decisions; also, through stakeholder participation [28
], this approach should promote sound value judgments at national and regional scales.
To summarize, drafting and implementing a National Set of Indicators in each MS is crucial at the country, as well as at the EU level, and provides (complementary to MAES): (a) assistance for implementing other Actions of the EU Biodiversity Strategy, (b) guidance on how to use information on ecosystem services in impact assessments or for policies needs and (c) the existing link of biodiversity and ecosystem condition to ecosystem services and human well-being. However, this set of indicators is not a “passe-partout” for the MAES implementation, and modifications and alterations should be welcome, assessed and considered for use at different scales. In fact, and as stated by Costanza et al. [28
], “there is not one right way to assess and value ecosystem services. There is, however, a wrong way, that is, not to do it at all”. We consider this must be an adaptive process that should involve incremental steps towards evolution, amelioration and frequent review of the efficiency, consistency and usefulness of the first set of chosen indicators.