Monetary valuation of ecosystem services aims to shed light on the economic value of functioning ecosystem services – or the other way around – the costs of the degradation of ecosystems and their services. Difficulties in incorporating the economic value of ecosystem services into decision-making may result in decisions that are suboptimal in the long term – not only ecologically, but also econom-ically. Mapping the monetary values of ecosystem services means an examination of how values vary across geographical areas. In order to do that, mon-etary values need to be assigned to mapped eco-system service provisions based on some kind of biophysical assessment. Schägner et al. (2013) car-ried out a review of monetary valuation mapping studies and classified the studies based on the type of the ecosystem service supply mapping method and the type of the valuation method.
The methodologies used for mapping the value of ecosystem service supply were divided into five main categories:
(1) One-dimensional proxies for ecosystem ser-vices, such as land use and land cover.
(2) Non-validated models based on likely causal combinations of explanatory variables, of which there are no real world observations but the basis is researchers’ assumptions.
(3) Validated models calibrated based on pri-mary or secondary data on ecosystem service supply.
(4) Maps based on representative data from at least one real world observation to quantify ecosystem service supply.
(5) Implicit modelling of ecosystem service supply using a monetary value transfer fun-ction.
Methodologies for distributing values to mapped ecosystem service supply across the study area were grouped as follows:
(1) Unit values: a constant value per unit for ecosystem services.
(2) Adjusted unit values: values are adjusted ac-cording to simple variables, such as popula-tion density, income levels or consumer price index.
(3) Value functions: values base on functions using multiple spatial variables.
(4) Meta-analytic value function transfers: va-lues base on functions estimated through statistical regression analysis of the results of primary valuation studies.
A synthesis of the combinations of the methodol-ogy used for assessing ecosystem service supply and the methodology for valuation in the mapping studies reviewed is presented in Table 4.1.2. We grouped the mapped and valued ecosystem servic-es according to sections of the CICES classification (www.cices.eu) and separated biodiversity related studies. As can be seen from the table, using unit values is the most common value mapping meth-odology and its most common counterpart in as-sessing ecosystem service supply is using proxies.
The choice of ecosystem service valuation mapping methodology is dependent on the policy context or scientific purpose (as it defines the accuracy and precision required), scale, availability and quali-ty of data, and amount of resources and time. Al-though the simplest combination, proxies together with unit values, might produce error prone results (Eigenbrod et al. 2010), they can be completely ap-propriate for, for example, quickly proceeding land use planning processes, when applied correctly.
The more complicated the methodologies for map-ping ecosystem service supply and valuing it, the more attention should be paid to the interpretation and communication of the results to the users.
44 The Finnish Environment 1en | 2015
table 4.1.2. the number of studies using different ecosystem service valuation mapping methodologies and the ecosystem services mapped classified according to CiCes v.4.3 (modified from schägner et al. 2013).
ES mapping methodologiesBD, ES sectionsMapped ES∑Mapped ES∑Mapped ES∑Mapped ES∑ Biodiversity B:2222B: 3 3 Provisioning servicesAP: 14, F: 1, FO: 6, Hun: 1, RM: 18, T: 4, WS: 1926Non-T: 1, T: 11F: 1, HUN: 1; WS: 2 2 Regulation and maintenance servicesBC: 17, DP: 19, E: 19, GHG: 23, GR: 16, MC: 1, NC: 18, P: 17, SF: 18, WR: 19, WT: 18 26RM: 1; DP: 2; WT: 2 2 Cultural ecosystem servicesCUL: 20, R: 2123CUL: 1, R: 12CUL: 1, R: 22 CUL: 1, R: 1, 2 Biodiversity B:22 Provisioning servicesAP: 3, RM: 5, T:1, WS: 18AP: 1, T: 12 Regulation and maintenance servicesDP: 1, E: 3, GHG: 7, GR: 2, NC: 4, SF: 2, WR: 5, WT: 29 Cultural ecosystem servicesCUL: 1, R: 55CUL: 11R: 11 Biodiversity B: 11 Provisioning servicesAP: 2, F: 2, Hun: 1 5AP: 3, T: 23 Regulation and maintenance servicesGHG: 7, GR: 1, E: 2, MC: 1, NC: 1, WR: 4, WT: 313WT: 11DP:11 Cultural ecosystem servicesR: 33R: 44R: 11 Biodiversity B:11 Provisioning servicesAP: 3, F: 2, Non-T: 1, RM:1, WS: 17AP: 11 Regulation and maintenance servicesGHG: 11 Cultural ecosystem servicesR: 22R: 11 Biodiversity Provisioning servicesAP: 11 Regulation and maintenance servicesDP: 11 Cultural ecosystem servicesCUL: 3, R: 23CUL: 1, R: 22
Not applicable ES abbreviations: AP: agricultural production, B: biodiversity, BC: biological control, CUL: cultural (including amenity), DP: disturbance prevention (including storm protection, flood protection and avalanche protection), E: erosion control, F: fisheries, FO: food production, GHG: greenhouse gasses regulation, GR: gas regulation (atmospheric chemical composition), Hun: hunting, MC: microclimate regulation, NC: nutrient cycling, Non-T: non-timber forest products, P: pollination, R: recreation, RM: raw material, SF: soil formation, T: timber, WR: water regulation, WS: water supply, WT: waste treatment (including soil, air and water quality) ∑ represents the number of studies in which a specific combination of mapping and valuation methodologies was used to valuate various ES (grouped here in sections as listed in CICES v4.3, www.cices.eu, 2013)
Proxies Non-validated models Validated models Representative data Implicit modelingNot applicable
MethodologyValuation methodologies Unit valuesAdjusted unit valuesValue functionsMeta-analytic value functions
It should be noted that the aspect of demand for ecosystem services integrated with supply is miss-ing from the valuation mappmiss-ing methodologies presented above. The demand strongly affects the value of ecosystem services because it complicates the generalization of value over space. For exam-ple, the accessibility of areas changes the value of similar types of biophysical areas. A place that has great natural assets but is far away from users and reachable only with difficulty does not have the same value as a similar place in a favorable loca-tion. Cultural and personal differences in appreci-ation of various ecosystems and ecosystem services make valuation mapping even more intractable.
This is reflected in the low number of studies ded-icated to mapping the value of cultural ecosystem services (Table 4.1.2).
To allow for easier use of monetary valuation mapping, several tools or toolkits have been de-veloped. A few of them are presented below as an example.
• The InVest toolset (http://www.natural-capitalproject.org/InVEST.html) including sixteen distinct models suited to terrestrial, freshwater, and marine ecosystems is pro-bably the most well-known toolkit. InVEST is designed to help decision makers to assess quantified trade-offs associated with alter-native management choices and to identify areas where investment in natural capital can enhance human development and conserva-tion.
• ARIES modelling platform (Artificial Intelli-gence for Ecosystem Services) (http://www.
ariesonline.org/about/approach.html) maps the potential provision of ecosystem services (sources), their users (use), and biophysical features that can deplete service flows (sinks) using ecological process models or Bayesian models. Agent-based flow algorithms are us-ed to map actual service flow from ecosystems to people. ARIES offers several approaches for economic valuation of ecosystem services.
After computing values for a set of ecosystem services of interest, multiple services can be paired with priority weightings stated by the user, in a multiple criteria analysis that will yield maps of concordance of the computed flows of ecosystem services with the levels of provision desired by the user. Such maps can be considered an ‘abstract’ quantification of relative value. Alternatively, ES flow informa-tion can be used to build a transfer funcinforma-tion to translate previously assessed economic va-lues for specific benefits into estimated
valua-tion portfolios. The transfer funcvalua-tion operates on the aggregated values retrieved from the Ecosystem Services Database with the help of a neural network classification algorithm that identifies the most likely candidates based on ecological and economic similarities between source and destination areas.
• TESSA toolkit (Toolkit for Ecosystem Service Site-based Assessment) http://www.birdlife.
org/worldwide/science/assessing-ecosys-tem-services-tessa) provides guidance on low-cost methods for evaluating the benefits people receive from nature at particular sites in order to generate information that can be used to influence decision-making (Peh et al. 2013).
The toolkit helps users to select appropriate methods according to the site characteristics through decision trees. Over 50 methods are available for assessing ecosystem services in TESSA. With these it is possible to valuate an
‘alternative state’, to compare with the current site state and estimate the impact of potential or actual ecosystem service changes. Examples are given on how to derive a value (quanti-tative, qualitative) for each service, including the difference in value between two site states.
The toolkit offers guidance on assessing how benefits are spread across local, national and global communities and advice on disaggrega-ting values at the local level into measures that reveal potential inequities in the costs borne and benefits received.
• i-Tree (Tools for Assessing and Managing Community Forest) (https://www.itreetools.
org/about.php) is a software suite from the USDA Forest Service that provides urban fo-restry analysis and benefits assessment tools.
i-Tree tools help communities of all sizes to st-rengthen their urban forest management and advocacy efforts by quantifying the structure of community trees and the environmental services that trees provide. i-Tree offers six different analysis tools to quantify urban fo-rest structure, environmental effects, values to communities, quantify the monetary va-lue, simulate the effects of changes within a watershed on stream flow and water quality, model the effects of planting scenarios on fu-ture benefits, amongst other things.
Monetary valuation mapping is seen to be bene-ficial in creation of policy applications, like green accounting, land use policy evaluation, resource allocation, and payments for ecosystem services (Schägner et al. 2013).
46 The Finnish Environment 1en | 2015 4.2