The concept of sustainable forest management (SFM) was first used at the Earth Summit held in Rio de Janeiro (UNCED, 1992) in reference to a type of management that considers social and environmental values of forests and other products apart from wood (Wijewardana, 2008). However, there is not a universal definition of SFM (Varma et al., 2000); the relative importance of the different aspects that SFM covers varies depending on the natural and anthropogenic influences on each type of forest (Castañeda, 2000; Barbati et al., 2007). Criteria and indicators (C&I) constitute a tool to spread an understanding of SFM: they provide the means to translate sustainability principles into measurable goals and achievements (Wijewardana, 2008).

Monitoring and evaluation processes through C&I depend a lot on the subjectivity of the one who carries out the evaluation, its experience, values and interests. To overcome this weakness of existing C&I standards1, Pokorny & Adams (2003) suggest that the meaning of C&I has to be clear, which means that their writing should be simple, understandable and specific.

There is general agreement that international C&I standards cover the following thematic areas: (1) area of forest resources, (2) biodiversity conservation, (3) forest health and vitality, (4) and (5) productive and protective functions of forests, (6) social functions, and (7) legal, political and institutional framework (FAO, 2006). They are particularly weak in the social and cultural areas. This fact likely reflects the strong emphasis that forestry has traditionally placed on natural sciences and a perceived division over responsibility for the social elements of SFM (Gough et al., 2008).

In order to adapt a typology of ecosystem services to Mediterranean conditions, different studies proposing them were revised. The inputs came mainly from the Common International Classification on Ecosystem Services (CICES) document (UN, 2010) and PATFOR (Generalitat Valenciana, 2011a). The first of them is a proposal of a United Nations expert committee. PATFOR adapts other existing frameworks to Mediterranean forests. Tables 1, 2 and 3 constitute a classification with examples of ecosystem services, and the references consulted. Then, to identify forestry criteria that maintain and improve their provision, those examples and kinds of the classification whose supply was considered that could be improved through management actions2 were transformed into criteria (Table 4).

It was considered that the provisioning services category could be associated to the economic pillar of sustainable development, the regulating one to the ecological pillar and the cultural category to social issues. The criteria were classified in three groups: economic, social and ecological, according to the ecosystem services categories. The criteria are indicated next:

It can be seen in Table 4 that the criteria employment and working conditions and participatory processes have not been associated to any ecosystem service kind or example. This is because they constitute requirements of forest management and thus have to be included as criteria, even though they do not maintain or improve the provision of any ecosystem service. On the other hand, no criteria have been associated to the following ecosystem services kinds:

The reason for not including them is because they happen either in specific situations or as a result of the management for providing other ecosystem services. The first situation corresponds to noise pollution reduction, air quality regulation and fishing. The first two services are relevant for humans in forest that are close to urban and industrial areas; fishing takes place in forests located next to a river, and the management of fish populations is a competence of the Central Government (Gobierno de España, 2001). Air flow regulation, water quality regulation and nutrient cycling occur in forests where vegetation and soils are kept in good conditions; these conditions are taken into account in other criteria, therefore, there is no need to consider them explicitly.

Further references and legislation were revised for describing and explaining the criteria (Table 5). Later on, some forest management experts were consulted about the criteria and their descriptions. They were both invited to participate and explained what the research was about and which the objectives of the consultation were. Attached to the e-mail via which they were contacted, a file with the criteria was sent so that they were able to correct and comment on them. A total of 4 experts participated: 2 university academics and 2 civil servants. They were asked the following questions:

Next, to identify indicators of SFM, existing international C&I standards were revised: ATO/ITTO, 2003; UNDP/FAO/SADC, 1999; Montréal Process, 2007; ITTO, 2005; FAO, 1999; FAO, 1997; International Expert Meeting on Monitoring, Assessment and Reporting on the Progress towards Sustainable Forest Management, 2001; Kotwal et al., 2008; SFI, 2010; GTC-FSC, 2007; AENOR, 2007a; AENOR, 2007b. Other studies that propose C&I were also consulted (Table 7).

All the indicators taken from the review were classified according to the criteria identified. After this, indicators were rephrased to be simple and easily understandable, as recommended by Pokorny & Adams (2003). The last task consisted of proposing new indicators in the issues for which less attention had been paid in the literature.

Later on, a participatory process in Ayora, a village located 100km southwest from the city of Valencia, was carried out. Its objective was to test if the topics included by the C&I identified are comprehensive and realistic. For this step, and in order to facilitate the process to participants, the indicators were grouped into aspects, which are defined as the specific issues covered by a criterion. Their meaning is broader and their writing less technical than that of the indicators.

The process was open to anyone living there. Participants were asked to value the criteria and, for each criterion, the aspects that it covers. They valued according to their management preferences for a public forest located in the municipality of the village, which is called La Hunde y La Palomera. Several authors of academic papers propose to identify and pre-select C&I based on relevant literature, followed by a process of verification or refinement by stakeholders (Kurka & Blackwood, 2013).

The participatory process was publicly announced hanging papers on walls and shop windows, and it was advertised in the local radio. Local associations whose interests are related to forest management or forest conservation were personally contacted (via telephone or face-to-face) in order to get a representation of the different stakeholders involved.

Figure 1 displays the structure of the proposed standard for this research. Every participant received a questionnaire with 19 questions, each of them containing a list of elements to value: 15 questions to value the aspects of each criterion, 3 questions to value the criteria of each group and 1 question to value the three groups of criteria.

The weighting method selected corresponds to a multi-criteria analysis (MCA) technique described by Gómez-Orea (2002) that is applied when participants are asked to value the elements of a list according to a predetermined scale whose values can be repeated. The elements of any question are valued giving a 1 to the most important for the participant and so progressively. As mentioned, the weighting method allowed participants to repeat values: for example, in a question comprising 7 elements, these could be valued 3-4-2-2-1-5-1; this would mean that for that participant there are two elements in the first order of importance and two in the second.

The aggregated weights of every aspect and every criterion, which take into account the values from all participants, are calculated following the method recommended by Gómez-Orea (2002). This method implies that the higher the value the better. However, in this research the lowest value (1) is the best. Therefore, the scale of the answers was inverted like this: value 1 changes into the number of elements of the list and it reduces progressively (this way the answers look like participants had valued according to a scale that equals the number of elements of the list). In the example aforementioned, it would be like asking participants to value 7 elements in a scale from 1 to7, the inverted scale would be:

1→7

2→6

3→5

4→4

5→3

6→2

7→1

The previous scheme shows for this example how would the values of the answers change when inverting the scale: on the left are the old values and on the right the new ones. The result would be 5-4-6-6-7-3-7. The inversion of the scales was done for all the questions of all the participants. Next, aggregated weights were calculated according to the method indicated, which consists of the following steps:

This research dives into the considerations of SFM under Mediterranean conditions. A collection of 15 criteria applicable at the FMU level have been identified. These criteria intend to maintain and improve the provision of ecosystem services and cover the three pillars of SFM: economic, social and ecological. The existing C&I standards treat mainly ecological and resource quantity topics.

An assortment of 7 of the criteria identified in this research is social. The relevance of this type of issues is emphasized by other works. A similar study developed by Maroto et al. (2013) in the same region as this research (Valencia), but applied at a regional scale, highlights that social criteria of SFM are more important than economic ones for most stakeholder groups. Likewise, in a Mexican local community case study, the health of the forest was highly respected because the forest represented community pride, spiritual enjoyment, personal health and family cohesion. The researchers of this case study argued that the social dimensions of sustainability are more important where the economic role of forestry activities is marginal, like in most Mediterranean forests (Rodriguez-Piñeros & Lewis, 2013).

Ecosystem services are important in forests under all type of conditions. However, in Mediterranean forests they gain relevance because their productivity is low but the society appreciates and benefits from these services. Besides, the special characteristics of these forests make some of the ecosystem services, and therefore their associated criteria, very relevant:

Apart from the benefits mentioned, applying an ecosystem services classification into the thinking of SFM has the advantage of encouraging an integrated approach with other land uses: a common language across sectors and more explicit focus on trade-offs and synergies. Nevertheless, it could happen that an incomplete valuation of the services pushes attention on the ones that are already quantified and monetised. Besides, emerging markets for single services may discourage multifunctional forests (Quine et al., 2013).

Regarding the indicators, an effort has been made for them to be simple and easy to know what has to be measured or considered. These two characteristics are hardly found in existing standards. For example, the indicators of FSC-Spain (GTC-FSC, 2007) are perceived as clear in what they refer to but made of very long sentences. On the other hand, the indicators of PEFC-Spain (AENOR, 2007a; AENOR, 2007b) are seen like having a simpler wording, quite clear in their objectives, but less clear on what variables or qualities to look at. The standard proposed in this work just intends to offer another option for forest managers that overcomes these perceived weaknesses, but not to stay above the work developed by others.

Concerning the participatory process developed to verify that the issues addressed by the C&I proposed are sensible, the groups of participants are representative of the stakeholders related to the forest. However, the amount of members in each group is not even but, on the whole, the total number of participants is considered enough to draw conclusions. Results reveal that participants value ecological issues on top, followed by social ones, and noticeably economic ones at the bottom. The study by Maroto et al. (2013) also acknowledges the lesser relevance of economic criteria and the greater importance of ecological criteria in sustainable and participative management of Mediterranean forests.

With respect to the valuing and aggregation method, Mendoza & Prabhu (2000) conclude that MCA techniques are excellent for prioritizing a list of C&I. They describe two similar methods (ranking and rating) for establishing a hierarchy among principles and criteria (similar to criteria and aspects, as it has been done in this research). The aggregated weights that result from the participatory process show that participants cannot establish preferences easily. Therefore, few priorities can be made among criteria and aspects but, on the other hand, it suggests that the standard proposed is applicable. Similarly, Mendoza & Prabhu (2000) propose the use of the Analytic Hierarchy Process (AHP) as the one most involved and also providing the most information but also most complex and time consuming. They recommend the use of AHP to examine the relative weights at the indicator level because it is there where the principles and criteria are measurable and observable, and this is how it is intended to proceed with this research in next stages.

A similar study to this one shows that the methods followed is quite common and that the indicators presented here constitute a starting point from which more work is needed. Maes et al. (2011) developed an indicator framework to be applied at stand level in Flanders (Belgium). Their framework was set up by the authors and a few experts, resulting in 19 criteria and 157 indicators, which were selected from literature and assigned to a criterion. Later on, a validation step was carried out. In words of Maes et al. (2011), only a validation procedure can transform a potential set of indicators into a suitable set. Future steps of this research will consider the performance of the indicators in a specific FMU for different management scenarios.

This research set out to identify C&I of SFM under Mediterranean conditions, adapted to an ecosystem services framework, and applicable at the FMU level. The process followed for the identification includes literature review of themes related to the research topic, an expert consultation to improve a set of criteria previously proposed and a participatory process to verify the issues considered in the C&I set. A standard comprising 15 criteria and 133 indicators has been developed as a result.

SFM is based on the multifunctional use and exploitation of forests and it considers the social and environmental implications and consequences associated to forestry. The concept of SFM and its application have to be adapted to the particular conditions of each case; this is especially relevant in Mediterranean forests due to their specific characteristics.

Existing C&I standards and studies focus on the ecological and productive issues of SFM; social and cultural ones usually appear all together in a single criterion. The development of a C&I standard based on the maintenance and enhancement of the provision of ecosystem services searches for a balance among the three pillars of sustainability: economic, social and ecological. The criteria identified in this research adapt to an ecosystem services classification and so they cover these three pillars. The indicators proposed overcome another shortfall of existing C&I standards, whose wording is ambiguous and long. A big effort has been done for the indicators to have a simple and specific writing.

The results of the participatory process do not reveal big differences for most of the aggregated weights of the elements of the different questions. This findings make it difficult to establish priorities among criteria and aspects, but also suggest that the topics covered by the C&I proposed are suitable to Mediterranean conditions and that a standard adapted to ecosystem services is applicable.

This work has been conceived as an exploratory research. It has included top-down and bottom-up approaches to develop a proposal of C&I, which serves as a checklist of “what to look at” when managing Mediterranean forests sustainably. However, it remains to be seen whether the selected C&I can be successfully employed for decision making processes, by testing them in different scenarios in a specific case study. Besides, more case studies are needed to develop a general set applicable in Spanish forests under Mediterranean conditions. Nevertheless, this proposed set can serve for similar research or decision making situations as a starting point for C&I pre-selection. C&I constitute a piece of the puzzle; a sustainable management based on ecosystem services depends upon many drivers, not all of them coming from the forest sector (subsidies, payments for ecosystem services).