analysed the importance of three cloud forest reserves in central Colombia as providers of ecosystem services, as well as the social support to conservation ...
Reg Environ Change DOI 10.1007/s10113-012-0379-1
ORIGINAL ARTICLE
Social preferences towards ecosystem services provided by cloud forests in the neotropics: implications for conservation strategies Diego Higuera • Berta Martı´n-Lo´pez Andre´s Sa´nchez-Jabba
•
Received: 24 February 2012 / Accepted: 14 November 2012 Ó Springer-Verlag Berlin Heidelberg 2012
Abstract Despite the importance of neotropical cloud forests as providers of ecosystem services to society, they are one of the most threatened ecosystems in the world. We analysed the importance of three cloud forest reserves in central Colombia as providers of ecosystem services, as well as the social support to conservation actions in these ecosystems through willingness to pay (WTP) and willingness to give up time (WTT) estimates. Our results highlight the high commitment of all users of the cloud forest areas towards the conservation of the ecosystem services provided by these strategic ecosystems. We found that the most important perceived ecosystem services were water supply and habitat maintenance for species. Our findings also suggest that the respondents’ ecological knowledge (measured as the awareness of the ecosystem services supplied by cloud forests) was an important factor in determining both WTP and WTT for conserving cloud forests. Moreover, our results indicate that WTT should be a viable technique to explore individual preferences of different stakeholders towards conservation activities in cloud forests. Based on our results, we propose a conservation strategy of cloud forests that considers different users’ socio-economic and environmental characteristics, Electronic supplementary material The online version of this article (doi:10.1007/s10113-012-0379-1) contains supplementary material, which is available to authorized users. D. Higuera (&) A. Sa´nchez-Jabba Corporacio´n Sentido Natural, Bogota´ D.C., Colombia e-mail: higuera@sentidonatural.org B. Martı´n-Lo´pez (&) Social-Ecological Systems Laboratory, Department of Ecology, c. Darwin, 2. Edificio Biologı´a, Universidad Auto´noma de Madrid, 28049 Madrid, Spain e-mail: berta.martin@uam.es
in which both experimental and experiential knowledge should be incorporated in order to promote collective action. Keywords Cloud forests Ecosystem services Tropical Andes Willingness to give up time Willingness to pay
Introduction Eleven per cent of the tropical forests around the world are represented by montane and sub-montane cloud forests located in Central/South America, Africa, Southeast Asia, and the Pacific Islands (Doumenge et al. 1995). It is estimated that only 2.5 % of the world’s montane and submontane forests are actually cloud forests, so cloud forests occupy only 0.3 % of the earth’s surface (Bubb et al. 2004). However, cloud forests contain a major source of biodiversity, and 10 % of the world’s bird species with restricted distributions can be found in cloud forests (Armenteras et al. 2007). In Colombia, recent estimates suggest that cloud forests cover an area of 1,522.81 hectares (Mulligan and Burke 2005). This makes Colombia one of the countries with the highest cloud forest area in the world. Therefore, the protection and recovery of cloud forest habitats in Colombia is one of the most important challenges for the international conservation agenda because of their importance in terms of biodiversity, water supply, and their influence on water quality (Bonnell and Bruijnzeel 2005; Bruijnzeel 2004). Despite their importance for human populations, cloud forests are threatened to an advanced degree. Most threats are a result of production activities that generate isolation and fragmentation of these habitats. For instance, 90 % of the northern Andes cloud forests in Colombia have been
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converted to farming and pasture lands (Doumenge et al. 1995). Moreover, despite their importance and high degree of threat, very little is known about the ecosystem services supplied by cloud forests to humans (Armenteras et al. 2007; Guariguata and Balvanera 2009). Overall, cloud forests supply three main types of ecosystem services: provisioning, regulating, and cultural services (MA 2005). Regarding provisioning services, cloud forests are a water source that supplies drinkable high-quality water to nearby communities, as Martı´nez et al. (2009) show in tropical areas of Mexico. Regarding regulating services, cloud forests deliver an important water regulation service because they capture extra water as a result of their direct contact with the clouds, that is, cloud-stripping. The extra water obtained from cloud-stripping is generally equivalent to 15–20 % of ordinary rainfall, but it can reach 50–60 % in more exposed conditions (Aldrich and Hostettler 2000). The key function of cloud forests as providers of hydrologic regulation and security barriers against soil erosion is increasingly being recognised. In addition, because of their increased richness and abundance of plant species, cloud forests help to control, mitigate, and prevent soil erosion from water floods. Furthermore, the high number of dead and fallen leaves facilitates a continuous soil decomposition process, favouring nutrient accumulation and thereby soil fertility. Additionally, cloud forests perform a very important role in carbon sequestration and storage and consequently contribute to air purification (Higuera and Martı´nez 2006; Thompson et al. 2009). Finally, cultural services, such as nature tourism, landscape enjoyment, scientific research, and environmental education, have been promoted in many privately owned cloud forest reserves of Latin America (Aldrich and Hostettler 2000). Because of the fact that most of the ecosystem services provided by cloud forests are not considered in decisionmaking process, these ecosystems are being converted to other land uses on the basis of short-term financial gain rather than their long-term conservation value to society (de Groot 2006). In this context, the contingent valuation technique should be used to estimate the value placed on non-marketed ecosystem services (Mitchell and Carson 1989). This method typically asks individuals to state their willingness to pay (WTP) for an increase in the provision of a public good or the avoidance of a public damage. Three of the major problems of using WTP in environmental management are as follows: (1) it attempts to assign a monetary value to environmental assets that are considered incommensurable (Sagoff 1998); (2) there is no reference standard (i.e. what individuals would actually pay); and, most importantly, (3) basic needs have not been met in developing countries or in rural communities, so WTP is not a realistic vehicle payment (van Hore 1996). In fact, many
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developing countries or rural societies have informal or subsistence economies, in which people may have little experience of dealing with money (Pascual et al. 2010). Therefore, there is a key challenge regarding ecosystem services valuation in developing countries and rural societies to address this issue by estimating WTP in terms of other measures. Here, we used an alternative approach to obtain a time value through the metric of willingness to give up time (WTT) for conservation activities that contribute to the ecosystem services delivery in the cloud forest reserves. The potential advantage of using time instead of money is that it may be less value-laden (van Helvoort-Postulart et al. 2009). Although both elicitation methods intend to measure individuals’ preferences, few studies in the discipline of Health Economics have explored both WTP and WTT (e.g. Barner et al. 1999; Johannesson 1992; van Helvoort-Postulart et al. 2009) and, to our knowledge, only one empirical study has addressed valuation of ecosystem services through WTT elicitation format (Notaro and Paletto 2011). Here, we used both WTP and WTT to explore social preferences towards the conservation of cloud forests and the ecosystem services they provided, rather than indicators of economic preferences. This argument was previously developed by Kahneman and Ritov (1994) and Kahneman et al. (1999). The purpose of this study is to evaluate how important are the cloud forests of the Tequendama Fault (Colombia) for the stakeholders who use or enjoy the ecosystem services delivered by them. To address this objective, we specifically focused on three objectives: (1) to identify and classify the ecosystem service users in the cloud forest of the Tequendama Fault, (2) to analyse the social perception of users of the importance of cloud forests as ecosystem services providers, and (3) to estimate the conservation value of cloud forests as ecosystem service providers through the WTP and WTT estimates. We analysed the following ecosystem services: (1) provisioning services (e.g. providing drinkable water); (2) regulating services, including air purification, micro-climate regulation, soil fertility, erosion control, and habitat for important species; and (3) cultural services, such as nature tourism, environmental education, and aesthetic value associated with the landscape.
Methods Study area: Tequendama Fault The Tequendama Fault is located on the western slope of the eastern Andes mountain range, in the state of Cundinamarca (at the south-west border of the Bogota Plateau). This geological fault extends north-west for approximately
Social preferences
80 km and falls abruptly to the Magdalena River Valley (Fig. 1). A series of cloud forests with some fragmentation can be found across the fault line. This area constitutes one of the few remaining types of natural habitats in the state of Cundinamarca. Within the fault, there is a series of cloud forests on private land, as well as on public land. In this study, we selected three private areas of cloud forest: (1) Chicaque Natural Park, which has an area of 300 hectares that is mostly represented by cloud forest habitats; (2) Macanal Reserve, with an area of 249 hectares, of which 196 hectares are represented by cloud forests; and (3) the San Jose Reserve, which has an area of 124 hectares, of which 54 hectares are represented by cloud forests (Fig. 1). The aforementioned private natural reserves lie within the jurisdiction of the nearby towns of San Antonio del Tequendama, Bojaca´, and Tena, located in the state of Cundinamarca. These three municipalities have a high percentage of their population with unsatisfied basic needs (i.e. 31.4, 35.0, and 38.8 %, respectively), which measures household access to sanitation, housing conditions, and educational level. At a national level, Chicaque Natural Park and Macanal Reserve belong to the Integrated Management District of Natural Resources Salto of Tequendama-Cerro Manjuı´, which has an area of 11,000 hectares. Of the 11,000 hectares, 2,000 hectares are used for compulsory conservation purposes. Therefore, both of these reserves are located in the compulsory conservation area within the Integrated Management District. Additionally, the cloud forests located at the San Jose Reserve fall under the
protection scheme of the Productive Protective Forestry Reserve of Pedro Palo Lagoon. At an international level, all three areas within the Tequendama Fault are Important Bird Areas of Colombia (BirdLife International 2006). Presently, the land along the fault exhibits heterogeneous land use because there are areas allocated for the conservation of cloud forests and there are areas of pine and eucalyptus plantations. Furthermore, there are precincts dedicated to productive activities, such as farming, ranching, pasture, industry, and commerce. Moreover, many of these activities are developed in precincts that are adjacent to the cloud forest conservation areas. These activities represent a major threat to cloud forest habitats located along the fault. It is important to highlight the importance of the few precincts dedicated to conservation, research, and ecotourism activities (BirdLife International 2006). Sampling strategy and questionnaire design Survey sampling was conducted in the three private reserve areas between March 2008 and August 2009 after previous pretesting. To evaluate the social perception of cloud forests as providers of ecosystem services and determine their conservation value, surveys were applied to the local and visiting population through face-to-face interviews. The questionnaire was structured in four sections regarding the following topics: (1) environmental local knowledge related to cloud forests and ecosystem services provided to society; (2) development of a hypothetical
Fig. 1 Location of cloud forest reserves in the Tequendama Fault, Colombia (DMI = Integrated Management District)
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market through the contingent valuation method to conserve and protect ecosystem services provided by these habitats—here, we used both WTP and WTT for visitors and WTT for local inhabitants (see below); (3) environmental behaviour of the surveyed individuals; and (4) the economic and socio-demographic characteristics of the surveyed individuals. However, because of the sharp economic and social differences between the local and visiting population, we decided to develop specific types of surveys for each type of user (visitor or local). For visitors, we also incorporated a new section of questions related to travelling characteristics, visiting motives, and the activities conducted during the trip to the natural reserves. Consequently, 24 questions were included in the visitors’ survey, whereas the questionnaire for the local population had 13 questions. The questionnaire design was similar to those previously used in the topic of ecosystem services (e.g. Garcı´a-Llorente et al. 2011a; Martı´n-Lo´pez et al. 2012). Appendix 1 shows the questionnaires used for both visitors and local people (see Electronic Supplementary material). Because of the high poverty rates within the region, the survey of local users replaced the WTP for the conservation of cloud forests with the WTT for conservation actions that can contribute to the supply of ecosystem services in the cloud forest reserves (Chicaque, Macanal, and San Jose) across the Tequendama Fault. In both strategies (WTP and WTT), the elicitation was an open-ended format question if the response was affirmative in order to ascertain the respondent’s maximum WTP/WTT. Then, respondents were asked to distribute the total amount of money/time, WTP/WTT, for the protection of those ecosystem services they considered to be important. A list of the analysed ecosystem services was shown. If the response was negative, we asked about the motives for their lack of desire to pay or to invest time in order to distinguish protest responses from true zero values. Often, valuation researchers prefer the closed-ended format because open-ended questions are more difficult to answer and the question format is not incentive compatible (Carson et al. 2000). However, by using open-ended questions we obtained a more realistic and direct measure of maximum WTP without anchoring bias. Open-ended questions may result in lower WTP estimates than closedended format questions (Brown et al. 1996). Experimental results comparing hypothetical and actual WTP values showed that the hypothetical bias is lower for the openended questions than for the closed-ended questions (Balisteri et al. 2001). In the case of WTP, the selected payment mechanism would be an annual voluntary donation managed by the Corporacio´n Sentido Natural, a non-government organisation dedicated to the conservation and management of natural reserves in this area. In the case of WTT, we asked for the amount of hours that they would
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dedicate every month for conservation activities that ensure the preservation of the cloud forests’ capacity to deliver ecosystem services to society (Appendix 1). The WTT was considered after a presample exercise because all the local population and a significant portion of the visiting population have a monthly income of less than $250 USD. Consequently, the standard question regarding WTP in terms of monetary income resulted in many zero answers, leading to censored data issues. Therefore, we decided to inquire about WTT based on a valuation measure relying on the basis of Ricardo’s labour-value theory. In this manner, we used the WTP estimates for visitors, only and we used the WTT for both visitors and local users. Three districts that exist within the border of the natural reserves were selected for surveys of local users (Fig. 1): Chicaque District (Chicaque Natural Park), El Descanso District (Macanal Reserve), and Monte Redondo District (San Jose Reserve). These three districts have an aggregate population of approximately 400 people. Nearly 50 % of the population is younger than 18 years. A total of 339 surveys were conducted, including 220 surveys of visitors and 119 surveys of local residents. Data analysis Typology of users and their ecosystem services perception Agglomerative hierarchical cluster analysis was conducted to identify and characterise cloud forest user categories (i.e. ecosystem services beneficiaries). This analysis used Bray– Curtis distance and Ward’s method as agglomerative techniques (Ward 1963). We used those variables related to study the following: (1) knowledge of cloud forest reserves in the Tequendama Fault, (2) environmental attitudes, (3) social characteristics, and (4) visit characteristics (only for visitors) (see Appendix 2). We performed a Kruskal–Wallis test to analyse the different social perceptions of the importance of the ecosystem service delivery by cloud forests according to the user category. Valuation of ecosystem services In this study, a selection bias existed because the dependent variable (WTP or WTT) was only observed for a restricted sample. This was because surveyed individuals selected themselves to form part of the hypothetical market. To correct for the selection bias, we used the Heckman twostage model (Heckit), which is commonly used for the monetary valuation of ecosystem services (e.g. Garcı´aLlorente et al. 2011a; Martı´n-Lo´pez et al. 2007). The Heckman model consists of two stages. The first stage estimates the probability of ‘‘paying or not’’ (or
Social preferences
‘‘giving up time or not’’) through a probit model. The second stage estimates the WTP (or the WTT) in USD (or hours) for each individual through ordinary least squares (OLS) (Sigelman and Zeng 1999). Following Sigelman and Zeng (1999), the Heckit model is a response to sample selection bias, which arises when data are available only for cases in which a variable reflecting ‘‘pay’’, z*, exceeds zero: zi ¼ wi c þ li yi
¼ Xi b þ li
ð1Þ observed only if
zi
[0
ð2Þ
where for the ith individual, Xi is a vector of explanatory variables, b is a parameter vector common to all individuals, and li is a random disturbance term. The error terms are assumed to follow a bivariate normal distribution with means 0, variances rl = 1, and re = 1, and correlation coefficient q. The observed variable is z = 0 if z* B 0 and z = 1 if z* [ 0. Furthermore, y = 0 if z* B 0 and y = y* if z* [ 0. The expected Y is the following: E ðy j z [ 0Þ ¼ Xb þ qre kðwcÞ uðwcÞ 1UðwcÞ
ð3Þ
where kðwcÞ ¼ is the inverse of the Mill’s ratio, u is the standard normal density function, and U is the standard normal function. Equation (3) implies that the conditional expected value of y is Xb only when the errors of Eqs. (1) and (2) are uncorrelated. During the first stage, we obtained a probit estimation of Eq. (1) from c, where z = 1 if z* [ 0 and 0 otherwise. The pseudo-R2 of the probit regression was calculated according to the methodology proposed by Veall and Zimmermann (1992). At each model specification stage (probit and OLS regressions), we selected the best model from all candidate models using Akaike’s Information Criterion in order to compare models for parsimony (Burnham and Anderson 2002). The variables used in both stages are shown in Appendix 2 (Electronic Supplementary material). The presence of collinearity problem was tested through estimating pairwise correlations and judged not to be a serious problem because the correlation coefficients between independent variables were always lower than 0.8 (Kennedy 2003; Gujarati 2003). To avoid heteroscedasticity problems, we transformed the continuous variables with the natural log. We also adjusted standard errors for heteroscedasticity using Huber–White robust estimator (Hardin 2003). The results generated by the Heckit models were analysed using ANOVA with a sequential Bonferroni adjustment to test differences in the estimated WTP and WTT among user types. Finally, we compared and contrasted WTP and WTT through multiplying stated WTT by monthly earnings and considering monthly working time. Due to the fact that the
new variable—that is, WTT (USD year-1)—violated the normality assumption, a Kruskal–Wallis test followed by Dunn’s multiple comparison test was performed to compare among user types. Then, we carried out a Spearman correlation test to examine whether and how strongly the three estimations—that is, WTP (USD year-1), WTT (hours month-1), and WTT (USD year-1)—were related.
Results Characterisation of cloud forest users in the Tequendama Fault Of the participants polled (N = 339), 48 % were male and 52 % were female. Fifty-three per cent of the visiting population polled were male, and 40 % of the local population polled were male. The average age of the total population was 32 years; the average age of visitors was 29 years, and the average age of locals was 42 years. Fiftyseven per cent of the polled participants (mostly consisting of the local population) had a monthly income less than $250 USD. Of the local survey participants, 88 % reported a monthly income less than $250 USD, whereas only 40 % of the visitors reported the same. Ninety per cent of visitors were undertaking or had finished undergraduate or graduate studies at a university, whereas less than 2 % of locals had undertaken this kind of education. The hierarchical classification analysis indicated the formation of four types of cloud forest users in the natural reserve areas within the Tequendama Fault: (1) one-day visitors, (2) weekend visitors, (3) researchers and volunteers, and (4) the local population (Fig. 2).
Fig. 2 Hierarchical cluster analysis to categorise user groups for ecosystem services provided by cloud forests in the Tequendama Fault reserves
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The characterisation of cloud forest users in the Tequendama Fault is presented in Table 1. It is important to note that all user types associated cloud forest reserves with biodiversity conservation. Researchers and volunteers were the only group that also associated cloud forests with research and ecotourism activities. Additionally, all stakeholders recognised the importance of cloud forests as providers of biodiversity conservation service and also recognised their importance for water supply (with the exception of weekend visitors). Users’ perceptions of cloud forests as ecosystem service providers Overall, all users of cloud forests within the Tequendama Fault considered that the most important services provided by these habitats to society were as follows: water supply (61.0 % of participants polled), biodiversity conservation (58.8 %), and air purification and micro-climate regulation (58.1 %). In contrast, the least important ecosystem services provided by cloud forests were aesthetic values (37.2 %) and soil fertility and erosion control (40.5 %). Nonetheless, significant differences in the perception of ecosystem services provision by cloud forests were found
across all stakeholder groups (Table 2). Water supply was considered as important service for the local population, researchers, and volunteers. Air purification and micro-climate regulation were considered the most important services by one-day visitors. Scientific research was considered the most important service for researchers and volunteers. Monetary valuation of ecosystem services provided by the cloud forests of the Tequendama Fault Of the 220 polled visitors, 42.9 % were willing to pay to preserve cloud forests of the Tequendama Fault, 10.6 % stated that conservation activities rely on the government’s commitment to guarantee the preservation of important natural areas or are reluctant to pay because the proposed natural areas are on private property, and 46.5 % were not willing to pay because of their low income levels. The average estimated monetary value for the conservation of the cloud forests in every reserve of Tequendama Fault is $7.18 USD per year. We found four significant variables that explained the probability of participation in the conservation fund in the probit regression: the trip budget, the volunteering motivation, the tourism motivation, and the number of
Table 1 Characterisation of the four user groups generated by the agglomerative hierarchical cluster analysis Users (%)
One-day visitors (49.0 %)
Environmental local knowledge
Characteristics of the visit
Associates cloud forest reserves with
Ecosystem services identified
Aim of visit
Visited places
Conservation
Drinkable water
Tourism,
Chicaque,
Environmental education
Macanal
Air purification
Environmental behaviour
Demographic
Hours invested in the visit
Number of other PAs visited
Environmental NGO or local organisation (%)
Place of residence
3–12
0–8
19
Colombia (Bogota´, Chı´a, Quibdo´, Ibague´),
Biodiversity conservation
North and Central America
Environmental education Weekend visitors (11.6 %)
Conservation
Biodiversity conservation
Tourism, Environmental education
Pedro Palo,
Researchers and volunteers (4.5 %)
Conservation Research Ecotourism
Drinkable water
Environmental education,
Macanal,
Air purification
Research
Pedro Palo
Residents
Residents
15–36
0–10
13
Bogota´
2–8
8–20
53
Bogota´
0
0
9
Tequendama Fault
Chicaque
Biodiversity conservation Scientific research
Local population (35.4 %)
Conservation
Drinkable water Biodiversity conservation
PAs protected areas, NGO non-governmental organisation
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Social preferences Table 2 Mean values of users’ perception of the importance of ecosystem services supplied by cloud forests in the Tequendama Fault Ecosystem services
One-day visitors (%)
Weekend visitors (%)
Researchers and volunteers (%)
Local population (%)
v2
Provisioning
Drinkable water
50.3
43.6
80.0
79.0
29.24***
Regulating
Air purification and micro-climate regulation
72.4
48.7
60.0
43.7
25.23***
Erosion control and soil fertility Biodiversity conservation
45.4 60.7
38.5 66.7
40.0 73.3
34.5 51.3
3.48 5.32 0.12
Cultural
Nature tourism
46.6
25.6
46.7
44.5
Environmental education
51.5
38.5
40.0
37.0
6.67*
Scientific research
51.5
17.9
86.7
31.9
32.42***
Aesthetic values
38.0
25.6
46.7
38.7
2.95
Statistical differences were obtained by Kruskal–Wallis test (level of significance *** 1 %, and * 10 %)
Table 3 Estimated coefficients showing the determining factors influencing willingness to pay for protecting the ecosystem services provided by the cloud forests in the reserves of Tequendama Fault Variables
Probita
OLSb
Coefficients
Standard coefficients
Coefficients
Constant
-1.721***
-3.93
0.214
0.745
Trip budget
0.305***
0.471***
5.664
Volunteer motivation Tourism motivation
0.479* -0. 685***
No. of ecosystem services
0.302**
3.499 1.600 -3.559
0.495* -0.833***
2.186
NGOs
0.310**
2.354 0.896
2.277***
4.333
–
N
220
220
Log likelihood
-133.18
-251.95
Akaike I.C.
1.26
-0.48
Wald v2
30.76***
Pseudo-R2
0.23
% of correct predictions
69.09 %
Adjusted R2
1.795 -4.546
0.190
K
–
Standard coefficients
0.84
Probit regression results for the first stage of the Heckman model and the sample selection for the two-stage least squares regression (OLS) results for the second stage of the Heckman model. Standard coefficients were calculated using robust (Huber/White) standard errors (level of significance *** 1 %, ** 5 % and * 10 %) a
Dependent variable in probit regression, 0 when WTP = 0 and 1 when WTP [ 0
b
Dependent variable in OLS, Ln (WTP)
ecosystem services previously identified by respondents (Table 3). Visitors who only had tourism motivation in their visit to natural reserves were less willing to participate in the hypothetical market. The variables of trip budget, volunteering motivation, and the number of ecosystem services perceived by visitors were positively related to the probability of participation in the conservation fund. In the second stage of the Heckman model, we found three significant and positive variables: (1) trip budget, (2) volunteering as the aim of the visit, and (3) the number of ecosystem services perceived by respondents. Here, if the
aim of the visit was tourism, respondents were less willing to pay to protect the ecosystem services provided by cloud forests (Table 3). A higher level of environmental behaviour (volunteering motivation) and environmental knowledge (number of ecosystem services previously identified) promoted an interest in cloud forests conservation, reflected by higher donations. As expected, if visitors had a higher trip budget, they were more willing to donate money for conservation. Finally, the inverse Mill’s ratio was significant (Table 3), indicating correlation between the error terms in the two stages.
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D. Higuera et al. Table 4 Mean scores for WTP and WTT for conservation activities needed to maintain ecosystem services provided by cloud forests Ecosystem services users
One-day visitors
N
166
WTP (USD year-1)
WTT (hours month-1)
WTT (USD year-1)
Mean
SD
Mean
SD
Mean
SD
6.68b
5.72
21.41a
11.73
321.70b
442.39
b
5.14
b
11.77
8.75
463.73b
574.36
8.49
26.60a
9.60
507.85b
Weekend visitors
39
5.17
Volunteers and researchers
15
13.08a
Local population ANOVA (F-value)
119
–
–
5.36***
b
12.41
7.76
96.362
568.32 a
233.46
26.97***
Kruskal–Wallis (v2)
70.86***
Significant differences (a = 0.05 with a sequential Bonferroni adjustment) are shown using different lowercase letters. SD standard deviation (level of significance: *** 1 %)
ANOVA with sequential Bonferroni test (ANOVA test, F = 5.36, df = 2, p = 0.005) indicated that the stated economic contributions tend to be greater on volunteers and researchers than on visitors (both one-day and weekend visitors) (Table 4). Willingness to give up time for conservation actions in the cloud forests of the Tequendama Fault As mentioned previously, data trends and presample exercises suggested that the local population was not willing to pay for the conservation of the ecosystem services because of their low monthly income levels. Conversely, 60.4 and 69.8 % of visitors and local people, respectively, were willing to perform conservation duties once a month that would ensure the preservation of the cloud forests’ capacity to deliver ecosystem services in these natural reserve areas. The average time that both visitors and locals were willing to spend in such conservation activities was 19.9 and 12.4 h per month, respectively. The probit regression analysis detected five variables that explained the probability of giving up time for conservation activities in the cloud forest reserves (Table 5). Four variables were positively correlated with the probability of the user spending time on conservation duties: (1) the number of ecosystem services perceived by the respondent, (2) if the respondent was a resident of Tequendama Fault, (3) if the respondent associated the cloud forests with clean air, and (4) if the respondent associated the cloud forests with biodiversity conservation. However, age was negatively associated with the probability of participation. In the second stage of the Heckman model, we found five statistically significant variables. The number of ecosystem services identified by respondents and whether they associated the cloud forests with clean air, biodiversity conservation, and recreation activities had a positive impact, while age was a negatively correlated variable
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(Table 5). Younger people were willing to spend a higher amount of time on these activities. Finally, the inverse Mill’s ratio was significant (Table 5), indicating some correlation between the error terms in the two stages. The ANOVA analysis of the WTT showed differences among different users (ANOVA test, F = 26.97, df = 3, p \ 0.0001). Volunteers and researchers as well as one-day visitors were the users who spend the highest amounts of time conducting conservation activities, followed by local people and weekend visitors (Table 4). Comparison between willingness to pay and willingness to give up time for conservation actions in cloud forests The mean willingness to pay calculated according to the stated WTT (i.e. 268.4 USD year-1) shows that users were more willing to spend in conservation activities of cloud forests by donating time than simply paying money. While the WTP estimation declared in money was $7.18 USD year-1 in every reserve, the willingness to pay obtained from devoted hours was $268.45 USD year-1. However, we found differences in this variable among different users (Kruskal–Wallis test, v2 = 70.86, df = 3, p \ 0.0001; Table 4). In addition, the Spearman correlation test demonstrated that the three variables—that is, WTP (USD year-1), WTT (hours month-1), and WTT (USD year-1)—were positively correlated (Table 6), indicating that the three variables can measure social preferences towards conservation of cloud forests.
Discussion The importance of cloud forests for human welfare via the ecosystem services supply has been perceived by the users of the cloud forests in the Tequendama Fault. Specifically, researchers and volunteers considered the importance of
Social preferences Table 5 Estimated coefficients showing the determinant factors to be willing to give up time for activities related to the protection of cloud forest reserves in the Tequendama Fault Probita
Variables
Coefficients
OLSb Standard coefficients
Coefficients
Standard coefficients
Constant
1.985**
2.557
Resident
0.733***
3.104
4.194***
8.455
No. of ecosystem services Association with oaks
0.498*** 0.337
4.366 1.493
0.261*** 0.156
3.356 1.137
Association with clean air
0.910***
2.818
0.366*
1.847
Association with conservation
0.418**
2.357
0.274**
2.418
Association with recreation
0.310
1.489
0.406***
2.927
Age
-0.816***
K
–
N
339
339
Log likelihood
-192.56
-452.69
Akaike I.C.
1.18
-0.11
Wald v2
53.48***
Pseudo-R2
0.26
% of correct predictions
68.14 %
-3.545
-0.929***
–
0.893***
Adjusted R2
-6.703 6.856
0.52
Probit regression results for the first stage of the Heckman model and the sample selection for the two-stage least squares regression (OLS) results for the second stage of the Heckman model. Standard coefficients were calculated using robust (Huber/White) standard errors (level of significance *** 1 %, ** 5 % and * 10 %) a
Dependent variable in probit regression, 0 when WTT = 0 and 1 when WTT [ 0
b
Dependent variable in OLS, Ln (WTT)
Table 6 Spearman correlations among the three estimated variables—WTP (USD year-1), WTT (hours month-1), and WTT (USD year-1)—(level of significance *** 1 % and ** 5 %) WTP (USD year-1)
WTT (hours month-1)
WTP (USD year-1)
–
–
WTT (hours month-1)
0.158**
–
WTT (USD year-1)
0.300***
0.529***
these habitats for maintaining biodiversity (Table 2). In fact, cloud forests have been recognised not only for their species richness but also for their high endemism levels (Armenteras et al. 2007). In the case of cloud forests located at the Tequendama Fault, it is interesting to note that this service is highly recognised by all users because it still represents a relict area near Bogota, despite the advanced degree of landscape fragmentation. In this area, users exhibited a high valuation for the conservation of flora and fauna species, such as oak trees (Quercus humboldtii), ferns (Cyathea caracasana), primates (Aotus sp.), and sloth bears (Choloepus hoffmanni). There are more than 200 species of birds in the cloud forests studied, and five species have been registered as conservation-concerned migratory species (BirdLife International 2006). Hence, the positive social perception of cloud forests as
important habitats for species conservation should play a key role in the decision-making processes for the conservation of these habitats (Kniivila¨ 2006; Stevens et al. 1991). Additionally, this study clearly demonstrates that users of cloud forests (mostly researchers and volunteers and local population) considered the Tequendama Fault to be important in the provision of drinkable water to society (Table 2). District populations within the area consume and utilise drinkable water that is provided directly by cloud forests through horizontal precipitation for their daily living and production activities. Furthermore, the water sources obtained from cloud forests constitute the water supply mechanisms for accommodations in private reserve areas. The importance of cloud forests as water suppliers has been documented in several Latin American countries (Armenteras et al. 2007; Bonnell and Bruijnzeel 2005). As a result, cloud forests of the Tequendama Fault are a conservation priority because of their importance as water suppliers for two main reasons. First, the average precipitation in the Tequendama Fault cloud forests is lower than in other Colombian cloud forests. For instance, the average annual rainfall near the Macanal Reserve is 758 mm, whereas rainfall near Pedro Palo Lagoon can reach up to 2,000 mm a year. These are extremely low levels
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compared to other cloud forests located in the eastern Andean mountain range, such as the Cachalu Reserve, which has an average annual rainfall of 3,000 mm (Solano 2006). Second, cloud forests on the Tequendama Fault are mainly surrounded by agriculture precincts and the arid plateau of the Sabrinsky Desert. However, the presence of waterfalls combined with the remainders of forests provides the required conditions to allow the fog and clouds to convert into water, thus providing water to the nearby water bodies. Although the local population recognises cloud forests as water suppliers, a threatening deforestation process still occurs beyond the natural reserve areas. The inhabitants about the boundaries of the natural reserves have converted the surrounding area from native forest to open lands dedicated to agricultural and pasture activities. Mulligan and Burke (2005) demonstrated that the deforestation of cloud forests generates significant decreases in the water flow of rivers, especially during drought seasons. Deforestation still occurs because the opportunity costs of cloud forest conservation are very high for local populations, as it is more profitable to engage in agricultural or ranching activities. As long as these local populations do not derive a source of income from the conservation of cloud forests, they convert the land on agriculture (Martı´nez et al. 2009). Thereby, a considerable risk for water sources within the area will remain. Thus, despite the noticeable knowledge and commitment to cloud forest conservation by local users, inhabitants are generating significant pressure on these habitats and putting them at peril as a result of their need to generate sources of income and fulfil basic needs. Our results also suggest that the respondents’ knowledge about the ecosystem services provided by cloud forests plays a key role in determining the perceived importance of these ecosystems. Variables related to ecological knowledge, such as the number of services identified, increased both the probability and the amount that users are willing to pay or collaborate (in time) with conservation activities. This relationship suggests that ecological knowledge constitutes a vital strategy for conservation (Martı´n-Lo´pez et al. 2007). However, because environmental education was not perceived to be one of the most important services provided by cloud forests in the Tequendama Fault, it is important to promote environmental education programmes among local people and visitors to achieve significant progress for conservation. Furthermore, we found that WTT should be an interesting tool to develop environmental awareness in both rural (local population) and urban people (tourists and researchers and volunteers) (see Table 4) as these types of users are WTT in conservation activities in cloud forests. In addition, we found that WTT format question raises higher percentage of positive responses in the hypothetical
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market than WTP, while both measures are positively correlated (Table 6). This result is in accordance with previous research comparing WTT and WTP (van Helvoort-Postulart et al. 2009; Notaro and Paletto 2011). Therefore, WTT should be considered a useful option for designing conservation policies based on ecosystem services involving different users’ profiles. Garcı´a-Llorente et al. (2011b) found that WTT was the most favourite ‘‘payment’’ method to participate in conservation/restoration activities of ecosystem services for different types of stakeholders. Additionally, because the WTT for conservation actions towards cloud forests increased with younger users (Table 5), an opportunity exists to increase knowledge and appreciation for these habitats through environmental education activities. The high WTT rate of local users reveals their commitment towards the cloud forests protection.
Conclusions Because the results obtained for WTT were similar to those of the WTP estimations, our findings support the idea that the WTT for an environmental concern should be a viable technique to explore individual preferences towards conservation issues in rural communities or in developing countries. We also found that the users’ environmental knowledge and awareness of cloud forests is essential for future strategies regarding the conservation of these habitats. However, the conservation movement will need to diversify the outreach strategy to involve the entire user groups. Outreach strategies will also need to consider users’ socio-economic characteristics and environmental awareness. For visitors, the strategy should rely on the promotion of environmental awareness of cloud forests as providers of ecosystem services from which society obtains a direct benefit. The strategy should also depend on a conservation fund that addresses protection and recovery activities for the cloud forest reserves, thus combining WTP for the conservation of these habitats and requiring them to devote time to conservation activities. In this sense, the strategy should focus on promoting environmental NGOs and environmental education programmes because these strategies are the key drivers to change human attitudes towards biodiversity conservation (Knegtering et al. 2002; Lindemann-Matthies 2005). Conversely, for local users, the conservation strategy should consist of collaborating in conservation activities where they can incorporate all of their experiential knowledge (Fazey et al. 2006), which is also essential for maintaining social capital in local communities (Pretty and Smith 2004). Therefore, a combined strategy focused on visitors and local inhabitants should be a successful option for cloud forests conservation
Social preferences
in which, on the one hand, the payment for ecosystem services derived from the visitors’ WTP for cloud forests conservation would be a feasible and effective mechanism to obtain a major source of income in farmers’ community and, on the other hand, the farmers’ local knowledge would be incorporated through restoration and conservation activities in order to increase collective action in local communities (Pretty and Smith 2004). Additionally, these restoration and conservation activities should be also addressed to volunteers and researchers in order to build collective learning (Brechin et al. 2002) which combine both experimental knowledge from researchers and experiential knowledge from local actors. Moreover, combination of outdoor activities and environmental education should increase the public support for conservation activities, as people are more likely to invest effort in what they have experienced (Zaradic et al. 2009). Consequently, conservation of cloud forests could benefit from experimental exercises of stated preference methods which explore both WTT and WTP, in order to design environmental education programs, environmental voluntary initiatives, or Payments for Ecosystem Services schemes. In agreement with Armenteras et al. (2009), successful conservation in Colombian forests should balance the economic, cultural, social, and environmental aspects. Thus, the fate of cloud forests conservation in the Tequendama Fault may depend on users’ perception of the importance of these habitats for their welfare and also depend on the promotion of a conservation strategy based on different approaches regarding the stakeholders’ environmental awareness and socio-economic characteristics. Acknowledgments We thank the Macanal Forest Reserve, Chicaque Natural Park and San Jose Reserve (Pedro Palo), and the resident population of the Chicaque Village, The Leisure and Monte Redondo. We also thank Marina Garcı´a-Llorente for inspiring ideas about WTT as vehicle payment and two anonymous reviewers for constructive comments on early version of the manuscript.
References Aldrich M, Hostettler S (2000) Tropical montane cloud forest, time for action. UNEP-World Conservation Monitoring Centre, Cambridge Armenteras D, Cadena VC, Moreno RP (2007) Evaluacio´n del estado de los bosques de niebla y de la meta 2010 en Colombia. Instituto de Investigacio´n de Recursos Biolo´gicos, Alexander von Humboldt, Bogota´ Armenteras D, Rodriguez N, Retana J (2009) Are conservation strategies effective in avoiding the deforestation of the Colombian Guyana Shield? Biol Conserv 142:1411–1419 Balisteri E, McClelland G, Poe G, Schulze W (2001) Can hypothetical questions reveal true answers? A laboratory comparison of dichotomous choice and open-ended contingent values with auction values. Environ Resour Econ 18:275–292
Barner JC, Mason HL, Murray MD (1999) Assessment of asthma patients’ willingness to pay for and give time to an asthma selfmanagement program. Clin Ther 21:878–894 BirdLife International (2006) Fichas de especies migratorias neotropicales en las IBAs: Bosques de la Falla del Tequendama. http://www.birdlife.org. Accessed 1 Sept 2011 Bonnell M, Bruijnzeel LA (2005) Forests, water and people in the humid tropics: past present and future hydrological research for integrated land and water management. Cambridge University Press, Cambridge Brechin SR, Wilhusen PR, Fortwangler CL, West PC (2002) Beyond the square wheel: toward a more comprehensive understanding of biodiversity conservation as social and political process. Soc Nat Resour 15:41–64 Brown T, Champ P, Bishop R, McCollum D (1996) Which response format reveals the truth about donations to a public good? Land Econ 72:152–166 Bruijnzeel LA (2004) Hydrological functions of tropical forests: not seeing the soil for the trees? Agric Ecosyst Environ 104:185–228 Bubb P, May I, Miles L, Sayer J (2004) Cloud forest agenda. UNEPWCMC, Cambridge. http://www.unep-wcmc.org/resources/public ations/UNEP_WCMC_bio_series/20.htm. Accessed 1 Sept 2011 Burnham KP, Anderson DR (2002) Model selection and multi-model inference: a practical information-theoretic approach. Springer, New York Carson R, Groves T, Machina M (2000) Incentive and information properties of preference questions. Working Paper, Department of Economics, University of California, California, USA de Groot R (2006) Function-analysis and valuation as a tool to assess land use conflicts in planning for sustainable, multi-functional landscapes. Landsc Urban Plan 75:175–186 Doumenge C, Gilmour D, Ruiz–Pe´rez M, Blockhus J (1995) Tropical montane cloud forest: conservation status and management issues. In: Hamilton LS, Juvik JO, Scatena FN (eds) Tropical montane cloud forest. Springer, New York, pp 24–37 Fazey I, Fazey JA, Salisbury JG, Lindenmayer DB, Dovers S (2006) The nature and role of experiential knowledge for environmental conservation. Environ Conserv 33:1–10 Garcı´a-Llorente M, Martı´n-Lo´pez B, Dı´az S, Montes C (2011a) Can ecosystem properties be fully translated into service values? An economic valuation of aquatic plant services. Ecol Appl 21:3083–3103 Garcı´a-Llorente M, Martı´n-Lo´pez B, Montes C (2011b) Exploring the motivations of protesters in contingent valuation: insights for conservation policies. Environ Sci Policy 14:76–88 Guariguata MR, Balvanera P (2009) Tropical forest service flows: improving our understanding of the biophysical dimension of ecosystem services. For Ecol Manag 258:1825–1829 Gujarati DN (2003) Basic econometrics, 4th edn. McGraw Hill/Irwin, New York Hardin JW (2003) The sandwich estimate of variance. In: Fomby TB, Hill RC (eds) Maximum likelihood estimation of misspecified models: twenty years later, advances in econometrics series (17). Elsevier, Oxford, pp 45–73 Higuera D, Martinez E (2006) Sequestration and storage capacity of carbon in the canopy oak trees and their epiphytes in a Neotropic Cloud Forest, Colombia. Lyonia 11:17–23 Johannesson M (1992) Economic evaluation of lipid lowering a feasibility test of the contingent valuation approach. Health Policy 20:309–320 Kahneman D, Ritov I (1994) Determinants of stated willingness to pay for public goods: a study in the headline method. J Risk Uncertain 9:5–38 Kahneman D, Ritov I, Schkade D (1999) Economic preferences or attitude expressions? An analysis of dollar responses to public issues. J Risk Uncertain 19:203–235
123
D. Higuera et al. Kennedy P (2003) A guide to econometrics, 5th edn. The MIT Press, Massachusetts Knegtering E, Hendrickx L, van der Windt HJ, Schoot Uiterkamp AJM (2002) Effects of Species’ characteristics on nongovernmental organizations’ attitudes toward species conservation policy. Environ Behav 34:378–400 Kniivila¨ M (2006) Users and non-users of conservation areas: are there differences in WTP, motives and the validity of responses in CVM surveys? Ecol Econ 59:530–539 Lindemann-Matthies P (2005) ‘Loveable’ mammals and ‘lifeless’ plants: how children’s interests in common local organisms can be enhanced through observation of nature. Int J Sci Educ 27:655–677 Martı´nez ML, Pe´rez-Maqueo O, Va´zquez G, Castillo-Campos G, Garcı´a-Franco J, Mehltreter K, Equihua M, Landgrave R (2009) Effects of land use change on biodiversity and ecosystem services in tropical montane cloud forests of Mexico. For Ecol Manag 258:1856–1863 Martı´n-Lo´pez B, Montes C, Benayas J (2007) Influence of user characteristics on valuation of ecosystem services in Don˜ana natural protected area (south-west Spain). Environ Conserv 34:215–224 Martı´n-Lo´pez B, Iniesta-Arandia I, Garcı´a-Llorente M, Palomo I, Casado-Arzuaga I, Garcı´a del Amo D, Go´mez-Baggethun E, Oteros-Rozas E, Palacios-Agundez I, Willaarts B, Gonza´lez JA, Santos-Martı´n F, Onaindia M, Lo´pez-Santiago C, Montes C (2012) Uncovering ecosystem service bundles through social preferences. PLoS ONE 7(6):e38970. doi:10.1371/journal.pone.0038970 Millennium Ecosystem Assessment (MA) (2005) Ecosystems and human well-being: synthesis. Island Press, Washington, DC Mitchell RC, Carson RT (1989) Using survey to value public goods. The contingent valuation method. Resources for the Future, Washington, DC Mulligan M, Burke SM (2005) DFID FRP ZF-0216, Global Cloud Forest and Environmental Change in a Hydrological Context. Final Report. p 74. http://www.ambiotek.com/cloudforests/cloud forest_finalrep.pdf. Accessed 15 Aug 2011 Notaro S, Paletto A (2011) Links between mountain communities and environmental services in the Italian Alps. Sociol Ruralis 51:137–157
123
Pascual U, Muradian R, Brander L, Go´mez-Baggethun E, Martı´nLo´pez B, Verma M, Armsworth P, Christie M, Cornelissen H, Eppink F, Farley J, Loomis J, Pearson L, Perrings C, Polasky S (2010) The economics of valuing ecosystem services and biodiversity. In: Kumar P (ed) The economics of ecosystems and biodiversity: ecological and economic foundations. Earthscan, London, pp 184–255 Pretty J, Smith D (2004) Social capital in biodiversity conservation and management. Conserv Biol 18:631–638 Sagoff M (1998) Aggregation and deliberation in valuing environmental public goods: a look beyond contingent pricing. Ecol Econ 24:213–230 Sigelman L, Zeng L (1999) Analyzing censored and sample-selected data with Tobit and Heckit models. Polit Anal 8:167–182 Solano C (2006) Reserva Biolo´gica Cachalu. 10 an˜os de investigacio´n en bosques de roble. In: Solano C, Vargas N (eds) Memorias del I simposio internacional de Robles y Ecosistemas asociados. Fundacio´n Natura—Pontificia Universidad Javeriana, Bogota´, Colombia, pp 11–23 Stevens T, Echeverrı´a J, Glass R, Hager T, More T (1991) Measuring the existence value of wildlife: what do CVM estimates really show? Land Econ 67:390–400 Thompson I, Mackey B, McNulty S, Mosseler A (2009) Forest resilience, biodiversity, and climate change. A synthesis of the biodiversity/resilience/stability relationship in forest ecosystems. Secretariat of the Convention on Biological Diversity, Technical Series no. 43, Montreal, Canada´ van Helvoort-Postulart D, Dirksen CD, Kessels AGH, van Engelshoven JMA, Hunink MGM (2009) A comparison between willingness to pay and willingness to give up time. Eur J Health Econ 10:81–91 van Hore C (1996) Counting the social costs: electricity and externalities in South Africa. University of Cape Town Press, Cape Town Veall MR, Zimmermann KF (1992) Pseudo-R2s in the ordinal probit model. J Math Sociol 16:333–342 Ward J (1963) Hierarchical grouping to optimize and objective function. J Am Stat Assoc 58:236–244 Zaradic PA, Pergams ORW, Kareiva P (2009) The impact of nature experience on willingness to support conservation. PLoS ONE 4:e7367
