2.1. Development and Significance of Agro-Ecotourism in Yuanshan Township
The study site in the present study is Yuanshan Township (YST) with 16 villages (
Figure 1). The local residents are deeply land-reliant, traditionally involved in agriculture and currently involved in tilling and running the business of agro-ecotourism locally. These individuals are characterized by their dedication to working on the land. Their diligence shines through in their tireless efforts, persistence, and wholehearted commitment to their work [
6,
7,
8].
The vulnerability of YST illustrated the carrying capacity of the destinations. There are mainly three folds of local vulnerability that can be demonstrated by the digital elevation model in
Figure 1.
The geographical vulnerability of YST: the pushing of the continental plate crust causes high height differences in a small area.
The climatic vulnerability of YST: the terrain of YST is directly on the windward side of the typhoon, facing increasingly strong winds and heavy rainfall due to climate change.
The economic vulnerability: agriculture has gradually declined in Taiwan, and calls for water, soil and environmental protection are growing. If the local mountain villages experience economic depression, it will cause livelihood difficulties for residents.
Based on the above information, the natural environment of YST inherently has a carrying capacity that is a crucial aspect for understanding the region’s long-term sustainability. However, the development and prudent design of agro-ecotourism in YST have the potential to enhance carrying capacity by addressing and mitigating local vulnerabilities. Conserving forested land is a natural-based solution to climate change adaptation and represents a critical aspect of human–nature interactions. Government land use regulations based on scientific classifications are adopted to balance the conservation of marginal forest lands and tilling of traditional agriculture by the local community. By focusing on local resources and promoting eco-friendly tourism that supports both conservation and economic stability, agro-ecotourism can provide alternative livelihoods for residents, reduce economic depression in shallow mountain villages, and contribute to the long-term resilience of the area. Ultimately, with careful attention to these vulnerabilities, agro-ecotourism has the potential to not only protect the environment, but also boost the carrying capacity of YST, ensuring its sustainability in the future.
The township is a picturesque and beautiful place, surrounded by green mountains and rivers. Its stunning natural scenery, together with leisure agriculture activities, frequently attracts numerous visitors from the whole island of Taiwan. YST is regarded as the backyard of Taipei, situated just a mountain away from the city’s dense urban areas. It is known as one of the first destinations for those seeking a peaceful escape, offering tranquility to city dwellers. The distance is approximately 68.5 km, measured from Taipei City Hall to the Yuanshan Township Office.
Agricultural production and leisure agriculture is thriving in the villages of YST. The hilly terrain in YST has a climate conducive to the growth of various vegetables, fruits, and fruit trees such as tangerines, pineapples, bamboo shoots, ginger, starfruit, chives, guavas, wax apples, scallions, and Shanxi pears. During peak harvest seasons, the township offers agrotourism activities like fruit-picking, providing delightful experiences for family outings [
6]. The township’s rural scenery and diverse agricultural activities make it a prime location for agricultural leisure activities. Beyond its abundant natural resources, YST also boasts rich cultural resources. Agrotourism flourishes here, offering immersive experiences that connect visitors with the rural way of life. Government and community efforts converge to support small-scale farmers, foster innovation, and preserve natural beauty and cultural heritage [
6].
The development of leisure agriculture in Taiwan was initiated in 2000. Taiwan’s Agriculture Authority promotes agrotourism, highlighting its multifaceted benefits: economic, social, educational, environmental protection, recreational, medical, and cultural inheritance. The development of leisure agriculture is driven by changes in agricultural structure, urbanization, increased income, shifts in consumption patterns, more leisure time, and improved transportation infrastructure. As a result, traditional agriculture has transformed into leisure farms, integrating production, processing, sales, and tourism to enhance local community income and meet recreational demands [
4,
12]. Furthermore, local institutional development and organizational establishment has been made for advancing urban agriculture tourism. The establishment of leisure agriculture zones in Taiwan, promoted by the Council of Agriculture, aims to combat the declining role of traditional agriculture, meet the increasing demand for recreation, and strengthen local community income. Within these zones, the government establishes and maintains public infrastructure. Community-based governance ensures that leisure agricultural activities are planned and managed in a format of income creation to meet local feasibility, leading to a comprehensive strategy for agricultural product planning, marketing, and promotion [
10]. Taiwan’s leisure agriculture has been developing for decades, with significant progress up until the execution of this study’s survey in 2023. Through the promotion of Leisure Agriculture zones in local areas, the development of leisure agriculture in Taiwan has proven successful, particularly in agricultural counties such as Yilan County [
6,
7,
8].
In 2023, YST hosts three main recreational agricultural zones: Zhentoushan Agricultural Leisure Area, Hengshantou Agricultural Leisure Area, and Dahudi Agricultural Leisure Area. These zones feature flocks of agrotourism farms and provide a blend of recreational agriculture and forest ecotourism in the nearby forests. The main attraction of leisure agriculture in YST lies in utilizing the rich rural produces, natural landscape, rural culture, and local characteristics. This combination with ecological tourism develops high-quality tourism that offers entertainment, recreation, education, economic benefits, environmental protection, and health benefits [
6].
The hilly terrain serves as an ecotourism destination, with forest protection as a nature-based climate adaptation strategy. YST and the Lanyang River watershed are geologically and climatically fragile areas where forests play a crucial conservation role. Taiwan’s community forestry program empowers local residents in forest management, addressing long-standing issues of land reclamation and illegal logging through co-management [
17,
18]. Integrating forestry ecotourism with leisure agriculture has become a policy solution to farmers’ livelihood challenges, offering climate adaptation opportunities [
13]. This approach improves environmental quality, balances ecosystem and land use, aids soil and water conservation, and preserves landscapes and cultural assets. It provides recreation for visitors from Taipei and Yilan County, delivering benefits such as stress relief, rural cultural connections, and improved quality of life [
10].
2.2. Travel Cost Method
In the context of nature-based solutions to the increasingly severe environmental and climate challenges, assessing the value of natural resources and ecosystem services is crucial for developing strategies that promote ecological protection and facilitate the rational use of land. The travel cost method (TCM) is a widely used non-market valuation technique to estimate economic values associated with ecosystems or recreational sites. It is based on the premise that the travel cost incurred by visitors can be used to derive a demand curve for a recreational site. This method is mainly applied to regions rich in natural and cultural tourism resources, using the tourism market as a surrogate market for the value of ecosystem services to estimate their worth. The theoretical and empirical development of TCM has been significantly advanced by key works, notably those of Clawson and Knetsch [
19] and Parsons [
20]. Furthermore, Freeman [
21] and Freeman et al. [
22] provided a comprehensive guide to measuring environmental and resource values, including the calculation of consumer surplus using TCM. Haab and McConnell [
23] discussed various econometric approaches to non-market valuation, including detailed explanations of consumer surplus calculations by TCM. Parsons [
20] offers a primer on non-market valuation techniques, with practical examples of consumer surplus calculations in TCM.
Recreational activities have gained more attention in recent years, and there has been a surge in the literature estimating the services value of ecosystems using the TCM. Sinclair et al. [
24] estimated the economic value of natural ecological recreational resources using the TCM, providing strong evidence for the need to protect environmental ecosystems and promoting the rational use of land. Swinton et al. [
25] analyzed the relationship between ecosystem services and leisure agriculture using the TCM, evaluating the value of leisure agriculture tourism supported by a healthy agricultural ecosystem. Ezebilo [
26] assessed the non-market value of ecosystem services through the economic evaluation of natural recreation in Sweden. Wilson and Carpenter [
27] analyzed the economic value of ecosystem services in U.S. freshwater bodies, and Nandagiri [
28] evaluated the economic value of lake ecosystems.
When modeling the number of visits to a recreational site, count data models are often used due to the discrete nature of the dependent variable (i.e., the number of visits). Studies involving the application of count data models for TCM include Haab and McConnell [
23] and Cameron and Trivedi [
29]. The count data model should be used, including Poisson count regression and negative binomial count regression. Both methods were applied in the assessment for recreation value. The Poisson model assumes that the mean and variance of the count variable are equal (equi-dispersion). The negative binomial model relaxes the equi-dispersion assumption of the Poisson model by allowing the variance to exceed the mean. For a count data model, the maximum likelihood estimation (MLE) technique is applied to estimate parameters. However, if the survey is conducted at an entertainment venue, the on-site survey will only include actual visitors and truncate potential visitors who do not come to the survey site. Shaw [
30] addressed these on-site truncation problems in his paper and applied on-site Poisson regression to model the demand for recreation in Montana, considering factors such as travel cost, time, and socio-economic characteristics. Englin and Shonkwiler [
31] utilized the Poisson model to analyze the demand for recreational fishing in the United States, focusing on travel cost and site quality. Furthermore, Creel and Loomis [
32] employed the negative binomial model to study the demand for deer hunting in California, accounting for overdispersion in the number of hunting trips. Hellerstein and Mendelsohn [
33] used the negative binomial model to estimate the demand for outdoor recreation in the Adirondacks, incorporating variables such as travel cost and site characteristics.
Moreover, an array of studies has applied these two methods. Grogger and Carson [
34] applied and compared the Poisson and negative binomial models in recreational demand, highlighting the importance of addressing overdispersion to improve model accuracy. Martinez-Espineira and Amoako-Tuffour [
35] conducted a comparative analysis of Poisson and negative binomial models for the valuation of national parks in Ghana, demonstrating the superiority of the negative binomial model in handling over-dispersed data. Although the TCM has been utilized for a long time, in recent years, there have been new applications in assessing the value for recreation, including Mohamed et al. [
36], Chettri and Kundu [
37], Aksoy et al. [
38], Verde [
39], and Chapagain, Poudyal, and Watkins [
40].
The aforementioned literature demonstrates that numerous studies have developed and used the TCM to estimate non-market values of ecosystem services, confirming that it is a relevant tool for this task. Therefore, this study considers agro-ecotourism in Yilan’s shallow mountain area as a local surrogate market to assess the value of ecosystem services from local natural resources. This estimated value will serve as an important foundation and driving force for balancing local natural ecosystems, climate change, human development policies, and strategic planning in the shallow mountain leisure agriculture areas. The results could be applied to affirm that the local agro-ecotourism can enhance local community income and meet recreational demands, as proposed by Liu et al. [
41] under a well-designed forest conservation policy.
The steps of the TCM are as follows: visitor survey, demand curve estimation, and consumer surplus calculation.
Step 1: A visitor survey was conducted to collect data on visitors’ travel costs, the number of trips made, socio-economic characteristics, and time spent at the site. Travel costs generally include direct costs actually expended in the trip, such as transportation and accommodation costs, and the indirect costs, such as the opportunity cost of time. Since the survey was carried out during a holiday period, the opportunity cost of time was not included in the present study. In the present study, six topics of questions were included in the survey questionnaires: (1) visiting information of respondent visitors, (2) departure places and transportation of visitors, (3) most valuable recreation resources to be protected as perceived by the respondents, (4) revisit Intention, (5) feasible institution to protect local natural recreation resources, and (6) demographic characteristics of the respondents.
Step 2: The relationship between visiting frequency and travel costs was used to estimate the demand curve. Typically, a negative relationship is expected. A demand function can be expressed as follows:
This demand function relates the number of visits, Q, to travel cost, TC, and a vector of other variables, X.
For a count data model, the demand function can be expressed as follows:
where
is the intercept,
is the coefficient for travel cost
, and
are the coefficients for other explanatory variables
, the subscript
j is the
j-th independent variables and subscript
i is the
i-th respondent, and
k is the sample size.
Step 3: Consumer surplus calculation is based on the area under the demand curve representing the consumer surplus, which is a measure of economic value. The consumer surplus of the demand curve in the TCM represents the difference between what visitors are willing to pay for access to a recreational site and what they actually pay. It is often calculated using the estimated demand function derived from the TCM model. In the aforementioned literature, Freeman [
21] and Freeman, Herriges, and Kling [
22] provide comprehensive methods for measuring environmental and resource values and discuss the theoretical foundations of consumer surplus calculations. The book by Haab and McConnell [
23] covers econometric techniques for non-market valuation, including detailed procedures for calculating consumer surplus using TCM models. Based on the formula in the literature (P279, Freeman, Herriges, and Kling [
22]; P167, Haab and McConnell [
23]), the economic value represented by consumer surplus for an average visitor is given by the following:
where
is the coefficient of variable of travel cost,
TC, in Equation (2).
2.3. Survey Data Descriptive Statistics
To collect information on the visitors’ travel expenditure to represent the value of the local recreational resources, an on-site questionnaire survey was carried out during peak travel season in January and February in 2023, which is around the Chinese Lunar New Year. The survey was prepared from in-person interviews in YST recreational resorts. A total of 500 residents were randomly selected by the convenient sampling method, and the number of incomplete questionnaires reached 100 samples. A total of 400 respondents completed the questionnaire.
The data descriptive statistics of six parts of questions in the survey questionnaires are presented in
Table 1,
Table 2,
Table 3,
Table 4,
Table 5 and
Table 6, corresponding to the six parts of questions in the survey questionnaire. The tables contain data from the survey, offering insights into various aspects of the respondents’ visiting habits, preferences, and demographics.
In
Table 1, it is shown that respondents visited YST an average of 2.78 times in the past year, traveling an average distance of 109.55 km with a single trip taking approximately 2.54 h. They stayed in the township for an average of 10.84 h, traveling with an average group size of 5.83 people, and spending an average of TWD 5616.74 per person (1 USD = 31.15 TWD). Notably, 71% of the trips were solely to YST, indicating a high ratio of single-destination visits.
Table 2 highlights the distribution of departure places and transportation modes used by the visitors. A significant majority, 55%, departed from the northern region, while 17% were from within Yilan County. Smaller percentages came from the eastern, middle, and southern regions, with only 1% from other places. In terms of transportation, 74% of respondents traveled by car, with fewer choosing bicycles (1%), locomotives (12%), passenger transport (3%), and buses (10%).
Table 3 explores the recreational resources that respondents consider most valuable to protect. Natural resources, including landscapes, flora, and fauna, were highly valued by 70% of respondents. Human resources, such as agricultural culture and local drama, were important to 19%, while recreational facilities were valued by 10%. A small percentage, 1%, had other preferences.
Table 4 examines the revisit intention of respondents using a five-point Likert scale. The data show a general interest to revisit, with most respondents agreeing with the statements about revisiting in the near future (mode = 4), recommending YST to friends and relatives (mode = 4) and prioritizing it for their next travel (mode = 4).
Table 5 identifies the institutions that respondents believe would be most effective in protecting local natural recreational resources. The Yilan County Government was the most preferred, with 38% support, followed by the Office of Recreational Agricultural Zone at 30%, and the Yuanshan Township Office at 15%. Other institutions, such as the Committee Office of Community Management (11%), a private foundation (4%), and others (2%), received less support.
Finally,
Table 6 provides demographic information about the respondents. The gender distribution was fairly balanced, with 52% male and 48% female. The majority of respondents were aged 21–29 years (37%), with lower representation from those under 20 years and over 60 years. In terms of education, most respondents had completed senior high school (68%). The occupational distribution showed that 42% were in industrial, commercial, and service sectors, while 20% were students. Monthly income varied, with the largest group (23%) earning less than TWD 20,000.
2.4. Model Specification, Variable Definitions, and Descriptive Statistics
The final model specification for the travel demand model is given by Equation (4).
Based on the count data model in Equation (2), the specifications selected for this study are presented in Equation (4). The independent variables in Equation (4) include either statistically significant determinants identified through the interpolative and extrapolative mechanisms or key variables that are statistically insignificant but relevant for policy implementation in decision-making. All of the variables in Equation (4) are measured on a per-person basis.
The variable represents the visit time in the past year. X represents the vector of independent variables, and E(Q|X) denotes the conditional expectation of Q given X. The variable represents the price of the visit. The price is measured by travel expenditure per trip per person. It is the cost of the traveler’s single visit. The variable is a dummy variable representing departure from Yilan, where local visitors are coded as 1, and all others as 0. Since the survey was conducted around the Lunar New Year in 2023, the respondents’ leisure time and the opportunity cost of foregone wages were negligible, so time value represented by wages was not considered in the travel cost model (TCM) model specification. However, the variables for travel time and stay duration were still included in the model to demonstrate if they are significant. The variables of and are the travel time and duration of stay, measured in hours. DEST is the destination dummy, where a value of 1 indicates a single stop to Yuanshan Township and 0 otherwise. The variable represents the visitor’s age, measured in years. Since we assume the variable of is likely non-linearly related to the dependent variable, , the specification of our final choice are quadratic function of variable . is the variable representing the total monthly income, which includes both the fixed salary and additional sources of income such as rental income, investments, and freelance work.
The corresponding variable definitions are defined, and descriptive statistics are calculated, please refer to the definitions and corresponding statistics in
Table 7. The results of the statistical tests are reported in
Table 8 and the interpretation of regression results are illustrated in the next section.
The descriptive statistics of variables in
Table 7 provide a comprehensive snapshot of the variables included in the regression analysis. The data highlight key aspects such as the average number of visits to YST in the past year, which stands at 2.78 times with a relatively high standard deviation of 4.06, indicating high variability among visitors in their visit frequency. The high disparity of the visiting frequency indicates the appropriateness of adopting the negative binomial count data model.
Travel expenses per person are on average TWD 5616.74, showing considerable variability with a standard deviation of TWD 5345.32, suggesting diverse spending patterns among visitors. Additionally, the departure dummy variable () indicates that 17% of visitors depart from local Yilan county, distinguishing local visitors from others. The mean travel time per single trip () is 2.54 h, with a standard deviation of 3.11 h, reflecting variability in travel distances or modes among visitors. Stay time in YST () averages at 10.84 h, though with a larger standard deviation of 17.57 h, suggesting varying durations of visitor stays.
The destination dummy variable () indicates that 71% of visits involve YST as the sole destination, illustrating its appeal as a primary destination for many visitors. Demographically, visitors have an average age of 36.77 years, with a standard deviation of 12.33 years, indicating a diverse age range among tourists. Personal monthly income () among visitors averages 45,354.24, with a standard deviation of TWD 23,368.58, highlighting varying economic backgrounds among travelers.