You are here





Thesis Title: Muddy waters: Case Studies in Dry Land Water Resource Economics

Author: Rosalind Bark


Arizona like many other semi-arid regions in the world is facing a suite of policy issues that stem from water scarcity and security of supply issues intersecting with growing and competing water demands. A vexing issue in southern Arizona has been the preservation of riparian habitat. The study of environmental economics provides researchers with techniques to estimate the value of natural resources, such as riparian habitat, to level the playing field in policy discussions on development and water management. In Appendices B-D results from two hedonic property analyses suggest that homebuyers, one of the main consumers of riparian habitat in urban areas, have preferences for greener and higher condition riparian habitat and furthermore that they are willing to pay property premiums to benefit from this resource. There is also some evidence that riparian habitat conservation and restoration can be self-financing. The economics of another water using sector in the state, the recreation sector, specifically winter-based recreation, is assessed in Appendix E. The analysis finds that although ski areas in Arizona are subject to large inter-year variability in terms of snowfall and season length that snowmaking adaptations, a technology that is water-intensive, is financially feasible in the medium term as a climate variability and climate change adaptation. Nevertheless, ski areas in the state are likely to face increased financial pressures if climate change scenarios are realized and will have to implement other adaptation strategies to remain viable. Finally, water competition in the state between Indian and non-Indian users and the techniques used to dispel such tensions, namely water settlements, are discussed in Appendix F. The research finds that settlements offer opportunities for win-win agreements between the settling tribe and other water users in the same watersheds and for the introduction of new water supply management tools that benefit signatory and non-signatory parties alike.


Thesis Title: Examining Drivers Of Post-Wildfire Vegetation Dynamics Across Multiple Scales UsingTime-Series Remote Sensing

Author: Grant Casady


Ecosystem response to disturbance is a function of environmental factors interacting at a number of spatio-temporal scales. This research explored ecosystem response to wild fire as a function of local and broad-scale environmental factors using satellite based time series remote sensing data. This topic was explored as a series of three independent but related studies.

The first study focused on the evaluation of techniques for the analysis of time-series satellite data for describing post-fire vegetation trends at sites in the US, Spain, and Israel. Time-series data effectively described post-fire trends, and reference sites were valuable for differentiating between post-fire effects and other environmental factors. The use of phenological indicators derived from the time-series shows promise as a monitoring tool, but requires further investigation.

The next study evaluated the influence of broad-scale climate factors on rates of post-fire vegetation regeneration across the western US. Rates of post-fire regeneration were higher with increased precipitation and higher minimum temperatures. Changes in climate are likely to result in shifts in post-fire vegetation dynamics, leading to important feedbacks into the climate system. The use of time-series data was a valuable tool in measuring trends in post-fire vegetation across a large area and over an extended period.

The final study used time-series vegetation data to measure variations in post-fire vegetation response across an extensive 2002 wildfire. Regression tree analysis related post-fire regeneration to local environmental factors such as burn severity, soil properties, vegetation, and topography. Residuals from modeled rates of post-fire regeneration were evaluated in the context of management activities and site characteristics using expert knowledge. Post-fire rates of regeneration were a function of water availability, pre-burn vegetation, and burn severity. Management activities, soil differences, and shifts in vegetation community composition resulted in deviations from the modeled post-fire regeneration rates.

The results of these three research studies indicate that remotely sensed time-series vegetation data provide a useful tool for measuring post-fire vegetation dynamics. Both broad-scale and local environmental factors play important roles in defining post-fire vegetation response, and the use of remote sensing and geospatial data sets can be useful in integrating these factors and enhancing management decisions.


Thesis Title: Climate Change and Agricultural Policy Effects on Water Use in Agricultural Production: A Positive Mathematical Programming Approach

Author: Andy Hale


Agricultural production is affected by a range of policy and climatic variables. This research explored the impacts of cap and trade, climate change and agricultural policy scenarios on water resource use and allocation in agricultural production. The research is organized into three separate studies, one for each set of scenarios.

The first study focused on cap and trade policy for controlling greenhouse gas emissions, combining cost of production estimates with output price projections to determine the overall economic impact of cap and trade legislation, as well as its impact on agricultural water consumption. Price projections that included carbon offsets were higher than projections that did not, due to land being taken out of production and prices being bid up. HR2454 will increase production costs, particularly energy intensive inputs. Output prices increase as producers reduce production in response to cost increases. If agricultural offsets are allowed, output prices will be bid up further. Offsets allow producers to receive payments for cutting emissions. Taking land out of production and tree planting are the most likely way for farmers to earn offsets. In this case, incomes increased for producers due to indirect price effects. Since water is quantity limited, total water use is unchanged.

The next study looked at the physical impacts of climate change on production, particularly rising temperatures and carbon dioxide concentrations. By analyzing the anticipated yield effects, it was found that overall net incomes would decrease and the water constraint would remain binding – meaning total water use is unchanged.

The third paper analyzed the effects of agricultural policy on land and water resource allocation. Cotton is directly subsidized. Corn and grain sorghum are subsidized indirectly through ethanol subsidies. Sugar cane prices are artificially high due to tariff rate quotas on sugar imports. Removal of any of these interventions decreased net profits to producers, but water use remains unchanged. Removing all farm programs, however, significantly decreases acres under cultivation, and reduces water use below the water constraint.

These papers collectively show how net income, as well as land and water resource allocation, is affected by changes in the agro-climatic and agricultural policy landscape. The demonstrate that because water is quantity-limited, only scenarios which shift the demand curve significantly to the left begin to curb agricultural water use.


Thesis Title: Human-Environment Relationships in Drylands-with a Focus on the West African Sahel

Author:  Stefanie Maria Herrmann


The study of human-environment relationships in drylands, a topic that has engaged scientists for many decades, has captured new interest since satellite observations of land cover change over time became widely available. Particularly interpretations of the nature, extent and causation of desertification - or land degradation in drylands – have been influenced by the availability of more and more extensive time series of satellite observations.

This dissertation reviews some three decades of debate on the problem of desertification by examining advances in four disciplinary contexts in which these debates have evolved: our understanding of climate, ecology, social and political processes. Changes over time in these contexts have significantly influenced the direction of the desertification debate and created some controversy.

The respective roles that climate and human factors might have played in causing or sustaining environmental changes are then explored at the example of the West African Sahel region. Linear regression of time series of remotely sensed vegetation greenness data against rainfall data reveals where and to which extent trends in vegetation greenness are determined by rainfall, and, conversely, where other factors are likely to have played a significant role. While the results of the remote sensing study point to areas in which the impact of human factors is likely to have modified the simple rainfall vegetation connection, claims of widespread human-induced desertification at a regional scale are challenged.


Thesis Title: The Black Mesa Case Study: A Postaudit And Pathology Of Coal-Energy  Groundwater Exploitation In The Hopi And Diné Lands, 1968-2008

Author: Daniel Brott Higgins


In 1968, Peabody Western Coal Company commenced operations of a massive 54,000 acre coal mine on Black Mesa, Arizona, an arid and semi-arid region inhabited by the Hopi Tribe and Diné Nation. The mine fuels the Navajo Generating Station, which was developed to power the Central Arizona Project canal, which annually pumps 1.6 million acre-feet of Colorado River water nearly 3,000 feet uphill during its 333 mile journey to Phoenix and Tucson. Water for mine operations is pumped from a non-renewable aquifer beneath the Hopi and Diné lands.

After more than forty years of development, conflict characterizes the history of industrial groundwater exploitation on Black Mesa, and there is little understanding of the relationship between industrial withdrawals and its impact upon the region’s hydrological and social-ecological systems.

This case study performs a postaudit of groundwater model predictions used in the mine’s impact assessment studies, and it evaluates the efficacy of regulatory oversight. The study demonstrates that groundwater models consistently underestimated water-level decline caused by industrial withdrawals, overestimated declines caused by tribal community withdrawals; failed to capture the linear relationship between declining water levels and spring discharge; and predicted water-level recoveries that have not occurred. Further, at least two of the Regulatory Authority’s four threshold criteria for material damage have been crossed, and two have never been evaluated as intended.

Peabody’s groundwater model was purportedly “validated” and subsequently implemented for regulatory purposes; it demonstrated that declining groundwater trends at 14 Moenkopi and Tuba City (60 miles from the mine) are the result of community withdrawals and recent drought conditions. However, this postaudit demonstrates that declining discharge from Moenkopi School Spring has a strong, statistically significant relationship with the rate of Peabody’s groundwater withdrawals (r = -0.84; R2 = 0.71; p < 0.0001), while neither community withdrawals nor local precipitation have a statistically significant relationship with this spring.

In 2008, the Regulatory Authority revised its material damage criteria: all prior criteria expressing negative trends were removed from regulatory purview, and remaining criteria acquired insurmountable damage thresholds and will be evaluated using Peabody model simulations rather than USGS monitoring data.


Thesis Title: Effects Of Vegetation, Structural And Human Factors On The Thermal Performance Of Residences In A Semi-Arid Environment

Author: Susan Schaefer Kliman


The objectives of the study were to examine and quantify the relationship between vegetation and the thermal performance of residences in a hot arid environment. Also explored were structural and human influences on residential energy consumption. A primary goal was to determine how much energy savings could be realized through strategic planting of vegetation. This study sought to validate previous simulation and modeling studies that documented annual savings of 2-11% on residential cooling loads.

Also examined was whether shrubs and grass could provide a benefit similar to that of trees, assessing the importance of evapotranspiration versus shading. An empirical study was conducted using 105 existing homes in the metropolitan area of Tucson, Arizona. Data included construction type, amenities, living habits of occupants, and energy consumption for heating and cooling over a two-year period. These data were analyzed with a combination of bivariate and multivariate analyses to examine direct correlations between specific variables and energy consumption and the relative importance of each variable. These analyses were unable to document any measurable savings in summer cooling loads as a result of vegetation adjacent to the house, and the presence of trees actually increased the winter heating load by 2%. While trees provide important shading benefits, and can reduce the direct solar gain through the windows of a house, analysis demonstrated that structural and human factors were the most important aspects in residential energy consumption. The size of the house is of primary importance. Houses with evaporative cooling consumed significantly less energy than those with air conditioning. Thermostat settings and habits regarding thermostat operation were the most critical human factors. Occupants who adjusted their thermostats a few degrees cooler in winter and warmer in summer realized measurable savings. Occupants who turned their heating and cooling equipment off when they were not home used significantly less energy for heating and cooling. These factors far outweighed any impact from vegetation on annual energy consumption. While trees should not be considered as a primary means of reducing annual energy consumption, properly placed vegetation can provide aesthetic benefits and increase the thermal comfort of the occupants.


Thesis Title: Riparian Dynamics: The Ebb and Flow of Ecological Function

Author:  Amy LaFerne McCoy


Competition over freshwater resources is increasing at local and global scales. Growing urban and suburban centers utilize surface and groundwater resources to meet municipal, industrial, and agricultural demands, often at the expense of riparian ecosystems. Paradoxically, those same urban centers produce a significant volume of treated effluent that can be reused to restore and sustain riparian systems. Use of effluent as a source of water for the environment raises important questions about the benefits and impacts of effluent on riparian functions and ecosystem services, particularly in the context of climate change and drought conditions. This dissertation addresses knowledge gaps surrounding riparian change and resilience along the effluent-dominated Upper Santa Cruz River in southern Arizona. Appendix A investigates whether the Netleaf hackberry (Celtis laevigata var. reticulata) tree can provide accurate information on historic changes in climatic and hydrological conditions. Results indicate that hackberry trees do record climate-related stress in annual ring-width patterns and can therefore provide a historic frame of reference against which to compare current and future changes in riparian conditions. Appendix B documents spatial and temporal patterns of effluent uptake by Fremont cottonwood trees (Populus fremontii) through development of a new application for dendrochronology, specifically endrochemistry. Results show that annual tree rings contain temporally variable concentrations of a micropollutant found only in effluent and may have the potential to record spatial and temporal patterns of effluent dispersion in riparian ecosystems. Appendix C investigates the complex interactions of ecohydrological conditions that led to a riparian mortality event along the Upper Santa Cruz River in 2005. Effluent is shown to contribute to riparian vegetation expansion, but also, due to its consistent delivery of nutrients and water, homogenize the system and ultimately diminish its resilience to perturbations and stress. Results highlight the paradoxical nature of effluent as both a contributor to riparian growth and a potential impediment to riparian function. This paradox can be resolved through a well-defined effluent impact monitoring and assessment program that incorporates historic information as well as current trends to detect significant changes in ecosystem functions and services.


Thesis Title: A Well-Founded Fear? Tracing the Footprints of Environmentally Influenced Human Mobility

Author:  Lezlie Moriniere


Humans have fled environmental degradation for many millennia. Due partially to climate change, environments across the world have often degraded to the point that they can no longer securely sustain livelihoods. Entire communities and households have been displaced by extreme, rapid or creeping disasters; during their flight, they have left footprints across the globe that merit tracing. Sometimes this mobility is forced and at other times it is purely voluntary; for both, the mobility has roots in a changing environment. The footprint of environmentally influenced mobility (EIM) was traced through a series of three independent but related studies.

The first study gained foundational perspective through an exploration of connections between climate drivers and natural and human impacts of climate change. This inquiry sought to answer the question, "How important is human mobility in the greater scheme of changing environments and changing climate?" Human mobility was one among 15 different climate drivers and impacts studied; the connections between all of them were examined to enable a quantitative comparison of system susceptibility, driving force, tight coupling and complexity. While degradation was the most complex of all natural elements, mobility surfaced as the human system element exerting the greatest forcing on other elements within the coupled system.

The next study focused only on human mobility to explore how scholarly literature portrayed the two possible directions of the link between mobility and degrading environments--with a particular focus on urbanization as one manifestation of the phenomenon. Type A links, in which human mobility triggers environmental degradation, are portrayed in the literature as often as Type B links, in which degrading environments trigger human mobility. Surprisingly, science has not lent support to urbanization being a result of environmental change; plausible reasons for this are discussed.

The final study canvassed expert opinion to examine why no scientific, humanitarian or governmental entity has succeeded in providing systematic support (e.g., policy and interventions) to populations enduring environmentally influenced mobility. Four very different discourses emerged: Determined Humanists, Benevolent Pragmatists, Cynical Protectionists and Critical Realists. The complexity these discourses manifest help explain the inaction--a stalemate between actors--while confirming the inappropriateness of one-sided terminology and linear quantifications of environmentally influenced mobility.

The results of these three studies demonstrate that human mobility has unequivocally destructive force that can trigger non-linear effects, potentially casting the coupled system into an unprecedented state; that the visible lack of scholarly exploration of environmentally influenced urbanization (EIU) can be partially explained by high system complexity and disciplinary research; and most important, that despite diametrically opposed viewpoints, experts unanimously agree that human mobility has strong connections to environmental change. Together, the results merge to confirm a "well-founded fear" on the part of those who dwell in degrading environments, and to highlight a pressing need to offer solutions both to those who remain in such environments as well as a name and protected status to those who flee them.


Thesis Title: Ecosystem Transformation by Buffelgrass: Climatology of Invasion, Effects on Arizona Upland Diversity, and Remote Sensing Tools for Managers

Author:  Aaryn Olsson


Invasive species drive ecosystem changes throughout the world introduced grasses in dryland ecosystems have driven a grass-fire cycle that transforms ecosystems in homogenized grasslands (Brooks et al.204; D’Antonio & Vitousek 1992). Little is known about the spread rats of these grasses, effects on native ecosystems or how climate modulates spread, yet these uncertainties may be the difference between success and failure. Equally important is a quantitative assessment of the current states if invasion, yet mapping efforts have been lacking and remote sensing assessments have been inadequate for regional and local assessments. This research examines these uncertainties in the context of buffelgrass (Pennisetum ciliare Link (l)), a C4 grass introduced into the Sonoran Desert. These are presented as three distinct but related studies.

The first study document changes in diversity and dominance at 11 sites in the Sonoran Desert with respect to time since infestation by buffelgrass. Dominant and rare species alike declined rapidly following infestation, although longer-lived shrubs showed no signs until after five years. This calls into question basic assumptions about the grass-fire cycle.

The second study assesses constraints to successful operational identification of buffelgrass via remote sensing. We combined ground-based spectral measurements with cover estimates and found that Landsat TM-based classification will result in high commission/omission errors regardless of timing. We also identified several spectral characteristics that distinguish buffelgrass that are only available using hyperspectral imagery.

The third study reconstructs spread of buffelgrass using historical aerial photography dating from 1979. Populations grew from small colonizing patches to 66 ha in 2008, doubling every 2-3 years since 1988. Although spread closely fit a logistic growth curve between 1989 and 2008, we found evidence that the 1980s were a period of rapid expansion. Thus, we may presently be a period of slower spread in which treatment efforts will be more effective than the long-term average.

This research documents grass-led ecosystem transformation without changes in the fire regime and constant spread rates over multiple decades. Along with suggested methods derived from our remote sensing study, this provides managers with critical information for managing buffelgrass in the long-term.


Thesis Title: An emergent ethnomedicine: Rastafaribush Doctors in the Western Cape, South Africa

Author:  Lisa Philander


This dissertation is based upon research of an emergent ethnomedicine in a botanically rich area, the Western Cape of South Africa.  It examines the interface between ethnobotany and medical anthropology by investigating the biological and social factors related to the knowledge, use and trade of medicinal plants by Cape bush doctors. Incredible syncretism was observed in the identity formation of this homogenous urban group of healers who combined elements of a globally recognized eco-religion and sociopolitical movement Rastafari with several South African cultures through knowledge of medicinal plants.  By rejecting colonial principals, by including capitalistic biomedical systems, bush doctors have crafted a niche acquiring knowledge and herbal remedies for the treatment of common ailments.  Transmission amongst Rastas and trail-and-error experimentation with herbs emphasize that plant knowldege is situational and arises through relationships.  From an estimated 200 bush doctors in the Cape, 62 almost exclusively middle-aged colorued males were interviewed.  They declared their mission was to 'heal all people' through a reintroduction of KhoiSan healing traditions, and indigenous ancestry largely rejected by coloureds during apartheid.  An ethnobotany of bush doctors revealed that of 192 species, 181 were medicinal and included various herbs important to most South African cultural groups.  This largely herbaceous pharmacopeia is narrow compared to the region's high biodiversity and thirty-three species were identified as conservation priorities.  The presence of bush doctors at transportation hubs as herbal hawkers creates a diversified economy through cultivation of relationships with primarily disadvantaged coloured and black consumers.  The consumption, trade and sale of local plants by bush doctors represent efforts to embody the landscape; it reasserts coloured links to indigeneity renews respect for their heritage and affords right to resources.  By evoking tradition within their tolerant philosophy, leaders of this emergent ethnomedicine develop a racially equitable and ecologically sustainable platform for health care evidenced by medicinal plant gardens in townships and transmission of diverse ethnomedical knowledge.  Bush doctors are legitimized through the performance of transmission.  This phytomedicinal knowledge reifies an ideology, repositioning coloureds in a moderate stance between colonial biomedicine and traditional African ethnomedicines, but also creates a unified South African medicine.

Thesis Title:  Soil carbon sequestration in small-scale farming systems: A case study from the Old Peanut Basin in Senegal

Author:  Petra Tschakert


Carbon sequestration in small-scale farming systems in semi-arid regions offers the possibility to increase local soil fertility, improve crop yields, enhance rural people's wellbeing, and strengthen the resilience of agricultural systems while reducing CO2 accumulation in the atmosphere and, thus, contributing to climate change mitigation. A variety of management practices and land use options have been proposed to increase carbon uptake and reduce system losses. So far, less attention has been paid to local smallholders, the ultimate agents of anticipated community carbon projects, and the complexity, diversity, and dynamics of their livelihoods in a highly variable and risk-prone environment.

A hybrid research approach, combining biophysical, economic, cultural, and institutional analysis, was used to assess the potential for soil carbon sequestration in the Old Peanut Basin of Senegal. In situ soil and biomass measurements provided current carbon accounts. Historic carbon changes and future sequestration rates under various management practices were simulated with CENTURY, a biogeochemical model. The simulation results well represented general historic trends and carbon storage potential. However, they did not accurately reflect variable and flexible site-specific management strategies as farmers adapt to stress, shock, and crises over time. To account for these, distinct pathways of agricultural and environmental change were examined in Wolof and Serer villages and viable options for carbon sequestration were evaluated. Systems analysis was used to explore the various components that influence farmers' perceptions, choices, and decisions with respect to land management. Results showed that resource endowment and institutional and policy incentives determine which carbon sequestration activities might be most appropriate for different groups of farmers. Finally, a cost-benefit analysis and a cash-flow analysis (using STELLA) were performed to assess the financial profitability and economic feasibility of proposed management strategies. The study reveals large differences in these measures between farmers with low and high resource endowments. In most cases, local smallholders are not likely to have the investment capital necessary to implement the alternative management practices. A farmer-centered approach to carbon sequestration, as proposed by the study, can be used to more effectively address the needs and capacities of smallholders in dryland carbon offset programs.


Thesis Title: Intranational variations in the key determinants of food security

Author:  Eric Weiss


"Food Security" is defined as the condition in which an assured, sustainable supply of enough nutritionally proper food is available for people to lead healthy, productive lives. The condition in which any of these requirements is missing is known as "Food Insecurity." In this paradigm, absolute food security as enjoyed by most people in the United States is at one end of the food security continuum and Famine is at the other; different levels of food insecurity make up the rest. The above definitions mandate that any analysis of why regions or populations are vulnerable to different levels of food insecurity must consider more than just the availability of food. The "Indicator Approach" to these analyses is based on the collection and analysis of diverse types of data, from multiple sources, which address socioeconomic, agroecological, demographic, environmental, agricultural and political factors in order to come to a more comprehensive understanding of food security conditions and their underlying causes in the areas studied. The hypotheses of this research are (1) That some of these "indicators" are correlated to measures or proxies for vulnerability and food insecurity at statistically meaningful levels, and (2) That the indicators so related will, in general, vary at the subnational level. The data set for this research consists of about 70 indicator and outcome parameters from different aspects of life in the Republic of Malawi, in Southern Africa. The analysis was performed through the following sequence of steps: (1) Definition of four national level proxies for Vulnerability and Food Insecurity, (2) Decomposition of Malawi's 154 EPAs into six non-overlapping EPA clusters, and (3) Independent analysis of each EPA cluster and the nation for each proxy variable with three analytic approaches (Bivariate Correlation, Regression Trees, and Multiple Linear Regression). The results of these 84 separate "mini-analyses" confirmed the research hypotheses and led to other conclusions about vulnerability assessments in general, and conditions in Malawi in particular. These results independently confirm that very small landholdings, female heads of household, and the lack of adequate employment opportunities are among the primary correlates of vulnerability and food insecurity in Malawi.


Thesis Title: Ecotourism as a Social-Ecological System: A Case Study in Guanacaste, Costa Rica

Author: Joanne Gallaher


Despite the dramatic increase in ecotourism as a sustainable development strategy over the last two decades (Honey 2008; Yunis 2000), theoretical models to interpret and evaluate ecotourism—as well as the broader field of tourism—are lacking (Farrell and Twining-Ward 2003; Weaver and Lawton 2007). Farrell and Twining-Ward (2003) call for a reconceptualization of tourism study that incorporates social-ecological systems (SES) theory. This dissertation responds by assessing ecotourism as an SES in a dryland setting, addressing the question: ―What key characteristics of ecotourism increase social-ecological resilience?‖ The study site is Santa Rosa National Park and surrounding communities in Guanacaste, Costa Rica. Higham and Lück (2008) cite sustainability as the ―ultimate goal of ecotourism‖ (Higham and Lück 2008, p 124); however sustainability itself proves to be a difficult concept to measure and evaluate (Cater and Lowman 1994; Dernbach 2002; Weaver 2001a). SES theory recognizes sustainability as a process rather than an end goal and identifies resilience as a key attribute (Berkes, Colding, and Folke 2003). With ecotourism as an economic strategy of nearly every developing country since the early 1990s and an increasing economic strategy in rural areas worldwide (Valaoras, Pistolas, and Sotiropoulou 2002; Honey 2008), this study investigates ecotourism through the lens of social-ecological resilience for increased sustainability. Based on a 12-month survey conducted in Santa Rosa National Park and the surrounding area, this study identifies characteristics of ecotourism that can cause different levels of resilience using indicators of increasing biodiversity, economic 13 diversity and social capital. These relationships are represented by linked and continually changing social and ecological systems, diagramed by Holling‘s adaptive renewal cycle (Berkes, Colding, and Folke 2003; Gunderson and Holling 2002). Three research papers are included as part of this dissertation: 1) Área de Conservación Guanacaste, Parque Nacional Santa Rosa Ecotourism Study: Final Survey Results, Analysis and Recommendations; 2) Ecotourism‘s Contribution to Social-ecological Resilience: A Case Study Analysis of Rural, Dryland Ecotourism in Guanacaste, Costa Rica; and 3) Barrier-free Ecotourism? The Costa Rican Approach. Findings of this study include recommendations for ecotourism programs to increase social-ecological resilience and contribute to the sustainability of linked SESs.

Last updated 25 Apr 2012