Ph.D. - Natural Resources and Environmental Management

Permanent URI for this collectionhttps://hdl.handle.net/10125/20037

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Mixed stand management between ‘iliahi and host plants in Hawaiian-restored tropical dry forests
(University of Hawai'i at Manoa, 2025) Wirabuana, Pandu Yudha Adi Putra; Idol, Travis W.; Natural Resources and Environmental Management
This dissertation aimed to assess the development and tradeoffs of key interactions between ‘iliahi (Hawaiian sandalwood, Santalum paniculatum) and host plants at the forest stand level. This was designed to fill knowledge gaps in ‘iliahi ecology and to recommend silviculture strategies for ‘iliahi restoration. Survey experiment was conducted to explore ‘iliahi-host plants interaction at the community stand level in a Hawaiian-restored tropical dry forest. Results found the interaction between ‘iliahi and host plants not only related to facilitation but also included competition and parasitism, wherein these interactions occurred simultaneously. Competition increased facilitation but mitigated parasitism. The levels of facilitation-parasitism crossed at a basal area of 24 m2 ha-1 which indicate an optimum level of competition to stabilize ‘iliahi-host interactions and lead to their balanced growth. Maintaining the ideal competition through silviculture intervention like targeted thinning seems to be required to optimum the growth of both species. Our study also realized that the magnitude of ‘iliahi-host interactions was also related to the proportion of both species at the forest stand. A host:’iliahi ratio of 2:1 was required to balanced competition, facilitation, and parasitism. This ratio can be considered for planting and maintenance to support long-term survival and growth of ‘iliahi and host plants. Pre-establishing hosts before planting 'iliahi and maintaining a host:'iliahi ratio of 2:1 are recommended to maximize establishment of ʻiliahi and long-term survival of all species and to optimize individual species and forest stand growth by optimizing 'iliahi-host interactions. This recommendation not only helps to preserve ‘iliahi and host plants in Hawai’i but also may support sandalwood conservation globally and represents alternative silviculture system to simple plantation models.
Inclusive or illusive? Assessing effects of voluntary private governance on smallholders, workers, and communities in palm oil industry in Indonesia
(University of Hawai'i at Manoa, 2025) Ekaputri, Andini Desita; Carlson, Kimberly M.; Natural Resources and Environmental Management
Voluntary private governance, including sustainability certification is often promoted as a market-based solution to mitigate the social harms of large-scale agricultural commodity production, yet its effects remain uncertain. This dissertation evaluates how multi-criteria sustainability certification of corporate oil palm plantation companies by the Roundtable on Sustainable Palm Oil (RSPO) benefits the diverse and vulnerable groups living within plantation landscapes: smallholder oil palm farmers, plantation workers, and resident communities. I first assessed whether certification enables equitable smallholder participation in certified supply chains by combining geospatial mill supply-shed maps with time series data on mill sourcing and certification across Indonesia. I found that contract smallholders were well integrated into certified markets, but independent smallholders were largely excluded by structural market barriers rather than direct removal. Next, I identified pairs of similar certified and non-certified oil palm plantations in Kalimantan (Indonesian Borneo). Here, I surveyed oil palm plantation workers housed by companies, and households in nearby resident communities, analyzing recall questions to assess the causal impact of certification on these populations. For plantation workers, certification was associated with perceived improvements in conflict resolution with companies, wage fairness, payslip detail, and housing quality, but declines in school facilities, training, equal employment opportunity, and union autonomy. Third, village-level surveys near certified and non-certified plantations find only limited benefits for resident communities, with perceptions of companies shaped more by long-standing relationships, elite capture, and pre-existing development programs than by certification. Taken together, these studies show that RSPO certification delivers uneven and often modest social gains, particularly for independent smallholders and local communities, while leaving many underlying power imbalances intact. The dissertation advances debates on the legitimacy, inclusiveness, and effectiveness of voluntary private governance in agrarian frontiers.
Public preferences, and willingness to pay for water allocation between local food production & watersheds in Oʻahu, Hawaiʻi
(University of Hawai'i at Manoa, 2025) Widanage, Rupananda; Chan, Catherine C.; Natural Resources and Environmental Management
This dissertation addresses a critical issue in water resource management by investigating public preferences for allocating water between local food production and watershed protection in Hawaiʻi. Given the increasing challenges of climate change, population growth, and resource constraints, the topic is timely and highly relevant to local and global contexts. Collectively, the chapters 4, 5, and 6 show that sustainable water–food–wetland management in Hawaiʻi requires a policy framework that (1) incorporates public preferences into water allocation, (2) uses partial social cost water pricing to promote efficient and ecologically sustainable water use, and (3) invests in watershed ecosystem restoration based on demonstrated public benefits. This integrated set of findings supports a shift toward holistic natural resource management that recognizes the interconnectedness of ecological health, cultural values, and resilient food systems. By integrating environmental economics, policy analysis, and agroecological perspectives, the dissertation highlights how market mechanisms and community values support ecologically resilient and culturally grounded natural resource management. Together, the results demonstrate that sustainable water–food–wetland systems require coordinated policies that balance efficiency, equity, and ecological sustainability. Such an approach is consistent with Hawaiʻi’s long-term goals for food self-sufficiency, sustainable water management, and restoring wetland ecosystem services. The dissertation investigates public preferences for water allocation between local food production and watershed protection, with a focus on policy implications for sustainable water management in Oʻahu, Hawaiʻi. Using a choice modeling approach, the dissertation employs a Multinomial Logit (MNL) model to quantify the relative importance of key water management attributes, such as food self-sufficiency, watershed health, and biodiversity richness, on stakeholder preferences. A Latent Class Model (LCM) further explores socio-demographic heterogeneity, identifying three preference segments: environmental stewards (57%), food security enthusiasts (36%), and cost-conscious households (7%). The willingness to pay (WTP) values to quantify the non-market benefits of water-related public goods, such as biodiversity richness and watershed health, are a strong point and add robustness to the analysis. The study's focus on sustainable agricultural water management through a public preference lens makes a significant contribution to policy discussions and water allocation frameworks, particularly in regions with competing demands for water resources. Findings reveal positive and significant WTP values for improving ecosystem services, indicating strong public support for sustainable water use. The study critiques existing water pricing practices in Hawaiʻi, noting that predetermined rates fail to account for the opportunity costs of agricultural water use. It recommends a partial social cost pricing approach that internalizes trade-offs between agricultural use and ecological conservation, such as promoting both environmental sustainability and increased revenue for the Department of Agriculture (DOA). The partial social cost price is $ 0.63 per 1,000 gallons of surface water use in local food production. The dissertation also applies the contingent valuation method (CVM) to estimate public WTP for restoring wetland ecosystem services in Kawainui Marsh. Restoration scenarios (moderate: 13 acres; high: 25 acres) yield monthly WTP estimates of $12 and $23, respectively. Results suggest that education, environmental awareness, outreach programs, and generating conservation funds enhance support for wetland restoration. The research concludes that scenario-based economic valuation of ecosystem services can guide more efficient and equitable water management policies aligned with the United Nations Sustainable Development Goals (SDG). This dissertation contributes to the theoretical and empirical foundations of ecosystem service valuation and water policy design, with implications for researchers, policymakers, and water-related agencies. It offers a replicable framework for integrated water resource management (IWRM) in Hawaiʻi and other tropical regions facing similar sustainability challenges. If I were to undertake this research again, I would incorporate a stronger participatory approach by engaging local stakeholders earlier in the survey design and scenario development phases. Their involvement would provide richer cultural and contextual insights, ensuring that the research outcomes are both relevant and actionable for local policy and management. I would also dedicate greater attention to refining data collection methods to more effectively capture uncertainty and heterogeneity in both expert and public responses. Overall, this dissertation has strengthened my conviction that sustainable agriculture and resource management demand interdisciplinary collaboration, cultural awareness, and methodological rigor. The experience has shaped my identity as a researcher committed to bridging food and resource economics with practical conservation efforts, working toward a future where Hawaiʻi’s food systems, water resources, and ecosystems continue to sustain both people and nature for generations to come.
Recognizing Indigenous Knowledge and Values Through the Discipline of Cultural Ecosystem Services: Insights for Research, Management, and Academia
(University of Hawai'i at Manoa, 2024) Nakachi, Alohi; Oleson, Kirsten; Leong, Kirsten; Natural Resources and Environmental Management
The discipline of cultural ecosystem services (CES) has gained momentum in recognizing some of the connection between social and ecological systems mainly through human-nature interactions. CES has gained recognition within management agencies as there have been national memorandums to include ecosystem service research in decision making within federal agencies. While the discipline of CES offers an avenue to recognize connections between humans and our surrounding environments, standard CES research and conceptualization does not do well at including diverse worldviews and values such as Indigenous Knowledge. In this dissertation I seek to explore avenues to elevate the CES discipline to better recognize and understand Indigenous Knowledge and diverse worldviews and values. I am conducting this research as a Native Hawaiian Indigenous social scientist funded by NOAA to support their West Hawaiʻi Integrated Ecosystem Assessment. I conducted this research in Hawaiʻi and within my own community of West Hawaiʻi with four main objectives. These objectives are: (Chapter 2) creating an elicitation tool, the levels of intensity, using a two-eyed seeing approach to present information in a way that could be used by management agencies while better acknowledging the diverse meanings and reasons humans interact with their environments; (Chapter 3) employing the levels of intensity tool in deliberative workshops to understand the deeper reasons of and meanings behind human-nature interactions and move CES research beyond a one-dimensional categorization; (Chapter 4) spatially representing socio-cultural relationships to place and Indigenous Knowledge by conducting participatory mapping interviews about kuleana with key informants of Native Hawaiian knowledge holders in West Hawaiʻi; and (Chapter 5) exploring the benefits and limitations of survey research on CES with a broad audience to better acknowledge some of the diverse meanings and interactions people have with their surrounding environments. Throughout this dissertation I explore ways to elevate Indigenous Knowledge and worldviews so they can be better recognized within current research and management practices.
Assessing thresholds and outcomes in marine social-ecological systems
(University of Hawai'i at Manoa, 2024) Perng, Lansing Y.; Oleson, Kirsten L. L.; Natural Resources and Environmental Management
In coastal social-ecological systems (SESs), ecosystem goods and services (EGS) are vital to many social, economic, and cultural objectives. However, the historical focus of monitoring and assessment efforts has predominantly centered on ecological states, underrepresenting equally vital social states. To support ecosystem-based management, which seeks to manage natural resources and human systems as integrated SESs, this dissertation aims to provide a comprehensive evaluation of SES conditions over time and space with an emphasis on EGS delivery. In Chapter 2, I reviewed analytical methods for identifying social thresholds and comparing achievement of social objectives across different states. I highlight methods such as Generalized Additive Modeling (GAM) and Data Envelopment Analysis (DEA) for their flexible ability to discern shifts and assess SES performance. Chapter 3 applies GAM and DEA to identify social shifts and compare outcomes in six U.S. marine SESs, shedding light on management insights and regional drivers. Chapter 4 expands these analyses to a case study in Hawai‘i, where I identify thresholds and trends in region-specific fisheries, tourism, and coastal employment and link them to regulatory and environmental drivers. Finally, Chapter 5 adopts a forward-looking perspective, examining future SES conditions in Hawai‘i by integrating climate scenarios with a spatially-explicit ecosystem model to project outcomes across the main Hawaiian Islands until the end of the century. Historical thresholds and significant trends coincided with management actions, economic changes, and to a lesser extent, environmental perturbations. Future projections reveal that environmental changes, particularly climate change, are poised to exert a more pronounced influence on SES outcomes in the coming decades. Collectively, these chapters highlight the importance of place-based approaches in SES research, the complexities inherent in reconciling conflicting objectives, the need for consistent social data collection, and the growing importance of climate change impacts in shaping SES trajectories.
Managing carbon in soils, feedstocks, and conversion pathways of tropical agricultural production systems for bioenergy
(University of Hawai'i at Manoa, 2020) Wells, Jon Michael; Crow, Susan E.; Natural Resources and Environmental Management
Achieving statewide 100% renewable energy and net carbon storage by 2045 in Hawaii will require exploration of all possible sustainable energy sources. This dissertation focused on one important component of Hawaii’s potential clean energy portfolio—biofuels produced from tropical perennial C4 grasses. Accurate system-level analyses of these tropical agricultural production systems were lacking information in critical areas, which created barriers to their full consideration for inclusion in the portfolio. To address this issue, several key data sets were collected, including: 1) physicochemical predictors of soil organic carbon under long-term C4 grass production, 2) carbon and energy conversion efficiency of several bioenergy grasses through two conversion pathways, and 3) lignin structural controls on conversion to energy. Belowground, aggregate stability, surface charge, and mineral-root interactions protected soil carbon from losses despite intensive agriculture practices. Aboveground, highly variable amounts of energy were recoverable across species and varieties of C4 grasses, with lignin ratios showing strong prediction of energy variance. Taken together, the data provides important system constraints that must be maintained to keep agricultural production of these grasses for bioenergy carbon neutral, allowing the first data-driven development of carbon and energy neutral production systems.
Causes and Mechanisms of Flooding in Hawaiʻi
(University of Hawai'i at Manoa, 2023) Huang, Yu-Fen; Tsang, Yinphan; Natural Resources and Environmental Management
Flooding often results from intense and localized nature of extreme rainfall events and poses a significant threat to communities of Hawaiʻi. This dissertation research deciphers the intricate relationship between extreme weather events and flooding within the unique context of tropical islands by advancing the rainfall dataset with best available gauge and radar data and investigating complex interactions between rainfall event characteristics and streamflow responses. First, I investigated the relationships temporally and spatially between the trends of annual maximum daily rainfall and peak streamflow. The results showed that, in general, the Hawaiian Islands experienced weaker extreme rainfall (67% of rain gauges) and streamflow (61% of stream gauges). The findings also emphasized that the annual peak streamflow cannot be fully attributed to the trends of annual maximum rainfall of one gauge per watershed. In addition, the timing of extreme rainfall and streamflow occurred earlier in the wet season during the El Niño years. Second, the high resolution (hourly, 250-m) rainfall dataset on Oʻahu has been produced by merging radar and gauge rainfall. Moreover, the advantages of the merging method, Kriging with external drift (KED) has been adopted and evaluated with storm types (i.e., Kona lows, tropical cyclones, cold fronts, and upper-level trough) and rainfall structures (i.e., stratiform or convective rainfall) within 17 severe storm events. The study highlighted that KED reduced the error from radar rainfall with an advantage on estimates of convective rainfall during severe storms. Lastly, building based on the improved rainfall datasets, the research expanded on the critical role of rainfall characteristics in influencing the magnitude of peak flow. I reconfigured WRF-Hydro, a physically-based and fully distributed hydrological model with 250m resolution, to simulate high flow events. I first evaluated the rainfall event characteristics on streamflow responses, and then I experimented the responses with designed rainfall with different spatial properties. The results underscored the significance of rainfall amount, intensity, and rainfall spatial characteristics effects on the event peak flow. In particular, rainfall spatial heterogeneity increased uncertainties of peak flow timing related to peak rainfall in small tropical watersheds. This extensive research represents a significant step forward in the quest to enhance our understanding of the complex hydrological processes and flooding dynamics in tropical island regions and provides valuable groundwork for improving flood study and forecasts that associated risks in Hawaiʻi and similar tropical island environments.
Regeneration Of ʻiliahi (santalum Paniculatum): Hemiparasitic Relationships In Hawaiian Tropical Dry Forests
(University of Hawaii at Manoa, 2023) Senegal-Thyroff, Emily; Idol, Travis W.; Natural Resources and Environmental Management
Santalum (sandalwood) species, including the endemic Hawaiian species known as ʻiliahi, are ecologically distinct as root hemiparasitic, evergreen trees requiring suitable hosts for long-term resource acquisition. Restoration and sustainable forestry of ‘iliahi at degraded sites, including threatened tropical dry forests, therefore, require supporting host plant populations. In this Ph.D. dissertation, I aimed to improve the survival and establishment of planted ‘iliahi, Santalum paniculatum, seedlings by better understanding the hemiparasitic relationship between ‘iliahi and native tropical dry forest host species. Three projects were implemented to address this overarching goal with the intention of integrating results into current stewardship strategies. The first project compared host dynamics for ʻiliahi paired with different species at varying planting distances. In June 2019, 360 one-year-old container ‘iliahi seedlings were planted in a completely randomized experimental design. ‘Iliahi seedlings were randomly assigned one of nine treatments: ‘iliahi with (1) no host (control), (2) koa at <0.2 m, (3) koa at 0.5 m, (4) koa at 1.0 m, (5) koa at 2.0 m, (6) ‘a‘ali‘i at <0.2 m, (7) ‘a‘ali‘i at 0.5 m, (8) ‘a‘ali‘i at 1.0 m, and (9) ‘a‘ali‘i at 2.0 m. After three years, ‘iliahi grew more and had greater foliar nitrogen concentration when paired with koa (Acacia koa) at a close distance than with ʻaʻaliʻi (Dodonaea viscosa) at any distance or the control with no host. In the second project, I assessed potential tradeoffs between competition and parasitism of ʻiliahi planted under an established koa host canopy. In August 2020, 324 nine-month-old container ‘iliahi seedlings were planted under the canopy of ten-year-old koa trees. Canopy openness above each ‘iliahi seedling varied throughout the planting site with a range of 8.8 % to 90.1 %. ‘Iliahi seedling height and diameter were greater with larger canopy openness, and physiological measurements also increased with greater canopy openness. In the third project, I examined the transfer of resources between ʻiliahi and its host. In April 2021, 2-pot and 3-pot experimental units were established with the roots of ‘iliahi and koa split between containers. The 2-pot and 3-pot units allowed the segregation of roots to examine root exudate transfer and haustoria transfer between ‘iliahi and koa. In April 2022, 15N and 13C stable isotope tracers were applied to specific units and species. We detected 15N root exudate transfer and 15N transfer from the host koa to the hemiparasite ‘iliahi. One- and two-way transfer of 13C were detected in the roots; however, we are cautious as to the biological significance of this result. These results contribute to our understanding of hemiparasitic plants and improve efforts to restore native Hawaiian dry forests, form a sustainable ‘iliahi silviculture basis, and contribute to sustaining functionally compatible and abundant forests.
Conflict Resolution Mechanisms For Developing Marine Protected Area Governance: The Case Of Ko Libong, Thailand
(University of Hawaii at Manoa, 2022) Supholdhavanij, Jutha; Oleson, Kirsten L.; Natural Resources and Environmental Management
This doctoral research aims to provide insight into what governance arrangements could enhance the performance of Thailand’s multiple-use marine protected areas (MPAs) by analyzing the critical features of conflict resolution mechanisms. Conflict resolution mechanisms, comprised of resource governance, applicable procedures, and institutional arrangements, are essential features of MPA governance, whose resilience is critical to marine conservation performance. Yet the role of conflict resolution mechanisms in developing governance that contributes to the performance of marine reserves is underspecified. Furthermore, more efforts are needed to explore social-fit aspects of conflict resolution mechanisms at the local level to explain the strength of the links toward MPA governance protocols. Based on the single-site case study in Thailand, this research focuses on governance aspects of conflict resolution surrounding dugong conservation management in the multiple-use MPA named the Mu Ko Libong Non-Hunting Area. The dissertation has three main research chapters, focusing on (1) the acceptance of rules, (2) the effectiveness of rulemakings, and (3) the range of third-party roles. The dissertation is structured around three main aspects of the linkages between governance and conflict resolution mechanisms, as described by social fit theory: (1) the appropriateness of resource governance to the local context (Chapter 3), (2) the alignment of applicable procedures for conflict resolution to meet the local need (Chapter 4), and (3) the adequacy of institutional arrangements for conflict resolution at the local level (Chapter 5). In the first chapter, I use the theory of self-determination to analyze people’s senses of acceptance. In the second chapter, I use environmental mediation effectiveness theory to evaluate the extent to which each indicator in a rulemaking effectiveness model exposes the achievement of proposed MPA rules and measures. The third chapter uses environmental conflict resolution theory to investigate the range of third-party roles. The research gathers data through various social science methods, including document reviews and analyses, semi-structured interviews, focus group discussions, and direct non-participant observations. Each research chapter purposefully selects key informants. The first chapter focuses on twenty MPA residents represented as local administrative organization staff, dugong conservation group members, and coastal resource users. The second chapter concentrates on ten participants of the rulemaking meetings the related government officials carried out to aid facilitation. The final chapter centers on two local support agent groups, including provincial government officials and local non-governmental organization (NGO) workers, as the potential advisory committee serving dugong conservation management in the Ko Libong area. All three research chapters use content analysis of detailed data to uncover the underlying issues of state-local interactions and explain specific context occurs. The first chapter reveals that the MPA rules facilitate community livelihood activities, as reflected by the perception that MPA rules are supportive and provide the opportunity to mitigate conflicts. In the second chapter, the effectiveness evaluation of rulemaking proceedings points out that meaningful responsiveness to livelihood needs with a concern of improving access to resources can decrease potential conflicts from conservation management. The third chapter determines that the institutional arrangement, through the aspect of the advisory committee possessing convening, facilitation, and mediation functions, is adequate to deal with a situation that needs an intervention. Integrating the three research chapters leads to the conclusion that three social-fit aspects of conflict resolution mechanisms at the local level have considerably contributed to developing the governance of the MPA. Particularly, locally accepted rules, effective rulemakings, and present third-party roles were crucial to pushing good governance in addressing conflicts associated with implementing conservation management, which was necessary to enhance the MPA performance. The critical chance that derives from the exploration in detail through the case is the recognition of relations with relatives as a traditional mechanism for gathering MPA residents to give their voices and taking responsibility for conservation according to MPA management. Relations with relatives enable a mechanism of ownership to build a local movement and acknowledge the community as a primary stakeholder in the planning and decision-making of MPA management initiatives. Ultimately, this dissertation grants insight for using a social-fit perspective to examine the governance of MPAs through understanding conflict resolution mechanisms’ contribution to collaborative conservation management. Collaborative interactions between officials and local people through informal and formal forms of legal proceedings can support the critical aspects of resilience governance. Analysis of the implications of the conflict resolution mechanism for MPA governance leads to understanding the bottom-line aspects of the employment of conflict resolution mechanisms in MPA governance. At the same time, the investigation of institutional arrangements for conflict resolution indicates the necessity to outgrow governance paradigms through adaptive approaches that maintain the balance of social and ecological objectives.
Temporal Ecology of Hawaiian Waterbirds
(University of Hawaii at Manoa, 2022) Harmon, Kristen C.; Price, Melissa R.; Natural Resources and Environmental Management
Conventional conservation has largely been informed by spatial ecology research, such as identifying optimal locations for conserving species and their habitats. However, in a rapidly changing world, it is becoming increasingly important to include temporal ecology, how ecological systems change over time, in conservation planning. In Hawai‘i, state and federal entities have created over 6,000 ha of protected wetland habitat for endangered, endemic Hawaiian waterbirds. Sea level rise poses a threat to many of these protected areas, as many of these wetlands are located on lowlands and nearshore. As Hawaiian waterbirds are currently habitat limited, creating new waterbird habitat will be necessary for the persitance of these populations. However, the uncertainty posed by climate change creates challenges for identifying optimal locations for new waterbird habitat that will be resilient to change. Restoration of Hawaiian wetland agroecosystems (loʻi) under an Indigenous Resource Management (IRM) paradigm may offer a sustainable land-scape level solution to expanding Hawaiian waterbird habitat, as the adaptive, social-ecological framework of these systems increases resilience following disturbance. However, incorporating IRM into conventional conservation approaches has been challenging, in part due to biased perspectives of human-wildlife relationships that are based on shortsighted historical ecology research. Moreover, current conservation goals for recovering Hawaiian waterbird populations are largely informed by research on present-day waterbird ecology. Thus, in this dissertation, I aimed to examine the temporal ecology, including past and present-day ecology, of Hawaiian waterbirds to better understand the future trajectory of their populations. My objectives were to: (1) review empirical evidence for the historical ecology of Hawaiian waterbirds; (2) determine impacts of seasonality and nest-site characteristics on nest survival of the Aeʻo (Hawaiian Stilt – Himantopus mexicanus knudseni); (3) quantify projected losses of Hawaiian waterbird nesting habitat due to sea level rise and the potential for Hawaiian wetland agroecosystems to compensate for these losses. In my first study, I found that the empirical evidence supports the notion that climate change and species introductions were major drivers of post-settlement Hawaiian waterbird extinctions during the Holocene, rather than overhunting and deforestation by Hawaiians. In my second study, nest survival of Aeʻo was found to decrease over the course of the nesting season, possibly due to changes in predation pressure. My results indicate that predation of nests by invasive species, particularly mammals that were introduced to Hawai‘i in the 19th century, is one of the largest threats to Aeʻo populations and likely other extant endangered waterbird populations. The preferred nest-site characteristics of Aeʻo do not improve nest survival, and thus continuous management of predators is critical for Aeʻo reproductive success. In my third chapter I found that sea level rise is projected to reduce currently existing potential waterbird nesting habitat across the main Hawaiian Islands by 29%; however, I found that restoration of loʻi systems may more than compensate for these losses. Together, findings from this dissertation research suggest that restoration of Indigenous agroecosystems, coupled with control of invasive vegetation and predators, may expand conservation of endangered, endemic Hawaiian waterbirds beyond state and federally managed protected areas. My findings help to inform how conservation approaches are most effective when viewed through the perspective of temporal ecology.
Speaking of Abundance: Taíno Ecolinguistic Ontologies, Pre-colonial Biocultural Systems, and Decolonial Pathways to Food and Material Sovereignty in Puerto Rico
(University of Hawaii at Manoa, 2022) Fisk, Jonathan James; Vaughan, Mehana; Natural Resources and Environmental Management
Puerto Rico’s food systems are dangerously precarious, with the islands importing about 90% of its food, a consequence of five centuries of colonialism prioritizing foreign profit over local welfare. Particularly in the aftermath of Hurricane Maria, though, there has been a swelling movement towards food sovereignty on the islands, often aligned with overlapping movements towards the resurgence of Taíno identity and culture. Bringing these movements together, this dissertation focuses on Taíno social-environmental systems, using the recorded Taíno language as the primary vantage point in order to understand the dynamics of pre-colonial social-environmental systems on the islands, the cultures that shaped such systems, and how that can guide us to food and material sovereignty on the islands. This dissertation is grounded in a decolonial research methodology, which I develop and provide as a generalized framework such that other researchers can make use of it as well. Delving into Taíno ecolinguistic ontologies – or the worldviews and relations revealed by the nexus between language and the environment – demonstrates a high degree of naming multiplicity in the Taíno lexicon, particularly for plants and animals with which there was greater intimacy in Taíno cultures. Additionally, redundancy was a prominent feature in pre-colonial Taíno bicultural systems, contributing to socioecological resilience, although there were several categories, especially related to spiritual functions, for which certain biota are simply irreplaceable. Although there are numerous critical barriers obstructing food and material sovereignty for Puerto Rico, the lessons gleaned from Taíno culture, particularly Taíno ecolinguistic ontologies and pre-colonial social-environmental systems, indicate several promising opportunities for cultivating sovereignty: research towards decolonization, mass (re)education, land reclamation, land cultivation & restoration, establishing constellations of care, and building a Pan-Caribbean coalition.
Soil Carbon In Hawaiian Rangelands: Evaluation Of Extent, Controls, And Options For Management
(University of Hawaii at Manoa, 2021) Krueger, Nicholas C.; Ryals, Rebecca; Natural Resources and Environmental Management
Rangelands are a land use type found extensively throughout both the globe and the Hawaiian Islands. These lands provide ecosystem services such as soil carbon sequestration, which can aid in slowing climate change, enhance soil physical and chemical qualities, and potentially provide diversified income for farmers. However, questions remain regarding the extent of sequestered carbon in rangeland soils, as well as the mechanisms controlling the variability of these stocks, especially in Hawaii. The majority of rangelands in Hawaii are situated on Andisols, a soil order known for high soil carbon content due to in part to unique mineralogy. Therefore, my dissertation research sought to intensively sample representative Hawaiian rangelands to identify baseline soil carbon stock, determine a minimum sampling density required for accurate estimates of landscape-scale variability, compare methods of spatial analysis, and to identify environmental factors that affect soil carbon stock distribution. Further, selective dissolution of mineral components of rangeland soils were carried out to relate mineralogy to soil carbon concentration. Finally, I investigated different methods of vegetation management in a silvopastoral production system in a replicated field trial to discern the effect of practice on soil carbon and sward characteristics.High levels of soil carbon stock were found throughout actively grazed rangeland, indicating the importance of these soils in contributing to the regulation of Earth’s climate. Carbon stocks and concentrations varied with environmental as well as mineralogical factors, presenting valuable potential co-variables for consideration in future sampling collections. Integration of livestock in koa (Acacia koa) production systems achieved some understory vegetation management goals, but did not significantly change in soil carbon concentration after one year, highlighting the requirement of long-term studies for soil carbon research. After baseline carbon characteristics are determined, repeated, long-term sampling will be required from different rangeland production systems to identify the effect of management on soil carbon resources. These land use types are important in providing food and ecosystem services to the human population, and a more complete understanding and quantification of their baseline soil qualities, as well as the factors driving those characteristics, will aid in future management decisions that seek to maximize both agricultural productivity and ecosystem health.
Development Of Refined Satellite Land Surface Phenology Detection Approaches For Robust Vegetation Monitoring
(University of Hawaii at Manoa, 2020) Kato, Anna; Carlson, Kimberly M.; Natural Resources and Environmental Management
Land surface phenology (LSP) from remote sensing data can serve as an integrative indicator of climate change impacts on terrestrial ecosystems. Accurate evaluations of changes in the number and timing of phenological events derived from LSP, such as the start of the growing season, are needed to support climate change mitigation and adaption. Yet, current LSP detection approaches are not fully capable of characterizing sub-annual phenological events across biomes. This dissertation aims to develop approaches that enhance robust detection of seasonal and sporadic phenological events from satellite vegetation indices (VIs) to support improved monitoring of vegetation signals. To address this goal, I conducted three studies focused on flux tower sites located across diverse biomes in the United States from 2003 to 2015. First, I evaluated the conditions under which the LSP detection algorithm developed for the Moderate Resolution Imaging Spectroradiometer (MODIS) robustly quantifies the inter-annual variability of growing season length derived from MODIS, Visible Infrared Imaging Radiometer Suite (VIIRS), and in-situ tower VI timeseries. Second, I developed a refined, adaptive LSP detection method and evaluated its ability to detect the start of the growing season across biomes. Algorithm performance was assessed by comparing signals derived from MODIS and VIIRS VIs to those from flux tower estimates of gross primary productivity. Finally, I applied this refined algorithm to detect the number and timing of phenological events across dryland sites with high intra- and inter-annual phenological variability. To identify a robust approach for quantifying such events in such dryland sites, I compared several VIs and phenological transition date detection approaches. Together, results suggest that the MODIS algorithm captures the inter-annual variability of major phenological events but often fails to detect sporadic events. The refined algorithm improved the detectability of irregular events commonly observed in dryland sites, especially when applied to the Enhanced Vegetation Index to quantify the number and peak of phenological events, and to water VIs to detect the start and end of events. The improved approaches to detect LSP developed here are expected to result in more accurate assessments of how climate change affects vegetation in regions with high current or projected future phenological variability.
Tracing Social-Ecologial Relationships: Hāʻena, Kaua‘i, Hawai‘i
(University of Hawaii at Manoa, 2017-08) Geslani, Cheryl; Natural Resources and Environmental Management
Natural resources are shared by heterogeneous populations. Each subgroup of resource users within a population has a different perspective of the resource's health, and their responsibility to steward that natural resource. This research was conducted under a premise that heterogeneous populations of resource users can arrive at a shared understanding of a social-ecological system's current state if they have a shared understanding of its history. Two established frameworks were operationalized to methodically examine the history of any social-ecological system. This is a case study about historical events that occurred in Hāʻena, Kaua‘i between 1975 and 2015. One framework exposed the introduction of actors and their relationships to the resource system over time. The benefits each resource user group receives from the ecosystem were also identified. The second framework linked related events in a way that revealed the historical management transitions for each of the major fresh water management areas in the social-ecological system. This broad historical understanding was used to create social time series variables from qualitative data that were tested for statistical correlation to existing ecological time series data. Correlations identified through multiple regression analysis showed Hurricane ‘Iniki may have had a negative influence on coastal salinity in Hāʻena, and positive influence on groundwater levels. Groundwater level is negatively related to well chlorides, which points to impending saltwater intrusion of the well. This research introduces a mixed method approach for understanding the social-ecological relationships within a system. These methods may be useful for disparate groups of people coming together to perpetuate a shared natural resource. Decision makers and concerned citizens can use research outputs to better understand how historical events shaped current issues and the perspective of different actors. The results of the correlational analysis of qualitative and quantitative data can be useful to guide environmental management based on scientific inquiry.
An Analysis of the Non-Adoption of an Introduced Conservation Agriculture (ca) Program by Village Farmers in Sāmoa
(University of Hawaii at Manoa, 2018-05) O Connor, Stephanie; Natural Resources and Environmental Management
With soil health declining in Samoa, interest in introducing Conservation Agriculture (CA) practices to improve crop yields and livelihoods has been ongoing since the 1970s. Despite the efforts of the institutions involved in the introduction of CA practices under different programs, village farmers have not adopted these CA practices. No universal theory explains why farmers adopt or reject a new idea. However, in the case of Samoa, labor issues due to out-migration and differences in perceptions of those involved in the implementation of programs could be hindrances to the adoption of these introduced programs. Thus, this study hypothesized that: (1) stakeholder differences impacted adoption and continued use of CA systems, and (2) labor availability constrained producers’ ability to use CA systems. Four specific studies were undertaken in order to test these hypotheses,: (1) an investigation of the rate of adoption and stakeholder participation in introduced CA programs in Samoa; (2) a comparison of the benefits and costs of the introduced systems relative to current practices; (3) an investigation of the socio-economic and cultural factors influencing farmers’ decisions to not adopt an introduced CA practice; and (4) the identification of stakeholders differences in goals, objectives and perceptions relative to an introduced CA practice. Ninety-one published and unpublished sources between 1970 and 2015 were reviewed, providing an overview of the introduced CA programs. Four CA programs have been introduced in Samoa, however, three were introduced so long ago that information on their effectiveness or ineffectiveness was extremely hard to find. Therefore, this study focused on the most recent program. i.e., the Soil Health Program utilizing mucuna (Mucuna pruriens) as a cover crop. In-depth interviews with farmers and key informants, participant observation, and focus group discussions were used to develop an understanding of the perceived issues with the introduced CA practice and an Analytic Hierarchy Process (AHP) was used to illustrate differences in stakeholder perceptions. Although a variety of resources were used in the programs implemented, the farmers were not convinced about the potential benefits of the introduced CA practices. Mucuna as a cover crop did not provide any relative advantage, was too complex and was not compatible with current practices, thereby requiring farmers to change their mindset in order to implement the system. Furthermore, not all farmers were included in the outreach efforts and farmers were not given enough time to test the introduced system to observe its relative benefits and limitations. Uncertainties associated with the introduced CA practice made farmers unwilling to take the risk of changing their current practices. The risk was perceived as serious as they depend on agriculture for their food and for income to fulfill their cultural obligations. The final study shows that differences exist in the perceptions of extension officers who are responsible for program outreach efforts to that of the farmers. More involvement of all farmers needs to be considered in the future with CA programs being introduced through the village councils within the respective villages in Samoa. Donors, government agencies and research institutions involved in the implementation of CA programs need to consider spending more time demonstrating their proposals with farmers and comparing these systems with current practices to help farmers reduce their uncertainty. Farmers should be involved from the beginning of the programs so that better management strategies can be utilized to help adapt the mucuna to suit their needs.
An Interdisciplinary Approach to Restoration: Hawaiian Seabirds as a Case Study
(University of Hawaii at Manoa, 2017-08) Rowe, Julia A.; Natural Resources and Environmental Management
Seabirds are experiencing dramatic declines in both their ranges and populations, resulting in decreases in ecosystem services they provide. Seabird breeding islands were historically rodent and mostly predator free, allowing seabirds to nest colonially and deposit large quantities of guano and other organic material. On average seabirds can increase inputs of nitrogen (N) and phosphorus, the two most common limiting and co-limiting nutrients to primary productivity, by 100 and 400% respectively. The goal of this research was to improve understanding of the impacts of decreased seabird numbers on ecosystems and the challenges to restoration. To address how losses of seabirds affect island ecosystems, the objectives of this research were to gain a better understanding of the historic role that seabirds played in the past, how that compares to current nutrient deposition, and how current efforts to restore seabird populations affect the native ecosystems. Using historical data and species habitat density models, I determined that seabird deposition of nitrogen into Hawaiian ecosystems was likely three – four orders of magnitude higher than it is today. During the pre-human era, seabirds could have deposited 1,460 – 5,290 kg of N ha -1 year -1. Based on current population estimates, and historic habitat, seabirds are currently contributing 0.535 kg of N ha-1 year-1. To address the current impact of seabirds on montane systems in Hawai‘i, I measured inorganic labile soil nutrients δ15N of seabird and non-seabird plots to determine marine-sourced N in the soil and foliage of two dominant plants. More NH4+ was found in the soil of seabird colonies than non-seabird colonies, and 28% of foliar N in the dominant tree and 17% of foliar N in a dominant understory plant, were from marine source. However, plant species composition was similar between seabird and non-seabird areas, despite differences in nutrient availability. Finally, I determined that costs of management actions vary widely depending on terrain and accessibility of the site, but all actions have positive ecosystem services benefits. As restoration of native ecosystems continue to be a priority, understanding the role seabirds played in the past and how they currently contribute to the ecosystem are critical for effective restoration efforts.
Data and Tools to Operationalize Ridge-to-Reef Management and Build Island Resilience in Oceanic Island Environments
(University of Hawaii at Manoa, 2017-08) Delevaux, Jade M. S.; Natural Resources and Environmental Management
Around the Pacific, a cultural renaissance rooted in the concern over declining natural resources seeks to revive traditional ridge-to-reef management approaches to promote social and ecological resilience in a changing climate. However, the effectiveness of ridge-to-reef management remains unclear due to a poor understanding of the cumulative effects of human and natural disturbances. In high Pacific islands, land and sea are tightly connected through social and ecological processes as a result of their small size and steep elevation gradients. Therefore, new tools are needed to inform resilience management over spatial scales relevant to Pacific Islanders. This research focused on three ridge-to-reef systems under community-based-management in Hawai‘i (Hā‘ena and Ka‘ūpūlehu) and Fiji (Kubulau), which capture a wide spectrum of natural disturbances governing high Pacific islands. Based on local data from Hā‘ena and Ka‘ūpūlehu, I developed a novel predictive modeling framework linking land and sea drivers to coral reef benthic and fish indicators, at fine spatial resolution. This framework was used to determine the effects of terrestrial and marine disturbances on coral reef communities and compare the effects of coastal development coupled with climate change on coral reef benthic communities and their targeted reef fish populations, given different natural disturbance regimes. I then transferred the framework to Kubulau to assess the effects of forest cover change on downstream coral reefs given uncertain climate impacts. The results revealed that sheltered and dry oceanic environments, such as Ka‘ūpūlehu, may be particularly susceptible to reduced water quality impacts. In contrast, exposed areas, like Hā‘ena, are less susceptible to anthropogenic activities due to dilution and mixing from higher wave power and freshwater discharge. However, reef fish populations across most study sites became vulnerable to the impact of land-based source pollution when models incorporated climate change. In all cases, terrestrial management actions aimed at improving coastal water quality through wastewater management or forest conservation, coupled with the protection of coral reef nurseries or deep-water refuges, improved coral reef resilience potential. This research demonstrates that locally developed and data-driven models offer a much-needed opportunity for aiding place based management of coral reef social-ecological systems in high oceanic island environments.
Integrated Hydrological Modeling for Water Resources Management of Heeia Coastal Wetland in Hawaii
(University of Hawaii at Manoa, 2017-05) Ghazal, Kariem A.; Natural Resources and Environmental Management
The integrated hydrological models are an important tools that can be used to assess the water resources availability and sustainability for food security and ecological health of the coastal regions. In addition, such models are useful in assessing the current and future water budget under different conditions of climate and land use changes. This study addresses the Heeia Wetlands Restoration whereby different scenarios were developed to assess the effects of land cover change (LU), climate change (CL), and sea level rise (SLR) on the water balance components (WBCs), fresh water submarine groundwater discharge (FSGD), seawater intrusion, dissolved silicate (DSi) fluxes, and heat transport within the Heeia Coastal Wetland. The watershed (SWAT) model, the groundwater flow (MODFLOW) model, and the density dependent groundwater flow (SEAWAT) model were utilized in this integrated approach. The SWAT model was used to assess the impact of CL and LU on the WBCs. The LU mainly focused on the conversion of a fallow wetland covered by california grass (invasive plant) to taro field (native plant). The groundwater recharge of the SWAT model output was used as input for both the steady state and transient-MODFLOW model to study the interaction between surface water and groundwater and its effect on the FSGD within the Watershed. The SEAWAT model was used to study the seawater intrusion, DSi fluxes and cold groundwater transport under several CL, LU, and SLR scenarios. The results indicated that the baseflow was the main components of the Heeia streamflow, especially during dry season. The annual recharge, surface runoff, lateral flow and ET comprised about 34%, 6%, 15%, and 45% of the annual rainfall, respectively. The WBCs were more impacted in the late of 2080s compared to the 2050s period. To understand the comprehensive relationships between coastal hydrological processes and ecosystems, the FSGD was estimated under different scenarios of LU, CL, and SLR. The current daily average of the Heeia coastal FSGD was about 0.43 m3/d/m, but expected to decrease by about 10% by the end of 21st century due to the combined effects of various changes. The FSGD comprised 18%, 11%, and 3% of the annual baseflow, recharge, and rainfall, respectively. Moreover, the FSGD fluxes would decline more during the dry season compared to the wet season. The FSGD fluxes were about 1.5 to 3.5 times than the fresh water delivered to the Kaneohe Bay via total Heeia streamflow. The outputs of SEAWAT model indicated that the seawater intrusion was not significantly influenced by SLR, CL, and LU. The average DSi fluxes was about 48 mole per day that increased by 15% during the wet season, but decreased by16% during the dry season. The DSi fluxes were a function of the FSGD. The CL more negatively affected the DSi fluxes compared to the SLR. The respective average heat energy reduction within wetland under california grassland and taro cultivation would be 0.81and 1.12 (Kj/m3) for inflow of cold groundwater, and 4.69 and 3.13 (Kj/m3) for outflow of groundwater. The cold groundwater discharge at the shoreline was significantly mitigated the seawater temperature due to the high thermal gradient between the FSGD and seawater. Despite data scarcity, the integrated hydrological modeling approach has provided a comprehensive assessment of the water resources that can help in the management of the Heeia Coastal Wetland under various land cover and climate conditions.
Forecasting Climate And Land Use Change Impacts On Ecosystem Services In Hawaiʻi Through Integration Of Hydrological And Participatory Models
(University of Hawaii at Manoa, 2018-12) Htun, Hla; Oleson, Kirsten L.; Natural Resources and Environmental Management
Water is critical for supporting life, and fundamental for provisioning, regulating, and cultural ecosystem services that support human wellbeing. However, freshwater resources are projected to become scarcer in Hawaiʻi due to a growing human population, a changing climate, and altered land use and land cover. Therefore, to meet future needs, society needs to manage water more effectively using an interdisciplinary ecosystem services-based approach that accounts for physical, social, and ecological interactions. In order to support holistic management of freshwater ecosystem services in Hawaiʻi, I developed a modeling tool that can integrate physical and ecological processes and social systems. First, I identified appropriate hydrological models to estimate the hydrologic attributes (quantity, quality, location, and timing) that underpin delivery of multiple freshwater ecosystem services. Due to Hawaiʻi’s unique hydrogeological conditions, many standard models cannot accurately quantify hydrologic processes, and thus cannot estimate hydrologic attributes or evaluate ecosystem services. I identified a suite of potential models, developed a set of criteria that I used to select candidate models for estimating freshwater ecosystem services in Hawaiʻi, and evaluated performance for the most promising models. In addition, I created a decision tree for model selection that decision-makers and researchers interested in modeling freshwater ecosystem services can use. Second, I coupled a hydrological model (AnnAGNPS) with a participatory model (using Fuzzy Cognitive Mapping) in a wetland ecosystem on Kauaʻi to translate hydrological model outputs into ecological benefits for three wetland birds: Hawaiian Stilt or Ae‘o (Himantopus mexicanus knudseni), Hawaiian Coot or ‘Alae ke‘oke‘o (Fulica alai), and Hawaiian Moorhen or ‘Alae ‘Ula (Gallinula galeata sandvicensis). Model coupling suggested that a decline in precipitation would reduce abundance of all three bird species. Results suggest that managers should focus on water depth, food availability, and disease in order to manage abundance. Finally, I used the coupled hydrological-participatory model approach to predict the management and policy outcomes of environmental scenarios for different stakeholder groups who hold diverse values for freshwater ecosystem services. Results revealed stakeholders’ agreement on key environmental stressors, as well as their differing views on restoring streamflow, which largely corresponded to their values for ecosystem services (agricultural production versus conservation). This study identified and used models in a coupled framework to simulate environmental changes, and inform enhanced management of freshwater ecosystem services in Hawaiʻi. The resulting decision support framework is easily adaptable for different ecosystems and islands.
Out-of-School Youth in Mindanao, Philippines: A Case Study Supporting the Upload Jobs Entrepreneurship- Training Program
(University of Hawaii at Manoa, 2016-12) Lai, Cynthia
The UPLOAD JOBS entrepreneurship-training program was implemented by the United States Agency for International Development to enable out-of-school youth (OSY, 18 – 24 years) entrepreneurship in Mindanao, Philippines. To effectively manage the program in this international context, this dissertation collected, assessed and contributed to a rare database of context and entrepreneurship-specific information about OSY, respectively. First, a ‘Youth Potential Entrepreneur’ (YPE) questionnaire was developed to gather and report OSY demographics, entrepreneurship characteristics, and personality traits to help customize the program’s design and implementation. Data collected from the YPE questionnaire informed that OSY are educated (i.e., high school diploma) and have potential for entrepreneurship (i.e., positive entrepreneurship motivations, aspirations and personality traits); however, represent necessity entrepreneurs that have minimal entrepreneurship knowledge and access to social, physical and financial resources to start a new business, respectively. Second, items measuring OSY autonomy, risk-taking propensity, and innovativeness, cited to characterize the ‘successful’ entrepreneur, proved effective as a measurement model to screen their entrepreneurship ‘potential’ for program entry to help manage resources and performance outcomes. Third, a ‘Youth Population Survey’ was developed to assess the program’s screening and performance outcomes by measuring OSY’s entrepreneurship perceptions, attitudes and activities. Data collected indicated that screening differentiated OSY’s responses compared to those who were not screened, and that the program succeeded in fostering new entrepreneurs (i.e., business owners); however, fell short on fostering their positive entrepreneurship perceptions and attitudes. Finally, it was determined that OSY employment (including self-employment) probabilities are significantly influenced by cultural (i.e., family business ownership) and psychological determinants (i.e., risk-taking), informing policy and programs that enabling OSY employment (including self-employment) in this region is complex and may go beyond basic skills and knowledge training that entrepreneurship-training programs provide. Findings suggest that OSY represent a valuable resource of entrepreneurship potential; however, existing measurement tools need to be adapted to OSY context to address the gap between the extant entrepreneurship, psychology and development literature, and the management of OSY and entrepreneurship training programs in developing countries.

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