Rozprawy doktorskie na temat „Environmental resource management”

This research explores the benefits of conjunctively managed surface and groundwater resources in a volcanic aquifer system to reduce stream temperatures while valuing agricultural deliveries. The example problem involves advancing the understanding of flows, stream temperature, and groundwater dynamics in the Shasta Valley of Northern California. Three levels of interaction are explored from field data, to regional simulation, to regional management optimization. Stream temperature processes are explored using Distributed Temperature Sensing (DTS) data from the Shasta River and recalibrating an existing physically-based flow and temperature model of the Shasta River. DTS technology can collect abundant high resolution river temperature data over space and time to improve development and performance of modeled river temperatures. These data also identify and quantify thermal variability of micro-habitat that temperature modeling and standard temperature sampling do not capture. This helps bracket uncertainty of daily temperature variation in reaches, pools, side channels, and from cool or warm surface or subsurface inflows. The application highlights the influence of air temperature on stream temperatures, and indicates that physically-based numerical temperature models, using a heat balance approach as opposed to statistical models, may under-represent this important stream temperature driver. The utility of DTS to improve model performance and detailed evaluation of hydrologic processes is demonstrated.

Second, development and calibration of a numerical groundwater model of the Pluto's Cave basalt aquifer and Parks Creek valley area in the eastern portion of Shasta Valley helps quantify and organize the current conceptual model of this Cascade fracture flow dominated aquifer. Model development provides insight on system dynamics, helps identify important and influential components of the system, and highlights additional data needs. The objective of this model development is to reasonably represent regional groundwater flow and to explore the connection between Mount Shasta recharge, pumping, and Big Springs flow. The model organizes and incorporates available data from a wide variety of sources and presents approaches to quantify the major flow paths and fluxes. Major water balance components are estimated for 2008-2011. Sensitivity analysis assesses the degree to which uncertainty in boundary flow affects model results, particularly spring flow.

Finally, this work uses optimization to explore coordinated hourly surface and groundwater operations to benefit Shasta River stream temperatures upstream of its confluence with Parks Creek. The management strategy coordinates reservoir releases and diversions to irrigated pasture adjacent to the river and it supplements river flows with pumped cool groundwater from a nearby well. A basic problem formulation is presented with results, sensitivity analysis, and insights. The problem is also formulated for the Shasta River application. Optimized results for a week in July suggest daily maximum and minimum stream temperatures can be reduced with strategic operation of the water supply portfolio. These temperature benefits nevertheless have significant costs from reduced irrigation diversions. Increased irrigation efficiency would reduce warm tail water discharges to the river instead of reducing diversions. With increased efficiency, diversions increase and shortage costs decrease. Tradeoffs and sensitivity of model inputs are explored and results discussed.

Dwindling freshwater resources are one of the largest challenges facing countries worldwide. For regional and local governments the task of managing fresh water resources falls the hardest. Reduced water quantity directly impacts water quality and thus preventing further depletion of freshwater levels is necessary for meeting existing and forth coming water quality regulations. Thus, finding effective ways to better understand water use at the local or regional level and better ways of communicating pressing water management issues with water users is imperative to the longevity of freshwater resources. Environmental communication campaigns are one way of reaching water users. Understanding water users personal relationship with water resources and nature in general can inform environmental campaigns in multiple ways.

This research provides insight into the ways in which environmental campaigns can be framed to effectively reach the target audience. Two methods of assessing stakeholder perceptions of water resources are also explored. First, systems thinking is used to compare the mental models of water managers and members of the development sector in order to find areas of common interest and importance regarding the management of freshwater resources in the Spokane-Coeur d'Alene Corridor of northeast Washington and northern Idaho. Second, a survey is used to evaluate characteristics of water use for residents in Spokane County, Washington.

This dissertation is centered on three primary research questions: (1) How are environmental communication campaigns framed?; (2) How do stakeholder groups who may appear to have very different values for a shared resource perceive a shared that resource?; (3) How do people's perceptions of nature, environmental issues, and their ability to impact those issues influence the way that they use water? Results of this research show that there are key areas of shared interest between water managers and developers suggesting that long-term water management goals do not have to conflict with the goals of local development. This research also suggests that residents who are willing to perform behaviors to reduce their water use are not necessarily doing so, pointing toward further research questions to bridge the gap between willingness and action.

Impacts of climate change on the already severely strained freshwater resources of approximately 1000 inhabited islands in the Pacific Ocean are of great concern. The Western Pacific region is one of the world’s most vulnerable when it comes to risk of disaster particularly for the several of the low-lying coral islands. Impacts have already been felt regarding the security of water resources that would directly impact agriculture, forestry, tourism and other industry-related sectors. The ironic and tragic aspect of the environmental crisis of greenhouse emissions is the fact that those parts of the world least responsible for creating the water security issues are the first to suffer its consequences. Pacific Island Nations are responsible for only 0.03 percent of the world’s carbon dioxide emissions, and the average island resident produces only one-quarter of the emissions of the average person worldwide.

Utilizing the historical data, the evidence of change in water quality and access on Guam has been examined. All indicators except for the precipitation support the hypotheses that climate change trends are impacting Guam’s water security. This will eventually weaken Guam’s resilience. As a result of this research and its recommendations, a sustainable freshwater resources management plan, for a water-secured Guam can be produced. Adaptive management provided here is based on a process that can measure the resilience of Guam to the issue of water security.

Parcelization is an increasing concern to land managers in the rural regions of the United States. In order to protect vital ecosystem goods and services, resource managers need to account for decreasing parcel sizes. The Catskill region of New York State contains both the New York City Watershed and the Catskill Preserve. In order to maintain ecosystem functions within these sensitive areas, wise planning is needed in the development of rural lands. This study documents the change in private, rural parcel dynamics from 2004 to 2010 in the Catskill region at the township scale. A parcel density map was developed to observe trends in distribution of small parcels. The average parcel size dropped from 13.9 acres in 2004 to 13.1 acres in 2010. The distribution of small private, rural parcels is diffuse across the study region, implying the transition from resource management focused land holdings to rural residential within the Catskill region.

Despite an increasing interest among land managers in collaborative management and learning from place-based Indigenous knowledge systems, natural resource management negotiations between Indigenous communities and government agencies are still characterized by distrust, conflict, and a history of excluding Indigenous peoples from decision-making. In addition, many scholars are skeptical of Indigenous communities attempting to achieve self-determination through bureaucratic and scientific systems, which can be seen as potential mechanisms for co-opting Indigenous community values (e.g. Nadasdy 2003).

This dissertation considers how Indigenous communities and state agencies are meeting contemporary natural resource governance challenges within the Pacific Northwest. Taking a community-engaged scholarship approach, the work addresses two exemplar case studies of Indigenous resource management negotiations involving forest management with the Karuk Tribe in California (U.S.) and the Xáxli'p Indigenous community in British Columbia (Canada). These cases explore the ways and degree to which Indigenous peoples are advancing their self-determination interests, as well as environmental and cultural restoration goals, through resource management negotiations with state agencies—despite the ongoing barriers of uneven power relations and territorial disputes.

Through the 1990s and 2000s, both the Xáxli'p and Karuk communities engaged with specific government policies to shift status quo natural resource management practices affecting them. Their respective strategies included leveraging community-driven management plans to pursue eco-cultural restoration on their traditional territories, which both overlap with federal forestlands. In the Xáxli'p case, community members successfully negotiated the creation of the Xáxli'p Community Forest, which has provided the Xáxli'p community with the exclusive right to forest management within the majority of its traditional territory. This de jure change in forest tenure facilitated a significant transfer of land management authority to the community, and long-term forest restoration outcomes. In the Karuk case, tribal land managers leveraged the Ti Bar Demonstration Project, a de facto co-management initiative between the Forest Service and the Karuk Tribe, to conduct several Karuk eco-cultural restoration projects within federal forestlands. Because the Ti Bar Demonstration Project was ultimately abandoned, the main project outcome was building the legitimacy of Karuk land management institutions and creating a wide range of alliances that support Karuk land management approaches.

Through my case studies, I examined how Indigenous resource management negotiations affect knowledge sharing, distribution of decision-making authority, and longstanding political struggles over land and resource access. I first asked, how is Indigenous knowledge shaping natural resource management policy and practice? My analysis shows that both communities are strategically linking disparate sets of ideas, including Traditional Ecological Knowledge (TEK) and Western scientific knowledge, in order to shape specific natural resource governance outcomes. My second question was, how does access to land and resources shift through Indigenous resource management agreements? This work demonstrates that both communities are shifting access to land and resources by identifying "pivot points": existing government policies that provide a starting point for Indigenous communities to negotiate self-determination through both resisting and engaging with government standards. And third, I considered how do co-management approaches affect Indigenous sovereignty and self-determination? The different case outcomes indicate that the ability to uphold Indigenous resource management agreements is contingent upon establishing long-term institutional commitments by government agencies, and the broader political context.

This work emphasizes the importance of viewing the world from the standpoint of individuals who are typically excluded from decision-making (Harding 1995, 1998). Pursuing natural resource management with Indigenous peoples is one way for state agencies to gain innovative perspectives that often extend beyond standard resource management approaches, and consider longstanding relationships between people and the environment in a place-based context. Yet the assumption that tribal managers would export Indigenous knowledge to agency "professionals" or other external groups, supposedly acting on behalf of Indigenous peoples, reflects a problematic lack of awareness about Indigenous perspectives on sovereignty and self-determination--central goals for Indigenous communities that choose to engage in natural resource management negotiations.

Several implications emerge from these findings. First, Indigenous community representatives need to be involved in every step of natural resource management processes affecting Indigenous territories and federal forestlands, especially given the complex, multi-jurisdictional arrangements that govern these areas. Second, there is a strong need to generate funding that enables Indigenous communities to self-determine their own goals and negotiate over land management issues on a more level playing field. Finally, more funding must be invested in government programs that support Indigenous resource management.

QC 20160516

Plant populations experience both spatial and temporal environmental heterogeneity, and their strategies for coping with environmental heterogeneity are shaped by their inability to move in response to unfavorable conditions. In addition, human induced land-use change, including changes in grazing regimes and shorter fire-return intervals, has become increasingly common as a source of environmental heterogeneity experienced by plant populations. This research focuses on how native Great Basin plants respond to environmental heterogeneity, studying three stages of plant life-histories: seed germination, seed banks, and mature plants. My dissertation sought to: 1) identify relationships between climate variability and population-level variation in germination strategies of arid land forbs, 2) use occurrence records from herbaria to compare the climate niches for a group of arid land forbs, and 3) investigate the relationship between disturbance history and seed bank dynamics in sagebrush steppe communities.

The second chapter examines the similarities and differences between the climate niches and the geographic distributions of a set of co-occurring understory forbs found in sagebrush steppe systems. We used distribution models of the potential habitat for our species to estimate the range size, niche breadth, and geographic overlaps between our species. Next, we used model results to identify climate variables most predictive of the distributions of the individual species. Lastly, we compared the mean and variability for precipitation and temperature across known occurrence locations for each species to assess similarities and differences in climate characteristics where these species grow. We found that species varied in their predicted area of occupancy, niche breadth, and the climate characteristics most predictive of their suitable habitat. Only two of the ten species shared a comparable climate niche. This work demonstrated that herbarium records can be used to estimate climate preferences and potential habitat for understudied species.

The third chapter investigates seed bank dynamics in a Great Basin sagebrush steppe system, comparing sites that differ in their disturbance history. We asked whether shrub cover, ground cover, climate, or disturbance history (fire and grazing) were predictive of the seed densities in the soil, the diversity of native and introduced species, the presence of rare species, and similarity between the above and below-ground species composition. We found that common measures of fire history and grazing use may be overly coarse for predicting the effects of disturbance on seed bank dynamics. We also found that shrub cover was highly predictive of the seed bank dynamics in this system. Shrub cover of early seral shrub species was predictive of patterns consistent with moderate disturbance or recovery from disturbance within the above and below-ground plant community, while increasing cover of later seral species, such as Artemisia tridentata, produced patterns indicating a longer time since disturbance.

The fourth chapter asks how mean climate and climate variation at individual sites and across a species’ range affects the specialist-generalist spectrum of germination strategies exhibited by ten arid land forbs. We investigated these relationships using climate data for the western United States, occurrence records from herbaria, and germination trials with field-collected seeds. We found that nine out of ten species exhibited population-level variation in germination, and that generalist strategies were associated with higher spatial variation in actual evapotranspiration at a local scale and higher variation in available water in the spring and annual precipitation at a range-wide scale.

Stream restoration is being conducted throughout the world at unprecedented rates to address stream channel degradation and water quality concerns. Natural Channel Design (NCD) is a common method used for restoration and has received governmental endorsement; however, the effects of NCD on channel stability and ecosystem functioning are poorly studied. We examined the effects of a reach-scale NCD project on channel stability, riparian vegetation, and water quality along the Cacapon River, West Virginia using a before-after-control-impact design and determined that restoration increased the abundance and diversity of woody vegetation, but had minimal effects on streambank stability and water quality. Increased erosion rates in some portions of the restored reach were attributed to differences in pre-restoration stability, vegetation removal, and soil composition among sub-reaches. No differences in in-stream concentrations of total phosphorus, nitrates, ammonia, or total suspended solids were detected following restoration; however, in-stream turbidity was drastically increased during construction. This study is a clear example of the value of monitoring streambank migration, vegetation communities, and soils to evaluate the effects of stream restoration and to provide insight on potential reasons for treatment failure. Ideally, pre-restoration monitoring should be used to inform project design by determining restoration potential of areas selected for restoration.

As a surrogate for process monitoring, we created a maximum entropy model of streambank erosion potential (SEP) in a Geographic Information System (GIS) framework to prioritize sites for management and to determine which variables in the watershed are associated with excessive rates of streambank erosion. Model development included measuring erosion rates throughout a central Appalachian watershed, application of a quantitative approach to locate target areas for management termed Target Eroding Areas (TEAs), and collection of environmental data throughout the study extent using high resolution, remotely sensed data. A likelihood distribution of TEAs from occurrence records and associated environmental variables over our study extent was constructed using the program Maxent. All model validation procedures indicated that the model was an excellent predictor of TEAs, and that the major environmental variables controlling these processes were streambank slope, soil characteristics, shear stress, underlying geology, and riparian vegetation. A classification scheme with low, moderate, and high levels of erosion potential derived from logistic model output was able to differentiate sites with low erosion potential from sites with moderate and high erosion potential. This type of modeling framework can be used in any watershed to address uncertainty in stream restoration planning and practice.

To address the need for accurate, high resolution estimation of streambank erosion, we also explored the role of laser scanning for estimating streambank migration and volumetric sediment loss. This was accomplished by comparing estimates of streambank migration and volumetric sediment loss derived from repeated erosion pin, streambank profile, and combined airborne and terrestrial light detection and ranging (LiDAR) surveys. Results indicated that LiDAR derived estimates were larger and highly variable compared to estimates derived from erosion pin and streambank profile surveys, which more accurately represented change along the study reach. Inflated LiDAR estimates were most likely the result of combining high resolution terrestrial LiDAR with relatively low resolution airborne LiDAR that could not effectively capture topographic features such as undercut banks. Although cost-prohibitive in some cases, repeated terrestrial LiDAR scans would likely circumvent these issues with higher point densities and better scan angles facilitating more accurate representation of streambank geometry, ultimately providing more accurate estimates of channel change.