In arid and semiarid environments, various natural and anthropogenic stressors have resulted in land cover change that has negatively impacted the ecological integrity of the landscape. Society, however, relies on many ecological processes and functions provided by the landscape to enhance its wellbeing. The direct and indirect benefits society receives from the landscape are collectively termed "ecosystem services." The overarching goal of this thesis was to examine how the landscape has changed and to analyze how these changes impact the ecosystem services supplied by the landscape. The Upper San Pedro watershed in southeastern Arizona and northern Sonora was used as a case study to link land cover change with an array of ecosystem services to understand the spatiotemporal dynamics of ecosystem service supply. To accomplish this, a multitemporal land cover dataset for the watershed was updated to extend the temporal coverage to 37 years across 5 land cover datasets. Indicators serving as proxy variables for a variety of ecosystem services were assessed for each land cover class. This linkage between land cover and ecosystem services enabled an analysis of the tradeoffs and synergies within the array of services each land cover class can provide. Combined with the multitemporal land cover dataset, the spatiotemporal dynamics of potential ecosystem service supply were analyzed across the watershed for a 37 year period. Rather than examining the impacts of land cover change on the biophysical aspects of the environment, this approach enables land managers and decision makers to explore the implications of a changing landscape on human wellbeing.

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 dendrochemistry. 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.

This research documents the societal worth of riparian resources in the Southwestern United States. Two case studies are developed for this inquiry, the first being Aravaipa Canyon Wilderness in Southern Arizona, an area containing one of the last perennial streams in the Sonoran Desert bioregion. A hiking use value per visitor-day is estimated via the Travel Cost Method at $25.06 and $17.31 (2003 dollars) respectively for two access sites. I hypothesize the value discrepancy to indicate a premium for remote recreation. These valuation results compare well with other published recreational use value estimates, though it is the only valuation study associated with instream recreation in the Sonoran Desert of which I am aware. Indeed the environmental valuation literature is thin for the desert region in any respect.The second case study values public restoration preferences for the Albuquerque reach of the Rio Grande in Central New Mexico. A Choice Experiment and Contingent Valuation are employed within an original survey instrument to estimate human values for various restoration strategies planned for the region. Through focus groups and stakeholder interactions four restoration attributes were defined: vegetation density; tree type; fish and wildlife population; and natural river processes. Quantified values for Albuquerque area households were estimated for each restoration attribute level of change, allowing construction of total benefits anticipated for various restoration scenarios considered for the region. This research is at the vanguard of quantifying human benefit for saltcedar control, and this particular restoration characteristic was the most highly valued of all, at $59.03 per household per year. Full restoration was valued at $156.60 per household per year. These results have meaning beyond the study area since river restoration efforts are increasing across the Western US, with many focusing on controlling saltcedar, an exotic invasive plant.The final phase of this research integrates riparian valuation concepts within a dynamic simulation framework to guide systems-level riparian management. Control variables are combined with known valuation pathways to predict riparian investment funding optimal in benefit-cost ratio. The model is built for the Middle Rio Grande in Albuquerque, however it was designed for easy adaptation to other Southwestern riparian areas. A detailed forest module is included, through which seven defined forest stocks may be managed through thinning, clearing, and revegetation. River management may occur through environmental river flow releases, reconstructing stream-overbank connections, and wetland construction. Recreational amenities may be improved through the four infrastructure categories of trails, toilet facilities, picnic areas, and parking areas. Benefits and costs are estimated through original research and region benefit transfer, and tracked for different investment scenarios to predict the highest-return strategies over a 100 year planning horizon. A sensitivity analysis is used to suggest areas of future research.

Precipitation, more than any other environmental factor, controls patterns of ecosystem production and biogeochemical cycling in arid and semiarid environments. Growing-season rains in these regions are highly unpredictable as they come in intermittent pulses varying in size, frequency and spatial extent, thereby producing unique hydrological patterns that constrain the location and residence time of soil water available for biological activity. In order to understand how arid and semiarid ecosystems respond to inputs of precipitation within the context of ecosystem science and global change studies, knowledge is needed on how plants and other organisms respond as an integrated system to such environmental control. The focus of my research was to understand how the distribution of precipitation events influences the dynamics of carbon cycling in semiarid ecosystems. At a semiarid riparian woodland, measurements of CO2 exchange and evapotranspiration revealed that following precipitation events occurring soon after prolonged dry periods the efficiency of rain-use (amount of carbon gain per unit of precipitation over a specific period time) was low. Precipitation did not readily stimulate primary productivity, water was mainly lost as soil evaporation and large respiratory CO2 effluxes were observed. This commonly observed features in seasonally dry ecosystems might have profound consequences for the seasonal and annual carbon balance. In this woodland, 47% of the precipitation within a single growing season (May-October) was returned to atmosphere as soil evaporation and the CO2 efflux observed just during the first rainy month (July) was equivalent to almost 50% of the net carbon gain observed over the six-month growing season. Results from experimental irrigations in understory plots of riparian mesquite woodland revealed that the magnitude and duration of the large CO2 fluxes occurring soon after rainfall was higher in plots located under tree canopies where, relative to intercanopy plots, the amount of plant litter was higher, soil evaporation and plant photosynthetic rates were lower. Efficiency of rain-use in semiarid ecosystems during the growing season apparently was determined by the degree of coupling between gross photosynthesis and ecosystem respiration, by the fraction of precipitation lost as soil evaporation and by the water-use efficiency of the component vegetation.

Human activities have caused acidification of freshwater systems on a large scale resulting in reduced species diversity and ecological functioning in many lakes and streams. However, many naturally acidic freshwater systems have also been found, for instance in northern Sweden. In regions where such naturally acidic aquatic ecosystems have prevailed over evolutionary periods, species diversity and ecological functioning are not automatically impaired due to possible adaptation to the putatively adverse environmental conditions. I studied species diversity patterns and ecological functioning in anthropogenically acidified, naturally acidic, circumneutral, and limed streams to test the adaptation hypothesis and examine the ecological effects of variation in naturally acidic water chemistry. Species diversity was studied using benthic macroinvertebrates, while functioning was modelled using the decomposition rates of leaf litter. In accordance with the evolutionary species pool hypothesis, species richness was reduced more strongly in regions with anthropogenic than natural acidity when compared to circumneutral streams, supporting the adaptation hypothesis. In contrast, the patterns in ecological functioning along the pH-gradients did not differ between regions with anthropogenic and natural acidity, likely resulting from compensation: the biomass of tolerant taxa probably increased which thus rescued the loss in functioning otherwise mediated by the more sensitive taxa. Furthermore, the naturally variable acidic water chemistry clearly supported distinct macroinvertebrate assemblages, as was reflected in differing patterns of species diversity and ecological functioning. Such naturally acidic waters that were rich in dissolved organic carbon supported higher ecosystem process rates and lower species diversity than waters that contained little dissolved organic carbon. Upon liming naturally acidic streams microbial leaf decomposition increased, whereas shredding decreased along with changes in shredder abundances. The abundance of large caddisflies decreased, while the abundance of small stoneflies increased. The results suggest that various types of benthic macroinvertebrates with varying levels of adaptation and tolerance inhabited the hydrochemically variable naturally acidic streams. The distributions of macroinvertebrates in response to different pH levels and differences in acid quality and how these distributions translate into varying patterns of species diversity and ecological functioning are worthy of further investigation. This will likely improve our understanding of how such naturally acidic streams and their biota can be successfully managed.

Climate change is an undeniable global event. Widely believed to be caused by human activities that release greenhouse gases, this change in climate will occur over a very short period of time when it is compared to natural climate variations. The effect the change will have on environments is somewhat unknown and any predictions are best guess scenarios. In British Columbia the mountain pine beetle has destroyed millions of pine trees but the infestation is not yet done. This may be one of the early symptoms of global warming on the British Columbia environment. Climate change will warm temperatures in BC and increase the annual precipitation. These warmer temperatures allow for longer growing seasons and in many cases, more favorable growing conditions. Studies on Sitka Spruce have found increases in volume growth by as much as 20% and growth in the boreal has been found to increase with higher CO2 levels and warmer temperatures. Climate change does not have to mean beetle epidemics and dying ecosystems. With proactive management British Columbia may actually find benefits in a warming climate.

This thesis aims at defining the connection between the increasingly popular ecosystem services theory and its practical implications for sustainable development in Swedish physical spatial planning. A literature study was made to summarize the ecosystem services and resilience thinking concepts (with an emphasis on ecosystem services), their definitions and potential uses in physical spatial planning. This overview was then applied in choosing a concept framework to be tested in a case-study: the possible changes in ecosystem services and their values in a land-use trade off situation. To gather insight into the benefits of the ecosystem services concept, compared to environmental integration into physical spatial planning on a municipal level today, the literature study was extended to encompass a short overview of environmental management in the Swedish planning system. Finally, the case study was introduced to municipal employees with strong ties to the planning process, in order to gage their opinions on the ecosystem services concept and its usefulness in planning for sustainability and increased human wellbeing. The results of these interviews showed a generally positive attitude towards the concept as a way to gather and communicate ecological and socio-cultural information to decision makers. The economic valuation was deemed less important as the method is fraught with such difficulties. Overall, the ecosystem services and resilience thinking concepts have great potential to gather the discontinuous environmental management methods toward sustainable (ecologic) development, but in order for this to happen, the municipalities need to be given the right resources, and incentives, for implementation.

Worldwide, finfish fisheries receive increasing assessment and regulation, slowly leading to more sustainable exploitation and rebuilding. In their wake, invertebrate fisheries are rapidly expanding with little scientific scrutiny despite increasing socio-economic importance. This thesis provides the first global analysis of the trends, drivers, and population and ecosystem consequences of invertebrate fisheries, in general, and sea cucumber fisheries, in particular, based on a global catch database in combination with taxa-specific reviews. Further, I developed new methods to quantify trends over space and time in resource status and fishery development. Since 1950, global invertebrate catches increased six-fold with 1.5 times more countries fishing and double the taxa reported. By 2004, 31% of fisheries were over-exploited, collapsed, or closed. New fisheries developed increasingly rapidly, with a decrease of six years (± three years) in time from start to peak from 1960 to 1990. Moreover, 71% of invertebrate taxa (53% of catches) are harvested with habitat-destructive gear, and many provide important ecosystem functions including habitat, filtration, and grazing. For sea cucumber fisheries, global catch and value has increased strongly over the past two to three decades, closely linked to increasing prices and demand on Asian markets. However, the catch of individual fisheries followed a boom-and-bust pattern, declining nearly as quickly as it expanded, and expanding approximately five times as quickly in 1990 compared to 1960. Also, new fisheries expanded increasingly far from their driving market in Asia, and encompassed a global fishery by the 1990s. One-third of sea cucumber fisheries experienced declines in average body size fished; half showed serial exploitation over space by moving further away from the coast; three-quarters showed serial exploitation from high- to low-value species; and two-thirds experienced population declines due to overexploitation with local extirpation in some cases. One-third of all sea cucumber fisheries remain unregulated. These findings suggest that the basis of marine food webs is increasingly exploited with limited stock and ecosystem-impact assessments, and a new management focus is needed to avoid negative consequences for ocean ecosystems and human well-being.

Nature has an effective approach to cycling materials and energy flows to promote life. This thesis aims to expose urbanite users to nature’s way of cycling materials. The seawall is the largest public space in Vancouver at the edge of land and sea. A neighbourhood community centre along the edge called the Conservatory for Community Matters is created to nurture environmental stewardship by mimicking natural cycles in its function. By conveying architectural systems and form in a cyclical and organic approach, an architectural intervention can address the daily environmental impact of urbanites while rooting people in place and nature in the city. The community centre’s program connects the individually focused daily rituals of eating, making, and exercising to benefit the larger community where urbanites can reintegrate their organic ‘wastes’ into usable by-products. This promotes a paradigm shift transforming the apathetic consumer into an active member of the urban ecosystem.

Sandhill Crane (Grus canadensis) migratory populations use wetland ecosystems on northern Vancouver Island for their breeding habitat. With wind energy development being proposed for the area, an ecosystem-based management approach is being used to maintain Sandhill Crane breeding habitat and biological diversity within the bog wetland complex of the Nahwitti Plateau at the northern tip of the island. Shelter, forage and nesting habitat suitability were identified and rated with a six-class scheme from April to October over a two-year period. Vegetation surveys and crane inventories were carried out in 2006 and 2007 to spatially map the structure and patterns of bog ecosystems used by migrating cranes. The highest-rated Sandhill Crane nesting habitat consisted of sedge and low shrub dominated blanket bog wetlands with vegetated mounds. Riparian features and bog forests were also determined to be important habitats for forage, shelter, and living habitat. Based on the analysis, three Wildlife Habitat Areas were proposed to maintain Sandhill Crane nesting habitat and connected ecological services that support ecosystem-based management objectives, including promoting human well-being.