A coupled terrestrial and aquatic biogeophysical model of the Upper Merrimack River watershed, New Hampshire, to inform ecosystem services evaluation and management under climate and land-cover change

Accurate quantification of ecosystem services (ES) at regional scales is increasingly important for making informed decisions in the face of environmental change. We linked terrestrial and aquatic ecosystem process models to simulate the spatial and temporal distribution of hydrological and water quality characteristics related to ecosystem services. The linked model integrates two existing models (a forest ecosystem model and a river network model) to establish consistent responses to changing drivers across climate, terrestrial, and aquatic domains. The linked model is spatially distributed, accounts for terrestrial–aquatic and upstream–downstream linkages, and operates on a daily time-step, all characteristics needed to understand regional responses. The model was applied to the diverse landscapes of the Upper Merrimack River watershed, New Hampshire, USA. Potential changes in future environmental functions were evaluated using statistically downscaled global climate model simulations (both a high and low emission scenario) coupled with scenarios of changing land cover (centralized vs. dispersed land development) for the time period of 1980–2099. Projections of climate, land cover, and water quality were translated into a suite of environmental indicators that represent conditions relevant to important ecosystem services and were designed to be readily understood by the public. Model projections show that climate will have a greater influence on future aquatic ecosystem services (flooding, drinking water, fish habitat, and nitrogen export) than plausible changes in land cover. Minimal changes in aquatic environmental indicators are predicted through 2050, after which the high emissions scenarios show intensifying impacts. The spatially distributed modeling approach indicates that heavily populated portions of the watershed will show the strongest responses. Management of land cover could attenuate some of the changes associated with climate change and should be considered in future planning for the region

Patterns, Processes, And Scale: An Evaluation Of Ecological And Biogeochemical Functions Across An Arctic Stream Network

Ecosystems are highly variable in space and time. Understanding how spatial and temporal scales influence the patterns and processes occurring across watersheds presents a fundamental challenge to aquatic ecologists. The goal of this research was to elucidate the importance of spatial scale on stream structure and function within the Oksrukuyik Creek, an Arctic watershed located on the North Slope of Alaska (68°36’N, 149°12’W). The studies that comprise this dissertation address issues of scale that affect our ability to assess ecosystem function, such as: methodologies used to scale ecosystem measurements, multiple interacting scales, translation between scales, and scale-dependencies. The first methodological study examined approaches used to evaluate chlorophyll a in ethanol extracts of aquatic biofilms. Quantification of chlorophyll a is essential to the study of aquatic ecosystems, yet differences in methodology may introduce significant errors to its determination that can lead to issues of comparability between studies. A refined analytical procedure for the determination of chlorophyll a was developed under common acidification concentrations at multiple common reaction times. The refined procedure was used to develop a series of predictive equations that could be used to correct and normalize previously evaluated chlorophyll a data. The predictive equations were validated using benthic periphyton samples from northern Alaska and northwestern Vermont, U.S.A. The second study examined interaction and translation between scales by examining how normalization approaches affect measurements of metabolism and nutrient uptake in stream sediment biofilms. The effect of particle size and heterogeneity on rates of biofilm metabolism and nutrient uptake was evaluated in colonized and native sediments normalized using two different scaling approaches. Functional rates were normalized by projected surface area and sediment surface area scaling approaches, which account for the surface area in plan view (looking top-down) and the total surface area of all sediment particles, respectively. Findings from this study indicated that rates of biogeochemical function in heterogeneous habitats were directly related to the total sediment surface area available for biofilm colonization. The significant interactions between sediment surface area and rates of respiration and nutrient uptake suggest that information about the size and distribution of sediment particles could substantially improve our ability to predict and scale measurements of important biogeochemical functions in streams. The final study examined how stream nutrient dynamics are influenced by the presence or absence of lakes across a variety of discharge conditions and how catchment characteristics can be used to predict stream nutrients. Concentrations of dissolved organic carbon (DOC) and other inorganic nutrients were significantly greater in streams without lakes than in streams in with lakes and DOC, total dissolved nitrogen (TDN), and soluble reactive phosphorus concentrations increased as a function of discharge. Catchment characteristic models explained between 20% and 76% of the variance of the nutrients measured. Organic nutrient models were driven by antecedent precipitation and watershed vegetation cover type while inorganic nutrients were driven by antecedent precipitation, landscape characteristics and reach vegetation cover types. The developed models contribute to existing and future understanding of the changing Arctic and lend new confidence to the prediction of nutrient dynamics in streams where lakes are present

A methodology for assessing spatio-temporal dynamics of flood regulating services

open5sìThe effects of land use alteration, migration and urbanization are key aspects in flood management, as human activities can strongly influence the capacity of ecosystems to provide flood regulating ecosystem services and determine their demand. This study analyzes spatio-temporal dynamics of flood regulating ecosystem services to support watershed management planning. A methodology for mapping the supply and demand of flood regulation is proposed and applied to the Arno River basin, in central Italy. The spatial explicit analysis of flood regulating ecosystem services supply is carried out with SWAT - Soil and Water Assessment Tool, whose outputs are synthetized by two indicators to evaluate the retention capacity of each land use class originating from CORINE data sets. Quantification of demand for flood regulating ecosystem services is based on flood hazard classes derived from the existing local flood management plans (i.e., PAI-Piano per l'Assetto Idrogeologico and PGRA-Piano di Gestione del Rischio Alluvioni). Supply and demand data are then combined to obtain budget maps of flood regulating ecosystem services and their evolution, between 1990 and 2018. The results show how both demand and supply of ecosystem services have changed in the last decades, highlighting the main hotspots at the catchment and subcatchment scales. With the increasing urbanization, the demand values have grown in the Arno floodplains, where residential, industrial and commercial zones are located. At the same time, land use changes have altered the water regulation supply, resulting in a generalized decrease of the basin capacity to provide flood regulation services. The maps and tables obtained show the fundamental role of forest and other vegetated areas whose protection is a priority to assure future flood regulation and associated co-benefits (e.g., regulation of air quality, reduction of erosion, improvement of water quality, wood fuel). The assessment of flood regulating here proposed is a powerful tool for decision makers to improve flood regulation and provides a sound base of knowledge to identify and locate flood prevention and mitigation measureArticle Number: 107963openMori, Stefano; Pacetti, Tommaso; Brandimarte, Luigia; Santolini, Riccardo; Caporali, EnricaMori, Stefano; Pacetti, Tommaso; Brandimarte, Luigia; Santolini, Riccardo; Caporali, Enric

Integrated Systems Modeling to Improve Watershed Habitat Management and Decision Making

Regulated rivers provide opportunities to improve habitat quality by managing the times, locations, and magnitudes of reservoir releases and diversions across the watershed. To identify these opportunities, managers select priority species and determine when, where, and how to allocate water between competing human and environmental users in the basin. Systems models have been used to recommend allocation of water between species. However, many models consider species’ water needs as constraints on instream flow that is managed to maximize human beneficial uses. Many models also incorporate uncertainty in the system and report an overwhelmingly large number of management alternatives. This dissertation presents three new novel models to recommend the allocation of water and money to improve habitat quality. The new models also facilitate communicating model results to managers and to the public. First, a new measurable and observable habitat metric quantifies habitat area and quality for priority aquatic, floodplain, and wetland habitat species. The metric is embedded in a systems model as an ecological objective to maximize. The systems model helps managers to identify times and locations at which to apply scarce water to most improve habitat area and quality for multiple competing species. Second, a cluster analysis approach is introduced to reduce large dimensional uncertainty problems in habitat models and focus management efforts on the important parameters to measure and monitor more carefully. The approach includes manager preferences in the search for clusters. It identifies a few, easy-to-interpret management options from a large multivariate space of possible alternatives. Third, an open-access web tool helps water resources modelers display model outputs on an interactive web map. The tool allows modelers to construct node-link networks on a web map and facilitates sharing and visualizing spatial and temporal model outputs. The dissertation applies all three studies to the Lower Bear River, Utah, to guide ongoing habitat conservation efforts, recommend water allocation strategies, and provide important insights on ways to improve overall habitat quality and area

Using CASIMIR-Vegetation model in the context of modeling riparian woods and fish species to support a holistic approach for environmental flows to be used on river management and conservation

The CASiMiR-vegetation model is a software that recreates the physical processes influencing the survival and recruitment of riparian vegetation, based on the relationship between ecologically relevant flow regime components and riparian vegetation metrics that reflect the vegetation’s responses to flow regime change. Working at a flow response guild level, this tool outperforms equivalent models by overriding various restrictions of the conventional modeling approaches. The potential of the CASiMiR-vegetation model is revealed in its application to different case studies during the development of a holistic approach to determine environmental flows in lowland Mediterranean rivers, based on woody riparian vegetation and fish species. Various modeling circumstances are described where CASiMiR-vegetation model was used with the purpose of sustaining the research addressing the thesis objectives. The main findings already accomplished in this research are highlighted to illustrate the outcomes that can be attained from the use of such a model

Lower Hobble Creek Ecosystem Flow Recommendations

This report describes the process and products of developing a suite of year-round instream flow recommendations for lower Hobble Creek in Utah County, Utah. This project was undertaken by the Utah Reclamation Mitigation and Conservation Commission (the Commission) as a component of the June Sucker Recovery Implementation Program (JSRIP) 2008 Work Plan (JSRIP 2008). The Commission is a Federal agency established by the Central Utah Project Completion Act (CUPCA [Titles II through VI of Public Law 102-575]). The Commission is responsible for mitigating impacts of the Bonneville Unit of the Central Utah Project (CUP) on fish, wildlife, and related recreation resources. The Commission is required to include in its fish and wildlife mitigation plans measures that it determines will “. . . restore, maintain, or enhance the biological productivity and diversity of natural ecosystems within the State and have substantial potential for providing fish, wildlife, and recreation mitigation and conservation opportunities,” and “. . . be based on, and supported by, the best available scientific knowledge”. 1 The JSRIP is a multi-agency cooperative program established to coordinate and implement recovery actions for June sucker (Chasmistes liorus), an endangered fish native to Utah Lake that historically used tributaries such as Hobble Creek for spawning (JSRIP 2002). The JSRIP attempts to balance June sucker recovery needs with the need to provide for ongoing water development for human needs within the Utah Lake basin