Upstream Land Research Articles

Defining the range of ecological shelter zones in the shore zone of Three Gorges Reservoir, China

To maintaining a health ecological environment in Three Gorges Reservoir (TGR) area, ecological shelter zones (ESZ) need to be built in the TGR shore zone urgently. Based on the implication and function of ESZ, this study first analyzed the relationships amongst three subsystems of the TGR area, including the upstream production-living land, the downstream reservoir water body, and the ESZ. Then a simple and practical hydrological environment model for controlling the eutrophication of the TGR water body was constructed to determine ESZ range of TGR. Additionally, based on the pollutant degradation efficiency of ESZ and the assimilative capacity of reservoir water body, a raster reverse tracking method was proposed to determine the range of ESZ. Thirdly, take Yangdu town in Zhongxian county as a typical region, the ESZ range under three scenarios of different rainfall intensity, degradation efficiency and inflow water quality that corresponding to the three decisive factors of defining ESZ range were discussed. Finally, the statistical laws of the ESZ’s width at each boundary points were discussed to facilitate the ESZ construction projects, and selected standardized rate at 70, 90, and 99 % were labelled as “General”, “Good” and “Excellent” level to represent the performance of the width of the ESZ range. In conclusion, it suggest “Good” level width as basic width of ESZ, and additionally a special protection zone should be put on upstream environment for the extreme large width at the boundary points.

A Financial and Environmental Analysis of Constructed Wetlands for Industrial Wastewater Treatment

SummaryThe Dow Chemical Co. (Dow) is actively working to develop an approach to value ecosystem services and incorporate them in business decisions. This study investigates the use of replacement cost methodology (RCM) for financial analysis and life cycle assessment (LCA) for environmental assessment. The case study analyzes a business decision made in 1995, where a constructed wetland was built instead of a sequencing batch reactor to solve a regulatory compliance issue in meeting suspended solids requirements for a wastewater treatment system at the Union Carbide Corp. (a subsidiary of The Dow Chemical Co.) plant in Seadrift, Texas. The financial results indicate that the total net present value savings calculated for implementing the constructed wetland instead of the sequencing batch reactor is $282 million over the project's lifetime. The LCA demonstrates that the lower energy and material inputs to the constructed wetland resulted in lower potential impacts for fossil fuel use, acidification, smog formation, and ozone depletion and likely lead to lower potential impacts for global warming and marine eutrophication. The result from the inventory of land use shows that both the upstream land burdens (for the sequencing batch reactor) and the on‐site acreage of the constructed wetland are similar in magnitude and importance, contrary to the assumption that green infrastructure always requires greater land area. This case study illustrates how Dow can consider financial and environmental analyses in comparing gray and green infrastructure solutions and further understand the benefits of implementing green infrastructure in an appropriate industrial application.

Influence of upstream land use on dissolved organic matter and trihalomethane formation potential in watersheds for two different seasons

Different land uses of upstream catchments may affect the quantity and the quality of dissolved organic matter (DOM) in watersheds, but the influence may differ by season. In this study, we examined concentrations and selected spectroscopic properties of DOM and the propensity to form trihalomethanes (THMs) for 19 different middle-sized watersheds across the Han River basin in Korea. Sampling was conducted for non-storm events during pre-monsoon (May) and monsoon seasons (July). The anthropogenic land uses including agricultural and residential areas occupied 2.3 to 49.4% of the upstream catchments of the watersheds. Non-aromatic, labile, and less condensed DOM structures were more abundant in the monsoon season. Parallel factor analysis (PARAFAC) modeling with fluorescence data demonstrated that a combination of three different fluorescence components could explain the seasonal and the spatial distributions of DOM characteristics. Terrestrial humic-like fluorescence was the most abundant component for all the DOM samples, while protein-like fluorescence became more pronounced for the monsoon season. THM concentrations did not differ between the two seasons. Observed seasonal differences in the concentrations and the characteristics of DOM suggested a greater contribution of groundwater to the streams in watersheds in the monsoon versus the pre-monsoon season. Significant correlations among anthropogenic land use, microbial humic-like fluorescence, and the propensity to form THMs were found only for the pre-monsoon season. Principal component analysis (PCA) demonstrated that, regardless of the season, anthropogenic land uses increased the concentrations of DOM and nutrients but that their effects on the DOM properties were not evident for the monsoon season.

Impact of land use and land cover dynamics on Zhalong wetland reserve ecosystem, Heilongjiang Province, China

In view of the significant hydrological and ecological role of wetlands, an analysis was made on the impact of land use and land cover dynamics on the spatial status of Zhalong wetland, a Ramsar site located downstream of Wuyuer River Basin in Northeast China. The impact assessment analyzed multi-temporal changes in the upstream land use/land cover characteristics of the wetland watershed using remote sensing data of Landsat MSS/TM. The multi-temporal land use/land cover statistics revealed that significant changes have taken place in the Wuyuer River Basin. In response to these upstream land use/cover changes, the marsh landscape in Zhalong wetland has showed changes in spatial extension, landscape pattern, and water quality characteristics. The major impacts have resulted from construction of a reservoir and water diversion engineering that has altered the wetland hydrological conditions and reduced the spatial distribution of the marsh landscape. In addition, inputs of agricultural nutrients, and industrial and human wastes from the upper catchments have resulted in increased signs of eutrophication. This study suggests that effective wetland hydrological restoration measures are needed to avoid further deterioration of this internationally important ecosystem.

Modeling of non-point source nitrogen pollution from 1979 to 2008 in Jiaodong Peninsula, China

Efforts to reduce land-based non-point source (NPS) pollutions from watersheds to coastal waters are ongoing all around the world. In this study, annual yield of NPS nitrogen (NPS-N) pollution in Jiaodong Peninsula, China from 1979 to 2008 was estimated. The results showed that: from 1979 to 2008, NPS-N yields exhibited significant inter-annual variations and an increasing trend on decadal scale. High NPS-N yield was mainly found in east and south parts, as well as the urbanized coastal regions in Jiaodong Peninsula. Among the 32 river basins, the three largest basins yielded more than 41.16% of the NPS-N. However, some small coastal watersheds along the South Yellow Sea and Jiaozhou Bay had higher per unit area yield. Most of the small watersheds characterized by seasonal runoff had coastal waters pertain to mild and moderate pollution levels. The ratio of watershed area to shoreline length and the up-stream land use had significant impacts on NPS-N flux through the shoreline. Among the four adjacent coastal areas of Jiaodong Peninsula, Jiaozhou Bay was the most noteworthy one not only because of high levels of land-based NPS-N pollution but also because of its nearly enclosed structure. The combination between integrated coastal zone management and integrated river basin management, land use planning and landscape designing in Jiaodong Peninsula is recommended. Copyright © 2013 John Wiley & Sons, Ltd.

The biogeography of stream bacteria

AbstractAimThe extent to which bacterial communities exhibit biogeographic patterns in their distribution remains unclear. We examined the relative influence of factors including geographic distance, latitude, elevation and catchment land use on the distribution and taxon richness of stream bacterial communities across New Zealand.LocationBacterial communities were collected from biofilm growing on submerged rocks in 244 streams. Sample sites spanned a north–south gradient of over 970 km, an elevational gradient of c. 750 m and were collected from a variety of catchment types across New Zealand.MethodsWe used automated ribosomal intergenic spacer analysis, a DNA fingerprinting technique, to characterize the structure and taxon richness of each bacterial community. Key attributes relating to sample location, upstream catchment land use and a suite of additional environmental parameters were collected for every site using GIS procedures. Univariate correlations between measures of bacterial community structure and latitude, elevation and distance were examined. Variance partitioning was then used to assess the relative importance of purely spatial factors versus catchment land use and environmental attributes for determining bacterial community structure and taxon richness.ResultsBacterial taxon richness was related to the geographic location of the sample site, being significantly greater at latitudes closer to the equator and reduced at higher elevations. We observed distance decay patterns in bacterial community similarity related to geographic distance and latitudinal distance, but not to elevational distance. Overall, however, bacterial community similarity and taxon richness was more closely related to variability in catchment land use than to climatic variability or geographic location.Main conclusionOur data suggest that stream biofilm communities across New Zealand are more influenced by catchment land use attributes than by dispersal limitation.

太湖水体溶解性氨基酸的空间分布特征

Amino acids( AAs) are important bio-available components of organic matter( OM) and are the major forms of organic nitrogen( ON) in aquatic ecosystem. They also represent significant fractions of OM in recent coastal marine sediments,water column particles and dissolved organic matters. They are typically labile composed relative to bulk OM and ON,and account for a considerable portion of the particulate OC and ON recycled in both water column and sediments,and therefore are an important nutrient form. Owing to the different AAs monomers have different biogeochemical stability,AAs are often used as an indicator of organic matter sources and as an index of OM degradation potential. Changes in amino acid composition exhibit consistent trends and demonstrate the degradation of cellular organic matter as it sinks through water column and is incorporated into sediments. Due to the labile character of AAs,the percentage of OC and N represented by amino acid( AA-C / OC% and AA-N / ON%) and the percentage of total amino acids have proven to be useful degradation indicators. They are sensitive at different stages of OM alteration and appear uncompromised by source variation. Dissolved amino acids( DAAs) characteristics were investigated in water of Lake Taihu,a large,shallow and eutrophic freshwater lake in China. The northern lake is characterized by phytoplankton dominance,high water turbidity,and severe Microcystis spp. algal blooms. In contrast,eastern lake is characterized by submersed vegetation,clear water,and diverse communities of fishes and invertebrates. The main upstream land use types of south Taihu were classified by the mountain forests and farmland. DAAs concentrations in Taihu ranged from 0. 27 to 3. 95 μmol / L,with a mean value of 1.38 μmol / L. The large regional differences in concentrations and yields of DAAs suggested that DOM produced in situ is an important source of bio-reactive of organic matter in waters of Taihu. The spatial distributions of DAAs concentrations in Taihu were less variable than those previously reported from other aquatic environments. DAAs concentrations of north Taihu were significantly higher than south lake and east lake,with mean values of( 2. 59±0. 71) μmol / L in north Taihu,( 0. 48±0. 14) μmol / L in south Taihu,and( 0. 48 ± 0. 16) μmol / L in east Taihu,respectively( P 0. 001). Based on the relationship between amino acid yields and percent labile DOC,( 17. 65 ±17. 84) % of fresh DOC in north lake is labile,which is higher than in south lake or east lake. The results showed internal sources mainly from the decomposing of phytoplankton should be the main source of DAAs in Taihu,and DAAs was important fraction of DOM. DAAs compositions were dominated by Phenylalanine( PHE) and lysine( LYS) in north lake,while only LYS in south and east lake.Compositions and concentrations of DAAs can be possible used as an indicator,which could provide useful information about the nutritional status and bio-available DOM in Lake Taihu. But because of high spatial heterogeneity in Taihu,we need to establish DAAs-liable DOC linear model for Lake Taihu,by the means of the algal-dominated and macrophytedominated DOM degradation experiments.

Changes in Sediment and Water Yield Downstream on a Small Watershed

In this study, sediment variation and water yield in a downstream direction over a six month period are presented for a watershed with mixed land use/cover, located in eastern Alabama, USA. The relative effects of pastoral, forested, and clear-cut areas on soil erosion, sediment delivery, and water yield are compared, and the efficacy of a streamside management zone (SMZ) at trapping sediment from a clear-cut was also explored. As expected, water and sediment yields increased in a downstream direction in the watershed study area. The furthest downstream section generally had the highest sediment concentration with the forested middle section having the lowest. The highest sediment yield per unit area originated from the pastoral portion of the watershed during rainfall events. The forested section generated less sediment than other parts of the watershed during storm events. Sediment loading increased due to clear cutting on the downstream section. The SMZ appeared incapable of trapping the sediment originating from the clear-cut during storm events. This study shows the importance of factoring in upstream land use/cover conditions when designing SMZs for sediment trapping.

Optimal Watershed Management for Reservoir Sustainability: Economic Appraisal

AbstractAccumulation of sediment from upstream agricultural land may shorten the lifetime of a reservoir and reduce its long-term benefits. This paper presents a framework for assessment of management strategies that simultaneously considers upstream soil conservation and downstream reservoir-level sediment control. A dynamic model that utilizes optimal control theory is developed for this purpose. Simulation results from the model are expected to provide practical information for policy makers, such as determination of the best sediment removal technology, the optimal timing to install this technology, and the optimal pattern of soil conservation efforts. An illustrative application to Lake Aswan, which is located between the Sudan and Egypt, indicates that the highest permissible level of soil conservation and the unconstrained dredging installed at 22 years are the best management practices, giving a sustainable life of the reservoir and net benefits of $117.8 billion. The cooperative strategy compared...

Meta-analysis of institutional-economic factors explaining the environmental performance of payments for watershed services

SUMMARYPayments for ecosystem services (PES) are a relatively new economic policy instrument, and the factors that drive and explain their environmental performance are poorly understood. Here a meta-analysis of causal relationships between the institutional design and environmental performance of 47 payments for watershed services (PWS) schemes worldwide showed a significant effect on environmental achievement of the terms and conditions of scheme participation, including the selection of service providers, community participation, the existence and monitoring of quantifiable objectives, and the number of intermediaries between service providers and buyers. Direct payments by downstream hydropower companies to upstream land owners for reduced sediment loads were identified as a successful PWS example. No other significant explanatory factors, such as specific type of watershed service, age or scale of implementation of the PWS scheme were detected. The results are highly dependent on the reliability of the input variables, in particular the measurement of the environmental performance variable. Despite efforts to find quantitative information on the environmental performance of existing PWS schemes, such empirical evidence is lacking in many of the schemes studied. International monitoring guidelines are needed to facilitate comparisons, identify success factors and support the future design of cost-effective PWS schemes.

Evaluation of non-point source pollution and river water quality using a multimedia two-model system

Summary In this study, an integrated two-model system composed of a multimedia watershed model and a river water quality model was developed to effectively simulate the impacts of non-point source (NPS) pollution on river water quality. NPS pollution loadings from Kaoping River Basin were calculated using the Integrated Watershed Management Model (IWMM). Results from the IWMM modeling were used as the input data for the Kaoping River water quality evaluation using the Water Quality Analysis Simulation Program (WASP) modeling. The land use patterns classified using SPOT images and Digital Elevation Model techniques with the aid of Erdas Imagine® process and ArcView® geographical information system were applied to assist the NPS pollution simulation. Results indicate that land use patterns of orchard farms and farmland areas were the major causes of the NPS pollution, and they should be effectively controlled. Results show that higher flow rates (>200 m 3 /s) were observed in the wet seasons, which would cause the increase in NPS pollution loadings. Results demonstrate that the integral approach could develop a direct linkage between upstream land use changes and downstream water quality. Using water quality modeling alone would underestimate the impact of NPS pollution on river water quality. The introduction of the integrated two-model system shows a significant advance in estimating the water quality.

Land‐use effects on water quality of a first‐order stream in the Ozark Highlands, mid‐southern United States

AbstractUrban and agricultural land uses can alter the natural hydrologic conditions of streams and rivers and often degrade water quality. In the Ozark Highlands of the mid‐southern United States, the climate, topography, soil properties, karst limestone geology, agricultural practices and rapid urbanization make water quality of particular concern due to the increased potential for water quality degradation by contaminant leaching to groundwater and runoff to surface waters. The objective of this study was to evaluate the effects of season (i.e. dry/cool and wet/warm) and riparian land use (i.e. urban, grazed pasture, ungrazed pasture, wetland, cultivated agriculture and grassland) on surface water quality in a first‐order stream within a diverse agricultural watershed in the Ozark Highlands. Water samples were collected twice a month within each land use during base‐flow conditions from October 2006 through October 2007. Samples were also collected periodically during storm‐flow conditions from October 2006 through December 2007. The greatest in‐stream pH was adjacent to the grazed pasture. In‐stream NO3‐N concentrations were greatest adjacent to the cultivated agriculture and grassland during the dry/cool season (i.e. October 2006 to March 2007) and averaged 2.67 mg L−1. In‐stream soluble reactive P (SRP) concentrations were greatest adjacent to the grassland during the wet/warm season (i.e. April 2007 to October 2007) and averaged 0.81 mg L−1. Concentrations of SRP, K, Mg and Zn were greater during storm‐ than base‐flow conditions and in‐stream As concentrations frequently exceeded 0.01 mg L−1. Discharge and in‐stream NH4‐N concentrations were unaffected by land use or season and averaged 0.003 m3 s−1 and 0.10 mg L−1, respectively, across all land uses and seasons. Results of this study clearly demonstrate the significant effect of adjacent land use on in‐stream water quality of a first‐order stream in a diverse agricultural watershed and highlight the importance of managing upstream land use in order to regulate downstream water quality. Copyright © 2010 John Wiley & Sons, Ltd.

Water-related conflicts in urban areas in Poland

Water-related conflicts in urban areas have a long history. Recently, the rapidly growing portion of the global population living in urban areas outnumbered the rural population, with consequences in the massive concentration of freshwater demands and of wastewater generation, lumped over land areas covered by the urban fabric. Water-related conflicts in urban areas may come about in relation to three categories of water problem: having too little water, too much water, or seriously polluted water. Conflict, controversies and tensions over water occur between urban and rural populations, between upstream and downstream riparians, and between different water uses (such as agricultural irrigation, municipal demands, industry and energy production). This study reviews the characteristics and mechanisms of water-related conflicts in urban areas in Poland. Diffuse water pollution in upstream land areas influences water quality (and water treatment) in downstream urban areas. In contrast, point-source water pollution via urban pollution load (e.g. raw, untreated municipal and industrial sewage) contaminates river water over a long distance downstream of a town. Levees protecting agricultural and rural areas upstream of a large town eliminate natural storage areas, whose presence would be beneficial for weakening the impetus of a flood wave in a large conurbation. During the dramatic River Odra flood in Poland in July 1997, breaching of levees upstream of a large town was considered as a lesser evil, but not implemented, due to strong resistance. Environmental legislation, such as directives of the European Union, generates another type of water-related conflict in Poland, which is also reviewed. Citation Kowalczak, P. & Kundzewicz, Z. W. (2011) Water-related conflicts in urban areas in Poland. Hydrol. Sci. J. 56(4), 588–596.

Prediction of biological integrity based on environmental similarity - Revealing the scale-dependant link between study area and top environmental predictors

Indices of Biological integrity (IBI) are considered valid indicators of the overall health of a water body because the biological community is an endpoint within natural systems. However, prediction of biological integrity using information from multi-parameter environmental observations is a challenging problem due to the hierarchical organization of the natural environment, the existence of nonlinear inter-dependencies among variables as well as natural stochasticity and measurement noise. We present a method for predicting the Fish Index of Biological Integrity (IBI) using multiple environmental observations at the state-scale in Ohio. Instream (chemical and physical quality) and offstream parameters (regional and local upstream land uses, stream fragmentation, and point source density and intensity) are used for this purpose. The IBI predictions are obtained using the environmental site-similarity concept and following a simple to implement leave-one-out cross validation approach. An IBI prediction for a sampling site is calculated by averaging the observed IBI scores of observations clustered in the most similar branch of a dendrogram –a hierarchical clustering tree of environmental observations- built using the rest of the observations. The standardized Euclidean distance is used to assess dissimilarity between observations. The constructed predictive model was able to explain 61% of the IBI variability statewide. Stream fragmentation and regional land use explained 60% of the variability; the remaining 1% was explained by instream habitat quality. Metrics related to local land use, water quality, and point source density and intensity did not improve the predictive model at the state-scale. The impact of local environmental conditions was evaluated by comparing local characteristics between well- and mispredicted sites. Significant differences in local land use patterns and upstream fragmentation density explained some of the model’s over-predictions. Local land use conditions explained some of the model’s IBI under-predictions at the state-scale since none of the variables within this group were included in the best final predictive model. Under-predicted sites also had higher levels of downstream fragmentation. The proposed variables ranking and predictive modeling methodology is very well suited for the analysis of hierarchical environments, such as natural fresh water systems, with many cross-correlated environmental variables. It is computationally efficient, can be fully automated, does not make any pre-conceived assumptions on the variables interdependency structure (such as linearity), and it is able to rank variables in a database and generate IBI predictions using only non-parametric easy to implement hierarchical clustering.

Naming Global Health

Dear Sir: During my senior year in college, a professor accused our small class of a topology reading seminar of trying to lord power through language. He argued, on several interminable occasions, that, instead of choosing words that we knew to be terms of art, we should speak as simply as possible. We should try to have any person understand and credit their thinking without punishing them for any failure of their vocabulary. Simplicity is beautiful. Language is beautiful whether simple or complex. I always have had trouble with that balance. However, making language complex has ancient roots. Knowing names that others do not secures possession. To name is to own. In the Judeo-Christian tradition, when man was granted dominion over creation, “and whatever the man called every living creature, that was its name” (Genesis 2:15).1 We do it with our children. My children have my name. We are doing this with global health. Wait, we are doing it with international health. That is, we are doing it with humanitarian assistance. At least we are not doing it with health aid, health development, relief, tropical public health, or developing world health. Actually, I think that last one is partially my fault. However, maybe not; maybe I saw it in a brochure by someone else and stole it. I have been doing that quite a bit lately, stealing names. Someone near me starts using new terms for areas in which I already am involved. Therefore, I take the name and help it find its way into the text of my brochure. It is a gentler practice than keeping that someone from growing whatever he is trying to grow over there, even if using the same water supply. No dams. No diverting irrigation channels. No poaching upstream land. Just name stealing. There is sufficient poverty and disease for everyone to work in decreasing them. I see the utility in naming to focus effort, enhance nuance, distinguish, and yet, remain eligible for multiple funding streams. However, being able to identify the roots of words is helpful as well. Work in the tropics and from the tropics spawned many of these disciplines. Additionally, the most egregious health disparities remain in the tropics. However, tropics and tropical are falling away from the language of what we do. We should be careful that our history, purpose, and so-named society fair better than them.

Risk-based modelling of diffuse land use impacts from rural landscapes upon salmonid fry abundance

Research has demonstrated that landscape or watershed scale processes can influence instream aquatic ecosystems, in terms of the impacts of delivery of fine sediment, solutes and organic matter. Testing such impacts upon populations of organisms (i.e. at the catchment scale) has not proven straightforward and differences have emerged in the conclusions reached. This is: (1) partly because different studies have focused upon different scales of enquiry; but also (2) because the emphasis upon upstream land cover has rarely addressed the extent to which such land covers are hydrologically connected, and hence able to deliver diffuse pollution, to the drainage network. However, there is a third issue. In order to develop suitable hydrological models, we need to conceptualise the process cascade. To do this, we need to know what matters to the organism being impacted by the hydrological system, such that we can identify which processes need to be modelled. Acquiring such knowledge is not easy, especially for organisms like fish that might occupy very different locations in the river over relatively short periods of time. However, and inevitably, hydrological modellers have started by building up piecemeal the aspects of the problem that we think matter to fish. Herein, we report two developments: (a) for the case of sediment associated diffuse pollution from agriculture, a risk-based modelling framework, SCIMAP, has been developed, which is distinct because it has an explicit focus upon hydrological connectivity; and (b) we use spatially distributed ecological data to infer the processes and the associated process parameters that matter to salmonid fry. We apply the model to spatially distributed salmon and fry data from the River Eden, Cumbria, England. The analysis shows, quite surprisingly, that arable land covers are relatively unimportant as drivers of fry abundance. What matters most is intensive pasture, a land cover that could be associated with a number of stressors on salmonid fry (e.g. pesticides, fine sediment) and which allows us to identify a series of risky field locations, where this land cover is readily connected to the river system by overland flow.

Freshwater conservation planning: the case for systematic approaches

Summary1. We review recent advances in systematic conservation planning in fresh waters. Most modern systematic planning approaches are based on the CARE principles: comprehensiveness, adequacy, representativeness and efficiency. Efficiency is usually provided by a complementarity‐based strategy, aiming to select new conservation areas in the light of previously protected features. These strategies have to be modified to account for the connected nature of rivers.2. Choice of surrogates for conservation features depends on the scale of the assessment, as well as the available expertise and resources. Ideally, real information about taxa or processes – extrapolated by models – ensures that target features are protected. Where this is not feasible, it is critical that the choice of environmental surrogates is informed by target biota or processes.3. Setting adequacy targets – the most challenging aspect in planning – needs to be evaluated in a freshwater‐specific context, as species–area relationships and the distribution of diversity differ in dendritic networks. Adequately designed conservation plans also need to consider upstream land use and catchment disturbances. Recent studies have largely addressed longitudinal connectivity either by setting rules to protect adjacent subcatchments (or even the entire catchment upstream), or by considering the magnitude of disturbance upstream of selected planning units. Very few studies have addressed lateral and vertical connectivity in a systematic way.4. To implement freshwater conservation plans, we recommend adopting a recently proposed hierarchical protection strategy, from ‘freshwater focal areas’ that contain the actual features to be protected to mixed‐use ‘catchment management zones’. Stakeholder involvement is crucial, especially in the large multi‐use areas upstream and in the surrounding catchment.5. We conclude that conservation planning using CARE principles is the only efficient way forward. This special issue shows significant efforts are under way to adapt freshwater‐specific adequacy, connectivity and implementation issues in conservation planning. However, a more holistic research investment is required to link freshwater, terrestrial and marine ecosystems.

Environmental drivers of fish functional diversity and composition in the Lower Colorado River Basin

Freshwater conservation efforts require an understanding of how natural and anthropogenic factors shape the present-day biogeography of native and non-native species. This knowledge need is especially acute for imperiled native fishes in the highly modified Lower Colorado River Basin (LCRB), USA. In the present study we employed both a taxonomic and functional approach to explore how natural and human-related environmental drivers shape landscape-scale patterns of fish community composition in the LCRB. Our results showed that hydrologic alteration, watershed land use, and regional climate explained 30.3% and 44.7% of the total variation in fish community taxonomic and functional composition, respectively. Watersheds with greater dam densities and upstream storage capacity supported higher non-native functional diversity, suggesting that dams have provided additional “niche opportunities” for non-native equilibrium life-history strategists by introducing new reservoir habitat and modifying downstream flow and thermal regimes. By contrast, watersheds characterized by greater upstream land protection, lower dam densities, and higher variation in spring and summer precipitation supported fish communities with a strong complement of native species (opportunistic–periodic strategists). In conclusion, our study highlights the utility of a life-history approach to better understand the patterns and processes by which fish communities vary along environmental gradients.

Valuing Drinking Water Provision as an Ecosystem Service in the Neuse River Basin

The valuation of ecosystem services such as drinking water provision is of growing national and international interest. The cost of drinking water provision is directly linked to the quality of its raw water input, which is itself affected by upstream land use patterns. This analysis employs the benefit transfer method to quantify the economic benefits of water quality improvements for drinking water production in the Neuse River Basin in North Carolina. Two benefit transfer approaches, value transfer and function transfer, are implemented by combining the results of four previously published studies with data collected from eight Neuse Basin water treatment plants. The mean net present value of the cost reduction estimates for the entire Neuse Basin ranged from $2.7 million to $16.6 million for a 30% improvement in water quality over a 30-year period. The value-transfer approach tended to produce larger expected benefits than the function-transfer approach, but both approaches produced similar results despite the differences in their methodologies, time frames, study sites, and assumptions.

Three centuries of change in the Peace–Athabasca Delta, Canada

The Peace–Athabasca Delta in northern Alberta, Canada, is a dynamic wetland ecosystem. Climatic, hydrologic, biological, and historical data are synthesized to elucidate how the ecosystem has changed over the past 300 years. Annual temperature is now higher than it has been in the past 300 years. For much of the 1700s, the Delta was colder in winter and had a lower flood frequency than that of the last 30 years. The 1800s were characterized by long and cold winters, 4–12 year-long episodes of high or low water, and repeated human epidemics. The early twentieth century was relatively moist and cool. Since mid-twentieth century the Delta has experienced periods of both intense warmth and cold, desiccation and recharge. Since the mid-1960s, local and regional mean annual temperatures have increased 0.30°C to 0.48°C per decade while winter temperatures have increased 0.68°C to 0.92°C per decade; annual snowfall has decreased 12 to 41 cm per decade while winter snowfall has decreased 12 to 34 cm per decade. Major events in the past 45 years include climatic changes favoring a warmer, drier ecosystem; cultural and socioeconomic changes; building of the Bennett Dam; prevention of the Athabasca River mainstem avulsion in 1972; the Cree Creek avulsion of 1982; large fluctuations in water, vegetation, and wildlife; and the development of the Alberta Tar Sands. Increased rates of basin desiccation and wildfire activity and upstream land disturbances may combine to alter the Delta’s biotic composition. There appears to be no relevant historical analogue of the present Delta.