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Elevated phosphorus and nuisance algae such as Cladophora have been persistent environmental concerns in the coastal areas of Lake Ontario. Phosphorus is regarded as one of the drivers of nearshore Cladophora and the most likely mitigation that can be used to control levels of this nuisance algae in the lakes. The Niagara River, carrying the Lake Erie interbasin load, is the major contributor of the overall phosphorus load to Lake Ontario. Due to circulation patterns in the lake, this contribution is especially significant in the southwestern nearshore areas. Here we apply a mathematical model to provide insight into the relative contribution of the Niagara River versus loadings from local rivers (intrabasin loads) on the nearshore phosphorus concentrations in this region. We performed numerical experiments to determine to what extent the Niagara, Genesee and smaller local rivers impact the nearshore (

We describe development anthropogenic stress indices for coastal margins of the Laurentian Great Lakes basin. Indices were derived based on the response of species assemblages to watershed-scale stress from agriculture and urbanization. Metrics were calculated for five groups of wetland biota: diatoms, wetland vegetation, aquatic invertebrates, fishes, and birds. Previously published community change points of these assemblages were used to classify each watershed as ‘least-disturbed’, ‘at-risk’, or ‘degraded’ based on community response to these stressors. The end products of this work are an on-line map utility and downloadable data that characterize the degree of agricultural land use and development in all watersheds of the US and Canadian Great Lakes basin. Discrepancies between the observed biological condition and putative anthropogenic stress can be used to determine if a site is more degraded than predicted based on watershed characteristics, or if remediation efforts are having beneficial impacts on site condition. This study provides a landscape-scale evaluation of wetland condition that is a critical first step for multi-scale assessments to help prioritize conservation or restoration efforts.

Biotic indicators are useful for assessing ecosystem health because the structure of resident communities generally reflects abiotic conditions integrated over time. We used fish data collected over 5 years for 470 Great Lakes coastal wetlands to develop multi-metric indices of biotic integrity (IBI). Sampling and IBI development were stratified by vegetation type within each wetland to account for differences in physical habitat. Metrics were evaluated against numerous indices of anthropogenic disturbance derived from water quality and surrounding land-cover variables. Separate datasets were used for IBI development and testing. IBIs were composed of 10-11 metrics for each of four vegetation types (bulrush, cattail, water lily, and submersed aquatic vegetation). Scores of all IBIs correlated well with disturbance indices using the development data, and the accuracy of our IBIs was validated using the testing data. Our fish IBIs can be used to prioritize wetland protection and restoration efforts across the Great Lakes basin. The IBIs will also be useful in monitoring programs mandated by the Agreement between Canada and the United States of America on Great Lakes Water Quality, such as for assessing Beneficial Use Impairments (BUIs) in Great Lakes Areas of Concern, and in other ecosystem management programs in Canada and the USA.

This report provides a detailed set of historical stressor data for 60 watersheds comprising the Laurentian Great Lakes basin. Archival records were transcribed from public records to create quantitative data on human activities: population, mining, deforestation, and agriculture. Yearly records of stressors are provided from 1780 through 2010. These data may be used to track historical impacts on Great Lakes coastal and open water conditions. They may further be used to examine corresponding effects on response variables such as biological communities quantified during monitoring and palaeoecological programmes. Open Practices This article has earned an Open Data badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://doi.org/10.1594/PANGAEA.885879. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.

Beaver ponds require a supply of water, which ultimately comes from precipitation. Although most of northern Minnesota’s precipitation is received in the summer months, snowmelt is the main driver of peak streamflow in the spring. I analyzed NOAA snowpack records and USGS streamflow records to show that peak annual streamflow was significantly related to maximum snow water equivalent during the winters of 2005–2016. We conducted intensive field studies of water fluxes in a Kabetogama Peninsula beaver meadow, measuring evapotranspiration, pond level, groundwater, streamflow, and runoff from watershed side slopes. Evapotranspiration was a significant source of water loss from the beaver meadow during late summer, with discernable diurnal effects on streamflow, water table, and pond level. Groundwater measurements showed recharge (i.e., water flowing from the surface into the ground) occurring within most of the beaver meadow, but periodic discharge (i.e., water flowing from the ground toward the surface) in sites closer to the stream flowing through the beaver meadow. “Edge collectors” positioned around the perimeter of the beaver meadow showed that lateral fluxes of runoff into the beaver meadow were spatially variable, such that the temporal pattern of flow in a gently sloping portion of the catchment with >0.3 m of soil was different than that for three sites with steeper slopes and shallower soils over bedrock. A spatially explicit model that routed flow within the beaver meadow catchment successfully replicated this difference.

To understand environmental conditions in Lake Superior over the last two centuries, we conducted a paleolimnological study on two sediment cores collected in the eastern and western regions of the lake. We examined the diatom fossil assemblages, sedimentation rates, organic and trace metal accumulation rates, and GIS-reconstructed human land use stressors in order to evaluate lake history and the impacts of human activities. There is evidence that the diatom community reorganized due to nutrient enrichment beginning around the time of European settlement and significant agricultural development. Trace metal profiles tracked a period of mining and ore processing which temporarily increased trace metal loads to the lake in the mid- to late-20th century. In recent decades, more oligotrophic diatom species were favored, suggesting nutrient decreases associated with remedial activities. The diatom community is now dominated by the Cyclotella comensis complex, suggesting changes in the lake's physical and chemical processes associated with climate change. Similar long-term environmental trends were observed in both core locations, but the timing of some events differed, indicating localized effects such as nutrient enrichment. An understanding of Lake Superior's past responses to human activities can inform management decisions that account for influences within and outside the lake's catchment.

Biological indicators can be used both to estimate ecological condition and to suggest plausible causes of ecosystem degradation across the U.S. Great Lakes coastal region. Here we use data on breeding bird, diatom, fish, invertebrate, and wetland plant communities to develop robust indicators of ecological condition of the U.S. Lake Superior coastal zone. Sites were selected as part of a larger, stratified random design for the entire U.S. Great Lakes coastal region, covering gradients of anthropogenic stress defined by over 200 stressor variables (e.g. agriculture, altered land cover, human populations, and point source pollution). A total of 89 locations in Lake Superior were sampled between 2001 and 2004 including 31 sites for stable isotope analysis of benthic macroinvertebrates, 62 sites for birds, 35 for diatoms, 32 for fish and macroinvertebrates, and 26 for wetland vegetation. A relationship between watershed disturbance metrics and 15N levels in coastal macroinvertebrates confirmed that watershed-based stressor gradients are expressed across Lake Superior's coastal ecosystems, increasing confidence in ascribing causes of biological responses to some landscape activities. Several landscape metrics in particular—agriculture, urbanization, human population density, and road density—strongly influenced the responses of indicator species assemblages. Conditions were generally good in Lake Superior, but in some areas watershed stressors produced degraded conditions that were similar to those in the southern and eastern U.S. Great Lakes. The following indicators were developed based on biotic responses to stress in Lake Superior in the context of all the Great Lakes: (1) an index of ecological condition for breeding bird communities, (2) diatom-based nutrient and solids indicators, (3) fish and macroinvertebrate indicators for coastal wetlands, and (4) a non-metric multidimensional scaling for wetland plants corresponding to a cumulative stress index. These biotic measures serve as useful indicators of the ecological condition of the Lake Superior coast; collectively, they provide a baseline assessment of selected biological conditions for the U.S. Lake Superior coastal region and prescribe a means to detect change over time.

Quantifying gradients of anthropogenic stress can inform the development of sample designs, provide an important covariate in modeling relationships of response variables, identify reference and highly-disturbed sites, and provide a baseline and guidance to restoration and remediation efforts. We describe development of SumRel, a composite index of anthropogenic stress, for the U.S. and Canadian Lake Superior basin. Key elements of the project include development of high-resolution watersheds throughout the basin, summarization of the major point and non-point stressors within these watersheds, and creation of tools for scaling the watersheds and stressor summaries. SumRel was calculated at two spatial scales: for high resolution subcatchments within the Lake Superior basin (mean watershed area = 93 ha) and for coastal watersheds of Lake Superior. An assessment of subcatchments within Minnesota's St. Louis River watershed showed a correlation between the degree of disturbance, as indicated by SumRel, and impaired water quality, as evidenced by in-stream conductivity. These data and tools allow identification and visualization of reference and highly-disturbed sites at multiple spatial scales, providing decision support for individual agency and binational monitoring, assessment and restoration initiatives across the Lake Superior basin.

Our overall goal was to develop indicators that both estimate ecological condition and suggest plausible causes of ecosystem degradation across the U.S. Great Lakes coastal region. Here we summarize data gathered along the U.S. Lake Huron coastline for breeding bird, diatom, fish, invertebrate, and wetland plant communities. We sampled these biotic communities on 88 sites in Lake Huron coastal wetlands, uplands, estuaries/bays, and high-energy shorelines. The sites were selected as part of a larger, stratified random design for the entire U.S. Great Lakes coastal region using gradients of anthropogenic stress that incorporated over 200 stressor variables (e.g. agriculture, land cover, human populations, and point source pollution). The U.S. Lake Huron coastal region exemplified wide variation in human-related stress relative to the entire U.S. Great Lakes coast. In general, levels of stress decreased from south to north partly reflecting the change in climate and physiography, but also due to the greater human influences in the southern region as compared with the north. The primary stressors in the southern region are due to agriculture and human development, while the northern region has substantially less agriculture and less human population. The biotic communities sampled were strongly related to the environmental stress gradients, especially agriculture and urbanization. The following indicators were developed based on responses to stress: 1) an index of biological condition for breeding bird communities corresponding to land use, 2) a diatom-inferred total phosphorus indicator corresponding to water quality, 3) exotic fish (carp [Cyprinus carpio] and goldfish [Carassius auratus]) corresponding to agriculture, and 4) a multi-taxa index for wetland plants corresponding to a cumulative stress index. These communities can all serve as useful indicators of the ecological condition of the Lake Huron coast. The ecological indicators provide a baseline on selected conditions for the U.S. Lake Huron coastal region and a means to detect change over time.

Developing indicators of ecosystem condition is a priority in the Great Lakes, but little is known about appropriate spatial scales to characterize disturbance or response for most indicators. We surveyed birds, fish, amphibians, aquatic macroinvertebrates, wetland vegetation, and diatoms at 276 coastal wetland locations throughout the U.S. Great Lakes coastal region during 2002-2004. We assessed the responsiveness of 66 candidate indicators to human disturbance (agriculture, urban devel- opment, and point source contaminants) characterized at multiple spatial scales (100, 500, 1,000, and 5,000 m buffers and whole watersheds) using classification and regression tree analysis (CART). Non- stressor covariables (lake, ecosection, watershed, and wetland area) accounted for a greater proportion of variance than disturbance variables. Row-crop agriculture and urban development, especially at

In an evaluation of diatoms as indicators of human disturbance in coastal ecosystems of the Laurentian Great Lakes, we characterized assemblage specificity to lake and habitat type to identify non-anthropogenic factors influencing indicator models. Surface sediment assemblages and environmental variables were collected along the U.S. coastline at 191 sample sites, which were classified by lake and geomorphic type: high-energy (HE), embayment (EB), coastal wetland (CW), riverine wetland (RW), protected wetland (PW), and open water (OP). Diatom inferred (DI) total phosphorus (TP) transfer functions (models) were developed for each lake and geomorphic type. Robust models included: the overall model (RMSEP; r2jack = 0.65; RMSEP = 0.005), Lake Superior (r2jack = 0.73; RMSEP = 0.003), Lake Ontario (r2jack = 0.73; RMSEP = 0.007), PW (r2jack = 0.64; RMSEP = 0.003), and EB (r2jack = 0.64;RMSEP = 0.007). Weaker models, indicating poorer diatom-TP relationships, included: RW (r2jack =0.03; RMSEP = 0.005), O...

Plant taxa identified in 90 U.S. Great Lakes coastal emergent wetlands were evaluated as indicators of physical environment. Canonical correspondence analysis using the 40 most common taxa showed that water depth and tussock height explained the greatest amount of species-environment interaction among ten environmental factors measured as continuous variables (water depth, tussock height, latitude, longitude, and six ground cover categories). Indicator species analysis was used to identify species-environment interactions with categorical variables of soil type (sand, silt, clay, organic) and hydrogeomorphic type (Open-Coast Wetlands, River-Influenced Wetlands, Protected Wetlands). Of the 169 taxa that occurred in a minimum of four study sites and ten plots, 48 were hydrogeomorphic indicators and 90 were soil indicators. Most indicators of Protected Wetlands were bog and fen species which were also organic soil indicators. Protected Wetlands had significantly greater average coefficient of conservatism (C) values than did Open-Coast Wetlands and River-Influenced Wetlands, but average C values did not differ significantly by soil type. Open-Coast and River-Influenced hydrogeomorphic types tended to have sand or silt soils. Clay soils were found primarily in areas with Quaternary glaciolacustrine deposits or clay-rich tills. A fuller understanding of how the physical environment influences plant species distribution will improve our ability to detect the response of wetland vegetation to anthropogenic activities.

In an effort to develop indicators for Great Lakes near-shore conditions, diatom-based transfer functions to infer water quality variables were developed from 155 samples collected from coastal Great Lakes wetlands, embayments and high-energy shoreline sites. Over 2,000 diatom taxa were identified, and 352 taxa were sufficiently abundant to include in transfer function development. Multivariate data exploration revealed strong responses of the diatom assemblages to stressor variables, including total phosphorus (TP). Spatial variables such as lake, latitude and longitude also had notable relationships with assemblage characteristics. A diatom inference transfer function for TP provided a robust reconstructive relationship (r2 = 0.67; RMSE = 0.28 log(μg/L); r2jackknife = 0.55; RMSEP = 0.33 log (μg/L)) that improved following the removal of 13 samples that had poor observed-inferred TP relationships (r2 = 0.75; RMSE = 0.22 log(μg/L); r2jackknife = 0.65; RMSEP = 0.26 log (μg/L)). Diatom-based transf...

Understanding the relationship between human disturbance and ecological response is essential to the process of indicator development. For large-scale observational studies, sites should be selected across gradients of anthropogenic stress, but such gradients are often unknown for a population of sites prior to site selection. Stress data available from public sources can be used in a geographic information system (GIS) to partially characterize environmental conditions for large geographic areas without visiting the sites. We divided the U.S. Great Lakes coastal region into 762 units consisting of a shoreline reach and drainage-shed and then summarized over 200 environmental variables in seven categories for the units using a GIS. Redundancy within the categories of environmental variables was reduced using principal components analysis. Environmental strata were generated from cluster analysis using principal component scores as input. To protect against site selection bias, sites were selected in random order from clusters. The site selection process allowed us to exclude sites that were inaccessible and was shown to successfully distribute sites across the range of environmental variation in our GIS data. This design has broad applicability when the goal is to develop ecological indicators using observational data from large-scale surveys.

As part of a plant succession/landscape ecology study of small, confined, emergent wetlands (boreal beaver meadows in northern Minnesota), we carried out an investigation of diffuse lateral flow of water and nutrients into the wetland from the local forested upland catchment. These local catchments may be very small (5–15 ha); flow routing is rarely considered at such a fine scale. Tape and compass surveying methods were successfully combined with GPS reference points to construct a detailed (10×10-m resolution) map of upland topography and vegetation. Analysis and modeling software were developed to trace flow from the local catchment into the meadow. Simplistic flow routing algorithms (D8) predicted uniform sheet flow with many artifacts in the predicted flow pattern, whereas a more sophisticated procedure (DEMON) suggested multiple hot spots of lateral input into the meadow along its perimeter. The flow model incorporated storage based on cover type. When considering the importance of flow from different zones in the catchment area, a simultaneous simulation of all flow to the meadow was found to be necessary to avoid serious execution order dependence. A number of edge flow collection devices were designed and installed. Collectors trapped flow across 2–3 m of meadow perimeter, and after rainfall, depending on placement, recorded flow values typically between 0 and 5–20 l/day, with peak flows in excess of 100 l/day. Concentrated points of water and nutrient input into the meadows may have a role in plant distribution and diversity.

Biological attributes of ecosystems often change nonlinearly as a function of anthropogenic and natural stress. Plant and animal communities may exhibit zones of change along a stressor gradient that are dispropor- tionate relative to the incremental change in the stressor. The ability to predict such transitions is essential for effective management intervention because they may indicate irreversible changes in ecological processes. De- spite the importance of recognizing transition zones along a stressor gradient, few, if any, investigators have examined these responses across multiple taxa, and no community threshold studies have been reported at large geographic scales. We surveyed benthic macroinvertebrate, fish, bird, diatom, and plant communities in coastal wetlands across a geospatially referenced gradient of anthropogenic stress in the Laurentian Great Lakes. We used Threshold Indicator Taxon Analysis (Baker and King 2010) to analyze each community's response to iden- tify potential zones of disproportionate change in community structure along gradients of major watershed-scale stress: agriculture and urban/suburban development. Our results show surprising congruence in community thresholds among different taxonomic groups, particularly with respect to % developed land in the watershed. We also analyzed uncertainty associated with the community-specific thresholds to understand the ability of different assemblages to predict stress. The high and congruent sensitivity of assemblages to development dem- onstrates that watershed-scale stress has discernible effects on all biological communities, with increasing poten- tial for ecosystem-scale functional changes. These findings have important implications for identifying reference- condition boundaries and for informing management and policy decisions, in particular, for selecting freshwater protected areas.

Irrigation of dairy farm effluent (DFE) onto pasture is the preferred treatment method in New Zealand for this very dilute organic effluent. Whereas the dynamics of the urine fraction is comparatively well understood, there is a lack of data on the fate of the mainly organic faecal fraction. To improve our understanding of the complex turnover processes, we labelled both the inorganic and organic N compounds of the faecal fraction of DFE with 15N. We then measured the 15N dynamics in various soil and plant fractions in a laboratory experiment at two water contents for up to 254 days. Feeding a dairy cow with 15N-labelled pasture yielded faeces that had a mean 15N abundance of 2.95 atom%. Unlabelled urine and water were added to the labelled faeces to construct the DFE, which contained 90.4% of the 15N in the organic nitrogen fraction (2.87 atom%) and 9.6% in the ammonium fraction (1.23 atom%). As N turnover and losses depend on the method of application and the soil structure, we simulated field conditions by surface-applying our DFE onto intact soil cores with pasture. Two soil water treatments were imposed; dry (30% water content) and wet (water table at 17 cm below the soil surface). The surface application resulted in filtration of the DFE, with a high proportion of the 15N remaining on the soil surface, where it was relatively unavailable for plant uptake but prone to gaseous and physical losses. Of the applied 15N, 9.9% in the dry and 13.5% in the wet treatment were still recovered as DFE on the soil surface at day 254. Plant uptake of faecal 15N accounted for 9.3% and 13.0% in the dry and wet treatments, respectively. The bulk of the 15N was recovered in the soil organic nitrogen fraction (35.1% in dry, 42.5% in wet), whereas 15N in inorganic and microbial nitrogen accounted for only very small amounts (< 2%). Total recoveries of the applied 15N in plant, soil and DFE remaining on the surface at day 254 were 58.4% in the dry, and 71.5% in the wet treatment. Separate analysis of the total and ammonium nitrogen contents and 15N enrichments of the constructed DFE and filtered subsamples (0.5 mm, 0.2 μm) showed that the faecal fraction was not labelled homogeneously. Due to this heterogeneity, which was exacerbated by the filtration of DFE on the soil surface, it was difficult to calculate the turnover of the total faecal fraction based on 15N results.

We describe an algorithm that uses pro rata allocation between inter-pool flows to meet conservation of mass/energy constraints and avoid execution order dependence. More commonly used clipping methods do not satisfy these constraints when multiple flows from small pools exceed the total size of the pool. Overrun, which occurs when a pool is increased or decreased beyond its capacity, typically a decrease below zero, leads to failure to conserve mass. Clipping avoids overrun by restricting the size of pools, usually by setting negative values to zero, which can in turn lead to unacceptable error levels in the simulation's output, particularly in terms of sensitivity to execution order. In addition to the normal ‘current’ and ‘next’ copies of the system's state variables, this algorithm requires an ‘output’ copy, which sums outputs from each pool. Individual flows from a pool are divided by the output sum to determine the proportion of the pool each flow receives. Additionally, the approach allows tracking of individual mass flows, which are sometimes more interesting than their net effect on the pools on which they operate. Implementation details and a comparison with a clipping type algorithm are given in terms of a GIS based meadow ecosystem hydrology submodel. In a simple test case, also presented, the pro rata algorithm more consistently tracks the target solution (given by an extremely small time step).

In New Zealand, regulatory authorities have selected controlled application of dairy farm effluent onto pasture as the best practical treatment option. Nitrogen leaching studies have found undissolved or particulate (>0.2 μm in size) as well as dissolved organic material in drainage waters as a result of the application of this effluent onto poorly drained soils. This paper describes a detailed investigation into the leaching behavior of the particulate fraction of dairy farm effluent applied onto a poorly drained soil. The study entailed dividing the particulate fraction of dairy farm effluent into a number of arbitrary size-classes and determining the amounts of organic carbon present in each of these classes by physical filtration and carbon measurement. This effluent was then applied to a number of undisturbed soil cores from soil horizons of a poorly drained soil. The filtration characteristics of the soil horizons were determined by differences between the carbon in the applied effluent and the leachate for each size-class. Results show that when the upper horizons of the soil are at water contents greater than field capacity, between 27 and 34% of the carbon applied in dairy farm effluent can be leached through the top horizons. As expected, most of the material that was filtered out came from the larger size-classes; 84% of the carbon applied was greater than 2.7 μm in size, and more than 83% of this was retained in the top soil horizons. In the smaller size-classes (

A simulation model is presented that produces and manipulates computer representations of plant root microbial ecosystems. The root system is described as a collection of nodes. A node records a position in three-dimensional space and may represent the origin of another root, a bend, or some change in the root's microbial status. Disease lesions, closely associated microbial populations such as mycorrhizal fungi, and free soil microbial populations may also be represented. A multi-dimensional matrix structure provides a useful conceptual framework for the numerous stochastic functions required by the model. Procedures for building the node-based root map, and for simulating root growth and microbial interaction, are presented in terms of such a matrix, in conjunction with the necessary manipulations of the node lists which represent the root system. This paper assesses the practicality of the approach described, which appears to be feasible and potentially useful. The model is considered as a step towards a generic framework for modelling root-architecture and the spatial structure of associated microbial ecosystems. The model has been successfully applied to a simulation of a Pinus radiata/Armillaria spp. pathosystem.

The highly variable nature of many biological entities, particularly those occurring in natural ecosystems, makes the validation of models and simulations extremely important. Valuable tools such as simulations should not be discounted simply because of a lack of cookbook validation procedures. This paper considers the process of validation as it relates to complex biological systems, and examines some methods to compare the inherently multivariate values required to characterise biological entities. A model of Pinus radiata root system morphology is used as a case study. It is concluded that, while time consuming, development of system-specific objective indices may often be the most useful way to compare simulation output and field data when complex biological entities are modelled.

Pinus radiata forestry is an important industry in New Zealand, and armillaria, a root rot fungus, is a major source of lost timber production. Chemical treatments are largely ineffective and physically removing contaminated material is prohibitively expensive. Biological control techniques give promising indications of effective and ecologically sound management, but the long timescales and concealed systems involved hamper field research. Here the role of simulation in the manipulation and understanding of the ecosystem is examined. The model developed defines a three-dimensional representation of root architecture, which is used as a temporal envelope for simulating root growth. The system then traces the spread of fungal populations along root surfaces. The resulting direct, structural simulation model provides a flexible tool for examining the effects of several factors whose importance is difficult to assess in the field. While there is enormous scope for further development of the system, the current implementation suggests that the model is a useful new approach to understanding the complex soil/root ecosystem. The validation of models of complex but largely random systems is also addressed.

Watersheds represent spatially explicit areas within which terrestrial stressors can be quantified and linked to measures of aquatic ecosystem condition. We delineated thousands of Great Lakes watersheds using previously proven and new watershed delineation techniques. These were used to provide summaries for a variety of anthropogenic stressors within the Great Lakes. All delineation techniques proved useful, but each had applications for which they were most appropriate. A set of watershed delineations and stressor summaries was developed for sampling site identification, providing relatively coarse strata for selecting sites along the U.S. Great Lakes coastline. Subsequent watershed delineations were used for high-resolution site characterization of specific sites and characterizing the full coastal stressor gradient. For these delineations we used three general approaches: 1) segmentation of the shoreline at points midway between adjacent streams and delineation of a watershed for each segment; 2) specific watershed delineations for sampled sites; and 3) a Great Lakes basin-wide, high-resolution approach wherein sub-basins can be agglomerated into larger basins for specific portions of the coast. The third approach is unique in that it provides a nested framework based on hierarchies of catchments with associated stressor data. This hierarchical framework was used to derive additional watershed delineations, and their associated stressor summaries, at four different scales. Providing anthropogenic stressor metrics in such a format that can quickly be summarized for the entire basin at multiple scales, or specifically for particular areas, establishes a strong foundation for quantifying and understanding stressor-response relationships in these coastal environments.

Two hydrological models, which used different methods to determine the soil water distribution in a soil profile, were evaluated against 4 years of data from large soil lysimeters. SWIM determines soil water distribution from a finite difference implementation of the Richards" equation. DRAINMOD uses a soil-specific relationship between the air volume in a profile and the watertable height to locate the depth to the saturated zone. An ‘equilibrium’ relationship between soil water tension and depth is then assumed to distribute the soil water in the unsaturated zone. Predicted values and measured values for drainage and watertable heights were compared for 3 drainage treatments. The drainage in the lysimeters was achieved by installing an outlet tube on the slowly permeable layer at 0·75 m from the soil surface. The conventional drainage treatment allowed gravity drainage to occur directly from this drainage outlet tube. The other 2 drainage treatments employed controlled drainage, where a step (or weir) is installed in the outlet tube. No drainage can occur from the lysimeters until the water table within the lysimeters reaches the step height. Two different step heights provided 2 controlled drainage treatments. Independently determined model parameters were used without additional calibration for the analysis. Both models performed well. DRAINMOD over-predicted the 4-year cumulative drainage for all treatments, with the largest error being 7%. SWIM conversely under-predicted cumulative drainage, with a maximum error of 16%. The standard error of estimation for the watertable height over the full 4-year data period was lower for SWIM, ranging from 0 ·06 to 0·12 m. DRAINMOD’s standard error over the same period for the watertable height ranged from 0·09 to 0·21 m. Generally, error values from this work were smaller than comparable values from other studies. The hydrology of the lysimeters where there was no lateral inflow, surface runoff, or deep seepage losses, coupled to an essentially 1-dimensional flow domain, probably contributed to the lower errors. Furthermore, limitation of the maximum watertable heights by the controlled drainage regime in the lysimeters also reduces the maximum possible magnitude of the standard error term.

Since European settlement, over 50 % of coastal wetlands have been lost in the Laurentian Great Lakes basin, causing growing concern and increased monitoring by government agencies. For over a decade, monitoring efforts have focused on the development of regional and organism-specific measures. To facilitate collaboration and information sharing between public, private, and government agencies throughout the Great Lakes basin, we developed standardized methods and indicators used for assessing wetland condition. Using an ecosystem approach and a stratified random site selection process, birds, anurans, fish, macroinvertebrates, vegetation, and physico-chemical conditions were sampled in coastal wetlands of all five Great Lakes including sites from the United States and Canada. Our primary objective was to implement a standardized basin-wide coastal wetland monitoring program that would be a powerful tool to inform decision-makers on coastal wetland conservation and restoration priorities throughout the Great Lakes basin.

A study to evaluate the efficacy of a simple and inexpensive diagnostic and therapeutic approach to stress incontinence in 46 elderly women is described. The treatment had two aspects: estrogens, both orally and topically, and a pelvic floor exercise program. The study shows that stress incontinence and stress incontinence with urgency incontinence in non-institutionalized, ambulant elderly women can be diagnosed and successfully treated in the great majority of cases without the need for expensive and potentially hazardous diagnostic and therapeutic modalities.