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This paper introduces and applies a novel methodology that integrates watershed modeling with the traditional regional flood frequency analysis. The methodology introduces a novel site-similarity measure that relies on hydrologic simulations and accounts for the effect of land depressions on streamflow generation. The new measure is tested along with other traditional measures for regional flood frequency analysis in the Canadian prairies. The case study is chosen carefully to critically test the new methodology. An application of 30 combinations of the new and traditional site similarity measures is assessed for pooling 109 sites. The homogeneity of the clustered groups is evaluated, and different probability distributions are applied to describe at-site and regional annual maximum flows. The results present enhanced groups' homogeneity when the new measure is employed due to a better representation of the hydrologic similarity between the pooled sites. Furthermore, the regionally estimated quantiles are found susceptible to the chosen site similarity measures in the pooling process, which highlights the importance of considering the proposed measure that describes a key hydrologic aspect when land depressions exist. [ABSTRACT FROM AUTHOR]

• Analyzes Saskatchewan government consultations on agricultural land ownership. • Responses do discursive work of challenging and reifying current property relations. • Stories told reinforce private property regimes, justify settler colonialism. • Values expressed suggest different social relations regarding land are possible. • Persuasive stories of alternatives, communicating values, could help induce change. Global conflicts over land grabbing, financialization, and conservation have generated resistance from diverse local peoples who insist that land must be more than a commodity; it has social, cultural, and ecological value alongside its economic productivity. Saskatchewan's government has recently responded to similar conflicts over investment, privatization, and concentration of landholding, by engaging in public consultations on farmland ownership. Analyzing comments from public consultation surveys in 2015 and 2017, the paper employs insights from property theory, legal studies, geography, and scholarship on storytelling to analyze how respondents' values, expressed through stories, work to change or maintain property relations. As a resource, agricultural land is endowed with value that changes over time and space. Land tenure regimes consist of shifting social relations regarding this resource, and these relations are often arrived at and maintained through persuasive narratives framed through social value claims about heritage, identity, livelihoods, and community norms. These stories also have a material effect on resource use and property regimes. In Saskatchewan, as survey respondents employ stories to influence policy decisions on agricultural land tenure and advocate for the status quo, they utilize social values that justify their entitlements. Alternative property relations, advocated or proposed by some respondents, provide more fundamental challenges to absolutist notions of private property rights and thus face ideological barriers to acceptance and implementation through policy. However, telling different stories can be a way to alter property relations. [ABSTRACT FROM AUTHOR]

Acesulfame (ACE), sucralose (SUC), cyclamate (CYC), and saccharin (SAC) are widely used artificial sweeteners that undergo negligible metabolism in the human body, and thus ubiquitously exist in wastewater treatment plants (WWTPs). Due to their persistence in WWTPs, ACE and SUC are found in natural waters globally. Wastewater samples were collected from the primary influent, primary effluent, secondary effluent, and final effluent of a WWTP in Alberta, Canada between August 2022 and February 2023, and the artificial sweeteners concentrations were measured by LC-MS/MS. Using wastewater-based epidemiology, the daily per capita consumption of ACE in the studied wastewater treatment plant catchment was estimated to be the highest in the world. Similar to other studies, the removal efficiency in WWTP was high for SAC and CYC, but low or even negative for SUC. However, ACE removal remained surprisingly high (>96%), even in the cold Canadian winter months. This result may indicate a further adaptation of microorganisms capable of biodegrading ACE in WWTP. The estimated per capita discharge into the environment of ACE, CYC, and SAC is low in Alberta due to the prevalent utilization of secondary treatment throughout the province, but is 17.4–18.8 times higher in Canada, since only 70.3% of total discharged wastewater in Canada undergoes secondary treatment. [Display omitted] • The occurrence and degradation of acesulfame, sucralose, cyclamate, and saccharin in a WWTP in Alberta, Canada was first reported. • The calculated daily consumption per capita of acesulfame in this WWTP catchment was 16.8 mg d−1 p−1, the highest globally. • Acesulfame, previously believed to be persistent under low temperatures, was removed over 96% in this facility, even during cold Canadian winter months. • The population-weighted effluent loads of sucralose, cyclamate, and saccharin in Canada were estimated to be among the highest globally. [ABSTRACT FROM AUTHOR]

Highlights • Modelled soil moisture was used to determine soil trafficability at soil polygon level. • Soil trafficabilty was determined for the climate base period 1971–2000. • Poor soil trafficability was found on soils with fine textures during the growing season (April to September). • Maps of soil trafficability provided baseline data for further research and risk assessment. Abstract The frequency of days with poor soil trafficability across the Canadian Prairies was determined from simulated soil moisture at soil polygon level during the growing season (April to September) with the Versatile Soil Moisture Budget (VSMB) model. Each soil polygon had a pre-determined critical soil moisture threshold in the first layer (0–5 cm) to trigger poor trafficability. The assessment of soil trafficability was limited to those polygons with good suitability rating for growing grain crops. For each of May, July and September, the polygon modelled soil moisture values were boot strapped into three percentile categories to reflect the highest risk (25th percentile), average conditions (50th percentile) and better than average conditions (75th percentile) for the entire climate period (1971 to 2000). We found that on average, soils with higher clay content (mostly those from eastern Manitoba, the northern fringes of the agricultural zone coinciding with the boreal forest zone and the Alberta Peace River region) had 5 to 9 days of poor trafficability at seeding time (May). In July, the zone with poor soil trafficability (close to two weeks) expanded northward to the Peace River Region of Alberta, northern Saskatchewan and eastern Manitoba. At harvest time (September), poor soil trafficability (>10days) was concentrated in eastern Manitoba which also had the most days with poor soil trafficability at the start and mid-season months. The wet phase represented by the 75th percentile category showed that 10–14 days of poor trafficability can be expected on soil polygons with heavy textures. There were fewer days (1–4) with poor trafficability during dry years (the 25th percentile binned values). The soil trafficability maps generated from this study are a baseline for comparing trafficability levels under climate change scenarios and for planning agricultural activities. [ABSTRACT FROM AUTHOR]

Abstract Globally, consumption of bovine meat is projected to increase by 1.2% per annum until 2050, a demand likely met in part by increased Canadian beef production. With this greater production on a finite agricultural land base, there is a need to weigh the contribution of this industry to the Canadian economy against the full range of positive and negative ecological and social impacts of beef production. This review, focussing on the prairie provinces of Alberta, Saskatchewan and Manitoba, which collectively support just over 80% of the Canadian beef herd, examines the social and ecological footprint of the cow-calf, backgrounding, finishing and forage/feed production stages of beef production within an ecosystem services framework. We summarise the literature on how beef production and management practices affect a range of services, including livestock; water supply; water, air and soil quality; climate regulation; zoonotic diseases; cultural services; and biodiversity. Based on 742 peer-reviewed publications, spanning all agricultural stages of beef production, we established a framework for identifying management practices yielding the greatest overall socio-ecological benefits in terms of positive impacts on ecosystem service supply. Further, we identified research gaps and crucial research questions related to the sustainability of beef production systems. Highlights • 742 publications on prairie beef production and ecosystem services were reviewed. • Beef management practices influence the supply of services from the system. • There is relatively little research on cultural services and service bundles. • Holistic assessment includes multiple production stages, practices and services. [ABSTRACT FROM AUTHOR]

Application of stable isotope methods to evaluate the contribution of different water sources to groundwater recharge relies on the knowledge about isotopic signatures of these sources. The data collected at study sites in the Canadian Prairies show that snowpack isotopic signatures exhibit a high spatial variability over a small scale (<100 m) limiting the usefulness of point samples to estimate an average isotopic composition of snow over a large area. Isotopic signatures of snowmelt runoff can be different from those of pre-melt snowpack, further undermining the applicability of snow isotopic signature to characterisation of snowmelt-driven hydrological processes. Accounting for the actual signature of snowmelt runoff has strong effects on its perceived role in recharging groundwater. The data also show that diffuse and depression-focussed components of groundwater recharge have different isotopic signatures, where the latter closely resembles snowmelt runoff. [ABSTRACT FROM AUTHOR]

Triticale is an emerging bioenergy crop in Canada, with potential as a feedstock for the production of ethanol and co-products from both its grain and straw. This study evaluates the commercial potential of introducing triticale as an industrial feedstock crop in the Brown agroecological soil zone of the Canadian Prairies, a semi-arid area which accounts for the highest share of underutilized summerfallow in the region. The study approach includes determination of location parameters (potential triticale land area, feedstock collection radius, and transportation distance), on-farm triticale yield, on-farm production cost, and feedstock chemical composition. Subsequently, SuperPro ® Designer was used to develop and simulate two processes using both grain and straw: a) integrated process that ferments both pentose and hexose (Process I); b) single process involving fermentation of hexose sugars only, while pentose sugar is diverted for biogas production and then combined with lignin for power generation (Process II). Triticale on-farm yield is analyzed for the range 5.1–6.8 t ha −1 (which corresponds to 74–126 thousand ha of triticale area). Triticale on-farm production cost is $473 ha −1 with corresponding on-farm profit of $570–$1150 ha −1 from grain and straw sale. The integrated grain and straw processing model is developed and simulated for a 200–550 million L annum −1 ethanol biorefinery, with corresponding total capital investment cost of $140–$240 million. Fermenting both grain and straw and using hydrothermal pretreatment for straw resulted a lower equipment purchase cost per litre of ethanol ($0.12–$0.14 L −1 ) compared with cellulosic ethanol production using other pretreatment methods ($0.60–$1.24 L −1 ). The process involving fermentation of both pentose and hexose (Process I) is more profitable compared with a hexose-only process (Process II). Ethanol selling price, plant capacity, and feedstock cost all have high impact on net present value. All plants generate negative net present value at ethanol prices of $0.60 L −1 or less, while a price of at least $0.80 L −1 is required for plants with capacity higher than 250 million L to generate positive net present value. This study provides a basis for further articulation of Canada’s triticale biorefinery concept beyond the near-term goal of producing ethanol, namely, sustainable production of a wide array of bioproducts (bioenergy, biofuels, biomaterials, biochemicals, and biologics) to enhance the profitability of the triticale biorefinery and contribute to Canada’s environmental goals for a bio-based economy. [ABSTRACT FROM AUTHOR]

• We developed an integrated dynamic and spatial modelling framework to map pollination supply at landscape scale within ARIES framework. • Results show landscape diversity and habitat quality as critical for bee abundance and successful pollination in agricultural landscapes. • The study encourages preserving wild bees on farms as a viable alternative to managed honeybees, positively impacting pollination service and crop yield. • Variance-based global sensitivity analysis demonstrates the significance of seasonal variation and complex interactions among input parameters. • Future pollination modeling should include abiotic, spatial, and management factors to provide a better understanding of pollination services. Mapping ecosystem services (ES), including crop pollination by wild insect pollinators, is challenging due to the number of variables involved and the spatial-temporal dimensions of their interactions. To enhance the synergistic relationship between pollination service and crop yield in agricultural landscapes, a better appreciation of the spatial dynamics of pollination service provisioning is needed. Spatially explicit modelling approaches have been used to investigate how different land cover types influence the distribution and abundance of wild bee pollinators in agricultural landscapes. However, an integrated dynamic and spatial modelling framework is needed to address the complexities of pollination supply mapping at the landscape scale. The Artificial Intelligence for Environment and Sustainability (ARIES) framework is a collaborative, spatially explicit and integrated tool for ES assessment. We applied a set of high-resolution process-based pollination models within ARIES to represent landscape capacity to supply pollination by wild bees at the local scale in the Canadian prairies. We also developed a systematic approach to perform a global sensitivity analysis by using a surrogate model (Gaussian Process Regression) and variance-based sensitivity analysis for the selected uncertain key parameters of the model. We modelled pollination dynamics through the mechanistic behavior of native bee guilds, including foraging distance, nesting ability, flight activity, the relative importance of bee guilds, and seasonal variation of floral resources. We focused on three guilds, bumblebees, sweat bees and mining bees, which differed by their nesting habits, floral preferences, and flight distances. We found that over 45% of pollination-dependent croplands in our study area lack wild pollination. The global sensitivity analysis revealed the significance of all key parameters, with seasonal activity across guilds identified as the key driving factors. Our results highlight the significance of the ecological role of wild bees in agricultural landscapes and the sensitivity analysis underscores the importance of temporal dynamics in ecological modeling and pollination. [ABSTRACT FROM AUTHOR]

This study undertakes technoeconomic analysis of commercial production of hydro-processed renewable jet (HRJ) fuel from camelina oil in the Canadian Prairies. An engineering economic model designed in SuperPro Designer® investigated capital investment, scale, and profitability of producing HRJ and co-products (biodiesel, naphtha, LPG, and propane) based on biorefinery plant sizes of 112.5–675 million L annum −1 . Under base case scenario, the minimum selling price ( MSP ) of HRJ was $1.06 L −1 for a biorefinery plant with size of 225 million L. However, it could range from $0.40 to $1.71 L −1 given variations in plant capacity, feedstock cost, and co-product credits. MSP is highly sensitive to camelina feedstock cost and co-product credits, with little sensitivity to capital cost, discount rate, plant capacity, and hydrogen cost. Marginal and average cost curves suggest the region could support an HRJ plant capacity of up to 675 million L annum −1 (capital investment of $167 million). [ABSTRACT FROM AUTHOR]

This study explores the potential effects of global warming on Mesoscale Convective Systems (MCSs) initiation and duration in the Canadian Prairies. By utilizing high-resolution convection-permitting climate models (CPCMs), the study examines 15 parameters to identify the most significant factor for predicting future changes, using the Pseudo Global Warming (PGW) approach. The results suggest that the frequency of MCSs will significantly increase in the future, with varying initiation and duration patterns between daytime and nighttime. The study highlights Preciptable Water (PW), Isentropic Potential Vorticity (IPV), and Most Unstable Convective Potential Energy (MUCAPE) as the most significant parameters for long-lived nighttime MCSs, while Relative Humidity at 850 hPa (RH850), PW, and Storm Relative Helicity 0-1 km (SRH1km) are identified as the most significant parameters for long-lived daytime MCSs. The findings are supported by violin plots that show the differences in the distribution of the 15 parameters in the initiation regions of short- and long-lived MCSs. Additionally, this study partially confirms previous research findings, such as the Mountain-plains solenoids, which suggest that increased PW and RH850 in the future are in agreement with increased total precipitation in the northern region. The study emphasizes the importance of utilizing newly released forcing datasets to investigate the potential impact of global warming on MCSs initiation and duration in the Canadian Prairies. • This study utilized novel forcing data (ERA5 and CMIP6) and convection-permitting climatological model simulations to investigate the impact of global warming on Mesoscale Convective Systems (MCSs) in the Canadian Prairies. • The study's findings provide guidelines for forecasters to better predict the duration of MCSs, based on the statistical significance of parameters such as Preciptable Water, Isentropic Potential Vorticity, Relative Humidity, and Storm Relative Helicity. [ABSTRACT FROM AUTHOR]

This study presents a technoeconomic analysis of commercial extraction of camelina oil as an aviation fuel feedstock. An engineering economic model was designed in Superpro Designer ® to quantify capital investment, scale, production cost, and profitability for a 120,000–1,500,000 tonnes annum −1 solvent extraction plant. The corresponding estimated capital investment was $24.7 - $155 million. Feedstock cost ($0.29–0.40 kg −1 ), seed yield (1400–2100 kg ha −1 ), oil content (38–47%), scale, and camelina meal revenue are key factors in the break-even selling price (BESP) and competitiveness of camelina oil as a feedstock. Feedstock represented 81–90% of operating cost. The BESP ranges from $0.43 -$1.22 L -1 . Larger plants have lower BESP compared to smaller plants which require higher breakeven prices. This suggests better economies of scale associated with higher plant scale. Camelina can be introduced into underutilized summerfallow land of semiarid Canadian Prairies of Saskatchewan. Swift Current is an ideal extraction plant location. These results can guide R&D and investment decisions for advancing camelina as an industrial feedstock within the innovation value chain. [ABSTRACT FROM AUTHOR]

This study evaluated costs and profitability associated with small scale camelina oil extraction plant in the Canadian Prairies for the purpose of selling camelina oil for further biodiesel production. In this case, Camelina sativa is targeted for production on underutilized summerfallow land to avoid displacement of crop lands. Saskatchewan soil zone 7A has the capacity to provide camelina for oil extraction based on small scale capacities of 30,000–120,000 t annum −1 and capital investment of $10-24 million. Oil production price is reduced with increased camelina oil content, field yield, plant scale, and camelina meal price. Oil production costs range from $0.39 to $1.88 L −1 when camelina meal has a market value of $0.30 kg −1 . These results provide an informative basis for investment decisions by farmers and investors vis-à-vis the advancement of farm-adoption of camelina as a dedicated industrial crop, as well as the development of an integrated camelina-to-processing oilseed value-chain. [ABSTRACT FROM AUTHOR]

Alternative cropping systems are gaining attention throughout the world in order to increase the sustainability of agro-ecosystems. On the Canadian prairies, the tillage-based crop-fallow system has been replaced by no-till reduced input systems or tillage-based organic systems with more diversity in crop rotations but with no external inputs. However, the long-term effects of these alternative systems on weed and yield parameters have not been assessed. A study to examine weed and crop yield dynamics under diverse cropping systems was conducted within a 18-year cropping systems study near Scott, Saskatchewan. The trial was laid out in a split-split-plot design with four replicates. The main plots were three levels of inputs; a high input system (HIGH) that used tillage and inputs to maximize yield, a reduced system (RED) that used no-till practices and minimal inputs, and a tillage-based organic system (ORG) with no external inputs. The subplots were cropping diversity (rotations); fallow-annual grains (LOW), diversified annual grains (DAG), and diversified annuals and perennial forage (DAP). The sub-sub plots were the six phases of each rotation. There was an input by rotation interaction for weed biomass but not for weed density and crop yields. ORG systems had 7× and 4× greater weed density (107 plants m −2 ), 4× higher weed biomass (154 kg ha −1 ), and 32% and 35% lower yields (1052 kg ha −1 ) than RED and HIGH systems respectively. RED and HIGH input systems had similar crop yields and lower weed density than ORG. The LOW rotation had the lowest weed density. LOW and DAG rotations had similar yields, which were higher than in DAP. All systems showed an increase in weed density and biomass over time but did not impact on crop yields which was increasing over time likely influenced by a concurrent increase in rainfall. This study concludes that eliminating tillage and reducing agrochemicals is possible but eliminating agrochemicals requires better crop rotations for weed management as well as for nutrient management. [ABSTRACT FROM AUTHOR]

Crop yield forecast models for barley, canola and spring wheat grown on the Canadian Prairies were developed using vegetation indices derived from satellite data and machine learning methods. Hierarchical clustering was used to group the crop yield data from 40 Census Agricultural Regions (CARs) into several larger regions for building the forecast models. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) derived from the Moderate-resolution Imaging Spectroradiometer (MODIS), and NDVI derived from the Advanced Very High Resolution Radiometer (AVHRR) were considered as predictors for crop yields. Multiple linear regression (MLR) and two nonlinear machine learning models – Bayesian neural networks (BNN) and model-based recursive partitioning (MOB) – were used to forecast crop yields, with various combinations of MODIS-NDVI, MODIS-EVI and NOAA-NDVI as predictors. Crop yield forecasts made using predictors from July and earlier were evaluated by the cross-validated mean absolute error skill score (in reference to climatological forecasts) during 2000–2011. While MODIS-NDVI was found to be the most effective predictor for all three crops, having MODIS-EVI as an additional predictor enhanced the forecast skills. While MLR, BNN and MOB all showed significantly higher skills than climatological forecasts for all three crops, barley was the only case where the nonlinear BNN and MOB models showed slightly higher skills than MLR. The lack of skill improvement by nonlinear models over MLR is likely due to the short (12 years) record available for MODIS data, which limits our study to 2000–2011, with very low yields coming from a single severe drought year (2002). [ABSTRACT FROM AUTHOR]

Summary Across the southern Canadian Prairies, annual precipitation is relatively low (200–400 mm) and periodic water deficits limit economic and environmental productivity. Rapid population growth, economic development and climate change have exposed this region to increasing vulnerability to hydrologic drought. There is high demand for surface water, streamflow from the Rocky Mountains in particular. This paper describes the application of dendrohydrology to water resource management in this region. Four projects were initiated by the sponsoring organizations: a private utility, an urban municipality and two federal government agencies. The fact that government and industry would initiate and fund tree-ring research indicates that practitioners recognize paleohydrology as a legitimate source of technical support for water resource planning and management. The major advantage of tree-rings as a proxy of annual and seasonal streamflow is that the reconstructions exceed the length of gauge records by at least several centuries. The extent of our network of 180 tree-ring chronologies, spanning AD 549–2013 and ∼20° of latitude, with a high density of sites in the headwaters of the major river basins, enables us to construct large ensembles of tree-ring reconstructions as a means of expressing uncertainty in the inference of streamflow from tree rings. We characterize paleo-droughts in terms of modern analogues, translating the tree-ring reconstructions from a paleo-time scale to the time frame in which engineers and planners operate. Water resource managers and policy analysts have used our paleo-drought scenarios in their various forms to inform and assist drought preparedness planning, a re-evaluation of surface water apportionment policy and an assessment of the reliability of urban water supply systems. [ABSTRACT FROM AUTHOR]

Summary This study is focused on the Saskatchewan River Basin (SRB) that spans southern parts of Alberta, Saskatchewan and Manitoba, the three Prairie Provinces of Canada, where most of the country’s agricultural activities are concentrated. The SRB is confronted with immense water-related challenges and is now one of the ten GEWEX (Global Energy and Water Exchanges) Regional Hydroclimate Projects in the world. In the past, various multi-year droughts have been observed in this part of Canada that impacted agriculture, energy and socio-economic sectors. Therefore, proper understanding of the spatial and temporal characteristics of historical droughts is important for many water resources planning and management related activities across the basin. In the study, observed gridded data of daily precipitation and temperature and conventional univariate and copula-based bivariate frequency analyses are used to characterize drought events in terms of drought severity and duration on the basis of two drought indices, the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Within the framework of univariate and bivariate analyses, drought risk indicators are developed and mapped across the SRB to delineate the most vulnerable parts of the basin. Based on the results obtained, southern parts of the SRB (i.e., western part of the South Saskatchewan River, Seven Persons Creek and Bigstick Lake watersheds) are associated with a higher drought risk, while moderate risk is noted for the North Saskatchewan River (except its eastern parts), Red Deer River, Oldman River, Bow River, Sounding Creek, Carrot River and Battle River watersheds. Lower drought risk is found for the areas surrounding the Saskatchewan-Manitoba border (particularly, the Saskatchewan River watershed). It is also found that the areas characterized with higher drought severity are also associated with higher drought duration. A comparison of SPI- and SPEI-based analyses suggests only little effect of considering temperature, in the form of evapotranspiration, on identifying drought vulnerable areas. It is expected that the findings of the study will be helpful in the management and efficient utilization of the water resources of this important river basin in Canada. [ABSTRACT FROM AUTHOR]

Summary Knowledge of changes in spatial and temporal distributions of actual evaporation would be useful for land surface parameterizations in the Prairie region of Canada. Yet challenges persist for examining the variability of evaporation from land surfaces and vegetation over such a large region. This is due in part to the existence of numerous methods of varying complexity for obtaining estimates of evaporation and a general lack of sufficient measurements to drive detailed models. Integrated approaches may be applied for distributing evaporation over vast regions using energy and mass balance methods that integrate remote sensing imagery and surface reference data. Whilst informative, previous studies have not considered the variability of actual evaporation under drought and above normal moisture conditions. Continuous physically-based simulations were conducted for a 46 year period using the Cold Regions Hydrological Model (CRHM) platform. The Penman–Monteith model was applied in this platform to calculate estimates of actual evaporation at point locations which had sufficient hourly measurements. Variations in the statistical properties and mapped distributions derived from point-scale modelling via CRHM were instructional for understanding how evaporation varied spatially and temporally for a baseline normal period (1971–2000) and the years 1999–2005 which included both drought and above normal moisture conditions. The modelling approach was applied successfully for examining the historical variability of evaporation and can be applied to constrain land surface parameterization schemes; validate more empirical predictive model outputs; inform operational agrometeorological and hydrological applications in the Canadian Prairies. [ABSTRACT FROM AUTHOR]

Abstract: Accounting for greenhouse gas (GHG) emissions at the production stage of a bioenergy crop is essential for evaluating its eco-efficiency. The objective of this study was to calculate the change in GHG emissions for canola (Brassica napus L.) production on the Canadian Prairies from 1986 to 2006. Net GHG emissions in the sub-humid and semi-arid climatic zones were estimated for fallow-seeded and stubble-seeded canola in intensive-, reduced- and no-tillage systems, with consideration given to emissions associated with synthetic nitrogen (N) fertilizer input, mineralized N from crop residues, N leaching and volatilization, farm operations, the manufacturing and transportation of fertilizer, agrochemicals and farm machinery, and emission and removal of CO2 associated with changes in land use (LUC) and land management (LMC). The GHG emissions on an area basis were higher in stubble-seeded canola than in fallow-seeded canola but, the opposite was true on a grain dry matter (DM) basis. Nitrous oxide emissions associated with canola production, CO2 emissions associated with farm energy use and the manufacturing of synthetic N fertilizer and its transportation contributed 49% of the GHG emissions in 1986 which increased to 66% in 2006. Average CO2 emissions due to LUC decreased from 27% of total GHG emissions in 1986 to 8% in 2006 and soil C sequestration due to LMC increased from 8% to 37%, respectively. These changes caused a reduction in net GHG emission intensities of 40% on an area basis and of 65% on a grain DM basis. Despite the reduction in GHG emission intensities, GHG emissions associated with canola in the Prairies increased from 3.4 Tg CO2 equiv in 1986 to 3.8 Tg CO2 equiv in 2006 because of the more than doubling of canola production. [Copyright &y& Elsevier]

Abstract: Wheat (Triticum aestivum L.) is the major grain crop grown in western Canada (Canadian Prairies) and soil water stress is considered the main limiting factor for crop growth. The objective of this study was to adapt and test the ability of the FAO developed AquaCrop model (v3.0) to simulate spring wheat yield and total soil water content (0–120cm layer) on the Canadian Prairies. Crop yield and soil water content data collected from five experimental sites across the Canadian Prairies from 2003 through 2006 were used in the study. Results showed that the AquaCrop model can be used to model both wheat grain yield and soil water content on the Canadian Prairies with acceptable accuracy. Overall, the relationship between observed and modelled wheat grain yield for all sites combined produced a R 2 of 0.66, slope of 0.96, index of agreement (d) of 0.99, root mean square error (RMSE) of 743kgha−1 and mean absolute error (MAE) of 611kgha−1. Similarly, the comparison between observed and modelled soil water content yielded a R 2 of 0.90, slope of 0.73, d of 0.99, RMSE of 49mm and MAE of 40mm. The difference between observed and modelled grain yield was only 3%, while that between observed and modelled total soil water was 2%. Consequently, AquaCrop can be a valuable tool for simulating both wheat grain yield and soil water content on the Canadian Prairies, particularly considering the fact that the model requires a relatively small number of explicit and mostly intuitive input data which can be readily available or easily collected. However, the performance of the model has to be evaluated and fine-tuned under a wider range of conditions, which we hope will be the next step. [Copyright &y& Elsevier]

Abstract: This paper describes how spatial dependence can be incorporated into statistical models for crop yield along with the dangers of ignoring it. In particular, approaches that ignore this dependence suffer in their ability to capture (and predict) the underlying phenomena. By judiciously selecting biophysically based explanatory variables and using spatially-determined prior probability distributions, a Bayesian model for crop yield is created that not only allows for increased modelling flexibility but also for improved prediction over existing least-squares methods. The model is focused on providing efficient predictions which stabilize the effects of noisy data. Prior distributions are developed to accommodate the spatial non-stationarity arising from distinct between-region differences in agricultural policy and practice. In addition, a range of possible dimension–reduction schemes and basis expansions are examined in the pursuit of improved prediction. As a result, the model developed has improved prediction performance relative to existing models, and allows for straightforward interpretation of climatic effects on the model''s output. [Copyright &y& Elsevier]

Summary: This statistical study examines the impact of storage upon the frequency and magnitude of runoff in the hummocky glacially transformed landscape of the Canadian Prairies. When runoff production is unaffected by depressions, the shape of the runoff frequency curve resembles the shape of the precipitation frequency curve, adjusted for the effects of infiltration, evaporation, sublimation, and wind redistribution of snow. However, the shape and slope of the runoff frequency curve can be affected by storage thresholds associated with hillslope and wetland depressions, and reflect the number, size and spatial distribution of depressions in the catchment. A comparison of runoff frequency curves from catchments with or without depressions provides a useful indicator of the amount of water retained by surface depressions without recourse to detailed topographic mapping of the basins. Results obtained from this study provide valuable insights into the complex function of closed and intermittently contributing drainage basins. [ABSTRACT FROM AUTHOR]

Abstract: Topographic depressions are abundant in topographically complex landscapes. A common practice with earlier, low resolution Digital Elevation Models (DEMs) was to remove all depressions to ensure that water flowed continuously to the edge of the DEM domain. The assumption was that most depressions were created due to errors in the DEMs. This practice is no longer justified with the increasing availability of high accuracy DEMs. However, very few studies have addressed how DEM processing options such as smoothing and coarsening and setting area and depth thresholds can affect depression identification. In this study, a site located in the Prairie Region of Canada was examined. The site is a hummocky glaciated landscape with many in-field wetlands. Lidar topographic data were collected and were used to generate a 1m by 1m square-grid DEM. Detailed error analyses of the lidar DEM were conducted. A set of DEMs were generated after different degrees of smoothing and coarsening. FlowMapR, an established terrain analysis tool, was used to identify depressions in each DEM with various user-defined area and depth thresholds. The results were validated against a field wetland survey. We determined that the problems associated with depression identification using a lidar DEM are two-fold. On one hand, artefactual depressions created due to DEM errors need to be eliminated, for which the raw lidar DEM need to be smoothed. On the other hand, it is also desirable to remove those topographic depressions that do not function as closed basins at the spatial or temporal scale of the processes of interest. Setting area and depth thresholds appeared to be the preferred choice for this. We suggested using the un-autocorrelated lidar DEM error as the criterion for DEM smoothing and considering depression connections in the selection of area and depth thresholds. Using lidar data on a hummocky landscape with loamy soils in the Prairie Region of Canada, 10 to 20 times smoothing operations with an area threshold of 200m2 and a depth threshold of 0.1m were recommended as guidelines for depression identification. [Copyright &y& Elsevier]

Abstract: Sandhills are islands of biodiversity in the southern Canadian prairies that sustain habitat for many rare and endangered species. These unique areas consist of large expanses of dune fields now mostly stabilized by grassland vegetation. Historically, the number of active dunes has decreased significantly due to vegetation stabilization, resulting in a dramatic decline of open-sand habitat for a variety of dune-dependent species. Without a certain level of wind erosion, opportunities for establishment of early-stage, species-rich vegetation types are diminished and open-sand habitat decreases by encroachment of the surrounding grassland vegetation. The current trend of dune stabilization, however, implies that wind erosion is decreasing, thereby threatening the continued existence of a variety of dune-dependent plants, arthropods and vertebrates, as well as other less-specialized species that benefit indirectly from these habitats. By reviewing factors contributing to the historical decline of active dunes, as well as the ecological implications of dune stabilization, the aim of this paper is to establish the biophysical context for new land management strategies that conserve valued landscape components, such as active dunes, and the processes therein. As dune stabilization continues management interventions will be required to sustain or re-establish open sand and the species that rely on these habitats. [ABSTRACT FROM AUTHOR]

Abstract: Establishing short-rotation tree plantations for bioenergy and fiber production on agricultural land (abandoned farmland) would provide significant environmental and economic benefits for rural communities and society as a whole. Walker hybrid poplar (Populus deltoides x P. nigra) is one of the most commonly used varieties cultivated in Saskatchewan, Canada; however, there are no existing hybrid poplar growth models in the literature. The aim of this work was to parameterize and evaluate the 3PG model (Physiological Principles in Predicting Growth) to predict Walker tree growth in the climate and soils of Saskatchewan. We used annual data from Walker poplar trials (4- to 11-yr old stands) established at three spacing levels (2.4, 3.0, and 3.7m) at three sites located in central Saskatchewan, Hnr, BH, and ML sites. The data were split into two sets – the modeling set from the Hnr site was used to parameterize 3PG, and the testing sets from the BH and ML sites were used to evaluate Walker growth predictions made by 3PG. The bias, sum(predicted minus observed) divided by number of observations, for tree height predictions ranged from −1.76 to 1.45m, and bias for diameter at breast height (DBH) ranged from −2.61 to 0.66cm. Regression R-square values of 3PG-predicted versus observed height and DBH ranged from 0.75 to 0.98. Our results indicated that, once parameterized, 3PG could predict Walker hybrid poplar growth with desirable accuracy by only utilizing commonly available soils and climate data for marginal or more productive agricultural land across Saskatchewan. [Copyright &y& Elsevier]

Similar to the San Joaquin Valley of California, the Canadian prairies are underlain with seleniferous shale and have recently witnessed a significant expansion in irrigated agriculture. The irrigated acreage in the prairies is expected to further increase due to global warming and changes in human use patterns. This raises concerns over potential selenium (Se) contamination in prairie surface waters and risk of adverse biological effects. To test the potential for elevated Se in the prairies, Se concentrations and speciation were examined in surface water, sediments, and sediment porewater in three water bodies in southern Manitoba, Canada, along a north–south transect with a gradient of irrigation and agricultural activities. A selenite addition experiment was also performed in mesocosms in a prairie wetland to assess the risk of increasing Se loading to the prairie waters. Overall, our results indicate that Se concentrations in the prairie waters of southern Manitoba are presently low except during the snowmelt season, that Se speciation is dominated by selenate which is of lower toxicity than selenite, and that if additional selenite is discharged into the prairie waters, it will be quickly removed from the surface water to the sediment. The low Se risk in the Canadian prairies is attributed to high soil drainability and relatively small scale of irrigation at present. The Se problem as being experienced in central California is thus unlikely to occur in surface waters of the Canadian prairies, although Se contamination in ground water is possible should the irrigated acreage continue to increase. [Copyright &y& Elsevier]

Abstract: A study to forecast regional spring wheat (Triticum aestivum L.) yields on the Canadian Prairies was conducted, based on simulated daily water use and soil water contents derived from the National Drought Model. Empirical linear regression models were calibrated from 1976 to 2006 spring wheat yield data for this purpose. Potential predictors assessed were mainly those indicators related to water stress conditions at different crop growth stages. Stepwise regression and cross-validation were employed for the selection of the predictors in multivariate linear regression models used for forecasting spring wheat yields from seeding to harvest. The cross-validated “forecasts” for 1976–2006, using data up to harvest, explained 77%, 64%, 63% and 70% of yield variances, respectively, for Alberta, Saskatchewan, Manitoba and the entire Prairie region. Root mean squared error of the “forecasts” ranged from 8% to 11% of the average yields. The prediction accuracy earlier in the season was often lower than later in the season. Usable prediction accuracy was found by the middle of the growing season (around heading or anthesis), but only marginally effective at seeding time, especially so for Saskatchewan. [Copyright &y& Elsevier]

The Canadian prairies represent one of the world's great breadbaskets, supplying people all over the world with agricultural commodities ranging from various grains, through legumes and oilseeds, to both grain and grass-fed meat products. However, the expansion and intensification of Canadian agriculture in the last century has significantly altered the structure and degraded the function of prairie ecosystems. This, combined with climate change, has put the ecological sustainability of the region at risk and raises questions about the region's ability to continue supporting millions of distant consumers. We use variants of two existing sustainability assessment tools, material flows analysis (MFA) and ecological footprint analysis (EFA) to estimate the terrestrial ecosystem area and other physical inputs used on the Canadian prairies to satisfy export demand and to link this production to documented processes of ecological degradation. We discuss the implications of this interregional framework for impact analysis and conclude that, in a globalizing, ecologically full-world, trade-dependence implies previously-ignored risks to both importers and exporters. The results underscore the importance for all countries to protect or restore their own natural capital assets and enhance their self-reliance. Citizens and their governments, particularly of countries that have become irreversibly import-dependent, have a direct interest in ensuring that the ecosystems that support them are sustainably managed, wherever in the world the latter may be located. [Copyright &y& Elsevier]

Abstract: The introduction of agriculture in the late 1800s and early 1900s brought about many changes in the natural prairie landscape of western Canada. The objective of this research project is to evaluate landscape response to land use change by relating observed changes in the sedimentary record of a lake drainage basin to documented land use change that has occurred since the onset of settlement. A 52 cm lake sediment core was sectioned into 1 cm layers. The sediment was separated into allogenic and authigenic fractions using a wet chemical extraction technique. Close interval 210Pb dating enabled the calculation of sediment and elemental influx rates. Prior to European settlement, erosion rates were low (<0.1 Mg ha−1 year−1). In the 1910s, when the first settlers arrived in the area, erosion rates increased, and in the 1920s and 1930s, when the area of improved land rapidly increased and conditions were dry, erosion rates reached peaks of 1.5 and 2.2 Mg ha−1 year−1. Erosion rates in the latter part of the 20th Century range from 0.6 to 0.7 Mg ha−1 year−1. The composition of the allogenic fraction in the most recent, black sediment at the top of the core shows high concentrations of Ti and Zr, indicating a large contribution of topsoil to the allogenic fraction. In addition, elevated concentrations of Zn, Ni, Mo and U are likely explained by the application of phosphate fertilizers. Because of sediment deposition within the basin, e.g., on concave footslopes and on the valley floor, the erosion rates derived from the Thunstrom Lake core should be interpreted as net rates that likely mask values that are much higher locally within the basin. As a result, this study provides information on the erosional response of the prairie landscape to recent changes in land use at the scale of the Thunstrom Lake basin, but not necessarily on the sustainability of the soil as a resource, which would require information at the much smaller scale of the individual field. [Copyright &y& Elsevier]

Abstract: One of the main options for greenhouse gas (GHG) mitigation identified by the IPCC is the sequestration of carbon in soils. Since the breaking of agricultural land in most regions, the carbon stocks have been depleted to such an extent, that they now represent a potential sink for CO2 removal from the atmosphere. Improved management will however, be required to increase the inputs of organic matter in the top soil and/or decrease decomposition rates. In this paper we use data from selected regions to explore the global potential for carbon sequestration in arable soils. While realising that C sequestration is not limited to the selected regions, we have, however, focussed our review on two regions: (i) Canadian Prairies and (ii) The Tropics. In temperate regions, management changes for an increase in C involve increase in cropping frequency (reducing bare fallow), increasing use of forages in crop rotations, reducing tillage intensity and frequency, better crop residue management, and adopting agroforestry. In the tropics, agroforestry remains the primary method by which sequestration rates may be significantly increased. Increases in soil C may be achieved through improved fertility of cropland/pasture; on extensive systems with shifting cultivation cropped fallows and cover crops may be beneficial, and adopting agro forestry or foresting marginal cropland is also an alternative. In addition, in the tropics it is imperative to reduce the clearing of forests for conversion to cropland. Some regional analyses of soil C sequestration and sequestration potential have been performed, mainly for temperate industrialized North America where the majority of research pertaining to C sequestration has been carried out. More research is needed, especially for the Tropics, to more accurately capture the impact of region-specific interactions between climate, soil, and management of resources on C sequestration, which are lost in global level assessments. By itself, C sequestration in agricultural soils can make only modest contributions (3–6% of fossil fuel contributions) to mitigation of overall greenhouse gas emissions. However, effective mitigation policies will not be based on any single ‘magic bullet’ solutions, but rather on many modest reductions which are economically efficient and which confer additional benefits to society. In this context, soil C sequestration is a significant mitigation option. [Copyright &y& Elsevier]

Abstract: The Canadian Prairies have undergone important land use changes over the past 150 years. Beginning in the early 20th century, a significant portion of agricultural land was under summerfallow primarily to conserve soil moisture. The area under fallow grew to over 11Mha, which constitute about 25% of Canada''s cultivated land, and mostly remained at that level until 1975, subsequent to which improved land management practices led to significant reductions in areas under summerfallow. By 2001 summerfallow area had been reduced to 5.4Mha, and future projections expect it to fall to 3.5Mha. Numerous modeling studies and observations have shown that land use change can have a significant impact on regional and local climate. In the Canadian Prairies, these effects would likely be seen during the mid-June to mid-July period, when agricultural crops undergo rapid foliar expansion and substantial transpiration, thus contributing to significantly higher latent heat fluxes. Observations of 1976–2000 climate trends in the black, dark brown and brown soil zones of the Canadian Prairies showed that there have been substantial reductions in maximum temperature (1.7°Cdecade−1), diurnal temperature range (1.1°Cdecade−1) and solar radiation (1.2MJm−2 decade−1), as well as a corresponding increase in precipitation (10.3mmdecade−1) during the mid-June to July period. These findings are in opposition to trends that would be expected from climate change from an enhanced greenhouse effect, and suggest that there is substantial correspondence between reductions in summerfallow and changes in climate in the agricultural regions of the Canadian Prairies. [Copyright &y& Elsevier]

Abstract: High volume air sampling in the Canadian Prairies was used to characterize atmospheric concentrations for 10 herbicides (alachlor, atrazine, ethalfluralin, metolachlor, 2,4-D, dicamba, bromoxynil, MCPA, trifluralin, and triallate) along a 500-km north–south transect. Atmospheric concentration measurements at various altitudes identified that of the six herbicides present in the highest concentrations, triallate was strongly influenced by local sources, while 2,4-D, dicamba, bromoxynil, MCPA and trifluralin were dominated by regional atmospheric transport. Concentrations of the herbicides measured at various altitudes were compared with dry deposition rates measured using a dry/wet deposition sampler and used to calculate deposition velocities Vd. The primary atmospheric transport mechanism for MCPA and bromoxynil was shown to be adsorption to particles dispersed in the atmosphere, with the same mechanism also confirmed for 2,4-D and dicamba, while trifluralin was shown to be transported mainly in the gas phase. This method of calculation indicated that transportation of triallate was influenced by particle adsorption. Weekly maximum atmospheric loadings of the major herbicides present in the Prairies were estimated to range from 73kg for trifluralin to 541kg for 2,4-D. [Copyright &y& Elsevier]

Producers in the Canadian Prairies have begun to extend and diversify their cereal-based rotations by including oilseed and pulse crops, and by managing these newer cropping systems with minimum- and zero-tillage practices. This study examined the implications of these land use changes on non-renewable energy requirements (both direct and indirect), energy output, and energy use efficiency for monoculture cereal, cereal–oilseed, and cereal–oilseed–pulse rotations, each managed using conventional (CT), minimum (MT), and zero (ZT) tillage practices on a thin Black Chernozem in Saskatchewan, Canada. The crop rotations included: spring wheat (Triticum aestivum L.)–spring wheat–winter wheat–fallow (Ws–Ws–Ww–F), spring wheat–spring wheat–flax (Linum usitatissimum L.)–winter wheat (Ws–Ws–Fx–Ww), and spring wheat–flax–winter wheat–field pea (Pisum sativum L.) (Ws–Fx–Ww–P). The findings, based on 12 years of data, showed that non-renewable energy use for the complete cropping systems was largely unaffected by tillage method, but that it differed significantly with crop rotations. Energy requirements were lowest for Ws–Ws–Ww–F (average 6389 MJ ha−1), intermediate for Ws–Fx–Ww–P (11% more), and highest for the Ws–Ws–Fx–Ww (28% more). The substitution of pea for spring wheat in the Ws–Fx–Ww–P versus Ws–Ws–Fx–Ww rotation reduced total energy use by 13%, reflecting the minimal requirement for N fertilizer by pulses due to their ability to biologically fix N, and from the lower fertilizer N rate that was applied to spring wheat grown after the legume. The use of MT and ZT practices provided significant energy savings (compared to CT) in on-farm use of fuel and in machine operation and manufacture for some cropping system components (e.g., summerfallow preparation, spring wheat grown on pea stubble, and for pea grown on cereal stubble), but these savings were often offset by higher energy requirements for herbicides and for N fertilizer with conservation tillage management. Gross energy output averaged 32 315 MJ ha−1 for Ws–Ws–Ww–F, 41 287 MJ ha−1 (or 28% more) for Ws–Ws–Fx–Ww, and 42 961 (or 33% more) for Ws–Fx–Ww–P. Tillage method had little overall influence on energy output for the monoculture cereal and cereal–oilseed–pulse rotations, but it was generally lower with CT than with MT or ZT management for the cereal–oilseed rotation. Energy use efficiency, measured as grain produced per unit of energy input and as the ratio of energy output to energy input, was highest for the cereal–oilseed–pulse rotation (373 and 6.1 kg GJ−1, respectively) and lower, but generally similar, for the cereal–oilseed and monoculture cereal rotations (298 and 5.1 kg GJ−1, respectively). The use of conservation tillage management enhanced overall energy use efficiency for the two mixed rotations, but not for the monoculture cereal rotation. We concluded that adopting diversified crop rotations, together with minimum and zero tillage management practices, will enhance non-renewable energy use efficiency of annual grain production in this sub-humid region. [Copyright &y& Elsevier]

[Display omitted] • GHF filtering showed good potential for estimating groundwater variations using GRACE. • Northeast Manitoba and southwest of Calgary exhibit the maximum leakage-in effects. • Depletion of groundwater trend is significant in Palliser's triangle situated in the Canadian Prairies. • Maximum agreement between GRACE estimations and in-situ wells obtained in basin of North Saskatchewan. This study focuses upon development of a new filter, referred to as Gaussian-Han-Fan (GHF) filtering, and its application within a comprehensive procedure for estimating groundwater changes. The Canadian Prairies was the study area. Variations in groundwater were estimated by using 15 years of Gravity Recovery And Climate Experiment (GRACE) twin-satellite observations (April 2002 to June 2017). Surface water storage (sum of soil moisture, snow water equivalent, canopy water, and surface water bodies) was subtracted from reconstructed GRACE-based Terrestrial Water Storage (TWS) changes through GHF filtering. To estimate the required hydrological parameters, both the Global Land Data Assimilation System (GLDAS) and Water Global Hydrology Model (WGHM) were used and evaluated. Water level changes for major surface water bodies were estimated using satellite altimetry-based products. The monthly average of GWS variations over the Prairies ranged between −200 mm and +230 mm. A positive trend was found for both TWS and GWS variations, with the highest values in the region surrounding Hudson Bay, particularly in northern Manitoba (about 55 mm/year). Estimated GWS anomalies error was equivalent to about 10% of its absolute value, with a mean of 19 mm. GWS variations results were validated using 116 active in-situ groundwater level measurements in five different river basins (Peace-Athabasca, Churchill, North Saskatchewan, South Saskatchewan, Missouri), which were all located in Alberta (Canada). Good agreement was achieved in each river basin (correlation > r = |0.70|, P < 10−4, RMSE < 55 mm). Regardless of hydrological system (GLDAS or WGHM), better statistical metrics were found when the average of the five basins was considered (r > |0.90|, P < 10−4), with lowest errors (RMSE or UnRMSE < 30 mm). [ABSTRACT FROM AUTHOR]

• Impacts of biochar on soil nutrient cycling were investigated. • Biochar did not affect cumulative emissions of N 2 O-N or CH 4 -C from soil. • CO 2 -C flux response to biochar was dependent on soil type and application rate. • Biochar improved plant available nutrients when co-applied with NP-fertilizer. Amending soil with pyrogenic-C (biochar) has emerged as a potential best management practice to accumulate organic matter (OM), reduce greenhouse gas (GHG) emissions and increase nutrient retention among degraded, marginally-productive croplands. Nevertheless, the impact of biochar application on intensively cropped prairie eco-regions is not well documented, particularly when co-applied with chemical fertilizer. Our objective was to determine the effect of biochar on cumulative CO 2 -C, N 2 O-N and CH 4 -C emissions, water-extractable OM, and available N (AN; NH 4 -N + NO 3 -N) and P (AP; PO 4 -P) in the presence or absence of NP-fertilizer. Biochar was applied to two surface Chernozems (0–15 cm) of contrasting texture [i.e., sandy clay loam (Raymond) and clayey (Lethbridge)] at six rates (0, 0.15, 0.5, 3, 10 and 20 Mg ha−1) in combination with (+NP) or without (−NP) urea-N (150 kg N ha−1) and KH 2 PO 4 (50 kg P ha−1). A total of 72 soil columns were incubated at 21 °C for 86 d. Biochar addition increased soil total C up to 24.9 g kg−1 and 28.7 g kg−1 in Raymond and Lethbridge, respectively, but did not affect water-extractable OM. Cumulative N 2 O-N and CH 4 -C emissions were not influenced by biochar, regardless of whether or not NP-fertilizer was added (p > 0.05). Cumulative CO 2 -C emissions varied between soil textures and were increased or decreased non-linearly by biochar addition under –NP only. Available P increased within +NP soil with increasing biochar rates reaching 43.9 mg kg−1 in Raymond and 79.5 mg kg−1 in Lethbridge when biochar was applied at 20 Mg ha−1. A similar but less pronounced response was observed for AN. Our results indicate that biochar-only application is not a practical management approach for improving soil fertility and nutrient cycling in surface Chernozems. Nevertheless, co-applying biochar with NP-fertilizer appears to improve soil P availability in the short-term. [ABSTRACT FROM AUTHOR]

• Basins in the Canadian Prairies have varying contributing fractions of their areas. • Caused by the variable storage of water in depressions. • The effects of the spatial and frequency distributions of depressions are quantified. • Will lead to the development of improved hydrological models for the region. Runoff in many locations within the Canadian Prairies is dominated by intermittent fill-and-spill between depressions. As a result, many basins have varying fractions of their areas connected to their outlets, due to changing depressional storage. The objective of this research is to determine the causes of the relationships between water storage and the connected fraction of depression-dominated Prairie basins. It is hypothesized that the shapes of the relationship curves are influenced by both the spatial and frequency distributions of depressional storage. Three sets of numerical experiments are presented to test the hypothesis. The first set of experiments demonstrates that where the number of depressions is small, their size and spatial distributions are important in controlling the relationship between the volume of depressional storage and the connected fraction of a basin. As the number of depressions is increased, the areal fractions of the largest depressions decrease, which reduces the importance of the spatial distribution of depressions. The second set of experiments demonstrates that the curve enveloping the connected fraction of a basin can be derived from the frequency distribution of depression areas, and scaling relationships between the area, volume and catchment area of the depressions, when the area of the largest depression is no greater than approximately 5% of the total. The third set of experiments demonstrates that the presence of a single large depression can strongly influence the relationship between the depressional storage and the connected fraction of a basin, depending on the relative size of the large depression, and its location within the basin. A single depression containing 30% of the total depressional area located near the outlet was shown to cause a basin to be nearly endorheic. A similar depression near the top of a basin was demonstrated not to fill and was therefore unable to contribute flows. The implications of the findings for developing hydrological models of large Prairie drainage basins are discussed. [ABSTRACT FROM AUTHOR]

• Beef production systems in the Canadian prairies are complex social-ecological systems. • A social-ecological systems approach to ecosystem service assessment is described. • All agricultural stages of production considered: grazing, confined feeding, forage/feed production. • Local-scale assessments recommended to better inform farm management and policy decisions. Producing food to meet rising global demand requires a more thorough understanding of how farming systems can ensure food security without compromising economic, environmental, and social sustainability. This dilemma can be addressed through a social-ecological systems approach to ecosystem service assessment, which assesses the linkages between the different components of an agricultural social-ecological system – beef production in the Canadian Prairies. Using this framework, we documented the relationships between governance and management, social and ecological structures and processes, ecosystem services and human well-being for these systems. We also examined how this framework could aid in the greater integration of ecosystem services into decision-making and management practices for these systems. The framework was applied to all stages of the prairie beef production cycle, consisting of the cow-calf, backgrounding, finishing and feed production stages. The benefits, shortcomings and limitations of such an approach as well as the state of knowledge on relationships between the components of the system are discussed, and recommendations for future research directions, farm management strategies and policy are proposed. Overall, the high degree of heterogeneity in biophysical and socio-economic conditions across the prairie landscape underscores the need for more site-specific ecosystem service assessments and environmental stewardship policies that are tailored to these specific contexts. [ABSTRACT FROM AUTHOR]

Soil Moisture (SM) is a direct measure of agricultural drought. While there are several global SM indices, none of them directly use SM observations in a near-real-time capacity and as an operational tool. This paper presents a near-real-time global SM index monitor based on integrated SMAP (Soil Moisture Active Passive) and SMOS (Soil Moisture and Ocean Salinity) remote sensing data. We make use of the short period (2015–2018) of SMAP datasets in combination with two approaches—Cumulative Distribution Function Mapping (CDFM) and Bayesian conditional process—and integrate them with SMOS data in a way that SMOS data is consistent with SMAP. The integrated SMOS and SMAP (SMOS/SMAP) has an increased global revisit frequency and a period of record from 2010 to the present. A four-parameter Beta distribution was fitted to the SMOS/SMAP dataset for each calendar month of each grid cell at ~36 km resolution for the period from 2010 to 2018. We used an asymptotic method that guarantees the values of the bounding parameters of the Beta distribution will envelop both the smallest and largest observed values. The Kolmogorov-Smirnov (KS) test showed that more grids globally will pass if the integrated dataset is from the Bayesian conditional approach. A daily global SM index map is generated and posted online based on translating each grid's integrated SM value for that day to a corresponding probability percentile relevant to the particular calendar month from 2010 to 2018. For validation, we use the Canadian Prairies Ecozone (CPE). We compare the integrated SM with the SMAP core validation and RISMA sites from ISMN, compare our indices with other models (VIC, ESA's CCI SM v04.4 integrated satellite data, and SPI-1), and make a two-by-two comparison of candidate indices using heat maps and summary CDF statistics. Furthermore, we visually compare our global SM-based index maps with those produced by other organizations. Our Global SM Index Monitor (GSMIM) performed, in many tests, similarly to the CCI's product SM index but with the advantage of being a near-real-time tool, which has applications for identifying evolving drought for food security conditions, insurance, policymaking, and crop planning especially for the remote parts of the globe. [ABSTRACT FROM AUTHOR]

• First investigation of the dynamics of the soil water storage over the study domain. • Wavelet analysis to characterize inherent hydrologic memory in moisture storage. • Established decreased heterogeneity in moisture storage with increasing soil depths. • A long-memory feature was detected in the deep moisture store with implications. Anomalous atmospheric conditions which, for the most part, manifest in the form of heavy precipitation events leading to the generation of pluvial or fluvial flooding in some years, or as extended extreme dry spells resulting in the development of severe drought conditions in other years has significant implications for subsurface moisture budgets in regional and local catchments in the Canadian Prairies. The myriad implications of these frequent and extended dry spells over Alberta's Agricultural Region can be far reaching economically, socially and otherwise, thereby exerting substantial negative toll on agricultural productivity (crop cultivation, livestock husbandry, and pasture management) within the Province. Soil moisture dynamics both in spatial and temporal scales has critical implications for agricultural water management especially under semi-arid climate conditions that are typical of the local- and regional-scale catchments in southern Alberta. This study is focused on the assessment of the observations of the soil water storage, soil temperature and meteorological variables (precipitation and air temperature) acquired from 39 monitoring stations spanning a 12-year period with the principal objective of examining the spatial and temporal dynamics in the shallow and deep soil water storage processes across the study domain. This study revealed that the moisture anomalies in the deep soil moisture store exhibit the longest hydrologic memory relative to those in the shallow and intermediate soil moisture storages as well as those in the meteorological variables across the study domain. The anomalies computed for the soil moisture measurements undertaken in the deep soil moisture store revealed frequency features that are dominant at seasonal cycle (9-month) and at a higher periodicity of 32-month cycle. This low-frequency feature (32-month cycle) is evidently non-existent in the soil water storage measured at the shallower soil depths nor in the meteorological variables evaluated in this study. This implies that the low-frequency feature of the soil water storage wavelet spectra increases with increasing soil depth across the Agricultural Region; indicating that at deeper soil depths, the largest variances are shifted to lower frequencies. This observed dominant long-memory feature in the deep soil moisture store could have important implications for characterizing the development of temperature extremes as well as for the evaluation of the severity of the recurrent drought outbreaks over regional watersheds in Alberta and potentially for other Canadian Prairie catchments. [ABSTRACT FROM AUTHOR]

This study proposes a new approach that can be used to generate the optimal surface state information and associated uncertainties from the estimates provided by the six land surface models used by the Global Land Data Assimilation System (GLDAS). The Förstner and best quadratic unbiased variance component estimators are used simultaneously with the least-squares method to calculate optimal values and the associated uncertainties. To demonstrate the concept, the research focused on three GLDAS hydrological products, namely soil moisture (SM), snow water equivalent (SWE), and canopy water (CAN) over the Canadian Prairies. When the Förstner estimator is applied, the estimated SM and SWE differ from their corresponding mean values by 26 mm and 9 mm respectively. Almost similar result was found with the best quadratic estimator. The estimated maximum uncertainties of each component including SM, SWE and CAN vary from year to year (e.g. 35 mm in 2006, 12 mm in 2007 and 2009 and 0.1 mm in 2001, respectively). The uncertainties of the total water storage (TWS) are almost similar to that of SM, which contributes more importantly to TWS in the area considered. The results obtained by the two proposed estimators were compared to the waterGAP hydrological models (WGHM), and to the Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage anomalies. The optimal SWE anomalies generated from GLDAS using the proposed approach show a maximum correlation of r = 0.97 with the WGHM SWE anomalies. The optimal TWS anomalies have a correlation of r = 0.91 with WGHM, and r = 0.71 with GRACE. However, the correlation jumps to r = 0.81 when GRACE TWS is corrected for groundwater signals (with a mean RMSE of 8.5 mm). The RMSE and mean absolute error between our proposed methods and WGHM and GRACE are better than those obtained with each individual LSM or their average value. No significant mean bias error is observed in each case. Finally, the analysis of the time-lag characteristics of the resonance period between the results and their coherence was done by using a cross wavelet transform and a wavelet coherence analysis. Unlabelled Image • Förstner and BQUE provided satisfactory estimation of GLDAS product and uncertainties. • Optimal products estimated are in good agreement with corresponding WGHM products. • Subtracting GWS signals from GRACE TWSA improved correlation and RMSE in TWSA results. • XWT and WTC analysis show a good agreement with WGHM TWSA in a time-frequency domain. • XWT and WTC show a good agreement with GRACE TWSA obtained for longer scale periods. [ABSTRACT FROM AUTHOR]

• Landscape complexity was positively associated with crop yields at the district-level in four crops. • Farmers may be able to receive a small crop productivity benefit from enhancing landscape complexity. • Potential negative effects of non-crop land covers (e.g., as pest or weed reservoirs) were not dominant. • Increasing semi-natural vegetation may present few risks for crop productivity in Canadian Prairie annual croplands. Establishing semi-natural areas within annual croplands can provide habitat for beneficial organisms and ecosystem services to crops through a spillover effect. However, this approach to increasing landscape complexity may have no effect on crops, or it may promote pests, weeds and other disservices that reduce productivity. An argument for changing landscape complexity may be more persuasive if it is associated with higher crop yields. Here, we examine regions that vary in their landscape complexity and, therefore, may also naturally differ in the potential for ecosystem services, disservices and crop yields. Specifically, we examine crop-growing districts in the Canadian province of Alberta to test whether the presence of more non-crop land covers has increased crop yields. Our dataset covered about one-quarter of the seeded area in Canada between 2012 and 2017 consisting of 10,069 records representing average field-level yields reported to a crop insurance provider. In total, we analyzed summary data for 250,000 km2 of seeded area for seven grain crops. Using a functional regression approach, we found evidence for a plausibly positive association between yield and the non-crop land covers found within and near fields in four of seven crops. Landscape complexity, therefore, represented a measurable yield benefit for farmers, although the variance in yield explained by the landscape was small. These findings suggest there may be a low risk of disservices to crops from non-crop land covers in this region. Our study adds support at a broad geographic extent for initiatives that restore perennial and other semi-natural vegetation in annual cropping systems and suggests that, in this temperate grassland region, their promotion (e.g., as carbon stores or as biodiversity refugia) may have no adverse effects for crop production. [ABSTRACT FROM AUTHOR]