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Plant communities in North American prairie pothole wetlands vary depending on hydrology, salinity, and anthropogenic disturbance in and around the wetland. We assessed prairie pothole conditions on United States Fish and Wildlife Service fee-title lands in North Dakota and South Dakota to improve our understanding of current conditions and plant community composition. Species-level data were collected at 200 randomly chosen temporary and seasonal wetland sites located on native prairie remnants (n = 48) and previously cultivated lands that were reseeded into perennial grassland (n = 152). The majority of species surveyed appeared infrequently and were low in relative cover. The four most frequently observed species were introduced invasive species common to the Prairie Pothole Region of North America. Our results suggested relative cover of a few invasive species (i.e., Bromus inermis Leyss., Phalaris arundinacea L., and Typha ×glauca Godr. (pro sp.) [angustifolia or domingensis × latifolia]) affect patterns of plant community composition. Wetlands in native and reseeded grasslands possessed distinct plant community composition related to invasive species' relative cover. Invasive species continue to be prevalent throughout the region and pose a major threat to biological diversity, even in protected native prairie remnants. Despite efforts to convert past agricultural land into biologically diverse, productive ecosystems, invasive species continue to dominate these landscapes and are becoming prominent in prairie potholes located in native areas. [ABSTRACT FROM AUTHOR]

Private land conservation has become an important tool for protecting biodiversity and habitat, but methods for prioritizing and scheduling conservation on private land are still being developed. While return on investment methods have been suggested as a potential path forward, the different processes linking private landscapes to the socioeconomic systems in which they are embedded create unique challenges for scheduling conservation with this approach. We investigated a range of scheduling approaches within a return on investment framework for breeding waterfowl and broods in the Prairie Pothole Region of North Dakota, South Dakota, and Montana. Current conservation targeting for waterfowl in the region focuses mostly on the distribution and abundance of breeding waterfowl. We tested whether MaxGain approaches for waterfowl conservation differed from MinLoss approaches in terms of return on investment and which approach performed best in avoiding loss of waterfowl and broods separately. We also examined variation in results based upon the temporal scale of the abundance layers used for input and compared the region's current scheduling approach with results from our simulations. Our results suggested that MinLoss was the most efficient scheduling approach for both breeding waterfowl and broods and that using just breeding waterfowl to target areas for conservation programs might cause organizations to overlook important areas for broods, particularly over shorter timespans. The higher efficiency of MinLoss approaches in our simulations also indicated that incorporating probability of wetland drainage into decision‐making improved the overall return on investment. We recommend that future conservation scheduling for easements in the region and for private land conservation in general include some form of return on investment or cost‐effective analysis to make conservation more transparent. [ABSTRACT FROM AUTHOR]

The quality of plant community composition on US Fish and Wildlife Service (USFWS) lands in North Dakota and South Dakota has declined over the past several decades-the abundance of native species has decreased while the abundance of introduced species has rapidly increased. Extensive efforts have been made to improve plant community composition on USFWS prairies; however, there was not a unified approach to this end in North Dakota and South Dakota until the advent of the Native Prairie Adaptive Management (NPAM) program. The NPAM program provides decision support for the selection of management actions to improve plant community composition of tallgrass and mixed-grass prairies in the Northern Great Plains. We evaluated plant community composition on USFWS native tallgrass and mixed-grass prairie remnants enrolled in the NPAM program in North Dakota and South Dakota to examine effects of management on plant community composition. Our analysis suggests that incorporating certain management actions can improve plant community characteristics on the agency's tallgrass and mixed-grass prairies. We documented increased native species richness and decreased Bromus inermis (smooth brome) relative cover at sites that had been burned two or more times during a four-year period. In contrast, smooth brome relative cover was higher at sites managed by the exclusion of fire and intermittent light grazing or rest. Smooth brome is extremely invasive in native prairie remnants throughout the Northern Great Plains. Thus, our results have marked implications for managers working to reduce the prevalence of smooth brome on public and private lands. [ABSTRACT FROM AUTHOR]

Context: Agricultural land-use conversion has fragmented prairie wetland habitats in the Prairie Pothole Region (PPR), an area with one of the most wetland dense regions in the world. This fragmentation can lead to negative consequences for wetland obligate organisms, heightening risk of local extinction and reducing evolutionary potential for populations to adapt to changing environments. Objectives: This study models biotic connectivity of prairie-pothole wetlands using landscape genetic analyses of the northern leopard frog (Rana pipiens) to (1) identify population structure and (2) determine landscape factors driving genetic differentiation and possibly leading to population fragmentation. Methods: Frogs from 22 sites in the James River and Lake Oahe river basins in North Dakota were genotyped using Best-RAD sequencing at 2868 bi-allelic single nucleotide polymorphisms (SNPs). Population structure was assessed using STRUCTURE, DAPC, and fineSTRUCTURE. Circuitscape was used to model resistance values for ten landscape variables that could affect habitat connectivity. Results: STRUCTURE results suggested a panmictic population, but other more sensitive clustering methods identified six spatially organized clusters. Circuit theory-based landscape resistance analysis suggested land use, including cultivated crop agriculture, and topography were the primary influences on genetic differentiation. Conclusion: While the R. pipiens populations appear to have high gene flow, we found a difference in the patterns of connectivity between the eastern portion of our study area which was dominated by cultivated crop agriculture, versus the western portion where topographic roughness played a greater role. This information can help identify amphibian dispersal corridors and prioritize lands for conservation or restoration. [ABSTRACT FROM AUTHOR]

Quantitative log evaluation can provide mineralogical estimates of potash ore when core data is unavailable, such is largely the case with the Prairie Formation deposits underlying northwestern North Dakota. Estimates for the desired mineral fractions (halite, sylvite, carnallite, and insolubles) are obtained by solving four simultaneous equations which relate the fraction of each mineral and each mineral's log response to the total log response of three logs. Log analysis was performed on 117 wells throughout the potash-containing-area of northwestern North Dakota. A combination of gamma-ray (corrected for borehole size and drilling mud weight), neutron, and density logs were used when available. Sonic logs where used in calculations when a density log was not available. Maps were created depicting the estimated maximum concentrations of sylvite and carnallite over isopachs of each of the six potash-containing members of the Prairie Formation. These maps and additional log analysis may be useful in the planning of a potash exploration program. Log analysis of the Dakota Salts Eby-1 in central Burke County showed reasonably good agreement with laboratory measurements of core samples. It would be beneficial to compare additional core analysis with log evaluation calculations to better establish the ability of log evaluation to accurately identify the mineralogy of carnallitic-potash ores and the effect higher concentrations of insolubles have on calculations. [ABSTRACT FROM AUTHOR]

Prescribed fire is used widely to manage grasslands on National Wildlife Refuges and other public lands in the northern Great Plains, but its effects on habitat use or production of wildlife in the region are poorly understood. During 1998-2003, we used point counts to examine effects of prescribed fire on vegetation and passerines in a mixed-grass prairie complex in north-central North Dakota, USA (n = 7 units, each 40-70 ha). Vegetation structure and, to a lesser extent, plant community composition varied with year of study (likely related to changes in annual precipitation) and with number of growing seasons since fire. Fire altered plant structure, especially the amount of residual vegetation, which in turn influenced bird species richness and abundance. The number of indicated pairs for sedge wren (Cistothorus platensis), clay-colored sparrow (Spizella pallida), Le Conte's sparrow (Ammodramus leconteii), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus) were lowest during the first postfire growing season but generally increased and stabilized within 2-3 postfire growing seasons. Our results support the premise that grassland passerines are well-adapted to frequent, periodic fires, generally corresponding to those occurring prior to Euro-American settlement of the region. Prescribed fire is important for reducing tree and shrub invasion, restoring biological integrity of plant communities, and maintaining or enhancing populations of grassland-dependent bird species. Managers in the northern mixed-grass prairie region should not be overly concerned about reductions in bird abundances that are limited mostly to the first growing season after fire. [ABSTRACT FROM AUTHOR]

This study was conducted on a mixed-grass prairie in south-central North Dakota, USA, to test the effect of animal grazing on rhizome biomass. Below-ground plant biomass samples were collected from pastures with moderate and heavy grazing by beef cattle. Because the biomass data did not meet the normality assumptions, the computer resampling method involving a nested anova was used. A reduction in rhizomes was found under heavy grazing, as compared with moderate grazing. Although rhizomes only accounted for a small fraction of total below-ground plant biomass, our study suggested that the high rhizome density found in the moderately grazed pastures might be partly responsible for the greater potential of plant regrowth in the moderately grazed pastures than in the heavily grazed pastures on this mixed-grass prairie. [ABSTRACT FROM AUTHOR]

Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimate insect‐mediated pesticide flux from wetlands embedded in an important agricultural landscape, semipermanetly and temporarily ponded wetlands were surveyed in cropland and grassland landscapes across a natural salinity gradient in the Prairie Pothole Region of North Dakota (USA) during the bird breeding season in 2015 and 2016 (n = 14 and 15 wetlands, respectively). Current‐use pesticides, including the herbicide atrazine and the insecticides bifenthrin and imidacloprid, were detected in newly emerged insects. Pesticide detections were similar in insects emerging from agricultural and grassland wetlands. Biomass of emerging aquatic insects decreased 43%, and insect‐mediated pesticide flux increased 50% along the observed gradient in concentrations of insecticides in emerging aquatic insects (from 3 to 577 ng total insecticide g–1 insect). Overall, adult aquatic insects were estimated to transfer between 2 and 180 µg total pesticide wetland–1 d–1 to the terrestrial ecosystem. In one of the 2 study years, biomass of emerging adult aquatic insects was also 73% lower from agricultural than grassland wetlands and was dependent on salinity. Our results suggest that accumulated insecticides reduce the availability of adult aquatic insect prey for insectivores and potentially increase insectivore exposure to insect‐borne pesticides. Adult aquatic insects retain pesticides across metamorphosis and may expose insectivores living near both agricultural and grassland wetlands to dietary sources of toxic chemicals. Environ Toxicol Chem 2021;40:2282–2296. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Non-native plants can reduce grassland biodiversity, degrade wildlife habitat, and threaten rural livelihoods. Management can be costly, and the successful eradication of undesirable species does not guarantee the restoration of ecosystem service delivery. An alternative to the eradication of invasive species in rangelands is to target the restoration of diversity and heterogeneous plant structure, which have direct links to ecosystem function. In this study, we evaluate patch-burn grazing (PBG) with one and two fires per year and variably stocked rotational grazing in Poa pratensis- and Bromus inermis-invaded grasslands using traditional (cover) and process-based (diversity and vegetation structural heterogeneity) frameworks in central North Dakota, USA. Within 3–4 years of initiating management, we found little evidence of decreased Poa pratensis and Bromus inermis cover compared to continuous grazing (Poa pratensis F3,12 = 0.662, p = 0.59; Bromus inermis F3,12 = 0.13, p = 0.13). However, beta diversity increased over time in all treatments compared to continuous grazing (tPBG1 = 2.71, tPBG2 = 3.45, tRotational = 3.72), and variably stocked rotational treatments had greater increases in spatial heterogeneity in litter depth and vegetation structure than continuously grazed pastures (tvisual obstruction= 2.42, p = 0.03; tlitter depth = 2.59, p = 0.02) over the same time period. Alternative frameworks that promote grassland diversity and heterogeneity support the restoration of ecological services and processes in invaded grasslands. [ABSTRACT FROM AUTHOR]

Prescribed fire is used widely to manage grasslands on National Wildlife Refuges and other public lands in the northern Great Plains, but its effects on habitat use or production of wildlife in the region are poorly understood. During 1998-2003, we used point counts to examine effects of prescribed fire on vegetation and passerines in a mixed-grass prairie complex in north-central North Dakota, USA (n 5 7 units, each 40-70 ha). Vegetation structure and, to a lesser extent, plant community composition varied with year of study (likely related to changes in annual precipitation) and with number of growing seasons since fire. Fire altered plant structure, especially the amount of residual vegetation, which in turn influenced bird species richness and abundance. The number of indicated pairs for sedge wren (Cistothorus platensis), clay-colored sparrow (Spizella pallida), Le Conte's sparrow (Ammodramus leconteii), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus) were lowest during the first postfire growing season but generally increased and stabilized within 2-3 postfire growing seasons. Our results support the premise that grassland passerines are well-adapted to frequent, periodic fires, generally corresponding to those occurring prior to Euro-American settlement of the region. Prescribed fire is important for reducing tree and shrub invasion, restoring biological integrity of plant communities, and maintaining or enhancing populations of grassland-dependent bird species. Managers in the northern mixed-grass prairie region should not be overly concerned about reductions in bird abundances that are limited mostly to the first growing season after fire. [ABSTRACT FROM AUTHOR]

Insect communities with diverse life histories and morphologies, such as bees (Hymenoptera: Apoidea), are difficult to representatively sample. Methodological comparison studies have increased our knowledge of bee-sampling method biases. However, further understanding of how sampling methodologies are biased with respect to functional traits and the surrounding environment is needed. We examined the differences in taxonomic and functional trait representation of sampled bee communities between an active netting and passive bee bowl methodology. We also determined the influence of surrounding floral resources on each method's ability to capture bee abundance, richness, and diversity. We captured bees at 32 sites across North Dakota, USA using both methods. Netting and bee bowl methods reflected different bee communities defined by taxonomic families, genera, diet breadth, sociality, and body size. Bee bowls reflected more solitary and small-bodied bees while the netting method selected a greater representation of generalist, social, and large-bodied taxa. Bee bowls captured fewer bees as floral abundance increased, while bee abundance, richness, and diversity captured with the netting method showed the opposite trend with increasing floral resource availability. In addition, the netting method generally captured more varied samples than bee bowl surveys. Our results indicate the importance of using multiple types of sampling methods and of understanding how surrounding floral availability affects sampling of the target bee communities. Methodological biases influence how ecological studies interpret target communities, making it essential for future bee-sampling to incorporate multiple methods and to interpret their results carefully in the context of chosen methodologies and study systems. Implications for insect conservation: The essential ecological services many bees provide, coupled with the concern over declines in bee populations and diversity, fuels the increased interest in bees and studies involving bee-sampling. Management and conservation policy for declining bee populations depend on data that is representative of the sampled bee communities. Therefore, it is important to understand systematic biases in our sampling methods as well as the effects of surrounding habitat on these biases. [ABSTRACT FROM AUTHOR]

Prairie Harvest Germplasm common hackberry (Celtis occidentalis L. [Ulmaceae]) is a selected class of natural germplasm released for use in conservation plantings in the Northern Great Plains and Upper Midwest of the US. Originating from native trees located in Polk County, northwestern Minnesota, this northern selection is winter hardy with improved form and growth rates. This germplasm release is recommended for conservation use as a tall tree in windbreaks, wildlife areas, and riparian plantings. Prairie Harvest Germplasm represents the first northern source release of common hackberry for conservation use in the northern regions of Minnesota and North Dakota. [ABSTRACT FROM AUTHOR]

We used radiotelemetry to study mallard (Anas platyrhynchos) brood movements, wetland use, and duckling survival during a major drought (1988-1992) and during the first 2 years of the subsequent wet period (1993-1994) at 4 51-km² sites in prairie pothole landscapes in eastern North Dakota, USA. About two-thirds of 69 radiomarked mallard broods initiated moves from the nest to water before noon, and all left the nest during daylight. On average, broods used fewer wetlands, but moved greater distances during the dry period than the wet period. Broods of all ages were more likely to make inter-wetland moves during the wet period and probabilities of inter-wetland moves decreased as duckling age increased, especially during the dry period. Brood use of seasonal wetlands nearly doubled from 22% to 43% and use of semi-permanent wetlands declined from 73% to 50% from the dry to the wet period. Eighty-one of 150 radiomarked ducklings died during 1,604 exposure days. We evaluated survival models containing variables related to water conditions, weather, duckling age, and hatch date. Model-averaged risk ratios indicated that, on any given date, radiomarked ducklings were 1.5 (95% CI = 0.8-2.8) times more likely to die when the percentage of seasonal basins containing water (WETSEAS) was ≤ 18% than when WETSEAS was >40%. An interaction between duckling age and occurrence of rain on the current or 2 previous days indicated that rain effects were pronounced when ducklings were 0-7 days old but negligible when they were 8-30 days old. The TMIN (mean daily minimum temperature on the current and 2 previous days) effects generally were consistent between duckling age classes, and the risk of duckling death increased 9.3% for each 1°C decrease in TMIN across both age classes. Overall, the 30-day survival rate of ducklings equipped with radiotransmitters was about 0.23 lower than the survival rate of those without radiotransmitters. Unmarked ducklings were 7.6 (95% CI = 2.7-21.3) times more likely to die on any given day when WETSEAS was ≤ 18% than when WETSEAS was >40%. Higher duckling survival and increased use of seasonal wetlands during the wet period suggest that mallard production will benefit from programs that conserve and restore seasonal wetland habitat. Given adverse effects of low temperatures on duckling survival, managers may want to include this stochastic variable in models used to predict annual production of mallards in the Prairie Pothole Region. [ABSTRACT FROM AUTHOR]

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Copyright of Hydrological Sciences Journal/Journal des Sciences Hydrologiques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hairy prairie-clover [Dalea villosa (Nutt.) Spreng. var. villosa] is a threatened Canadian wildflower. To facilitate the efforts of conserving this threatened plant, amplified fragment length polymorphism (AFLP) technique was applied to assess genetic diversity in a remnant hairy prairie-clover population in the Canadian Prairie. Three AFLP primer pairs were employed to genotype 610 individual plants from the population and 15 plants from a North Dakota composite population, and 100 polymorphic AFLP bands were analyzed. The assayed plants displayed 23% AFLP variation present between the remnant population and the North Dakota composite population, but maintained a high level (91%) of AFLP variation within patches of the remnant population. The individual genetic distinctiveness measured by average AFLP dissimilarity was positively associated with latitude and negatively with elevation. The among-patch AFLP variation was significantly related to inter-patch distance, indicating local genetic differentiation within the remnant population. However, the proportions of within-patch AFLP variation were not associated with any patch characteristics assessed (i.e., patch size, perimeter, nearest neighbor distance, mean inter-patch distance). No fine-scale genetic structure was found within three large patches, suggesting little genetic correlations present for plants five meters apart. Some genetically distinctive and diverse patches were also identified. These findings indicate that the genetic risk of the remnant hairy prairie-clover population in the Canadian Prairie is low. [ABSTRACT FROM AUTHOR]

The large area occupied by temperate grassland ecosystems makes it important to determine their strength as a carbon sink. The Bowen ratio/energy balance (BREB) technique was used to determine CO2 fluxes over a moderately grazed mixed-grass prairie at Mandan, North Dakota, USA, over a 6-year period from 1996 to 2001. Above-ground biomass and leaf area index (LAI) were measured about every 21 days throughout the growing period. Root biomass was determined to 1.1 m depth in mid-July each year. Peak above-ground biomass typically occurred between mid-July to early August and ranged from 782 kg/ha in 1998 to 2173 kg/ha in 1999. Maximum LAI ranged from 0.4 in 1998 to 0.9 in 1999. Root biomass ranged from 11.8 Mg/ha in 1997 to 17.4 Mg/ha in 1996. Maximum daily CO2 fluxes generally coincided with periods of maximum LAI and above-ground green biomass. The average time period for CO2 uptake was 5 May to 3 October. Annual CO2 fluxes ranged from a low of 13 g CO2/m2 in 1998 to a high of 247 g CO2/m2 in 2001, nearly a 20-fold difference, and averaged 108 g CO2/m2. The cumulative annual flux over all 6 years was 646 g CO2/m2 or 176 g CO2-C/m2. These results indicate that the strength of the carbon sink for this moderately grazed prairie site is about 30 g CO2-C/m2/yr, which is quite small, but considering that the site was grazed and still remains a sink for carbon, it is significant. [ABSTRACT FROM AUTHOR]

North Dakota is a significant producer of wind energy in the United States. In the first decades of this century, the state went from almost zero production to over 25% of its electricity sourced from wind energy. Across the border in Canada, the province of Saskatchewan—which has the same wind capacity as North Dakota—did not develop wind energy during this same time period. This paper looks at print news media coverage of renewable energy, especially wind energy, in the two jurisdictions between 2009–2018. The main finding is that news media coverage of renewable energy is similar despite the very different wind energy portfolios. This suggests a possible disjoint between the media and public discourse on renewable energy politics. Regardless of the size of the renewable energy sector, the media reports very little on it. Overall, the study concludes that more robust discussions around the environment-energy nexus would be beneficial as the jurisdictions continue to grow their energy portfolios and potentially transition toward more renewable energies. [ABSTRACT FROM AUTHOR]

The Northern Prairie and Parkland Waterbird Conservation Plan calls for renewed attention to determining the current status of waterbird populations, their distributions, and conservation needs. It highlights the need for baseline information on the White-faced Ibis (Plegadis chihi). In response, we examined the historical and current distribution of the ibis in North Dakota and summarized first sightings and nest records for the provinces and other states composing the northern prairie and parkland region. The establishment of breeding colonies of White-faced Ibis here may be due to climate and precipitation patterns, invasion and spread of Narrowleaf Cattail (Typha angustifolia), changes in agricultural practices, habitat loss and range expansion in the southern and western portions of the species' range, and increases in ibis populations in the lntermountain West. We placed special emphasis on North Dakota, a state for which there is scant published information concerning the current status of this species. In recent decades, the ibis has become a regular breeding-season resident in North Dakota and in other areas of the northern prairie and parkland region. From 1882 to 2002, there were 145 reports of one or more White-faced Ibis in North Dakota, including 93 reports during the breeding season (15 May to 31 August), 49 during the non-breeding season (1 September to 14 May), and three for which the season of occurrence was not reported. Prior to the 1960s, there were only three records of the species in North Dakota. Observations of White-faced Ibises in North Dakota increased dramatically between the 1960s and the early 21st century, and the species has been observed nearly annually since 1971. The first White-faced Ibis nesting activity in the state was recorded in 1978, and to date, there have been 21 known records of nesting activity in the state. The species nested in large (>300 ha) semipermanent or permanent wetlands within mixed-species colonies ranging in areal extent from small (0.1 ha) to fairly large (27 ha), and colonies were located in patches of emergent vegetation dominated by cattails (Typha) and bulrushes (Scirpus). We classify the White-faced Ibis as a fairly common migrant and a locally uncommon breeder east of the Missouri River and a casual migrant west of the Missouri River. [ABSTRACT FROM AUTHOR]

We evaluated food habits of 4 species of spring-migrant calidrid sandpipers in the Prairie Pothole Region (PPR) of North Dakota. Sandpipers foraged in several wetland classes and fed primarily on aquatic dipterans, mostly larvae, and the midge family Chironomidae was the primary food eaten. Larger sandpiper species foraged in deeper water and took larger larvae than did smaller sandpipers. The diverse wetland habitats that migrant shorebirds use in the PPR suggest a landscape-level approach be applied to wetland conservation efforts. We recommend that managers use livestock grazing and other tools, where applicable, to keep shallow, freshwater wetlands from becoming choked with emergent vegetation limiting chironomid production and preventing shorebird use. [ABSTRACT FROM AUTHOR]

Grassland ecosystems established under the conservation reserve program (CRP) in the Prairie Pothole Region (PPR) currently provide soil conservation and wildlife habitat services. We aimed to determine if these lands also sequester soil organic carbon (SOC), as compared with neighboring croplands across multiple farms in the North Dakota PPR. We sampled soil from small plots at 17 private farms in the central North Dakota PPR, where long-term (≥15 years) grasslands managed under the CRP were paired with neighboring annual croplands. Cores were collected to 100 cm and split into 0-10, 10-20, 20-30, 30-40, 40-70, and 70-100 cm soil depth layers. We hypothesized the effect of land use on soil organic carbon (SOC), root carbon (C), and bulk density would be greatest near the surface. For 0-10 and 10-20 cm layers, grasslands managed under the CRP were lower in bulk density and higher in SOC. From 0 to 70 cm, grasslands managed under the CRP were higher in root C. Average (±standard error) SOC for re-established grasslands and croplands was 25.39 (0.91) and 21.90 (1.02), respectively, for the 0-10 cm soil layer and 19.88 (0.86) and 18.31 (0.82), respectively, for the 10-20 soil layer. Compared to croplands, re-established grasslands sampled in the North Dakota PPR were 3-13 % lower in bulk density and 9-16 % higher in SOC from 0 to 20 cm, while root C was 2-6 times greater from 0 to 70 cm. [ABSTRACT FROM AUTHOR]

The article focuses on the integration of smooth brome, a cold-season, perennial grass within a mixed-grass prairie landscape in North Dakota. Smoth brome was introduced to North America's prairie regions from Europe in the late 1800s for use as livestock forage. Its ability to spread and outcompete native prairie flora makes the grass a major obstacle to reestablishing native vegetation in prairie soils that were previously cultivated. To help provide such information for the northern mixed-grass prairie region, the researchers measured the occurrence of native forb species in tracts of cropland that had been seeded to brome on the 2,00 hectares wilderness area of Lostwood National Wildlife Refuge in northwestern North Dakota.

Managers of the nearly 0.5 million ha of public lands in North and South Dakota, USA rely heavily on manual measurements of canopy height in autumn to ensure conservation of grassland structure for wildlife and forage for livestock. However, more comprehensive assessment of vegetation structure could be achieved for mixed-grass prairie by integrating field survey, topographic position (summit, mid and toeslope) and spectral reflectance data. Thus, we examined the variation of mixed-grass prairie structural attributes (canopy leaf area, standing crop mass, canopy height, nitrogen, and water content) and spectral vegetation indices (VIs) with variation in topographic position at the Grand River National Grassland (GRNG), South Dakota. We conducted the study on a 36,000-ha herbaceous area within the GRNG, where randomly selected plots (1 km in size) were geolocated and included summit, mid and toeslope positions. We tested for effects of topographic position on measured vegetation attributes and VIs calculated from Landsat TM and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data collected in July 2010. Leaf area, standing crop mass, canopy height, nitrogen, and water content were lower at summits than at toeslopes. The simple ratio of Landsat Band 7/Band 1 (SR71) was the VI most highly correlated with canopy standing crop and height at plot and landscape scales. Results suggest field and remote sensing-based grassland assessment techniques could more comprehensively target low structure areas at minimal expense by layering modeled imagery over a landscape stratified into topographic position groups. [ABSTRACT FROM AUTHOR]

The article analyzes the influences of management regimes on breeding bird densities and habitat in mixed-grass prairie in North Dakota. The results provide some evidence that in this region, bird use can be higher under moderate cattle-stocking rates without fire than under a regime of low bison-stocking rates combined with fire. Because higher bird use does not necessarily indicate higher reproductive success or survival, researchers should compare avian vital rates across management regimes and examine the factors regulating these vital rates to understand the impacts on these populations.

Mammalian predation influences waterfowl breeding success in the U.S. northern Great Plains, yet little is known about the influence of the landscape on the ability of predators to find waterfowl nests. We used radiotelemetry to record nightly movements of red foxes (Vulpes vulpes) and striped skunks (Mephitis mephitis) in two 41.4-km² study areas in North Dakota. Study areas contained either 15-20% grassland (low grassland composition) or 45-55% grassland (high grassland composition). Grasslands included planted cover, pastureland, and hayland. We predicted that the type and composition of cover types in the landscape would influence both predator movement across the landscape (as measured by the fractal dimension and displacement ratio) as well as localized movement (as measured by the rate of movement and turning angle between locations) within patches of different cover types. Red fox movements were straighter (lower fractal dimensions and higher displacements) across landscapes with a low grassland composition, indicating directed movement between the more isolated patches of planted cover. Striped skunk movements did not differ between landscape types, illustrating their movement along wetland edges, which had similar compositions in both landscape types. The high variability in turning angles by red fox in planted cover and pastureland in both landscape types is consistent with restricted-area foraging. The high rate of movement by red foxes in planted cover and by striped skunks in wetland edges suggests that spatial memory may influence movement patterns. Understanding the behavior of predators in fragmented prairie landscape is essential for managing breeding habitat for grassland birds and for predicting the spatial and temporal dynamics of predators and their prey. [ABSTRACT FROM AUTHOR]

• Premise of the study : Climate change is associated with phenological shifts in an increasing number of organisms worldwide. However, accurate estimates of these shifts are dependent on long-term data sets that include phenological observations from before annual average temperatures began to rise. • Methods : We compared the first flowering times of native prairie plants between 2007 and 2010 with historical data recorded by O. A. Stevens from 1910 to 1961. By merging climate variable data from the same time period, it also was possible to correlate first flowering dates with associated climate variables. • Key results : Over the past 100 years, spring temperatures in the Red River Valley near Fargo, North Dakota, USA, have increased, and growing seasons have lengthened significantly. Seventy-five percent of the 178 species observed by Stevens had flowering times that were sensitive to at least one variable related to temperature or precipitation. Over the past 4 yr, 5% to 17% of the species observed have significantly shifted their first flowering time either earlier or later relative to the previous century. • Conclusions : The results of this study indicate that as spring temperatures in the northern Great Plains have increased and the growing season has lengthened, some spring flowering species have advanced their first flowering time, some fall species have delayed their first flowering, and some species have not changed. Given the importance of flowering timing for reproductive success, the changing climate in the Great Plains is expected to have long-term ecological and evolutionary consequences for native plant species. [ABSTRACT FROM AUTHOR]

Arthropods are key components of grassland ecosystems. Though arthropod communities are often strongly influenced by plant communities, plants and arthropods may respond differently to disturbance. Studying plant responses alone may, therefore, not fully capture altered ecosystem dynamics; thus multi-trophic approaches are critical to fully understand ecosystem responses to disturbance. Energy development is a large-scale driver of disturbance in northern Great Plains rangelands, and recovery of arthropod communities following reclamation is not well understood. We sampled Orthoptera and spiders in western North Dakota, United States, in 2016. Samples were collected from 14 reclaimed oil well sites ('reclaims') 2–33 yr since reclamation, and native prairie at two distances (50 and 150 m) from reclaim edges. Overall Orthopteran and spider abundances on reclaims and native prairie did not differ; however, Orthopteran community composition and species abundances were distinct on reclaims versus native prairie, including increased abundances of Melanoplus femurrubrum (De Geer) (Orthoptera: Acrididae) (a noted crop pest) on reclaims. In contrast, NMS analyses revealed no differences in spider community composition between reclaims and native prairie, although abundances of one group (Salticidae) strongly decreased on reclaims. We present one of the first studies to investigate impacts of energy development and reclamation on arthropod communities. While reclamation efforts successfully recovered abundances and biomass of arthropod herbivores and predators, Orthopteran (but not spider) community composition on reclaims has not recovered to match that of intact prairie even 30 yr after reclamation. These findings suggest that energy development may have long-term or potentially irreversible impacts to rangeland arthropod communities. [ABSTRACT FROM AUTHOR]

Historically, wetland and grassland ecosystems throughout the Prairie Pothole Region (PPR) of North America were shaped by fire, grazing, and alternating drought and deluge conditions. These historic disturbance patterns of the PPR have been altered by human modifications to the landscape. In recent years, managers have attempted to implement practices that simulate historic disturbance patterns in order to improve the diversity of structure and function in impacted ecosystems. This study evaluated the characteristics of restored and native wetland/grassland plant communities located within two National Wildlife Refuges (NWR) in the PPR of North Dakota. An extensive analysis of plant community composition following an environmental gradient was conducted in order to relate the composition and quality of wetland communities to the condition of adjacent upland grasslands and to compare the composition and quality of native and restored sites. Plant communities were evaluated using quadrat and transect methods and a Floristic Quality Index (FQI). Statistical analyses employed Nonmetric Multidimensional Scaling ordination and Multi-Response Permutation Procedure. We found wide variability in the composition and quality of the plant communities evaluated. Native plant communities were generally of higher quality than restored communities; also, plant communities located at Lostwood NWR generally contained more native components than those located at Tewaukon NWR. The results of this study show that restoration efforts, when properly managed, have the potential to improve the composition and quality of wetland and grassland plant communities. It is likely that the quality of the restored plant communities evaluated in this study will continue to improve with time and sustained management. [ABSTRACT FROM AUTHOR]

We evaluated the ability of Ikonos imagery from August and October 2000 to classify prairie pothole community types of the Missouri Coteau of North Dakota. Classification tree analyses were conducted to create land-cover maps at three levels of detail. The analyses successfully distinguished broad cover types (potholes including emergent vegetation versus upland vegetation) at 92 percent overall accuracy. Overall accuracy dropped to 80 percent when upland vegetation was segregated into woody and grassy communities and to 71 percent when we attempted to classify at the species or near-species levels. The use of two image dates was of importance in the classifications; the failure to acquire early season imagery, therefore, might have impaired our results. [ABSTRACT FROM AUTHOR]

Detailed case histories of long-term successional changes in vegetation are crucial for assessing ecological integrity and developing restoration objectives on prairie preserves in North America's northern Great Plains. Such documentation generally is lacking, however. We used aerial photo measurements plus records from land surveyors and other sources to document change in extent of woodland across four National Wildlife Refuges in northern North Dakota during the 1800s and 1900s. Woodlands were rare when Europeans settled the region in the early 1900s, except green ash (Fraxinus pennsylvanica Marsh.)-American elm (Ulmus americana L.) woodland occurred within the floodplain of the Souris River, and stunted copses of quaking aspen (Populus tremuloides Michx.)-bur oak (Quercus macrocarpa Michx.) occurred along fire-protected scarps of sandhills prairie in north central North Dakota. Ash-elm woodland expanded in the Des Lacs and Souris River valleys especially along adjoining, intermittent tributaries (coulees) of the Souris River, mainly during the early- to mid-1900s. During the mid- to late-1900s, aspen woodland expanded in sandhills of the Souris Lake Plain and in the Missouri Coteau, changing much of the mixed-grass prairie to parkland. With settlement by people of European descent, large herbivores were extirpated from the region and natural and anthropogenic fires were suppressed. These changes are implicated in expansion of woodland into native prairies. [ABSTRACT FROM AUTHOR]

Opportunities for conserving native plant diversity in the northern Great Plains should be found on National Wildlife Refuges (NWRs), but floristics of these areas are largely undocumented. During 1998-2002, we used 25-m belt transects (n=713) to measure the general floristic makeup of a northern mixed-grass prairie on 4300 ha of glacial drift plain soils at Des Lacs NWR and J. Clark Salyer NWR in North Dakota. These prairies had been managed mainly by rest since the 1930s. For comparative purposes, we also measured about 1200 ha of nearby, privately owned prairies (n= 154 transects), which had been annually grazed since at least the mid-1900s. Vegetation dominated by low (<1.5 m) native shrubs were common on both NWR prairies and on grazed prairies near Des Lacs NWR, occurring roughly in a 1:3 ratio with herbaceous-dominated vegetation. Nearly all prairies were moderately to severely invaded by introduced plant species, mainly smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poapratensis L.) on NWRs, and Kentucky bluegrass, almost exclusively, on adjacent grazed prairies. Plant assemblages composed of native species were encountered rarely (3-6%), except they occurred fairly often (16%) on grazed prairie next to J. Clark Salyer NWR. Our study demonstrates pitfalls of managing disturbance-dependent grasslands as relatively static, late-succession systems for many decades, without basic inventory and monitoring to comprehend and address associated ecological changes. A consequence of this course of action on NWR prairies we studied was a hastened invasion by introduced grass species, especially smooth brome. [ABSTRACT FROM AUTHOR]

Background: Sustainable rangeland management balances production and conservation. While a broad literature describesthe conservation benefits of prescribed fire, benefits for livestock production have emerged more slowly. Mineral nutrition is important for livestock health and performance, but the impact of prescribed fire on mineral concentration of forages, especially in the northern US Great Plains, remains unknown. Aims: We investigated how burning affects the mineral concentration of forage early and late in the growing season. Methods: Data were collected on mixed-grass prairie in south-central North Dakota, USA. Vegetation was clipped from recently burned, 1 year post-fire, 2 years post-fire, and not-yet-burned patches at the same sampling points in spring and late summer. Samples were analysed for calcium, phosphorus, magnesium, potassium, copper, iron, manganese, and zinc concentration. Key results: Burning increased forage mineral concentration across most minerals. Phosphorous, potassium, copper and zinc were higher in burned areas in late spring and summer; calcium, magnesium and manganese were only higher during the late summer; Late-season iron levels increased with time since fire. Conclusions: Prescribed fire has a positive effect on forage mineral content. Implications: Prescribed fire has the potential to reduce mineral supplementation costs and improve cow performance. Prescribed fire has a positive effect on forage mineral content and has the potential to reduce mineral supplementation costs and improve cow performance. [ABSTRACT FROM AUTHOR]

Unconventional oil and gas production (i.e., horizontal drilling and hydrofracturing) has expanded rapidly in the US. One important region where this expansion has occurred is the Bakken/Three Forks Formation, a tight oil play that has made North Dakota a major U.S. oil producer. Using a spatial well database and satellite imagery, we directly measured land‐use changes caused by recent oil and gas activities in two important natural habitats in North Dakota. These two habitats were prairie potholes and public lands that include conservation of wildlife as part of their publicly stated mission. For public lands, we found that about 2,600 ha have been developed, edge habitat increased by almost 30 km (3.65% increase), and average fragment size decreased by 0.70%. Few prairie potholes were directly impacted by this activity, but distance to development decreased for almost one third (434/1,300) by an average of about 400 m. Although land cover changes have been measured in this region in previous publications, our results showing changes in fragmentation, edge habitat, and distance to development provide new metrics for how these habitats in North Dakota are being affected by fossil fuel activity. Observed land‐use changes, while modest, likely have negative impacts on wildlife, including increased mortality or habitat avoidance. Given the potential spread of unconventional oil and gas across the globe, understanding these patterns should help inform land and wildlife managers, as well as the oil and gas industry, about strategies to limit impacts of well and infrastructure placement on valuable wildlife habitats. [ABSTRACT FROM AUTHOR]

Grassland fires have been shown to influence grasshopper community composition and population dynamics, but studies of their effects on rangeland grasshopper assemblages in the northern Great Plains are lacking. This study was designed to examine the effect of a grassland wildfire on grasshopper community composition and population densities of three grasshopper subfamilies in western North Dakota northern mixed-grass prairie with sampling in paired burned and unburned plots. A rapidly moving fire occurred in late October 1999, after egg-overwintering grasshoppers had died. Vegetation biomass and nitrogen content of grasses did not differ statistically between burned and unburned plots in 2000. The fire negatively affected grasshopper population densities the year after the fire, but species diversity was not affected by the fire. Much of the reduction in grasshopper population densities was caused by a decline in densities of Gomphocerinae species. Grasshopper subfamily densities did not differ statistically between burned and unburned plots in 2001. Additional research is needed to determine the mechanisms leading to the reduction in Gomphocerinae species densities. [ABSTRACT FROM AUTHOR]

In the Prairie Pothole Region (PPR) of North Dakota, USA, American mink (Mustela vison) are a major predator of ducklings. Mink populations plummet during severe droughts, but some mink survive where permanent fresh water is available. In 1992-1993, we evaluated whether development of a permanent water body, the 125-km McClusky Canal (MC), had affected survival of gadwall (Anas strepera) and mallard (A. platyrhynchos) broods and ducklings in surrounding wetland complexes. Twelve of 25 radiomarked gadwall and mallard hens experienced total brood loss, and 148 of 199 radiomarked ducklings from 58 broods died by day 30. Cadwall broods (n = 18 radiomarked hens) survived to 30 days at a lower rate (0.52) than predicted for similar areas in the region with limited permanent fresh water (0.85; P = 0.009). Observed (n= 162 radiomarked ducklings from 48 broods) survival rates also were lower than predicted for gadwall ducklings 0-7 days old (0.42 vs. 0.60; P < 0.001) and 8-30 days old (0.41 vs. 0.80; P < 0.001). We attempted to include mallards in models constructed to predict brood and duckling survival rates in the Koenig Study Area (KSA), but data were too sparse. Rates of survival to 30 days for gadwall and mallard ducklings declined from an estimated 0.83 and 0.68 in 1976-1981 (Lokemoen et al. 1990), when the MC was first filling with water, to 0.36 and 0.31 (adjusted for radiotransmitter effects) in 1992-1993 after the MC had become a permanent freshwater body. Estimated gadwall recruitment rate (females fledged per hen) during 1992-1993 was 0.5, < 50% of the estimated recruitment rate in 1976-1981. Of 130 radiomarked ducklings (both species) for which we determined cause of death, 114 mortalities were attributed to predation; at least 65% of 62 deaths in which the predator type could be discerned were caused by mink. Environmental planners and waterfowl managers should be aware of potential risks to waterfowl production from development of permanent ... [ABSTRACT FROM AUTHOR]

While many studies have characterized small mammals of the southern and central Great Plains (USA), far fewer have documented small mammals of the northern Great Plains which differ dramatically in plant structure and composition. We examined the presence and distribution of small mammals captured at a salinity-affected grassland in northeastern North Dakota (2018–2021). We captured 12 species from 8 genera including Microtus pennsylvanicus (n = 724), Peromyscus (maniculatus) sonoriensis (n = 114), Sorex cinereus (n = 54), and Zapus hudsonius (n = 43). We evaluated the extent to which these species varied with plant and environmental characteristics. M. pennsylvanicus was positively associated with plant cover and soil moisture and P. (maniculatus) sonoriensis was positively associated with forb cover and negatively associated with litter and elevation. Z. hudsonius was negatively associated with forb cover and soil moisture and S. cinereus was positively associated with cover and negatively associated with salinity. These species associated with their environments differently than their more southern counterparts and reinforce the notion that not all areas, even in relatively intact grasslands, are available to all species. Future studies are needed to further examine more infrequently captured species, including a Sorex hoyi, an Onychomys leucogaster, and eight Myodes gapperi in this region. [ABSTRACT FROM AUTHOR]

Land surface phenologies and seasonalities in the US Prairie Pothole Region (PPR) were characterized using land surface variables derived from the coarse spatial resolution (25 km) Advanced Microwave Scanning Radiometer (AMSR) blended data for 2003 to 2016 linked with the optically based USDA NASS Crop Data Layer (CDL) at a much finer spatial resolution. Two transects of AMSR pixels—one in east-central North Dakota and the other in eastern South Dakota—were selected for analysis. The AMSR data were grouped earlier (2003–2005, 2007) and later (2013–2016) to emphasize temporal change and to avoid data discontinuity in 2011–2012 and a major drought in 2006. The nonparametric Mann-Kendall trend test on the CDL data revealed that area in grasslands and wetlands strongly decreased in both transects, while corn and soybean coverage strongly increased. In crop-dominated sites, the AMSR vegetation optical depth (VOD) time series caught the early spring growth, ploughing, and crop growth and senescence. In contrast, the VOD time series at grassland dominated sites exhibited a lower peak but extended growth period. Crop-dominated sites had significantly higher amplitude VODs in both periods and transects. Based on the paired two-sample t-test, neither the peak VOD amplitude nor the peak VOD timing measured in accumulated growing degree-days was significantly different between temporal groups in the North Dakota transect. In contrast, in South Dakota, both the peak VOD amplitude and its timing were significantly different with shifts to later peak timing during the 2013–2016 period. In addition, in South Dakota but not North Dakota, there were significantly earlier shifts in the timing of peak growing degree-days and peak precipitation water vapor. Both spatial and temporal changes in AMSR land surface variables are linked to shifts in land cover along the South Dakota transect as revealed in the CDL data. More research is required to understand the dynamics evident in the passive microwave time series. [ABSTRACT FROM AUTHOR]