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Disturbances are drivers of ecosystem function and play important roles in shaping ecological communities. Prescribed fire and grazing disturbances are common management tools in restored and remnant grasslands. The effects of these management actions on plant communities and on vegetation-dwelling invertebrates are generally well studied. However, less is known about their effects on ground-dwelling invertebrates, which can contribute to important ecosystem processes like herbivory, predation, and decomposition. We examined bison grazing and prescribed fire effects on abundance, diversity, and community composition of ground-dwelling invertebrate groups in restored tallgrass prairies using pitfall trap samples. Surprisingly, invertebrate Shannon diversity decreased when bison were present and was unaffected by fire or the fire–bison interaction. Bison, and to a lesser extent fire, also shifted community composition, increasing abundance of ground, rove, and dung beetles, as well as orthopterans and spiders. Prescribed fire generally increased beetles but caused declines in several ecologically diverse invertebrate groups, including harvestmen and true bugs, although these reduced abundances did not lead to differences in overall diversity. Bison presence may amplify the abundances of dominant groups, such as ground and dung beetles and orthopterans, that outcompete other invertebrates and reduce diversity. Implications for insect conservation: Prescribed fire and grazing by bison change ground-dwelling invertebrate community composition, but bison presence did not reduce the abundance of most taxonomic groups. Fire may have short-term negative impacts on some invertebrate groups that promote desirable invertebrate-driven ecosystem processes, but these effects are likely short-lived, and the resulting environmental mosaic under bison and fire management could support biodiversity over the long-term. [ABSTRACT FROM AUTHOR]

Less than 1% of native prairie lands remain in the United States. Located in eastern Washington, the rare habitat called Palouse prairie was largely converted to wheat monocropping. With this conversion came numerous physical, chemical, and biological changes to the soil that may ultimately contribute to reduced wheat yields. Here, we explored how wheat (Tritcum aestivum L.) seedling establishment, plant size, and heading, signifying the developmental transition to flowering, were affected by being planted in prairie soil versus agricultural soils. We then sought to understand whether the observed effects were the result of changes to the soil microbiota due to agricultural intensification. We found that prairie soil enhanced both the probability of wheat seedling survival and heading compared to agricultural soil; however, wheat growth was largely unaffected by soil source. We did not detect effects on wheat developmental transitions or phenotype when inoculated with prairie microbes compared with agricultural microbes, but we did observe general antagonistic effects of microbes on plant size, regardless of soil source. This work indicates that agricultural intensification has affected soils in a way that changes early seedling establishment and the timing of heading for wheat, but these effects may not be caused by microbes, and instead may be caused by soil nutrient conditions. [ABSTRACT FROM AUTHOR]

Grassland restoration efforts typically aim to recover lost biodiversity, guided by biologically diverse old‐growth grasslands as a benchmark. In most old‐growth grasslands, forbs greatly outnumber grasses in terms of richness and therefore contribute most to diversity, but globally, restoration practitioners continue to disproportionately focus on increasing perennial grass cover. While such grass‐centric restoration approaches might be appropriate for meeting some restoration goals, an increasing number of studies reveal negative effects of perennial grass cover on forb and total plant diversity in restored grasslands—with cascading consequences for other trophic levels and grassland functionality. To that end, we urge restoration practitioners to recognize the biodiversity costs of grass‐centric approaches and embrace forb‐centric approaches to meet the goal of increasing biodiversity in restorations. Transferring knowledge between well‐studied and understudied grassland systems around the world will facilitate the shared vision of conserving and restoring global grassland biodiversity. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques 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.)

In her novel Faillir être flingué (2013), contemporary author Céline Minard revisits in her own way the Western, in a context where other writers in France and directors in the United States seize this genre that one might have thought exhausted. After so many films and books, how does it give new perception to the great prairie of the American West, this mythical and founding space? Drawing on the concept of "espace lisse" at Deleuze and Guattari, but also on the recent reflections of ecopoetics in terms of animal tracking, we will try to show that the meadow brings the many characters of this novel to a form of learning in several stages, which the reader also goes through as the pages. [ABSTRACT FROM AUTHOR]

Global warming, elevated atmospheric CO2 concentrations and increased likeliness of extreme drought and wildfires in many regions will likely favour C4 grass species. To support future management actions, we explored the effect of the encroachment of an invasive perennial C4 grass, Sporobolus cryptandrus on the composition of soil seed banks in dry sand grasslands in Central Europe. In five mass‐locality sites of the species we assessed the composition and vertical segmentation of the soil seed bank in 12 1‐m2 plots along an increasing cover of the invasive species. We found that the seed bank diversity and density decreased with increasing sampling depth; the decrease in density was affected by the increasing S. cryptandrus cover. Neither the diversity nor the seed bank density of other species were affected by increasing S. cryptandrus cover but both were affected by the sampling site. Most of the studied seed bank characteristics were affected by the sampling depth, but none of them were affected by the increasing cover of S. cryptandrus. Increasing cover of S. cryptandrus in the vegetation was associated with an increasing proportion of S. cryptandrus seeds in the seed bank, and we found a low‐density soil seed bank of the species even in plots with no S. cryptandrus cover. Our finding that S. cryptandrus forms a massive soil seed bank, together with the predicted decrease in the precipitation of the summer months and increase in the frequency of droughts in the region, projects further rapid spread of the species. [ABSTRACT FROM AUTHOR]

In many regions, the climate is changing faster during winter than during the other seasons, and a loss of snow cover combined with increased temperature variability can expose overwintering organisms to harmful conditions. Understanding how species respond to these changes during critical developmental times, such as seed germination, helps us assess the ecological implications of winter climate change. To address this concern, we measured the breaking of seed dormancy and cold tolerance of temperate grassland species in the lab and field. In the lab, we ran germination trials testing the tolerance of 17 species to an extreme cold event. In the field, we deployed seeds of two species within a snow manipulation experiment at three locations and measured germination success biweekly from seeds subjected to ambient and reduced snow cover from winter into spring. From lab trials, cold tolerance varied among species, with seed germination decreasing <10%–100% following extreme cold events. Cold tolerance was related to seed traits, specifically less round seeds, seeds that required cold stratification, and seeds that mature later in the season tended to be more impacted by extreme cold temperatures. This variation in seed cold tolerance may contribute to altered community composition with continued winter climate change. In the field, germination increased through late winter, coinciding with the accumulation of days where temperatures were favorable for cold stratification. Through spring, germination success decreased as warm temperatures accumulated. Collectively, species‐specific seed cold tolerances and mortality rates may contribute to compositional changes in grasslands under continued winter climate change. [ABSTRACT FROM AUTHOR]

Juvenile survival is critical to population persistence and evolutionary change. However, the survival of juvenile plants from emergence to reproductive maturity is rarely quantified. This is especially true for long‐lived perennials with extended pre‐reproductive periods. Furthermore, studies rarely have the replication necessary to account for variation among populations and cohorts. We estimated juvenile survival and its relationship to population size, density of conspecifics, distance to the maternal plant, age, year, and cohort for Echinacea angustifolia, a long‐lived herbaceous perennial. In 14 remnant prairie populations over seven sampling years, 2007–2013, we identified 886 seedlings. We then monitored these individuals annually until 2021 (8–15 years). Overall, juvenile mortality was very high; for almost all cohorts fewer than 10% of seedlings survived to age 8 or to year 2021. Only two of the seedlings reached reproductive maturity within the study period. Juvenile survival increased with distance from the maternal plant and varied more among the study years than it did by age or cohort. Juvenile survival did not vary with population size or local density of conspecific neighbors. Our results suggest that low juvenile survival could contribute to projected population declines. [ABSTRACT FROM AUTHOR]

Monitoring snow cover in prairie environments is important for understanding water and energy fluxes, agricultural production, and flooding, but difficult due to shallow snowpack and considerable snow heterogeneity. Cosmic ray neutron sensors (CRNS) are sensitive to snow within a radius of 150–250 m, which allows for continuous estimation of snow water equivalent (SWE) over a large footprint and may better represent area‐averaged snow cover in prairies than conventional SWE instruments, such as snow pillows. A CRNS was installed at Montana State University's Central Agricultural Research Center (CARC; 47.06°, −109.95°) in Moccasin, MT in coordination with NASA's SnowEx 2021 field campaign. This work assesses the feasibility of a CRNS for SWE monitoring in prairies by comparing CRNS SWE estimates to spatially distributed SWE derived from uninhabited aerial vehicle lidar snow depths within the sensor's footprint and manual snow pit measurements. Lidar observations show snow cover was highly spatially variable, with the largest snow accumulation near barriers and the least in barren fields. Additionally, we evaluate our CRNS SWE estimates using Ultra Rapid Neutron Only Simulation (URANOS) Monte Carlo simulations. Comparisons of SWE estimates derived from lidar, CRNS, and URANOS for shallow snowpack at the site yielded root mean square values of about 2 mm (approximately 30% of the mean SWE). These results suggest that the CRNS is effective at integrating over significant spatial variability within its footprint at this site. However, the spatial distribution of snow exerts a strong influence on the CRNS signal and must be considered when interpreting CRNS observations. Plain Language Summary: Snow in prairie environments can be highly variable due to a lack of tree cover and generally low relief, combined with windy conditions. In this study, we determine how accurately a cosmic ray neutron sensor (CRNS) can estimate snow water equivalent (SWE) for an agricultural site in central Montana. We found that our CRNS was sensitive to changes in the amount of water within a radius of 100–200 m from the instrument. For winter 2020–2021, the site experienced high spatial variability in snow depth, ranging from 1.7 m deep snowdrifts along a major windbreak to shallow snow or bare conditions in the agricultural fields that covered most of our 1 km2 study site. We compared CRNS SWE estimates at the site to independent SWE estimates derived from lidar snow depth maps and model simulations, and generally found agreement within the uncertainty of each SWE estimation method. This study supports that CRNS can integrate over the significant spatial variability common in prairie snowpacks, but how the snow varies around a given sensor has a strong influence on CRNS SWE estimates and must be considered when interpreting these types of observations. Key Points: We evaluate cosmic ray neutron sensor (CRNS) snow water equivalent (SWE) estimates using spatially distributed snow observations from lidar at a prairie siteWe use neutron transport model simulations to calibrate a site‐specific weighting function to represent the spatial sensitivity of a CRNSComparison to model‐ and lidar‐derived SWE show that our CRNS effectively estimates SWE for this heterogenous snowpack [ABSTRACT FROM AUTHOR]

Recently exposed reservoir sediments, prone to colonization by invasive species, provide novel settings to test hypotheses related to soil conditions and propagule supply as potential drivers of plant assembly in disturbed ecosystems. We used a dam removal site in southwestern Wisconsin to examine the relationship between the physiochemical properties of dewatered sediments, seeding density, and plant community assembly. The plant communities from five seed densities (1000, 500, 250, 125, and 0 seed m−2) were annually assessed over four years. We hypothesized (1) that the native aboveground biomass and the proportion of native to invasive (non-seeded species) aboveground biomass would increase with the seeding density and (2) that the diversity of seeded native species would increase with a higher seeding density. We found evidence that sowing at least 500 seeds m−2 of prairie species increased their abundance, establishment, and plot diversity compared to non-seeded plants that persisted four years after seeding (p < 0.05). The seeding density treatments led to the assembly of two distinct communities: "native" and "invasive". The "native" community, assembled in plots seeded with at least 500 seeds m−2, had a greater aboveground biomass and diversity (i.e., richness) of seeded plants compared to plots with lower seed densities, and its productivity was positively related to this richness. In the "weedy" community, the diversity of invasive species had no relationship to their aboveground biomass, likely because these species share similar traits (i.e., redundancy) and may have performed similar functions within the plant community. These findings suggest that the seeding density interacted with the disturbed soil resources to increase the diversity and productivity of seeded native species and may serve as a positive feedback mechanism for the establishment of native communities in dewatered sediments. [ABSTRACT FROM AUTHOR]

Restoration outcomes are variable, which impairs our ability to plan projects, meet goals, and predict restoration outcomes. Understanding the drivers of this variation is an important research need, especially within urban ecosystems, which support altered abiotic and biotic conditions and face higher rates of loss and degradation than non‐urban areas. Despite the importance of urban areas for restoration, research and practice have largely focused on non‐urban areas. It is unclear if we can extend current knowledge from restoration ecology to urban systems. Here, we surveyed 30 urban prairie restoration plantings across southern Michigan. We collected plant community and site condition data (e.g. soil attributes) and we quantified landscape context as the percentage of urban land surrounding each site. Variation in plant community composition among restorations was related primarily to site‐level factors, such as soil compaction, texture, and water‐holding capacity, rather than landscape context. Non‐prairie species were structured primarily by the local site conditions. There was an increase in non‐prairie richness for sites that experienced warmer local climate conditions, while there was a decrease in non‐prairie richness for sites where soils were less compacted, sandier, and had elevated water‐holding capacity. Prairie species richness responded oppositely. Overall, our study revealed specific factors structuring restoration outcomes in urban contexts and illustrated the importance of local site conditions, not surrounding landscape context, for shaping plant community composition. Restoration practices developed in non‐urban areas should be extended to urban contexts to better understand the impact of local site conditions on plant community development. [ABSTRACT FROM AUTHOR]

Monoculture switchgrass and restored prairie are promising perennial feedstock sources for bioenergy production on the lands unsuitable for conventional agriculture. Such lands often display contrasting topography that influences soil characteristics and interactions between plant growth and soil C gains. This study aimed at elucidating the influences of topography and plant systems on the fate of C originated from switchgrass plants and on its relationships with soil pore characteristics. For that, switchgrass plants were grown in intact soil cores collected from two contrasting topographies, namely steep slopes and topographical depressions, in the fields in multi-year monoculture switchgrass and restored prairie vegetation. The 13C pulse labeling allowed tracing the C of switchgrass origin, which X-ray computed micro-tomography enabled in-detail characterization of soil pore structure. In eroded slopes, the differences between the monoculture switchgrass and prairie in terms of total and microbial biomass C were greater than those in topographical depressions. While new switchgrass increased the CO2 emission in depressions, it did not significantly affect the CO2 emission in slopes. Pores of 18–90 µm Ø facilitated the accumulation of new C in soil, while > 150 µm Ø pores enhanced the mineralization of the new C. These findings suggest that polyculture prairie located in slopes can be particularly beneficial in facilitating soil C accrual and reduce C losses as CO2. [ABSTRACT FROM AUTHOR]

Water returned to the atmosphere as evapotranspiration (ET) is approximately 1.6x global river discharge and has wide‐reaching impacts on groundwater and streamflow. In the U.S. Midwest, widespread land conversion from prairie to pasture to cropland has altered spatiotemporal patterns of ET, yet there is not consensus on the direction of change or the mechanisms controlling changes. We measured ET at three locations within the Long‐Term Agroecosystem Research network along a latitudinal gradient with paired rainfed cropland and prairie sites at each location. At the northern locations, the Upper Mississippi River Basin (UMRB) and Kellogg Biological Station (KBS), the cropland has annual ET that is 84 and 29 mm/year (22% and 5%) higher, respectively, caused primarily by higher ET during springtime when fields are fallow. At the southern location, the Central Mississippi River Basin (CMRB), the prairie has 69 mm/year (11%) higher ET, primarily due to a longer growing season. Differences in climate and that the CMRB prairie is remnant native prairie, while the UMRB and KBS prairies are restored, make it challenging to attribute differences to specific mechanisms. To accomplish this, we examine the energy balance using the Two‐Resistance Method (TRM). Results from the TRM demonstrate that higher surface conductance in croplands is the primary factor leading to higher springtime ET from croplands, relative to prairies. Results from this study provide insight into impacts of warm season grasses on the hydrology of the U.S. Corn Belt by providing a mechanistic understanding of how land use change affects the water budget. Plain Language Summary: Evapotranspiration (ET) consists of evaporation from bare soil and plant leaves. ET is ∼1.6x greater than global river flow and has wide‐reaching impacts on groundwater and streamflow. In the U.S. Midwest, widespread land conversion from prairies to croplands has altered patterns of ET, yet there is no consensus on the direction of this change or the mechanisms controlling changes. In this study we use measurements of ET at three locations within the Long‐Term Agroecosystem Research (LTAR) network that have paired cropland and prairie sites. Surprisingly, we found that in the two northern sites, the croplands had higher ET than the prairies, particularly during springtime when the croplands are fallow. We used mathematical analysis of the energy budget to show that a parameter called the surface conductance controls the differences in ET between the croplands and prairies. During springtime in prairies, the standing, dormant vegetation blocks transfer of water vapor from the land surface, reducing the surface conductance, and limits the ET. Results from this study provide insight into the impact of land conversion from prairies to croplands on the hydrology of the U.S. Corn Belt by providing a mechanistic understanding of how land use change affects the water budget. Key Points: Differences in evapotranspiration between croplands and prairies was quantified by a mechanistic Two Resistance MethodBowen ratio during springtime is higher in prairies than croplandsSurface resistance is the primary factor causing springtime evapotranspiration differences between croplands and prairies [ABSTRACT FROM AUTHOR]

Groundplum milkvetch (Astragalus crassicarpus Nutt. [Fabaceae]) is a native herbaceous forb found in the Great Plains of North America that has high seed dormancy. Previous research found that despite 100% viability, no seeds germinated without treatments to alleviate dormancy (scarification with sandpaper). The goal of this project is to expand on that research and examine the efficacy of additional treatments to alleviate dormancy in groundplum milkvetch seeds. Treatments were designed to mimic fire cues (dry heat, flaming, and smoke) along with a control (no treatment) and scarification. Historically, the Great Plains had frequent fires to which native plants were exposed so it is a reasonable question to ask if fire cues promote germination. We found that the seeds responded to treatment. Final germination percentage was greatest in seeds treated with dry heat or scarification. Smoke treatment did not impact germination differently than the control. Flaming resulted in a faster rate (seeds per day) of germination but longer time to germination compared to the control. Results suggest that groundplum milkvetch seeds did sense and respond to temperature-driven fire cues, but not chemical-driven (smoke), and that dry heat may be the best treatment to promote germination of groundplum milkvetch seeds. [ABSTRACT FROM AUTHOR]

Myxospermy, the release of seed mucilage upon hydration, plays multiple roles in seed biology. Here, we explore whether seed mucilage occurs in a suite of temperate grassland species to test if the prevalence of species producing seed mucilage is associated with habitat type or seed characteristics. Seventy plant species found in wet or dry North American temperate grasslands were tested for the presence of seed mucilage through microscopic examination of seeds imbibed with histochemical stain for mucilage. Mucilage production was compared among species with different moisture requirements and seed mass. In this study, 43 of 70 of species tested produced seed mucilage. Seed mucilage did not differ based on habitat type, species moisture requirements, or seed mass. Most seed mucilage was non‐adherent and did not remain stuck to the seed after extrusion. Seed mucilage was a common trait in the surveyed temperate grassland species and was observed in 61% of evaluated species. Surprisingly, seed mucilage was more common in temperate grasslands than in previous ecological surveys from arid/semiarid systems, which found 10%–31% myxospermous species. Given the high prevalence, seed mucilage may influence seedling ecology in temperate grasslands and requires further investigation. [ABSTRACT FROM AUTHOR]

Fire is a vital management tool for maintaining prairie ecosystems. Prescribed burns control invasive species, regulate succession, stimulate plant growth, and are a cheap and effective method for removing excess biomass; however, fire can also inadvertently cause wildlife mortality, placing land managers in a challenging situation. Turtles are especially at risk of mortality from fire because of their low mobility and population sensitivity to reductions in adult survival. We studied ornate box turtles (Terrapene ornata) at 3 sites in Illinois, USA, from 2019–2022 to determine the best predictors of above‐ground activity so land managers can conduct prescribed burns when turtles are underground. We used turtle shell temperature, air temperature, soil temperature, and precipitation data to develop a predictive model of above‐ground activity. The best model for predicting above‐ground activity included an interaction between day of year and current air temperature. Earlier in spring and later in fall, above‐ground activity is more likely at higher air temperatures compared to later in spring and earlier in fall when the same likelihood of above‐ground activity is predicted at lower air temperatures. In spring, we recommend burning in Illinois ornate box turtle habitat before 1 April when air temperature is <10°C and in fall after 1 November when air temperature is <15°C. Above these temperature thresholds, there is a >5% likelihood that turtles in northern populations are above ground. [ABSTRACT FROM AUTHOR]

Prairie moonwort, Botrychium campestre, was discovered in 1990 in the Bonny Prairie Natural Area of eastern Colorado, the species' southernmost occurrence in the Great Plains. In the years following discovery, the population was monitored by recording the number of aboveground plants. From the initial discovery of three plants in 1990, numbers remained low through 1996, and none were observed from 1997 through 2009. An analysis of soil samples collected in 2007 from the site confirmed belowground viable gemmae (vegetative sporophytic propagules produced by the sporophyte stem). Following two years of above-average precipitation in 2008 and 2009, plus artificial watering in those years, 12 aboveground plants were found in 2010. In 2011, another wet year, 63 aboveground plants were recorded. In the following two drought years, the number returned to zero and has remained low in subsequent years. We address the belowground biology of Botrychium and its mycorrhizal symbiont that make possible the persistence of populations in the absence of aboveground plants, as well as correlation with precipitation and implications for detection and conservation of Botrychium populations. [ABSTRACT FROM AUTHOR]

Abiotic stressors can be major sources of selection, resulting in diverse demographic responses operating via multiple direct and indirect mechanisms. However, unusual weather events are notoriously difficult to study due to their spatial and temporal unpredictability. A severe drought affected the Flint Hills of Kansas in 2018, occurring during the ongoing population‐level studies of three species of declining grassland songbirds: Eastern Meadowlarks (Sturnella magna), Grasshopper Sparrows (Ammodramus savannarum), and Dickcissels (Spiza americana). We compared nest survival, nest initiation date, and potential behavioral drivers of reproductive differences (i.e., nest orientation, investment) between the 2018 drought year and 2–6 years of average‐to‐wet years. Nest initiation in the drought year was concentrated early in the season, suggesting that birds did not renest or attempt second broods. The two species that build domed nests shifted the orientation of nest entrances away from early morning sun and toward the direction of prevailing winds in the drought year. Multiple nest‐level metrics of investment and success were similar in drought and nondrought years. These results suggest that demographic changes during droughts can reflect both direct responses and may also involve biotically mediated trophic consequences. [ABSTRACT FROM AUTHOR]

We established a tallgrass prairie restoration experiment on a high school campus in Kansas. This easily accessible natural environment provides students and teachers many options including scientific research, artistic ventures, or simply relaxing in nature. Our restoration project has four main objectives: (1) practicing science; (2) increasing prairie habitat; (3) fostering a sense of place by getting students outside; and (4) facilitating community collaboration. Here, we present an overview of our restoration as a general model that is adaptable for a variety of ecosystems and circumstances. [ABSTRACT FROM AUTHOR]

Phylogenetic and functional diversity are theorised to increase invasion resistance. Experimentally testing whether plant communities higher in these components of diversity are less invasible is an important step for guiding restoration designs.To investigate how phylogenetic and functional diversity of vegetation affect invasion resistance in a restoration setting, we used experimental prairie restoration plots. The experiment crossed three levels of phylogenetic diversity with two levels of functional diversity while species richness was held constant. We allowed invaders to colonise plots; these included native species from neighbouring plots and non‐native invasive species from a surrounding old field. We tested if invader biomass was influenced by phylogenetic and functional diversity, and phylogenetic and hierarchical trait distances between invaders and planted species. We binned each invader into three categories: native species from neighbouring experimental plots (site‐specific invaders), native species not part of the experimental species pool (native invaders) or non‐native species (non‐native invaders).Counter to expectation, both non‐native and native invaders became more abundant in more phylogenetically diverse plots. However, plots with higher abundance of planted Asteraceae, a dominant family of the tallgrass prairie, had lower invader biomass for both native and non‐native invaders.We also found that hierarchical trait differences shaped invasion. The species that became most abundant were non‐native invaders that were taller, and native invaders with low specific leaf area relative to planted species. Site‐specific invaders were not influenced by any plot‐level diversity metrics tested.Synthesis and application: Our results suggest that greater phylogenetic diversity may lower resistance to invasion. This effect may be due to more even but sparser niche packing in high‐diversity plots, associated with greater availability of unsaturated niche space for colonisation. However, trait composition fostered invasion resistance in two ways in our study. First, establishment of native species with strongly dominant traits may confer invasion resistance. Second, species mixes that optimise trait differences between planted vegetation and likely invaders may enhance invasion‐resistance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Raptor Research is the property of Raptor Research Foundation 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.)

To our knowledge, the study interconnection between inherent chemical functional group spectral features and nutrient utilisation is still limited. The objective of this study was to test the adequacy of vibrational Fourier transform infrared attenuated total reflectance (ATR‐FTIR) spectroscopy as a fast tool to assess the interactive relationship between the nutritive value of the Prairie cool‐season oat (Avena sativa L.) varieties in dairy cows and inherent chemical functional group spectral features. The chemical functional group spectral features of the Prairie cool‐season oat varieties in western Canada were determined by Fourier transform infrared attenuated total reflectance spectroscopy. The protein‐related spectral parameters of chemical functional groups included peak height and peak area intensity of Amide I, Amid II, protein structural α‐helix and β‐sheet, and their ratios. The rumen degradation kinetics were determined using in situ techniques with four rumen‐canulated lactating dairy cows. The intestinal digestion was evaluated using a three‐step in vitro technique with 12 h preincubation. The experiment was an randomized complete block design. The data were analysed using the mixed‐model procedure of the Statistical Analysis System. The results showed that the interconnection between rumen degradation kinetics, intestinal digestion and true nutrient supply to dairy cows and protein‐related chemical functional group spectral features could be revealed by ATR‐FTIR with univariate and multi‐variate spectral analyses. These findings indicate that ruminant relevant nutritive value of cool‐season oats could be rapidly evaluated and predicted using oat‐specific functional group spectral characteristics which could be obtained by a non‐distractive bioanalytical tool of ATR‐FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

Ecosystem restoration is a critical conservation strategy, especially for increasing resilience and resistance to climate change. Current restoration efforts that convert reclaimed agricultural land to native tallgrass prairies typically focus on aboveground communities, but it can take decades to restore soil microbial biodiversity and function using these strategies, if they recover at all. This incomplete restoration can have detrimental impacts on longer-term restoration goals, such as supporting late-successional plant species and facilitating soil carbon sequestration. Soil microorganisms are key components in determining the fate of organic material that enters the soil. They mediate decomposition rates and contribute to plant-microbe-soil interactions, produce microbial biomass, necromass, and metabolic products, and physically protect soil carbon through aggregation. Interactions with plants and controls over soil carbon vary widely depending on the specific microbial taxa present, their physiology, their functional capabilities, and their responses to environmental stressors. Thus, the ability for new restorations, prairie conservation corridors, and prairies planted in marginal lands to act as carbon sinks and help balance greenhouse gas emissions can depend on the success of microbial restoration. Next-generation sequencing approaches can support novel methods for evaluating existing restoration practices and developing microbially focused management strategies. This review summarizes the growing body of literature describing microbially focused tallgrass prairie restoration and considers when and how integrating next-generation sequencing approaches into management efforts can be beneficial. We provide a roadmap for future restoration efforts where microbial ecologists, restoration ecologists, and land managers can work together to meet their goals to promote climate-ready restored ecosystems. [ABSTRACT FROM AUTHOR]

Invasive plant species' success may be a result of allelopathy, or the release of secondary metabolites that are harmful for surrounding plant species. Allelopathy can be mediated through the abiotic environment by chemical sorption or transformation, so the substrate on which interactions occur can lead to differential outcomes in allelopathic potential. One aggressive invader, Pyrus calleryana, has become dominant in many ecosystems throughout Eastern US, and has reduced the abundance of native species where it invades. Thus, our goal was to identify if P. calleryana had allelopathic potential by testing the impact of leaf and flower leachate on gemination of six common grassland species (three grasses and three forbs) in either sterilized sand or field collected soils. Germination of five out of six tested species was reduced by P. calleryana leaf litter, with weaker impacts from flower leachate. This suggests that allelopathy is one mechanism driving the success of P. calleryana and that allelopathic effects may change with plant phenology. For instance, P. calleryana has late leaf senescence in the fall and copious blooming in the spring that may elongate the timeframe that allelopathic inhibition can occur. Further, germination was higher in sand than in soil, suggesting that the context of the abiotic environment can mediate this relationship. In our study, two grass species that could be overabundant in restored grasslands had higher germination rates in soil than sand and one was not altered by P. calleryana suggesting that this relationship could further promote the overabundance of grass species. Taken together, P. calleryana likely inhibits the germination of native species where it invades, but there is context dependency of this relationship with both soil chemistry and seasonality. [ABSTRACT FROM AUTHOR]

Purpose: Climate change may alter interactions between plants and their associated soil microbial communities, including microbe-mediated plant-soil feedbacks (PSF). If PSF influence plant performance and abundance in natural communities, climate-induced changes in soil communities might affect local extinction. Here, we examine whether warming-induced shifts in plant-soil interactions are associated with local species loss in tallgrass prairie. Methods: We conducted a traditional two-phase PSF experiment. In phase 1, phylogenetic pairs of locally extinct and extant prairie species were grown under ambient or elevated temperature conditions in the field. In phase 2, soil microbial communities were collected from below those plants and inoculated onto conspecific and heterospecific seedlings grown in the greenhouse. We compared warming effects on plant performance in soil conditioned by locally extinct and extant species as well as net-pairwise PSF between phylogenetic pairs. Results: Locally extinct prairie species were more sensitive to soil biota than extant species, generally performing better when grown in soils cultivated by certain extant species. Meanwhile, extant species were more responsive to warming effects on soil communities than locally extinct species, although the direction and magnitude of temperature effects varied across species. We detected no significant overall effects of warming on net-pairwise PSF. Conclusion: These findings suggest that soil biota might have affected historical plant species losses via negative effects of locally extinct species' soil on their own growth. Warming-induced shifts in soil communities might influence extant prairie species' performance under climate change, indicating a need to consider plant–microbe interactions in future prairie conservation efforts. [ABSTRACT FROM AUTHOR]

As anthropogenic factors continue to degrade natural areas, habitat management is needed to restore and maintain biodiversity. However, the impacts of different habitat management regimes on ecosystems have largely focused on vegetation analyses, with limited evaluation of downstream effects on wildlife. We compared the effects of grassland management regimes (prescribed burning, cutting/haying, or no active management) on rodent communities and the viruses they hosted. Rodents were trapped in 13 existing grassland sites in Northwest Arkansas, USA during 2020 and 2021. Rodent blood samples were screened for antibodies against three common rodent‐borne virus groups: orthohantaviruses, arenaviruses, and orthopoxviruses. We captured 616 rodents across 5953 trap nights. Burned and unmanaged sites had similarly high abundance and diversity, but burned sites had a higher proportion of grassland species than unmanaged sites; cut sites had the highest proportion of grassland species but the lowest rodent abundance and diversity. A total of 38 rodents were seropositive for one of the three virus groups (34 orthohantavirus, three arenavirus, and one orthopoxvirus). Thirty‐six seropositive individuals were found in burned sites, and two orthohantavirus‐seropositive individuals were found in cut sites. Cotton rats and prairie voles, two grassland species, accounted for 97% of the rodents seropositive for orthohantavirus. Our study indicates that prescribed burns lead to a diverse and abundant community of grassland rodent species compared with other management regimes; as keystone taxa, these results also have important implications for many other species in food webs. Higher prevalence of antibodies against rodent‐borne viruses in burned prairies shows an unexpected consequence likely resulting from robust host population densities supported by the increased habitat quality of these sites. Ultimately, these results provide empirical evidence that can inform grassland restoration and ongoing management strategies. [ABSTRACT FROM AUTHOR]

Premise: Fire induces flowering in many plant species worldwide, potentially improving reproductive fitness via greater availability of resources, as evident by flowering effort, and improved pollination outcomes, as evident by seed set. Postfire increases in flowering synchrony, and thus mating opportunities, may improve pollination. However, few studies evaluate fire effects on multiple components of fitness. Consequently, the magnitude and mechanism of fire effects on reproductive fitness remain unclear. Methods: Over multiple years and prescribed burns in a prairie preserve, we counted flowering stems, flowers, fruits, and seeds of three prairie perennials, Echinacea angustifolia, Liatris aspera, and Solidago speciosa. We used aster life‐history models to assess how fire and mating opportunities influenced annual maternal fitness and its components in individual plants. Results: In Echinacea and Liatris, but not in Solidago, fire increased head counts, and both fire and mating opportunities increased maternal fitness. Burned Echinacea and Liatris plants with many flower heads produced many seeds despite low seed set (fertilization rates). In contrast, plants with an average number of flower heads had high seed set and produced many seeds only when mating opportunities were abundant. Conclusions: Fire increased annual reproductive fitness via resource‐ and pollination‐dependent mechanisms in Echinacea and Liatris but did not affect Solidago fitness. The consistent relationship between synchrony and seed set implies that temporal mating opportunities play an important role in pollination. While fire promotes flowering in many plant species, our results reveal that even closely related species exhibit differential responses to fire, which could impact the broader plant community. [ABSTRACT FROM AUTHOR]

Changes in precipitation due to climate change will have consequences for plant and herbivorous insect communities alike. Multiple hypotheses explain how changes in plant diversity and productivity can lead to changes in herbivore community composition. Yet as rainfall patterns change, the bottom‐up effects on the relationships between plant and herbivore communities are less well understood.Using a long‐term rainfall manipulation experiment in a remnant patch of Garry oak (Quercus garryana) savanna, we examined how plant diversity and productivity have responded to variation in soil moisture over 6 years. This highly endangered ecosystem is predicted to experience significantly wetter springs and drier summers by 2080. We also investigated plant‐mediated, indirect effects of manipulated rainfall on herbivore diversity and abundance, drawing on multiple hypotheses describing the relationships between plant and herbivore communities. For example, the more individuals hypothesis predicts that increased plant productivity results in increased herbivore abundance which, in turn, results in increased herbivore diversity.We found that plant productivity was influenced by soil moisture, but the direction and magnitude of the response varied across years, and found no support for plant diversity influencing productivity. We also found that the cover and productivity of grasses increased significantly with increasing precipitation. In addition to a direct negative effect on herbivore diversity, soil moisture had an indirect negative effect on herbivore abundance, via the negative effect of plant productivity on abundance, contradicting the more individuals hypothesis.Synthesis. Our results highlight that not only can drought result in significant reductions in plant productivity in this threatened ecosystem, but that these changes will also result in increases in herbivore abundance. In contrast, where soil moisture is higher, grasses will become more dominant resulting in decreased herbivore abundance. Ultimately, predicting how this system responds to changes in precipitation will depend on the ability to predict whether growing season soil moisture will be consistently drier or wetter in the future, a significant challenge. Going forward, investigating how variation in precipitation due to climate change affects the links between trophic levels, including how herbivores affect plant communities, remains critical for understanding ecosystem processes and stability. [ABSTRACT FROM AUTHOR]

Mounting evidence suggests that plant–soil feedbacks (PSF) may determine plant community structure. However, we still have a poor understanding of how predictions from short‐term PSF experiments compare with outcomes of long‐term field experiments involving competing plants. We conducted a reciprocal greenhouse experiment to examine how the growth of prairie grass species depended on the soil communities cultured by conspecific or heterospecific plant species in the field. The source soil came from monocultures in a long‐term competition experiment (LTCE; Cedar Creek Ecosystem Science Reserve, MN, USA). Within the LTCE, six species of perennial prairie grasses were grown in monocultures or in eight pairwise competition plots for 12 years under conditions of low or high soil nitrogen availability. In six cases, one species clearly excluded the other; in two cases, the pair appeared to coexist. In year 15, we gathered soil from all 12 soil types (monocultures of six species by two nitrogen levels) and grew seedlings of all six species in each soil type for 7 weeks. Using biomass estimates from this greenhouse experiment, we predicted coexistence or competitive exclusion using pairwise PSFs, as derived by Bever and colleagues, and compared model predictions to observed outcomes within the LTCE. Pairwise PSFs among the species pairs ranged from negative, which is predicted to promote coexistence, to positive, which is predicted to promote competitive exclusion. However, these short‐term PSF predictions bore no systematic resemblance to the actual outcomes of competition observed in the LTCE. Other forces may have more strongly influenced the competitive interactions or critical assumptions that underlie the PSF predictions may not have been met. Importantly, the pairwise PSF score derived by Bever et al. is only valid when the two species exhibit an internal equilibrium, corresponding to the Lotka–Volterra competition outcomes of stable coexistence and founder control. Predicting the other two scenarios, competitive exclusion by either species irrespective of initial conditions, requires measuring biomass in uncultured soil, which is methodologically challenging. Subject to several caveats that we discuss, our results call into question whether long‐term competitive outcomes in the field can be predicted from the results of short‐term PSF experiments. [ABSTRACT FROM AUTHOR]

An understanding of interactions between anthropogenic stressors and intrinsic population drivers is needed to fully understand wildlife population declines. Density dependence is a key aspect of population regulation for many species, especially for species that have high reproductive potential, such as amphibians. However, patterns of density dependence have been characterized for only a few species and little work has evaluated how density‐dependent interactions may be altered by anthropogenic stressors. We combined the results of a mesocosm experiment with demographic population modeling to investigate how the conversion of native prairie to agricultural grasslands dominated by Tall Fescue grass (Lolium arundinacea) affected larval density dependence and adult population size of an imperiled amphibian, Lithobates areolatus (Crawfish Frog). Overall, density dependence was overcompensatory, suggesting that L. areolatus exhibits scramble competition as larvae. Both vegetation treatments had low survival at high densities, but more individuals survived to metamorphosis at moderate densities in Fescue treatments compared to Prairie treatments. We evaluated the implications of our experimental results using a stochastic density‐dependent matrix population model to project long‐term population dynamics. Simulated populations breeding in Fescue‐dominated wetlands had a more variable population size and up to 400% higher probability of quasi‐extinction within 200 years, compared to populations breeding in ponds with prairie vegetation. Without varying density in experimental treatments and using mathematical models to project emergent population dynamics, our mesocosm experiment results would have suggested a slightly positive effect of Fescue grass on amphibian development and survival. Vegetation changes surrounding breeding wetlands might play an important role in the decline of amphibian populations persisting in low‐intensity agricultural areas. [ABSTRACT FROM AUTHOR]

The development and assessment of Piedmont upland grassland restoration efforts is hampered in part by continued challenges in identifying immature individuals of three associated pines, Pinus echinata, P. taeda, and P. virginiana, the penultimate of which is thought alien to the system. To help fill this gap, we studied three quantitative and 25 qualitative characters in 174, 2- to 5-year-old saplings in managed stands in Durham County (North Carolina) and 169 herbarium specimens of mature individuals from 94 Piedmont counties from Georgia to Virginia. Although mean short-shoot needle and fascicle sheath lengths differed significantly between lifestage classes of the three species (F8,335=185, p<0.0001 and F8,335=173.5, p<0.0001, respectively), there was substantial range overlap, likely contributing to diagnostic confusion in the field when existing keys are applied. For example, needle length ranges of all lifestage classes of all species overlapped with those of mature P. echinata and 2-year-old P. virginiana. In addition, at the apex of the previous season's growth, 2-year-old saplings of P. echinata and P. virginiana exhibited needles either predominantly or in higher percentages of threes, than the contrasting described preponderance of pairs for mature individuals. Of the 25 qualitative characters evaluated, we found (1) absence of decurrency glaucescence distinguishes 2- to 5-year-old saplings of P. taeda from P. echinata and P. virginiana, and (2) absence of stomatal plugs distinguishes P. virginiana from the others. A diagnostic key to saplings is provided. [ABSTRACT FROM AUTHOR]

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Summary: Shifts in flowering phenology are important indicators of climate change. However, the role of precipitation in driving phenology is far less understood compared with other environmental cues, such as temperature.We use a precipitation reduction gradient to test the direction and magnitude of effects on reproductive phenology and reproduction across 11 plant species in a temperate grassland, a moisture‐limited ecosystem. Our experiment was conducted in a single, relatively wet year. We examine the effects of precipitation for species, functional types, and the community.Our results provide evidence that reduced precipitation shifts phenology, alters flower and fruit production, and that the magnitude and direction of the responses depend on functional type and species. For example, early‐blooming species shift toward earlier flowering, whereas later‐blooming species shift toward later flowering. Because of opposing species‐level shifts, there is no overall shift in community‐level phenology.This study provides experimental evidence that changes in rainfall can drive phenological shifts. Our results additionally highlight the importance of understanding how plant functional types govern responses to changing climate conditions, which is relevant for forecasting phenology and community‐level changes. Specifically, the implications of divergent phenological shifts between early‑ and late‐flowering species include resource scarcity for pollinators and seed dispersers and new temporal windows for invasion. [ABSTRACT FROM AUTHOR]

In the American Midwest, grasslands are highly diverse, endangered ecosystems that require conservation and restoration because they face the threat of plant species invasions. Pyrus calleryana (Decne.; Rosaceae) is a particularly problematic invasive tree in these ecosystems and relatively little is known about the factors that dictate its success. Landscape features regulate the spread of some invasive plants and may play an important role in dictating the vulnerability of grasslands to P. calleryana invasion. Towards developing a predictive framework for grassland invasion, we performed a fine-scale spatial assessment of invaded and uninvaded prairies to determine if landscape characteristics including proximity to forest edge, roads or residences, plant communities or soil characteristics could be used to predict P. calleryana invasion. We found increased invasion near forest edges, likely due to bird dispersal and optimal foraging habitats. Within invaded prairies, P. calleryana was prevalent where there was lower ground cover by grasses and forbs and where there was limited organic matter but increased soil phosphorus, nitrate and micronutrients. This study could not determine if P. calleryana caused these changes or if it established because these parameters were favorable. Our data also indicated an intriguing relationship of increased species richness in P. calleryana invaded sites, potentially because uninvaded sites were characterized by dominant grasses that may reduce available niche space. Taken together, this work suggests that P. calleryana establishment depends on the relative propagule pressure and niche availability and indicates potential for developing a predictive framework for landscape invasion. [ABSTRACT FROM AUTHOR]

Premise: How the environment influences the distribution of trait variation across a species' range has important implications for seed transfer during restoration. Evolution across environments could influence fitness when individuals are transferred into new environments. Here, we evaluate the role the environment has had on the distribution of genetic variance for traits important to adaptation. Methods: In a common garden experiment, we quantified trait differentiation for populations of Geum triflorum sourced from three distinct ecoregions and evaluated the ability of climate to predict trait variation. Populations were sourced from the Manitoba and Great Lake alvar ecoregions that experience predictable extremes in seasonal water availability and the prairie ecoregion which exhibits unpredictable changes in water availability. Results: Plants sourced from alvar ecoregions exhibited smaller but more stomata and greater intrinsic water‐use efficiency relative to prairie plant populations, supporting the evolution of ecotypic differences. Estimates of standing genetic variance and heritable genetic variation for quantitative traits suggest alvar populations have greater adaptive potential. However, low evolvability suggests all populations likely have limited capacity to evolve in response to environmental change. Conclusions: These results highlight the importance of the environment in influencing the evolution and distribution of genetic differences across populations used as seed sources for restoration. Additionally, these data may inform recommendations for seed transfer across novel environments and our expectations of populations' adaptive potential. [ABSTRACT FROM AUTHOR]

Reference conditions for river bioassessment should be established inside ecoregions. Our objectives were (1) to implement a bioassessment methodology for Uruguayan prairie streams regarding ecoregions and land use and (2) to assess the ecological integrity of streams of the Río Negro basin in Uruguay. Due to logistical constraints, sampling was divided into two collection trips: one including the upper basin in fall 2015 and the other including the lower basin in spring 2016. Basins were analyzed separately due to seasonal and geographical differences. In the streams sampled in fall 2015, conductivity, total nitrogen (TN), and total phosphorus (TP) were higher in sedimentary ecoregions than in crystalline ones, independent on land use. In those sampled in spring 2016, these variables showed the highest values in the ecoregions dominated by agriculture. Eighty percent of the sampled streams presented the impact of cattle in their riparian zone. Discriminant analysis showed a similar composition of macroinvertebrates among ecoregions in 2015, but different composition between land uses. Conversely, in 2016, there were differences among some ecoregions, but not between land uses. Agriculture was correlated with tolerant invertebrates, while natural land use and afforestation were correlated with sensitive ones. The BMWP-Colombia showed the impact of livestock on streams, but in general good water quality, while an index of genera for Uruguay, indicated that all streams are eutrophic, thereby confirming the importance of using different types of metrics. Due to its geographical homogeneity and small size, a smaller number of ecoregions could be defined for stream assessments in the Río Negro basin. [ABSTRACT FROM AUTHOR]

The encroachment of woody plants into grasslands is an ongoing global problem that is largely attributed to anthropogenic factors such as climate change and land management practices. Determining the mechanisms that drive successful encroachment is a critical step towards planning restoration and long‐term management strategies. Feedbacks between soil and aboveground communities can have a large influence on the fitness of plants and must be considered as potentially important drivers for woody encroachment. We conducted a plant–soil feedback experiment in a greenhouse between eastern redcedar Juniperus virginiana and four common North American prairie grass species. We assessed how soils that had been occupied by redcedar, a pervasive woody encroacher in the Great Plains of North America, affected the growth of Andropogon gerardi, Schizachyrium scoparium, Bromus inermis, and Pascopyrum smithii over time. We evaluated the effect of redcedar on grass performance by comparing the height and biomass of individuals that were grown in live or sterilized conspecific or redcedar soil. We found redcedar created a negative plant–soil feedback that limited the growth of the cool season grasses B. inermis and P. smithii, reducing their overall biomass by >60%. These effects were found in both live and sterilized redcedar soils. In live soils, some growth suppression can be attributed to the negative effects of soil microbes. The limitation of grass growth in sterile soils indicates redcedar may exude an allelochemical into the soil that limits grass growth. Our results demonstrate that plant–soil feedback created by redcedar inhibits the growth of certain grass species. By creating a plant–plant interaction that negatively affects competitors, redcedars increase the probability of seedling survival until they can grow to overtop their neighbors. These results indicate plant–soil feedback is a mechanism of native woody plant encroachment which could be important in many systems yet is understudied. [ABSTRACT FROM AUTHOR]

Certain traits, including those that make species more vulnerable to consumption by predators, may make species inherently susceptible to population declines and local species loss (i.e. extirpation). To examine whether small mammal and arthropod granivory is a mechanism of community change via association with extirpation events, we studied seed predation on six phylogenetically paired extirpated and extant species from Kalamazoo, Michigan, using a seed removal experiment in a restored prairie. We also examined differences in granivore preferences for seed traits (seed mass, water content, C:N content) and differences in seed traits between extirpated and extant taxa. Granivory was independent of extirpation status but was affected by seed traits. Small mammals consumed more seeds than arthropods and preferentially consumed large seeds, while arthropods consumed small seeds and those with higher C:N ratios (lower nitrogen content). Extirpated and extant taxa did not differ in seed traits, perhaps explaining why they did not differ in granivory. Granivory was phylogenetically conserved, suggesting that certain plant families are more susceptible to granivores than others. This study indicates that granivory varies across species and seed traits in a prairie restoration, but does not likely influence extirpation in this system. Understanding granivore preferences may help managers predict establishment success for rare or extirpated species with particular traits being introduced into prairie restorations. [ABSTRACT FROM AUTHOR]

Extinctions are predicted to rise by an order of magnitude over the next century. Although contemporary documented extinctions are uncommon, local extirpations likely provide hints about global extinction risks. Comparing responses to global change of locally extinct versus extant species pairs in a phylogenetic framework could highlight why certain species are more vulnerable to extinction than others and which anthropogenic changes are most relevant to their decline. As anthropogenic changes likely interact to affect population declines, demographic studies partitioning the effects of multifactorial stressors are needed but remain rare. I examine demographic responses to nitrogen addition and deer herbivory, two major drivers of species losses in grasslands, in experimental reintroductions of 14 locally extinct and extant confamilial native plants from Michigan prairies. Nitrogen consistently reduces survival, especially in locally extinct species, and growth of locally extinct species benefits less from nitrogen than growth of extant species. Nitrogen reduces population growth rates, largely via reductions in survival. Deer herbivory, meanwhile, had inconsistent effects on vital rates among species and did not affect population growth. Nitrogen and herbivory rarely interacted to affect vital rates. These results link community-level patterns of species loss under nitrogen addition to the population-level processes underlying those losses. [ABSTRACT FROM AUTHOR]

We investigated the effects of pipeline construction and environmental factors on the occurrence and characteristics of the endangered plant Halimolobos virgata (Nutt.) O.E. Schultz. The plants were surveyed from 2007 to 2016 at three sites along the Keystone Pipeline in southern Alberta, Canada. Plant height, number of flowers and siliques, as well as microhabitat and climate data were collected up to 300 m away from the pipeline. Pipeline construction and distance had no effect on plant numbers or physical characteristics, with occurrences increasing markedly over time. Greater litter cover and depth and spring precipitation were associated with plant height and number of flowers and siliques. Vegetation cover was negatively correlated with H. virgata cover; however, plant height and number of flowers and seed pods were positively influenced by graminoid cover. The highest occurrences of H. virgata coincided with the driest and wettest years, and higher winter and spring temperatures. Some of this pattern can be attributed to the plant's annual, biennial, and short perennial life forms, which may overlap and create a temporary exponential growth rate for an annual plant under ideal conditions. This research highlights the importance of understanding a species' life history for the development of effective conservation and recovery strategies. [ABSTRACT FROM AUTHOR]

Electric powerline corridors are informal green spaces that encompass large areas of land and have the potential to support biodiversity in urban and suburban landscapes. However, the extent to which these corridors provide novel habitats compared to the surrounding landscape is unclear. Biodiversity in corridors is often compared to that of "natural" habitats despite the fact that the corridors are subject to frequent vegetation management. In urban and suburban landscapes, residential yards may provide a more appropriate comparison because they are a dominant type of green space and are also characterized by frequent vegetation management. We conducted a study of the biodiversity in suburban powerline corridors in northern Illinois, USA, and compared it to the biodiversity found in nearby residential yards. Our goal was to determine whether powerline corridors added ecological value to these suburban landscapes. We included three different management styles of powerline corridors: (1) frequently mowed and kept as lawn, (2) brush mowed on a five-year cycle ("old-field"), and (3) restored and/or maintained as native prairie. We measured the species richness and composition of plants, birds, and insect pollinators in corridors and yards. The corridor management types and comparison yards differed significantly in the richness of all three taxa, with old-field and/or prairie sites having greater species richness than mown corridors and/or comparison yards. Community composition also differed by management category. While the species richness of old-field sites tended to be high, prairie sites generally had more species of conservation interest. Our study shows that both old-field- and prairie-managed powerline corridors add habitat value to Midwestern U.S. suburban landscapes by providing alternative habitat types that support many species. Nonetheless, we suggest that managers looking to specifically support native and/or grassland specialist species in this region should manage sites as prairies when possible. [ABSTRACT FROM AUTHOR]

Historically, grasslands with limited tree presence were embedded in a matrix of predominantly open oak and pine forests in the eastern United States. These open ecosystems mostly have been lost to other land uses, particularly agriculture, and also to closed forests under fire exclusion because frequent surface fire prevents tree encroachment. We located the potential extent of eastern fire‐maintained grasslands by applying the random forests and C5.0 classifiers to determine the relationship between mapped areas of historical grasslands and topography and wind speed, which are proxies for surface fire frequency. A generalized ruleset was that fire‐maintained grasslands occurred at roughness values of less than 95, or flatter sites, and wind speeds ≥3.4 m s−1, which created large fire compartments. Potential grasslands covered 27 million ha, or 14% of the 200 million ha of the eastern United States, although these fire‐maintained locations also may have been savannas or open woodlands historically. Currently, potential grassland locations are 40% crops, 25% pasture, 18% forests, and 13% developed land, with about 1.5% each of herbaceous upland vegetation, herbaceous wetlands, and shrublands. According to historical accounts, fire‐maintained grasslands generally transitioned to dense young tree growth within a 20‐year interval after fire exclusion; in Kentucky, the transition transpired during the periods 1790–1810 or 1810–1830, but dates vary with Euro‐American settlement time. Finding the forgotten grasslands of the eastern United States, with this mechanistic approach to estimate fire disturbance, is an important first step for recovering and managing eastern grassland biodiversity. [ABSTRACT FROM AUTHOR]

Wetland drainage has been pervasive in the North American Prairie Pothole Region. There is strong evidence that this drainage increases hydrological connectivity of previously isolated wetlands and, in turn, streamflow response to precipitation. It can be hard to disentangle the role of climate from the influence of wetland drainage in observed streamflow records. In this study, a basin classification-based virtual modelling approach is described that can isolate these effects on runoff regimes. Three knowledge gaps were addressed. First, it was determined that the spatial pattern in which wetlands are drained has little influence on how much the runoff regime was altered. Second, no threshold could be identified below which wetland drainage has no effect on the streamflow regime, with drainage thresholds as low as 10 % by area were evaluated. Third, wetter regions were less sensitive to drainage as they tend to be better hydrologically connected even in the absence of drainage. Low flows were the least affected by drainage. During extremely wet years, runoff depths could double as the result of complete wetland removal. Simulated median annual runoff depths were the most responsive, potentially tripling under typical conditions with the high rates of wetland drainage. As storage capacity is removed from the landscape through wetland drainage, the size of the storage deficit of median years begins to decrease and to converge on those of the extreme wet years. Model simulations of flood frequency suggest that because of these changes in antecedent conditions, precipitation that once could generate a median event with wetland drainage can generate what would have been a maximum event without wetland drainage. The advantage of the basin classification-based virtual modelling approach employed here is that it simulated a long period that included a wide variety of precipitation and antecedent storage conditions across a diversity of wetland complexes. This has allowed seemingly disparate results of past research to be put into context and finds that conflicting results are often only because of differences in spatial scale and temporal scope of investigation. A conceptual framework is provided that shows, in general, how annual runoff in different climatic and drainage situations will likely respond to wetland drainage in the Prairie Pothole Region. [ABSTRACT FROM AUTHOR]

The quantity of grass-root exudates varies by season, suggesting temporal shifts in soil microbial community composition and activity across a growing season. We hypothesized that bacterial community and nitrogen cycle-associated prokaryotic gene expressions shift across three phases of the growing season. To test this hypothesis, we quantified gene and transcript copy number of nitrogen fixation (nifH), ammonia oxidation (amoA, hao, nxrB), denitrification (narG, napA, nirK, nirS, norB, nosZ), dissimilatory nitrate reduction to ammonia (nrfA), and anaerobic ammonium oxidation (hzs, hdh) using the pre-optimized Nitrogen Cycle Evaluation (NiCE) chip. Bacterial community composition was characterized using V3-V4 of the 16S rRNA gene, and PICRUSt2 was used to draw out functional inferences. Surprisingly, the nitrogen cycle genes and transcript quantities were largely stable and unresponsive to seasonal changes. We found that genes and transcripts related to ammonia oxidation and denitrification were different for only one or two time points across the seasons (p < 0.05). However, overall, the nitrogen cycling genes did not show drastic variations. Similarly, the bacterial community also did not vary across the seasons. In contrast, the predicted functional potential was slightly low for May and remained constant for other months. Moreover, soil chemical properties showed a seasonal pattern only for nitrate and ammonium concentrations, while ammonia oxidation and denitrification transcripts were strongly correlated with each other. Hence, the results refuted our assumptions, showing stability in N cycling and bacterial community across growing seasons in a natural grassland. [ABSTRACT FROM AUTHOR]

Occupancy models have been underused in multispecies plant studies. We evaluated the effectiveness of occupancy models to document impacts of management on grassland plant species populations in a pilot study. The study was designed to answer three questions: (1) From a list of 44 plant species, how many will have sufficient frequency to be analyzed? (2) Within a single site, which factor (sampling year or unit) influences occupancy and detection of each plant species? (3) How does the number of plots and visits affect the number of species with sufficient frequency for analysis? In 2012 and 2013, occupancy and detection probabilities of 44 plant species were assessed using permanently marked plots on two different grassland sites. Within each site, a fire and grazing managed unit and a burn‐only control unit were used to test the efficacy of occupancy modeling for multiple plant species and study design. Four of the 44 species had sufficiently high known presence (π) on both sites and years to be analyzed. There was little evidence to support that occupancy was different between years, despite very different weather patterns. There was support that occupancy was different in the burned and grazed unit compared with the control for Rhus copallinum L. Detection was highest (≥0.8) for R. copallinum, while the other species analyzed varied. In 2012, eight species had sufficient π for analysis. In 2013, 12 species had sufficient π for analysis. Occupancy models can be useful for investigating multiple plant species; however, a priori investigation of species' distribution is necessary to ensure species can be analyzed. Detection of plants was never 1, and therefore, detection should continue to be incorporated in plant population models, regardless of modeling technique. [ABSTRACT FROM AUTHOR]

High heterogeneity in the spatial distribution of soil organic carbon (SOC) in grasslands causes uncertainty in estimating its content and storage. In this study, we investigated the spatial distribution of SOC content and storage in the prairies of southern Alberta, Canada, and how it is affected by land use such as irrigated cropping and other environmental conditions such as cattle grazing, slope landscape position and dominant plant species. The mean SOC content was determined to be 11.5 g kg–1 (range: 8.9 to 22.4 g kg–1) in the 0–10 cm layer and 6.8 g kg–1 (range: 4.0 to 13.3 g kg–1) in the 10–30 cm layer; mean SOC storage was 1.59 kg C m–2 (range: 1.23 to 2.78 kg C m–2) in the 0–10 cm layer and 2.07 kg C m–2 (range: 1.21 to 3.62 kg C m–2) in the 10–30 cm layer. The SOC content was significantly affected by slope position in both the 0–10 and 10–30 cm layers, in the following order: bottom >middle > top position. Moreover, SOC storage was higher in sites dominated by shrubs than graminoid/forb communities. Thus, SOC content and storage had distinctly clustered spatial patterns throughout the study area and were significant differences between the 0–10 and 10–30 cm soil layers. Prior land‐use change from arid grassland to irrigated cropland increased SOC content and storage in bulk soils. [ABSTRACT FROM AUTHOR]

Increasing nitrogen deposition threatens many grassland species with local extinction. In addition to the direct effects of nitrogen deposition, nitrogen can indirectly affect plant populations via phenotypic shifts in plant traits that influence plant susceptibility to herbivory. Here, I test how herbivory varies across an experimental nitrogen gradient and whether differences in susceptibility to herbivory might explain patterns of local species loss. Specifically, I examine how increasing nitrogen availability in a restored prairie influences leaf traits and subsequent herbivory (by leaf-chewers like insects/small mammals versus deer) and the severity of herbivore damage on confamiliar pairs of extirpated versus extant species from Michigan prairies. Nitrogen increased herbivory by both leaf-chewers and deer as well as herbivore damage (proportion of leaves damaged). Leaf hairiness and specific leaf area affected patterns of herbivory following nitrogen addition, although patterns varied between extirpated vs. extant taxa and herbivory type. Nitrogen increased leaf hairiness. At high levels of nitrogen addition, hairy extant plants experienced less herbivory and damage than smooth-leaved plants. In contrast, hairy extirpated plants were more likely to experience leaf-chewer herbivory. Extirpated plants with thin leaves (high specific leaf area) were less likely to experience leaf-chewer herbivory; the opposite was true for extant species. Generally, extant species experienced more herbivory than locally extirpated species, particularly at high levels of nitrogen addition, suggesting that increasing herbivory under nutrient addition likely does not influence extirpation in this system. This study suggests that trait-mediated responses to nitrogen addition and herbivory differ between extant and extirpated species. [ABSTRACT FROM AUTHOR]

Urea can degrade water quality and stimulate toxic phytoplankton in P-rich lakes, yet little is known of its sources, abundance, or transportation in lotic systems, particularly within the Northern Great Plains. We measured physico-chemical parameters biweekly during May–September 2010–2012 at 16 stations along a 250 km lotic continuum to quantify spatial and temporal variation in urea concentrations and discharge, and to identify potential regulatory processes. Urea concentrations were similar to those in regional prairie lakes (range 5.2–792.1, median 78.6 μg N L−1) with variable seasonal mean (± SD) concentrations (96.6 ± 96.1 μg N L−1) and fluxes (4.22 × 105 ± 257.6 μg N s−1). Landscape analysis with generalized additive models explained 68.3% of deviance in urea concentrations, with high temporal variability predicted mainly by positive relationships with nutrient content and chlorophyte abundance, but not temperature, dissolved organic matter, bacterial abundance, or urban effluent. Seasonal analysis revealed that during spring, urea content was correlated negatively with leguminous forage cover (% area) and positively with stream discharge, oilseed and cereal crops, and shrubs or deciduous plants, while during summer, urea concentrations were correlated negatively with discharge and leguminous crop cover, as well as nutrient levels. Mean porewater urea concentrations (528.5 ± 229.8 μg N L−1) were over five-fold greater than stream concentrations, suggesting that hyporheic production may offset declining influx from terrestrial sources during summer. We conclude that urea may be ubiquitous in eutrophic prairie streams and that management of its export from land may reduce detrimental effects on downstream lakes. [ABSTRACT FROM AUTHOR]

This article overviews the prairie and tree planting tool or PT2 (1.0), an online GIS-based decision support tool for landowners interested in exploring opportunities to plant prairie or trees in and around their farm fields for conservation or production purposes. PT2 1.0 can be found online at: https://pt2.nrem.iastate.edu/. With the PT2 (1.0) users locate farm fields of interest in an online aerial photograph and mapping geographic information system (GIS). Users explore areas they are considering for prairie or tree cover by examining different data layers: soil maps, 2-foot contour topography maps, LiDAR hillshade maps, and a map of current land values based on estimated land rent. Users then utilize scaled dimensional drawing tools to measure and delineate areas of interest for planting trees and or prairie. Once an area is delineated, users select from drop-down menus prairie seed mixes or woody species that are suitable for the soils present, and users can select basic long-term management options. PT2 (1.0) estimates total annualized costs for tree or prairie establishment, long-term management, and opportunity costs (based on area weighted expected soil rent), and factors in the potential benefit of utilizing government cost-share programming, e.g., Environmental Quality Incentive Program or the Conservation Reserve Program. Key data layers are currently functional in Iowa, likewise the financial data underlying the cost analysis are specific to Iowa. PT2 (1.0) is, however, open source and open code and guidance is provided regarding how to access and adapt the data for use in other states. [ABSTRACT FROM AUTHOR]

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