Search

The Canadian Prairies are one of the major agricultural regions of the world in terms of cereal, oilseed and pulse crop production. With few exceptions, major insect pests like grasshoppers, flea beetles, Lygus bugs, wireworms and pea leaf weevils are controlled with insecticides. Wheat stem sawfly is managed through host plant resistance and endemic natural enemies, whereas cereal leaf beetle is managed through classical biological control. Large farms and short growing seasons in the region present logistical challenges to adopt time intensive pest management systems such as trap crops. Therefore, there is no adoption of trap crops even though some research has demonstrated their potential. In this article we present a brief overview of the pest status and management, and we summarize research on trap crops in the Prairies Ecozone and adjacent ecoregions. We conclude the review with some innovative research ideas to make trap cropping a more appealing pest management system in our quest to reduce dependency on chemical insecticides and increase the environmental resilience of Canadian agroecosystems. [ABSTRACT FROM AUTHOR]

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]

Insect declines have become pronounced in prairie ecosystems, particularly in areas of agricultural intensification. Non-target pesticide exposure has been raised as a key concern for prairie remnant health. Over seven years, we screened grass and soil samples for the presence and quantities of hundreds of pesticides from five prairies in Minnesota and South Dakota that are designated as Critical Habitat for two globally endangered butterflies: Poweshiek skipperling and Dakota skipper. We documented dozens of pesticides across all sites and years on their larval host grasses. Interiors of prairies were not less likely to have detectable pesticides than along prairie-agriculture edges. Broad-spectrum organophosphate and pyrethroid insecticides were common in late season. Chlorpyrifos quantities were higher at sites where both endangered species have been extirpated. Neonicotinoid insecticides, which have been frequently attributed to declines in insect pollinators, did not present a significant exposure signal in these prairie habitats. Few pesticides were detected in soil or early season grass samples. The prevalence and quantities of pesticides we observed are likely underestimates, and additional research is needed on the landscape of risk at small and large scales. Implications for Conservation: Protected prairies are not immune to the risk of pesticide exposure, which may impact efforts to re-establish lost populations of imperiled prairie insects, including endangered butterflies. [ABSTRACT FROM AUTHOR]

The article discusses the lack of attention given to belowground plant organs and their functions by researchers. It highlights the various functions of these organs, such as resource acquisition, clonal multiplication, and carbon sequestration, that are not well understood due to their belowground position and the difficulty of studying them. The article introduces a special issue of the journal Folia Geobotanica dedicated to belowground plant organs, featuring seven papers from four continents covering a range of topics. These include the role of belowground bud bearing organs in response to disturbance and competition, the diversity of belowground storage and bud bearing organs in different regions, methods for manipulating root architecture, and the discovery of rare and interesting morphological traits. The article concludes by expressing hope that the special issue will inspire further research and interest in belowground plant organs. [Extracted from the article]

Whole-plant hydraulics provide important information about responses to water limitation and can be used to understand how plant communities may change in a drier climate when measured on multiple species. Here, we measured above- and belowground hydraulic traits in Cornus drummondii, an encroaching shrub within North American tallgrass prairies, and Andropogon gerardii, a dominant C4 grass, to assess the potential hydraulic responses to future drought as this region undergoes woody expansion. Shelters that reduced precipitation by 50% and 0% were built over shrubs and grasses growing in sites that are burned at 1-year and 4-year frequencies. We then measured aboveground (Kshoot), belowground (Kroot), and whole-plant maximum hydraulic conductance (Kplant) in C. drummondii and Kroot in A. gerardii. We also measured vulnerability to embolism (P50) in C. drummondii stems. Overall, we show that: (1) A. gerardii had substantially greater Kroot than C. drummondii; (2) belowground hydraulic functioning was linked with aboveground processes; (3) above- and belowground C. drummondii hydraulics were not negatively impacted by the rainfall reductions imposed here. These results suggest that a multi-year drought will not ameliorate rates of woody expansion and highlight key differences in aboveground and belowground hydraulics for dominant species within the same ecosystem. [ABSTRACT FROM AUTHOR]

Woody encroachment—the spread of woody vegetation in open ecosystems—is a common threat to grasslands worldwide. Reversing encroachment can be exceedingly difficult once shrubs become established, particularly clonal species that resprout following disturbance. Single stressors are unlikely to reverse woody encroachment, but using multiple stressors in tandem could be successful in slowing or reversing encroachment. We explored whether increasing fire frequency in conjunction with multi-year drought could reduce growth and survival of encroaching shrubs in a tallgrass prairie in northeastern Kansas, USA. Passive rainout shelters (~ 50% rainfall reduction) were constructed over mature clonal shrubs (Cornus drummondii) and co-existing C4 grasses in two fire treatments (1-year and 4-year burn frequency). Leaf- and whole-plant level physiological responses to drought and fire frequency were monitored in shrubs and grasses from 2019 to 2022. Shrub biomass and stem density following fire were unaffected by five years of consecutive drought treatment, regardless of fire frequency. The drought treatment had more negative effects on grass leaf water potential and photosynthetic rates compared to shrubs. Shrub photosynthetic rates were remarkably stable across each growing season. Overall, we found that five consecutive years of moderate drought in combination with fire was not sufficient to reduce biomass production or stem density in an encroaching clonal shrub (C. drummondii). These results suggest that moderate but chronic press-drought events do not sufficiently stress encroaching clonal shrubs to negatively impact their resilience following fire events, even when fire frequency is high. [ABSTRACT FROM AUTHOR]

Meteorological data are essential in precision agriculture in the Canadian Prairies and are often associated with spatiotemporal discontinuity and scarcity. Reanalysis data products aim to address this challenge and have recently gained popularity. The European Centre for Medium-Range Weather Forecasts' ERA5, and its high-resolution land component, ERA5-Land, are two reanalysis datasets that provide hourly estimates of many climate variables globally. This paper focuses on evaluating the performance of ERA5 and ERA5-Land over the Canadian prairies, utilizing data from 109 weather stations situated in southern Manitoba, Canada. Various variables are investigated at daily, monthly, and annual aggregation periods, including air temperature, ground temperature, soil water content, wind speed, precipitation, and evaporation. The datasets are evaluated regarding seasonal bias and spatial distribution of errors over the study area. Regression parameters are also presented to address the biases. Among the investigated variables, air temperature and wind speed exhibit the lowest errors. The evaluation further reveals an overall tendency to overpredict ground temperatures and precipitation while underpredicting evaporation. Based on these findings, the ERA5 and ERA5-Land datasets hold significant potential in applications such as climate-smart agriculture, energy demand analysis, assessing renewable energy resources, and facilitating sustainable urban development. [ABSTRACT FROM AUTHOR]

Peak spring streamflow is triggered in the Canadian prairies with complex generation mechanisms. The study characterizes the generation mechanisms of peak spring streamflow and models the basin response to changing hydro-climatic basin conditions. Key hydro-climatic basin descriptors were defined and used to set criteria for identifying different flood generation mechanisms, associated with the historical floods at 109 Canadian prairie basins. The temporal and spatial heterogeneity of these mechanisms were investigated, and a t-copula model was used to model the dependence structure between the basin descriptors and peak spring streamflow. The study: (1) suggests seven basin descriptors for characterizing the generation mechanism of peak spring streamflow; (2) discloses four levels of wetness conditions and nine flood generation mechanisms in the Canadian prairies; and (3) highlights the advantages and challenges of probabilistically assessing the basin response (peak spring streamflow) in relevance to historical and hypothetical basin conditions. We deem these results enhance the characterization of flood generation mechanisms in the Canadian prairies and advance the risk estimation of peak spring streamflow. [ABSTRACT FROM AUTHOR]

Climate change is altering biodiversity of ecosystems worldwide by causing shifts in species' home ranges, potential extinctions of species, and Extreme Climatic Events (ECEs), such as hurricanes and extreme temperatures. The purpose of this study was to examine effects of two extreme weather events on butterfly populations in the Gulf Prairies and Marshes ecoregion in Willacy and Kenedy Counties, TX, USA. These weather events occurred during an ongoing study of effects of prescribed burning during summer or winter on butterfly populations. We tested effects of Category 1 Hurricane Hanna by comparing butterfly abundance in the month prior to and following the hurricane (July and August 2020). We tested effects of Winter Storm Uri by comparing butterfly abundance in the three months following the storm (March through May 2021) with abundance during the same period in the previous year (March through May 2020). We measured no effect of the Category 1 hurricane on butterfly populations overall and across all prescribed fire regimes. There was a significant reduction in butterfly abundance following the 2021 winter storm, and effects depended on prescribed fire regime. Our findings indicate that extremely cold temperatures in subtropical regions will likely have greater negative effects on butterfly populations than low-magnitude hurricanes. Implications for insect conservation: With extreme climate events (ECEs) predicted to increase in the future, measures should be taken to provide protection and refugia for butterflies, particularly from prolonged, uncharacteristically low temperatures. Protection includes maintaining undisturbed areas with accumulated plant matter, in preparation for these unpredictable events. [ABSTRACT FROM AUTHOR]

Copyright of Fire Ecology is the property of Springer Nature 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.)

A comparison was made of the supercooling points (SCPs) of questing Dermacentor variabilis adults from two populations located ca. 800 km apart on the Canadian prairies. This is also the first study to examine whether there are seasonal fluctuations in the SCP of questing D. variabilis adults. The SCPs of adult ticks from Lizard Lake Community Pasture, a recently established population in west-central Saskatchewan, varied over spring and summer, with the median SCP warming over time. In addition, the SCPs of ticks from Lizard Lake Community Pasture were significantly higher than those of adult ticks collected from Sandy Hook in Manitoba, a population that has been established for decades. The off-host survival of adults from Sandy Hook between summer and spring has been shown previously to be significantly greater than that of adults from Lizard Lake Community Pasture. The findings of the present study suggest that there may be geographical variation in the SCPs of D. variabilis adults which may be associated with differences in overwinter survival. The relatively low SCPs of questing D. variabilis adults, and the ability of some adults to survive off-host during winter, may be factors contributing to the range expansion of this tick species in Canada. [ABSTRACT FROM AUTHOR]

The eastern spotted skunk (Spilogale putorius) is of increasing conservation concern across its range, with managers requiring information on the species' spatial ecology to design conservation actions. The Florida spotted skunk (Spilogale putorius ambarvalis) is the smallest and least-studied subspecies, with little known about its home range size and movement ecology. We fitted Florida spotted skunks with VHF radio-transmitters and tracked them to diurnal den sites in 2016 and 2017 to estimate home range sizes. We were able to calculate 95% kernel density estimates of home range size for 12 skunks (7 males, 5 females) and found that males had significantly larger (mean ± SE) home range sizes (1.60 km2 ± 0.38) than females (0.36 km2 ± 0.06). Additionally, to gather information on the nightly activity patterns and fine-scale movements of Florida spotted skunks, we fitted skunks with Global Positioning System (GPS) collars in 2017 and successfully retrieved location data from 24 individuals (12 males, 12 females). We tracked GPS-collared skunks over an average of 5.7 days (range = 1–9 days) and a mean of 115.75 locations per skunk (range = 4–223). The mean distance traveled per night for a skunk in our study area was 1874 m (range = 437–3451 m). Mean distance traveled per night was positively influenced by mean nightly temperature, but did not differ significantly by sex, moon illumination, or rainfall. Florida spotted skunks were most active ~ 2 h after sunset and nightly activity declined from that period on. Home range estimates (100% minimum convex polygons) derived exclusively from daytime den locations were significantly smaller than those derived from nighttime locations. Our research advances our understanding of Florida spotted skunk spatial ecology, including the first use of GPS collars on the subspecies, and provides novel information for future ecological comparisons with other populations. Our results suggest that the frequent practice of relying solely on daytime locations when tracking spotted skunks may under-represent their areas of habitat use and might fail to capture important nocturnal foraging areas. [ABSTRACT FROM AUTHOR]

The effects of temperature and relative humidity (RH) on female reproductive output, egg development and larval survival were determined for Rocky Mountain wood ticks (Dermacentor andersoni) from a prairie population (Chin Lakes, Alberta, Canada) near the northern distribution limit of this species. The responses of D. andersoni eggs and unfed larvae to different temperature (25 or 32 °C) and RH (35, 55, 75, 85 or 95%) regimes were compared to our previously published data (Diyes et al. 2021) for a northern prairie population of American dog ticks (Dermacentor variabilis). Oviposition by D. andersoni females took 21–30 days at 25 °C and 95% RH compared to 10–21 days for D. variabilis. The number of eggs laid by female ticks was strongly dependent on their engorgement weight, and D. andersoni females produced more eggs than D. variabilis females of an equivalent body weight. Eggs of D. andersoni took less time to develop at 32 °C than 25 °C with ≥ 85% RH, and hatched faster than those of D. variabilis. Larval survival times declined as temperature increased and RH decreased, but D. andersoni survived longer at 32 °C and ≤ 75% RH than D. variabilis. The interspecific differences in responses to the same temperature and humidity regimes indicate that D. andersoni is xerophilic, whereas D. variabilis is hydrophilic. Hence, 'prairie' populations of the Rocky Mountain wood tick occur in the drier grassland ecoregions but are absent in Aspen Parklands Ecoregion which is located to the north and east of the distributional range of D. andersoni. [ABSTRACT FROM AUTHOR]

Endangered in Canada and the United States, the Poweshiek skipperling's (Oarisma poweshiek (Parker) (Lepidoptera: Hesperiidae)) recovery likely depends on understanding more about its ecology. The characteristics of locations which facilitate various adult activities, such as oviposition and resting, in Manitoba tall grass prairie are unknown. We followed adults in prairie patches to identify locations associated with various behaviours, and subsequently measure vegetative, structural and microclimatic attributes at these microhabitats. Adult skipperlings were observed 34 times resulting in 24 flight tracks and 56 point interactions being recorded. Skipperlings flew almost exclusively in the prairie plant community, with few flights into wetter communities and none in forests. Tracks tended to be tortuous, typical of occupancy in higher-quality habitats. Adult activities appeared to be distributed along a soil moisture gradient: oviposition was associated with the relatively mesic section, resting and/or basking with the drier section, and nectar feeding generally associated with sections throughout the gradient. Adults nectared from a mixture of species during the flight period, consuming nectar from Rudbeckia hirta Linnaeus (Asteraceae) most often. We report previously unknown aspects of O. poweshiek's ecology. Implications for conservation: Our findings describe how adult skipperlings might use sections of prairie with different soil moistures to lay eggs, rest, bask and consume nectar. We visualise approaches to ensure all sections are disturbed during stewardship activities and evaluate the degree to which all facilitative soil moistures are present in candidate (re)introduction sites, for the successful recovery of O. poweshiek. [ABSTRACT FROM AUTHOR]

Demand for energy and the environmental consequences associated with fossil fuel emissions has created a need for alternative energy sources. To avoid conflict over the conversion of existing agricultural land from food production to fuel production, bioenergy crops could instead be cultivated on marginal land. This study compared the performances, biomass yield, tiller density, and lignocellulosic bioenergy feedstock composition of four prairie cordgrass populations with two-row spacings cultivated on a waterlog-prone marginal land, as well as three other bioenergy candidate crops used as controls: big bluestem, M. × giganteus, and switchgrass. Across all populations and spacings, annual biomass yield of prairie cordgrass was 13 Mg ha−1. Row spacing had significant impacts on prairie cordgrass productivity, with higher biomass yields observed in the 45 cm spacing than in the 90 cm spacing. Feedstock composition (cellulose, hemicellulose, ADL, and ash concentration) was not influenced by row spacing and did not deviate from expected values for growth on agricultural lands. However, biomass yields of the control species M. × giganteus and switchgrass planted in 45 cm spacing were higher than the prairie cordgrass. Our results provide evidence that prairie cordgrass could be a good energy crop with comparable biomass yield production to the energy crops M. × giganteus and switchgrass on waterlogged marginal land. [ABSTRACT FROM AUTHOR]

Play Fairway Analysis (PFA) methodology was adapted for geothermal exploration at Camas Prairie, Idaho. Geophysical data, structural and geologic mapping, volcanic rock ages and vent locations, and the distribution of thermal springs and wells all indicated a relatively high geothermal potential along the southern margin of the Prairie. An exploration well (USU Camas-1) was drilled to a depth of 618.3 m to validate the PFA. A permeable zone was encountered at ~ 357.5 m with a maximum measured temperature of ~ 80 °C, which was suppressed following the injection of cold water. A moderate transmissivity of ~ 0.25–1 cm2/s estimated from an injection test as well a seasonal artesian flow at ~ 0.7 L/s corroborate the presence of a permeable zone. The existence of a lacustrine clay seal was confirmed near the bottom of the basin-fill sediment occupying the upper 314 m of the well. Geothermometers suggest the USU Camas-1 well water equilibrated at a reservoir temperature of ~ 120 °C. Based on the locations of both thermal and cold wells, geothermal fluids appear to be flowing upward along one or both of two fault systems. The presence of young basalts and elevated helium isotope ratios suggest that the heat source of Camas Prairie is magmatic. However, the faults may be acting as a conduit for geothermal fluids to rise from great depth without a shallow magmatic source being present. Camas Prairie is a promising area for geothermal development, but the relatively low reservoir temperatures indicate this resource may not be suitable for electric generation. Perhaps the best use would be for heating. [ABSTRACT FROM AUTHOR]

Net primary productivity (NPP) is a key ecosystem function of plant communities. Climate change is expected to affect NPP both directly and indirectly through associated edaphic and plant community factors. Changes in soil nutrients, plant species richness and/or functional group dominance may amplify or counteract direct climatic effects on NPP, and responses may differ above-versus belowground, making it challenging to predict the net effects on NPP. In this study, we manipulated temperature and precipitation at four sites spanning a latitudinal Mediterranean-climate gradient in the Pacific Northwest, USA, and measured aboveground, belowground, and total NPP responses in experimentally assembled prairie plant communities. Using structural equation models, we disentangled the direct effects of climate from its indirect effects through soil nutrient availability and plant community responses. We found that warming, primarily by reducing soil moisture (that is, drying), had a net negative effect on all aspects of NPP, but these negative effects were partially ameliorated by increasing nitrogen and phosphorus availability, as well as changes to the plant community. Specifically, warming, drying, and greater nutrient availability caused species richness to decline, leading to greater dominance by a restricted set of functional groups, which positively affected aboveground NPP. Furthermore, a shift from perennial grass to annual grass dominance increased the ratio of aboveground to belowground NPP. Our results demonstrate that the indirect effects of climate change can help partially buffer the negative direct effects on NPP in Mediterranean-climate prairies. However, increasing soil moisture limitation may still overwhelm the positive effects of such intermediary pathways. [ABSTRACT FROM AUTHOR]

The present paper aims to model statistical structure of heavy-tailed precipitation data. In particular for agricultural purposes in Canadian Prairies, this is essential in many aspects such as assessing and managing risks resulting from the occurrence of unexpected precipitation events. Daily (or weekly) precipitation time series often contain many zeros (on dry days) and also exhibit important characteristics such as heavy-tailedness and volatility clustering. These features make it challenging to develop an effective model from both theoretical and practical viewpoints. In this paper, we propose a dynamic mixture model constructed based on a generalized Gaussian crack distribution with a GARCH specification to take into account the full range of precipitation measurements with a sufficient flexibility to fit both thin- and heavy-tailed data, and stochastic volatility. The method of maximum likelihood estimation with the profile log-likelihood algorithm is illustrated with some simulation studies. The model fitting results on a historical dataset from twelve stations in Canadian Prairies show the applicability of the proposed model. [ABSTRACT FROM AUTHOR]

Periodic assessments of reference condition wetlands are needed to determine changes over time; however, they are rarely conducted. The vegetation from past assessments, 1998 to 2004, was compared to 2016 assessments of 12 reference wetlands in the Missouri Coteau sub-ecoregion of the Prairie Pothole Region using nonmetric multidimensional scaling and permutational multivariate analysis of variance. Analyses indicated the vegetation in the 2016 assessments trended away from the abundance of native highly conservative species as found during the 1998 to 2004 assessments. Instead, the 2016 plant communities trended towards lower abundance of the same native conservative species and higher abundance of non-native species. Both the average coefficient of conservatism values and floristic quality index values significantly declined, supporting the interpretation that reference wetlands were moving towards plant communities with lower abundance of highly conservative species. The assumption that reference wetlands in the Prairie Pothole Region will change little over time is challenged by these findings. Vegetation in refence wetlands within the Prairie Pothole Region is no longer resembles past monitoring and is trending towards a distinct vegetation composition. Future management will need to consider the potential of reference wetlands' vegetation composition moving away from a historic baseline and how this may impact future wetland assessment, especially when vegetation is compared to reference conditions. [ABSTRACT FROM AUTHOR]

The potential nitrogen-fixing bacterial diversity in the rhizospheric soil of the native switchgrass (Panicum virgatum L.) from Tall Grass Prairies of Northern Oklahoma was studied using a partial region of nitrogenase structural gene—nifH. Eleven clone libraries constructed from nifH amplicons gave 407 good-quality sequences. More than 70% of sequences showed similarity of nifH with uncultured bacteria (< 98%). The dominance of sequences affiliated with Deltaproteobacterial nifH was observed, followed by Betaproteobacterial nifH sequences. The nifH gene library was dominated by the genera Geobacter, Rhizobacter, Paenibacillus, and Azoarcus. Sequences affiliated with rhizobia, such as Bradyrhizobium, Methylocystis, Ensifer, etc., were also in the rhizosphere in small numbers. From Deltaproteobacteria, five genera, namely Geobacter, Pelobacter, Geomonas, Desulfovibrio, and Anaeromyxobacter, contributed to 48% of the total sequences suggesting the dominance of group Deltaproteobacteria in the rhizosphere of native switchgrass. Considering the percent similarity of the nifH sequences with cultivated bacteria, this study demonstrated the presence of novel bacterial species in switchgrass rhizospheric soil from Tall Grass Prairie. [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]

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]

Many productive agricultural soils have naturally poor drainage characteristics and may intermittently pond water even where artificial drainage infrastructure is present, especially in topographic depressions. Soil organic carbon (SOC) is often higher in depressions than uplands, but whether temporary ponding increases SOC by suppressing decomposition remains an important knowledge gap. We measured SOC and inorganic C (carbonate) along topographic gradients from tile-drained depressions to adjacent uplands and tested their relationships with hydrological and biogeochemical properties in corn/soybean fields in Iowa, USA, and examined soil respiration and its stable C isotopes (δ13C) by lab incubation. The 0–30 cm SOC concentration was greatest at depression bottoms, as expected, while carbonate C was highest at boundaries between depressions and uplands. However, only carbonate C, not SOC, increased in depressions with increasingly poor drainage (greater ponding duration). Silt + clay content was the strongest positive predictor of SOC, while ponding duration and oxalate-extractable iron were negatively related to SOC in a statistical model (R2 = 0.83). These negative relationships are consistent with suppression of crop biomass production and iron-mediated decomposition in periodically anoxic soil. Soil C/N ratios were similar in depressions and uplands, indicating that plant detritus did not accumulate with ponding. Stable C isotopes of respiration from incubated soils indicated a similar C3/C4 plant mixture in depressions and uplands, consistent with decomposing soybean and corn residues. In contrast, depression soil organic matter had lower δ13C and δ15N values than uplands, more consistent with pre-agricultural prairie plants than crop residues. Accumulation of SOC in these agricultural depressions is more likely explained by erosion than by suppression of decomposition due to temporary ponding. Gaining additional SOC may require fundamental changes in management, or wetland restoration. [ABSTRACT FROM AUTHOR]

Woody encroachment has impacted grassland ecohydrology worldwide, prompting management strategies aimed at woody vegetation removal to prevent or mitigate loss of water yield. We measured stream discharge following sustained cutting of riparian trees (2010–2020) in a native tallgrass prairie (northeastern Kansas, USA). Discharge has declined at this site since the 1980's despite a concurrent increase in precipitation. This decline has been previously attributed to increased transpiration of stream water by riparian vegetation. We used water stable isotopes (δ18O and δ2H) to determine whether riparian grasses, shrubs, and trees primarily used stream/groundwater or soil water. Additionally, we quantified the increase in riparian and non-riparian woody cover (1978–2020) and combined it with sap-flux data to estimate changes in transpirative water loss. Sustained cutting of riparian trees did not result in increased discharge. Rather than stream/groundwater, the largest proportion of water used by riparian trees (Quercus spp.) was deep soil water. Cornus drummondii (clonal woody shrub) used a higher proportion of stream water and had greater overall variability in water-use. Riparian shrub cover increased about 57% from 1978 to 2020. Over the same time period, shrub cover increased about 20% in areas outside the riparian zone, resulting in an estimated 25% increase in daily transpirative water loss. Although stream water use was less than 50% for all riparian zone species, the total increase in shrub cover on this watershed, coupled with higher transpiration rates of shrubs, suggests that these woody species—within and outside the riparian zone—are key contributors to observed declines in stream flow in this system. [ABSTRACT FROM AUTHOR]

This paper undertakes a comparative analysis of Coloured gangs in Cape Town, South Africa, and Indigenous gangs in Canadian Prairie cities—Calgary, Winnipeg, Saskatoon, and others—looking at how members of each engage in street culture. It finds that street cultural participation in both settings is largely a collective response to globally recognizable—yet locally articulated—experiences with joblessness, over-incarceration, racialized poverty, and other forms of structural oppression. The paper uses life history research that was conducted with a sample of 24 gang members in South Africa and with another 53 from cities in Canada. Overall research findings are focused through the individual stories of Gavin and Roddy—research participants from Cape Town and Winnipeg, respectively—to provide personal and contextualized representations of broader key street cultural concepts and processes in each setting. The paper adds to a growing body of gang literature that draws comparisons across national contexts to show how street cultures are similarly used in an attempt to counteract experiences with vulnerability, exclusion, and alienation within distinct cultural contexts, socioeconomic situations, and colonial legacies. [ABSTRACT FROM AUTHOR]

Ecosystems are faced with an onslaught of co-occurring global change drivers. While frequently studied independently, the effects of multiple global change drivers have the potential to be additive, antagonistic, or synergistic. Global warming, for example, may intensify the effects of more variable precipitation regimes with warmer temperatures increasing evapotranspiration and thereby amplifying the effect of already dry soils. Here, we present the long-term effects (11 years) of altered precipitation patterns (increased intra-annual variability in the growing season) and warming (1 °C year-round) on plant community composition and aboveground net primary productivity (ANPP), a key measure of ecosystem functioning in mesic tallgrass prairie. Based on past results, we expected that increased precipitation variability and warming would have additive effects on both community composition and ANPP. Increased precipitation variability altered plant community composition and increased richness, with no effect on ANPP. In contrast, warming decreased ANPP via reduction in grass stems and biomass but had no effect on the plant community. Contrary to expectations, across all measured variables, precipitation and warming treatments had no interactive effects. While treatment interactions did not occur, each treatment did individually impact a different component of the ecosystem (i.e., community vs. function). Thus, different aspects of the ecosystem may be sensitive to different global change drivers in mesic grassland ecosystems. [ABSTRACT FROM AUTHOR]

Ecosystems often experience small-scale disturbances through recreational foot and bike traffic. The intermediate disturbance hypothesis predicts that frequent disturbances in grasslands can negatively impact native species and lead to invasion by disturbance-adapted, non-native species. Disturbance studies often examine intentional or unintended larger scale disturbances, but do not commonly focus on common small-scale disturbances such as those caused by trampling along trails. As such, we were interested in how trail disturbance affects the vegetative growth and reproductive output of in situ native (Danthonia californica Bol. and Stipa pulchra Hitchc.) and invasive (Dactylis glomerata L. and Holcus lanatus L.) perennial bunchgrasses commonly found on California coastal prairies. We measured the basal circumference and seed production of plants located on-trail and off-trail on five coastal prairies in Santa Cruz, CA, USA. We hypothesized that native grasses located on-trail would have lower growth and reproductive output and non-native grasses would be unaffected. We found that native and non-native plants had differences in growth and reproductive output on-trail and off-trail. S. pulchra had lower reproductive potential (via culm sterility) with trail disturbance, whereas both native grasses showed evidence of compensatory growth on-trail. Invasive non-native D. glomerata and H. lanatus growth was unaffected by trail disturbance, but H. lanatus had lower reproductive output on-trail. Results suggest that it may be prudent to restore trails with disturbance tolerant species like D. californica and use less tolerant species like S. pulchra further into the central habitat space. [ABSTRACT FROM AUTHOR]

Cover crops are increasingly being used in ecological restoration projects, and are hypothesized to facilitate establishment of sown species by reducing weed abundances without competing with the target mix. We tested these predictions and examined the role of cover crop species on later species composition and diversity using cover crop seed treatments. Treatments included a fall seeding of one annual (Raphanus sativus or Avena sativa), one biennial (Oenothera biennis), one perennial species (Elymus canadensis), two grass-forb species combinations, or nothing as a control. All plots received the same diverse tallgrass prairie seed mix in March of the following year. Plant communities were sampled through five growing seasons. We found that cover crop treatments influenced community assembly, and that cover crop species varied in their effectiveness at reducing weed abundances, with the perennial grass E. canadensis being especially effective at reducing weeds. After 5 years, treatments were neutral in their effects on species diversity. However, composition of establishing plants (not including the cover crop) differed significantly among cover crop treatments on all sampling dates, indicating that treatments had long-term effects. Plots containing the C3 grass E. canadensis had greater abundance of C3 grasses and forbs, and reduced C4 grass abundance compared to other treatments. Our results indicate that cover crop species differ in their effects on assembling tallgrass prairie communities and that niche modification (i.e., species altering the abiotic environment in a way that favors species that benefit from the alterations) occurs when the cover crop is a perennial grass. [ABSTRACT FROM AUTHOR]

Although much has been written on the topic of social behavior, many terms referring to different aspects of social behavior have become inappropriately conflated and the specific mechanisms governing them remains unclear. It is therefore critical that we disentangle the prosocial and antisocial elements associated with different forms of social behavior to fully understand the social brain. The lateral septum (LS) mediates social behaviors, emotional processes, and stress responses necessary for individuals to navigate day-to-day social interactions. The LS is particularly important in general and selective prosocial behavior (monogamy) but its role in how these two behavioral domains intersect is unclear. Here, we investigate the effects of chemogenetic-mediated LS activation on social responses in male prairie voles when they are 1) sex-naïve and generally affiliative and 2) after they become pair-bonded and display selective aggression. Amplifying neural activity in the LS augments same-sex social approach behaviors. Despite partner preference formation remaining unaltered, LS activation in pair-bonded males leads to reduced selective aggression while increasing social affiliative behaviors. These results suggest that LS activation alters behavior within certain social contexts, by increasing sex-naïve affiliative behaviors and reducing pair bonding-induced selective aggression with same-sex conspecifics, but not altering bonding with opposite-sex individuals. Selective DREADD-mediated activation of the lateral septum reveals its importance in enabling male prairie voles to adjust selective and nonselective social behavior to account for important life-history shifts linked with reproductive success. [ABSTRACT FROM AUTHOR]

The subterranean microbiota of plants is of great importance for plant growth and health, as root-associated microbes can perform crucial ecological functions. As the microbial environment of roots is extremely diverse, identifying keystone microorganisms in plant roots, rhizosphere, and bulk soil is a necessary step towards understanding the network of influence within the microbial community associated with roots and enhancing its beneficial elements. To target these hot spots of microbial interaction, we used inter-kingdom network analysis on the canola growth phase of a long-term cropping system diversification experiment conducted at four locations in the Canadian Prairies. Our aims were to verify whether bacterial and fungal communities of canola roots, rhizosphere, and bulk soil are related and influenced by diversification of the crop rotation system; to determine whether there are common or specific core fungi and bacteria in the roots, rhizosphere, and bulk soil under canola grown in different environments and with different levels of cropping system diversification; and to identify hub taxa at the inter-kingdom level that could play an important ecological role in the microbiota of canola. Our results showed that fungi were influenced by crop diversification, which was not the case on bacteria. We found no core microbiota in canola roots but identified three core fungi in the rhizosphere, one core mycobiota in the bulk soil, and one core bacterium shared by the rhizosphere and bulk soil. We identified two bacterial and one fungal hub taxa in the inter-kingdom networks of the canola rhizosphere, and one bacterial and two fungal hub taxa in the bulk soil. Among these inter-kingdom hub taxa, Bradyrhizobium sp. and Mortierella sp. are particularly influential on the microbial community and the plant. To our knowledge, this is the first inter-kingdom network analysis utilized to identify hot spots of interaction in canola microbial communities. [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]

We investigated variability in δ2H values for two aquatic food webs involving avian consumers (lesser scaup, Aythya affinis Eyton and tree swallow, Tachycineta bicolor Vieillot) foraging from boreal lakes in the Yukon Flats (Alaska, United States) and wetlands in the Prairie Pothole Region (Saskatchewan, Canada), respectively. Generalized linear mixed-effects models were used to decompose sources of variation in water and tissue δ2H. We found inter-annual variation in boreal lakes δ2HW influenced by surface water connectivity (e.g., open vs. closed basins) and distance to the nearest river. Prairie pothole wetland δ2HW displayed intra-annual variability dictated by wetland type (e.g., semipermanent and seasonal) with a range greater than 60‰, which incrementally increased over the summer months. Variance in invertebrate δ2HI was explained by taxonomic category, but factors such as the relative distance to the nearest river (boreal model) and wetland type (prairie model) should be explored in future studies. Lesser scaup duckling feather δ2HF displayed inter-annual and spatial variability with the top model explaining 86% of the overall variation, including the following fixed effects: basin type (open/closed), year, and calendar date of sampling. Similar spatial patterns with known lesser scaup prey items, such as relative site distance to the nearest river, most closely aligned with Amphipoda δ2HI. Variation in tree swallow nestling δ2HF was attributed to sampling date with the top model explaining 38% of overall variation, while sampled prey items (e.g., Chironomidae) did not closely follow this pattern. Our findings quantify the extreme temporal and spatial δ2H variability in food webs fundamentally linked to seasonal evaporative effects in shallow lentic aquatic ecosystems. [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]

Rhizosphere microbiomes have received growing attention in recent years for their role in plant health, stress tolerance, soil nutrition, and invasion. Still, relatively little is known about how these microbial communities are altered under plant competition, and even less about whether these shifts are tied to competitive outcomes between native and invasive plants. We investigated the structure and diversity of rhizosphere bacterial and fungal microbiomes of native annual forbs and invasive annual grasses grown in a shade-house both individually and in competition using high-throughput amplicon sequencing of the bacterial 16S rRNA gene and the fungal ITS region. We assessed how differentially abundant microbial families correlate to plant biomass under competition. We find that bacterial diversity and structure differ between native forbs and invasive grasses, but fungal diversity and structure do not. Furthermore, bacterial community structures under competition are distinct from individual bacterial community structures. We also identified five bacterial families that varied in normalized abundance between treatments and that were correlated with plant biomass under competition. We speculate that invasive grass dominance over these natives may be partially due to effects on the rhizosphere community, with changes in specific bacterial families potentially benefiting invaders at the expense of natives. [ABSTRACT FROM AUTHOR]

Context: Human-modified landscapes can structure species' distributions and supplant traditional biotic range-limiting processes. Understanding the direction and scale of these processes is necessary to enhance species conservation efforts. Objectives: We investigated how the distribution of a prairie-obligate carnivore, swift fox (Vulpes velox), is influenced by landscape pattern at the eastern edge of their used range. We also assessed the effects of a popular conservation effort, the conservation reserve program (CRP), on swift fox distributions. Methods: We used three years of detection/non-detection data (2018–2020) from camera traps at 381 sites to evaluate the spatial distribution of swift foxes at the eastern edge of their extant range in Kansas, USA. We used Gaussian Kernel functions to identify optimal scales of effect for measured landscape covariates and multiseason use models to reveal potential range-limiting constraints. Results: Swift foxes were more likely to occur at sites with moderate landcover diversity within 254.47 ha, greater proportion of shortgrass prairie (7.07 ha) and loamy soil types (0.79 ha), and lower proportions of CRP landcover (78.54 ha). Swift foxes were more likely to colonize sites with less diverse landcover, a greater proportion of loamy soil types, and lower proportions of CRP landcover. Swift foxes were insensitive to the proportion of row-crop agriculture surrounding sites (3.14 ha). Conclusions: Loamy soils and distribution of shortgrass prairie ecosystems may shape the periphery of the distribution for swift foxes. Landscape-scale use of CRP may constrain swift fox distributions at their range edge because managed vegetation structure of CRP does not mimic native shortgrass prairie. [ABSTRACT FROM AUTHOR]

"Prairie madness" is a documented phenomenon wherein immigrants who settled the Great Plains experienced episodes of depression and violent behavior. The cause is commonly attributed to the isolation of the households and settlements. Historical accounts and literature from the late 19th and early 20th centuries also specify the loud sound of the winds on the plain as a catalyst for prairie madness. This study uses audiometric analysis of general human-hearing patterns combined with spectral data on the soundscape of the Great Plains region to investigate the possible effect of soundscapes on historical-period plains settler populations. I propose that a number of settlers may have suffered from conditions such as misophonia and acute hyperacusis that can cause increased sensitivity to environmental sounds. Both conditions can result from high-stress environments and cause behavior consistent with descriptions of prairie madness, such as depression, insomnia, and violent or irrational behavior. [ABSTRACT FROM AUTHOR]

Anthropogenic noise is increasing worldwide because of growing human populations, transportation, and resource extraction. This excessive noise negatively impacts humans and wildlife. To mitigate noise pollution, the use of vegetation in urban planning is becoming increasingly common. However, noise attenuation can be influenced by poorly understood differences in land cover and seasonality that exist across complex urban and peri-urban environments. We compared the noise attenuation capacity of sites typifying dominant land covers in southern Ontario, Canada (forest, tallgrass prairie, and agriculture) across three seasons (summer, fall, and winter). We found that total noise attenuation was affected by a complex interaction of both site and season across low (250 Hz), mid (500 Hz), and high (1000 Hz) frequency sound. Seasonal changes in vegetation density varied between sites and seemed to play only a partial role in total noise attenuation. While forest, trees, and shrubs continue to be effective for managing noise pollution, our results suggest that other types of land cover can also be useful (e.g., tallgrass prairie). With growing interest in the potential noise attenuating capabilities of vegetation, we recommend further consideration of the seasonal variation in attenuation that can occur across the diverse land covers of urban and peri-urban environments. [ABSTRACT FROM AUTHOR]

Sustainable reclamation practices for large surface coal mines in USA semiarid environment contribute to the quality of the environmental on a long term basis where environmental resources are protected for future generation. Land, after reclamation, must be suitable for the previous use of greatest economic or social values to the community area. In the semiarid climate of USA, non-developed land is mainly utilized for crops, grazing, and wildlife. Completion of various stages of the reclamation processes includes verification and approval of reclamation criteria and performance standards created by state agencies. The sustainable reclamation practices were investigated at the USA's largest surface coal mine of the semiarid environment in Wyoming. These practices include building post-mining topography to the approximate original contour and reestablish a stable hydrologic system to drain surface water. All available spoil material is backfilled and graded to achieve the post-mining topography which closely resembles the pre-mining topography. No overburden material or other coal waste material is left in stockpiles at the mine. Detailed planning until the end of mining, the knowledge of available volumes of suitable backfill material and soil is necessary for sustainable management practices. Diverse and permanent vegetation capable of stabilizing soil surfaces and capable of self-regeneration is established. Sustainable management of the reclamation effort is achieved by enforcement processes developed by the state and federal agencies. Monthly inspections of mining and reclamation operations and reviews of annual reports submitted by the operator help determine if the reclamation processes are occurring according to the permit plan. [ABSTRACT FROM AUTHOR]

Context: Area sensitivity, a behaviour whereby smaller patches of habitat are avoided, is of significant conservation concern for North American grassland birds. However, it is unclear whether area sensitivity is caused by patch size per se, or whether it results from factors such as landscape openness, which often covaries with patch size. Objectives: We aimed to determine which characteristics of a grassland patch or the landscape surrounding it most influence habitat use by tall-grass prairie birds. Methods: Using point-count data collected from 20 tall-grass prairie patches in Southern Manitoba, Canada, we determined which spatial extent and landscape characteristics contributed most to area sensitivity for five species of grassland passerines and grassland bird species richness. We assessed the relative importance of patch size, landscape composition within spatial extents ranging up to 8000 m from sampling locations, and edge proximity then compared the importance of landscape characteristics to that of local habitat structure. Results: The proportion of open landscape dominated by low-stature plants had a positive effect on species richness and the relative abundances of all focal species, and was generally more important than patch size, habitat amount, edge proximity, or local habitat structure. Conclusions: These results suggest that landscape openness, not patch size or habitat amount, drives area sensitivity of grassland birds. Grassland patches embedded in open landscapes are less susceptible to area sensitivity and may be of high conservation value for grassland birds, even when small. [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]

Evaluating the impact of land-use practices on soil organic carbon (SOC) in the Canadian prairie pothole region (PPR) is of concern due to the potential to sequester carbon and sustain soil health. In a field experiment, SOC content, carbon fractions, and chemical composition were assessed under short-rotation willow (SRW) plantation in the marginal riparian zones of two PPR wetland sites and compared with adjacent annual crop (AC) and pasture (PA). The SOC, water extractable (WEOC), light fraction (LFOC), and particulate organic carbon (POC) were used to evaluate the content and its fractions, whereas Fourier Transform Infrared (FTIR) spectroscopy was used to characterize the chemical composition. The SOC was higher in PA in both sites; however, significant (p < 0.05) only in site B. The SOC, LFOC, and POC followed a similar land-use pattern in both sites, i.e., PA > SRW = AC. The SOC and WEOC were significantly higher (p < 0.05) in 0–15 cm across all land-use practices. The ratios of phenolic and amides to polysaccharides were significantly higher (p < 0.05), while aromatic and carboxylic to polysaccharides were lower under SRW in both sites indicated microbial synthesis of these substances. The abundance of SOC functional groups was higher in the subsoil, accompanied by altered spectral properties with depths showing the potential soil organic matter transformation related to carbon fractions changes. The higher alkyl-C to O-alkyl-C ratio at 15–30 cm under SRW suggested better SOC stability and the potential advantage of C sequestration in the PPR. [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]

The Prairie Pothole Region (PPR) of North America has experienced extreme changes in wetland habitat due to proliferation of invasive plants. Typha × glauca is a highly competitive hybrid between native T. latifolia and non-native T. angustifolia, and it is likely the predominant taxon in PPR wetlands. Genetics-based studies are limited, and distributions are poorly known for the first-generation (F1) hybrid and advanced-generation hybrids from F1 mating. Information pertaining to the distribution of T. × glauca could benefit efforts to understand the mechanisms of its spread and to develop management strategies to limit hybrid expansion and preserve progenitors. We used microsatellite markers of field-collected tissue samples from 131 wetlands spread over approximately 350,000 km2 in the PPR to assess the distribution of hybrid T. × glauca relative to its parental species and to examine the prevalence of F1 hybrids and advanced-generation hybrids. Typha × glauca was found in over 80% of wetlands throughout the PPR, compared to 26 and 18% of wetlands with T. latifolia and T. angustifolia, respectively. Advanced-generation hybrids were more common than F1 hybrids, suggesting that hybridization is not a recent phenomenon. Hybrids were significantly taller than T. latifolia, indicating heterosis. Only 7% of sampled individual genets were pure T. latifolia. These results suggest that T. × glauca is pervasive throughout the PPR and may spread independently of both parents. In addition, limited prevalence of native T. latifolia indicates the need for active management to preserve the species. [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]

Context: Vegetation quantity and quality influence the degree to which large grazers shape grassland structural heterogeneity. Invasive plants threaten the function of cross-scale interactions that exist when multi-scale effects such as fire and grazing interplay to form patterns of grassland structural heterogeneity. Objectives: We investigated how grazing pressure and time since fire at the patch scale influenced patch utilization and production as well as forage quality in experimental grassland pastures dominated by an invasive grass, tall fescue (Schedonorus arundinaceous). We also assessed the response of tall fescue utilization and production to interactive fire-and-grazing under moderate and heavy grazing pressure. Methods: We collected data on vegetation quantity and quality over two grazing seasons to evaluate the role of fire and grazing across time in shaping structural heterogeneity among patches in invaded tallgrass prairie in Iowa, USA. We anticipated greater initial patch-scale utilization in patches burned for the first time in two years than patches not burned in two years in our experimental pastures. We expected that greater utilization in recently-burned patches would reduce tall fescue production, mostly where grazing pressure was highest. Results: The contrast in the availability of live herbage between patches was half the level typical for native-dominated tallgrass prairie. Under increased grazing pressure, the interplay between fire and grazing did not result in greater broad-scale heterogeneity (among-patch heterogeneity) or an invasive grass reduction in experimental pastures. Yet, increased grazing early in the season did promote native-grass production in this invaded grassland landscape. Conclusion: Our results suggest that the dominance of tall fescue mediates the lack of structural heterogeneity induced by patch-level prescribed fire and grazing. Unlike native perennial grasses, tall fescue provides access to forage in unburned patches through its low-stature growth form. Diminished cross-scale interactions through a weak coupling of fire and focal grazing in invaded tallgrass prairie may facilitate structural homogenization of fire-dependent grassland. [ABSTRACT FROM AUTHOR]

In this essay, I consider the use of mathematical statistics in the study of biological systems in the field, using as case studies the work of Ruth Geyer Shaw and her colleagues at the University of Minnesota. To address practical issues, like how to enhance prairie restoration, and how to prepare for (and perhaps prevent) the effect of rapid climate change, she and her colleagues combine mathematical modeling and intensive data collection in the field. Using ANOVA and the more versatile approach of Aster Models, they show the effects of inbreeding (which follows from the fragmentation of prairie) to lower the fitness of plant populations. They study the genetic variance of plants in stable populations, which is important when that population must deal with changing conditions. And they study the consequences of rapid climate change: even good genetic variance and initial fitness may not save a given population from extinction. This leads to a new alliance of science with local, state, federal and global politics. [ABSTRACT FROM AUTHOR]

Climate change will have considerable impact on the global economy. Estimates of the economic damages due to climate change have focused on the effect of average temperature, but not the effect of other important climate variables. Related research has not explored the sub-annual economic cycles which may be impacted by climate volatility. To address these deficits, we propose a flexible, non-linear framework which includes a wide range of climate variables to estimate changes in GDP and project sub-annual economic cycle adjustments (period, amplitude, trough depth). We find that the inclusion of a more robust set of climate variables improves model performance by over 20%. Importantly, the improved model predicts an increase in GDP rather than a decrease when only temperature is considered. We also find that climate influences the sub-annual economics of all but one province in Canada. Highest stressed were the Prairie and Atlantic regions. Least stressed was the Southeastern region. Our study advances understanding of the nuances in the relationship between climate change and economic output in Canada. It also provides a method that can be applied to related economies globally to target adaptation and resilience management. Climate change will impact the global economy. Here, the authors propose a framework to evaluate its effect on economies across multiple regional and temporal scales, and project decreased financial stability in a northern temperate economy. [ABSTRACT FROM AUTHOR]

Nitrogen (N) from anthropogenic sources has dramatically increased in terrestrial ecosystems globally. Although belowground microbial processes and events that release N into the atmosphere, such as fire, could support ecosystem resilience to eutrophication, little is known about how these factors might affect N loss following chronic fertilization, thus promoting ecosystem recovery. We studied how N pools, N-cycling potential rates and their affiliated microbial populations, and microbial community composition responded to the factorial effects of cessation of 30 years of chronic N fertilization and annual burning at a tallgrass prairie. Soil N availability in previously fertilized plots recovered by 86% (using never-fertilized control plots as a 100% recovery reference), while plant and microbial biomass did not change. Nitrification potential recovered (80%), and denitrification potential partially recovered (50%), in previously fertilized plots. There were differential responses among key groups of nitrifiers (archaea vs. bacteria) and denitrifiers (nosZ clade I vs. clade II from Anaeromyxobacter dehalogenans) to long-term N fertilization and cessation despite the whole microbial community composition not shifting significantly after fertilization ceased. Also, N-cycling potentials were consistently higher in unburned prairie. Together, results suggest that fire is a prominent mechanism for ecosystem N removal in annually burned prairie, while N-cycling microbes will have an important role in the absence of fire; however, the recovery to pre-fertilized condition, with or without fire, will take longer than 1 year. Overall, differential resilience of biotic populations and processes can potentially shape different outcomes of soil N loss and tallgrass prairie ecosystem recovery from long-term N fertilization. [ABSTRACT FROM AUTHOR]

Soil respiration, the major pathway for ecosystem carbon (C) loss, has the potential to enter a positive feedback loop with the atmospheric CO2 due to climate warming. For reliable projections of climate-carbon feedbacks, accurate quantification of soil respiration and identification of mechanisms that control its variability are essential. Process-based models simulate soil respiration as functions of belowground C input, organic matter quality, and sensitivity to environmental conditions. However, evaluation and calibration of process-based models against the long-term in situ measurements are rare. Here, we evaluate the performance of the Terrestrial ECOsystem (TECO) model in simulating total and heterotrophic soil respiration measured during a 16-year warming experiment in a mixed-grass prairie; calibrate model parameters against these and other measurements collected during the experiment; and explore whether the mechanisms of C dynamics have changed over the years. Calibrating model parameters against observations of individual years substantially improved model performance in comparison to pre-calibration simulations, explaining 79–86% of variability in observed soil respiration. Interannual variation of the calibrated model parameters indicated increasing recalcitrance of soil C and changing environmental sensitivity of microbes. Overall, we found that (1) soil organic C became more recalcitrant in intact soil compared to root-free soil; (2) warming offset the effects of increasing C recalcitrance in intact soil and changed microbial sensitivity to moisture conditions. These findings indicate that soil respiration may decrease in the future due to C quality, but this decrease may be offset by warming-induced changes in C cycling mechanisms and their responses to moisture conditions. [ABSTRACT FROM AUTHOR]

Lawns as a landcover change substantially alter evapotranspiration, CO2, and energy exchanges and are of rising importance considering their spatial extent. We contrast eddy covariance (EC) flux measurements collected in the Denver, Colorado, USA metropolitan area in 2011 and 2012 over a lawn and a xeric tallgrass prairie. Close linkages between seasonal vegetation development, energy fluxes, and net ecosystem exchange (NEE) of CO2 were found. Irrigation of the lawn modified energy and CO2 fluxes and greatly contributed to differences observed between sites. Due to greater water inputs (precipitation + irrigation) at the lawn in this semi-arid climate, energy partitioning at the lawn was dominated by latent heat (LE) flux. As a result, evapotranspiration (ET) of the lawn was more than double that of tallgrass prairie (2011: 639(±17) mm vs. 302(±9) mm; 2012: 584(±15) mm vs. 265(±7) mm). NEE for the lawn was characterized by a longer growing season, higher daily net uptake of CO2, and growing season NEE that was also more than twice that of the prairie (2011: −173(±23) g C m−2 vs. -81(±10) g C m−2; 2012: −73(±22) g C m−2 vs. -21(±8) g C m−2). During the drought year (2012), temperature and water stress greatly influenced the direction and magnitude of CO2 flux at both sites. The results suggest that lawns in Denver can function as carbon sinks and conditionally contribute to the mitigation of carbon emissions - directly by CO2 uptake and indirectly through effects of evaporative cooling on microclimate and energy use. [ABSTRACT FROM AUTHOR]