Chamaecrista Fasciculata Research Articles

Blooming and Forage Characteristics of Twelve Native Forbs Subjected to Repeated Defoliation

Insect pollinators are in population decline due to environmental and chemical stressors. Including native forbs in pastures could benefit grazers and pollinators; however, their forage and flowering characteristics are not fully documented. The objectives of our research were to evaluate 12 native forbs for persistence, forage mass, nutrient composition, and flowering patterns under repeated defoliation. Twelve species were planted in a small-plot experiment in 2018. Response variables were measured from 2020 to 2022. Annual (partridge pea, PPEA, Chamaecrista fasciculata) and biennial (black-eyed Susan, BESU, Rudbeckia hirta) species established high (p < 0.05) plant populations during the first season; however, the PPEA declined (p < 0.05) in forage mass during 2021. Tall species (Maximilian sunflower, MSUN, Helianthus maximiliani; cup plant, CUPP, Silphium perfoliatum) increased in forage mass, produced high-quality forage, and flowered during early fall. Lanceleaf coreopsis (LCOR, Coreopsis lanceolata) produced consistent (p > 0.05) forage mass and flowered in spring. The purple coneflower (PURC, Echinacea purpurea), Illinois bundleflower (ILBF, Desmanthus illinoensis), and oxeye sunflower (OSUN, Helopsis helianthoides) produced high-quality, consistent (p > 0.05) forage mass and flowered mid-season. Interseeding the BESU, ILBF, PPEA, LCOR, PURC, OSUN, and MSUN or CUPP would produce high-quality forage and floral resources throughout summer.

Comparing the Predicted versus Realized Rate of Adaptation of Chamaecrista fasciculata to Climate Change.

AbstractFisher's fundamental theorem of natural selection (FTNS) can be used in a quantitative genetics framework to predict the rate of adaptation in populations. Here, we estimated the capacity for a wild population of the annual legume Chamaecrista fasciculata to adapt to future environments and compared predicted and realized rates of adaptation. We planted pedigreed seeds from one population into three prairie reconstructions along an east-to-west decreasing precipitation gradient. The FTNS predicted adaptation at all sites, but we found a response to selection that was smaller at the home and westernmost sites and maladaptive at the middle site because of changes in the selective environment between generations. However, mean fitness of the progeny generation at the home and westernmost sites exceeded population replacement, which suggests that the environment was sufficiently favorable to promote population persistence. More studies employing the FTNS are needed to clarify the degree to which predictions of the rate of adaptation are realized and its utility in the conservation of populations at risk of extinction from climate change.

Benefits of assisted gene flow diminish with latitudinal distance between populations in Chamaecrista fasciculata

In ecological restoration, seed sourcing is often among the first and most critical steps in achieving restored populations that establish and reproduce successfully, while also having the genetic capacity to adapt to future change. Many approaches have been proposed to guide seed sourcing for restoration, including a strong focus on local seed sources, the use of assisted gene flow or assisted migration, and regional admixture provenancing. The goal of this research was to evaluate these issues in the context of grassland restoration. We collected seed of Chamaecrista fasciculata, an annual native to the prairies of North America, from four locations along a latitudinal gradient. We generated inter‐ and intrapopulation crosses and grew them in two common gardens located in restored prairies in southeast Minnesota. We found that northern populations tended to flower and fruit earlier than southern populations, while hybrids generally had intermediate phenologies. There were strong fitness benefits of hybridization, particularly among the local crosses. However, the plants grown from our southernmost seed source produced few mature seed pods in the common gardens before the advent of fall frost, suggesting that translocating populations across significant latitudinal distances may be problematic. Taken together, our findings support a regional admixture provenancing approach while indicating that assisted migration and assisted gene flow across latitudinal distances of three degrees or more compromises fitness in this species.

Fine-scale genetic structure in rhizosphere microbial communities associated with Chamaecrista fasciculata (Fabaceae).

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of ~400 square meters to investigate the presence of SGS in microbial communities. Bacteria of Acidobacteria, Protobacteria, and Bacteroidetes and fungi of Basidiomycota, Ascomycota, and Mortierellomycota were dominant members of the rhizosphere. Although microbial alpha diversity did not differ significantly among plants hosts, we detected significant compositional differences among the microbial communities as well as isolation by distance. The strongest factor associated with microbial distance was genetic distance of the other microbial community, followed by geographic distance, but there was not a significant association with plant genetic distance for either microbial community. This study further demonstrates the strong potential for spatial structuring of soil microbial communities at the smallest spatial scales and provides further insight into the complexity of factors that influence microbial composition in soils and in association with host plants.

Response of Common Wildflower Species to Postemergence Herbicides

Wildflowers attract wildlife, increase pollinator habitat, and enhance the aesthetic value of the landscape. Wildflower establishment is increasingly part of an effort to reduce maintained turfgrass on golf courses, lawns, and other maintained environments. Weed competition decreases wildflower establishment and results in poor long-term stands. Research was conducted in a controlled environment to investigate the tolerance of wildflower species to common postemergence herbicides. Wildflower species included California poppy (Eschscholzia californica Cham.), common sunflower (Helianthus annuus L.), cornflower (Centaurea cyanus L.), garden coreopsis (Coreopsis lanceolata L.), partridge pea [Chamaecrista fasciculata (Michx.) Greene], plains coreopsis (Coreopsis tinctoria Nutt.), purple coneflower [Echinacea purpurea (L.) Moench], rosering gaillardia (Gaillardia pulchella Foug.), and violet prairie clover (Dalea purpurea Vent.). Herbicides evaluated were fluazifop at 0.28 kg⋅ha–1 a.i., mesotrione at 0.14 kg⋅ha–1 a.i., clopyralid at 0.29 kg⋅ha–1 a.i., bentazon at 0.56 kg⋅ha–1 a.i., halosulfuron at 0.053 kg⋅ha–1 a.i., and imazaquin at 0.42 kg⋅ha–1 a.i. An untreated check was included for comparison. Excessive damage (≥ 53% phytotoxicity) was observed on all wildflower species in response to clopyralid, except for California poppy. Fluazifop and bentazon were relatively safe (≤ 19% phytotoxicity, regardless of herbicide) on all wildflower species; however, bentazon resulted in ≥ 40% aboveground biomass reduction in several species. Common sunflower and garden coreopsis were susceptible to halosulfuron (37% and 73% phytotoxicity, respectively) and imazaquin (37% and 87% phytotoxicity, respectively), but on all other wildflower species, phytotoxicity was ≤ 18%. Although both halosulfuron and imazaquin only resulted in ≤ 18% phytotoxicity to purple coneflower, a 43% to 44% aboveground biomass reduction was recorded. Mesotrione was only safe on California poppy and cornflower (≤ 11% phytotoxicity and ≤ 24% aboveground biomass reduction). Results suggest high tolerance variability across herbicides and species considered, but may prompt new investigation of safety and utility within field and production scenarios.

Urban grassland restorations have reduced plant fitness but not pollinator limitation

Native grasslands worldwide have been greatly reduced due to anthropogenic activities. Grassland restoration efforts strive to increase biodiversity and ecosystem services of these habitats, but often fall short of management goals. This is especially true for small-scale restoration efforts in urban areas, which face unique challenges including increased surface temperatures, increased pollution, decreased habitat connectivity, and decreased pollinator availability. In 2019–2020, we conducted a seed-addition field experiment in four restoration sites near Louisville, KY USA to examine how urbanization influenced survival, growth, and reproduction of a common native forb, Chamaecrista fasciculata. We also conducted observations twice per week to characterize the active pollinator community in each site. We found that plants in urban restoration sites had reduced growth, flowering period, and reproduction compared to those in rural restoration sites. However, pollination rates (visits/flower) in urban sites did not differ from those in rural sites, and urban sites even tended to have greater pollinator effectiveness (seeds/flower) than rural sites. Our results suggest that pollination services are adequate in urban restorations, but that other factors associated with urbanization, such as increased drought stress, can reduce growth and fitness of native plants. Further work is needed to better characterize environmental stresses associated with urban grassland restoration in order to minimize fitness effects on target plant species.

Determinants of Population Genetic Structure in Chamaecrista fasciculata (Michx.) Greene (Fabaceae) in the Southeastern United States

Chamaecrista fasciculata is a widely distributed, phenotypically variable species in the eastern U.S. Whereas studies have demonstrated genetic structure and local adaptation in northern areas of its distribution, there has been no comparison of genetic variability among populations at the southern extent where phenotypic variation is more complex. We characterized genetic variation at 14 microsatellite loci for populations in Mississippi and Alabama and compared this to variation in a phenotypic trait, leaf pubescence. Geographic distance, climatic variables, and elevation were evaluated as factors to explain the observed patterns of genetic diversity. A significant amount of variation (19%) resided among populations, but most variation (68%) was among individuals. Assignment of individuals into genetic groups suggests two primary clusters, but these groups are not concordant with known geographical or ecological breaks, nor phenotypic variants. Genetic structure at a regional scale can be characterized as isolation by distance, while environmental factors may play a secondary role in limiting gene flow at local scales. Mean population FST is strongly associated with allelic diversity and heterozygosity, suggesting that genetic drift influences population variation. Despite the presence of genetic and phenotypic variation in southern populations of C. fasciculata, the lack of concordant patterns between these types of variation indicate that they are not driven by the same factors. This study demonstrates how local factors differentially influence the maintenance of intraspecific variation and suggest the southern distributional range is an active area of evolution for C. fasciculata.

Variation in overall fitness due to seed source: projections for predictive provenancing

Seed sourcing decisions affect short‐ and long‐term restoration outcomes. Seeds sourced closer to restoration sites are likely to be better adapted to local conditions and therefore may perform better than those sourced farther away, following assumptions of local adaptation. However, plants may not be adapted to future conditions under climate change; hence, managers are considering a predictive provenancing approach, where plant materials adapted to predicted conditions are used at a site. Currently, there is little empirical evidence available to inform this approach. To address this, we evaluate predictive provenancing using three species of forbs used in tallgrass prairie restorations (Allium cernuum, Chamaecrista fasciculata, and Rudbeckia hirta) in a common garden experiment in northeastern Illinois, U.S.A. We compared the fitness in plants sourced from three regional zones across a latitudinal gradient that represents different climate projections, relative to the planting site. Data were analyzed using Aster life‐history models and generalized linear models. We found that source affected overall fitness in all three species, but no climate proxy had the highest fitness across all species. The performance at each life stage had different effects on overall fitness, which varied by source. We observed later reproductive phenology in southern‐sourced plants for all three species, possibly due to adaptation to longer growing seasons. The mixed results of this study suggest that climate proxy alone would not be sufficient to determine an effective and accurate predictive provenancing strategy. Long‐term tests are needed to pursue such a strategy for high‐priority species.

A generalist nematode destabilises plant competition: no evidence for direct effects, but strong evidence for indirect effects on rhizobium abundance.

Difficulties quantifying pathogen load and mutualist abundance limit our ability to connect disease dynamics to host community ecology. For example, specific predictions about how differential pathogen load is hypothesised to drive host competitive outcomes are rarely tested. Additionally, although infection is known to affect mutualists, we rarely measure the magnitude of pathogen effects on mutualist abundance across host competitive contexts. We tested for both mechanisms in a plant-rhizobia-nematode system. We paired the legume Medicago lupulina with intraspecific and interspecific plant competitors, with and without a generalist nematode parasite Meloidogyne sp. Relative change in plant biomass was used to determine how nematode inoculation affected plant competitive outcomes. We counted nematode galls to test for direct effects of parasitism on plant competition and rhizobia nodules to test for indirect effects of nematode presence on rhizobium abundance. Parasites were destabilising despite similar nematode load across competition treatments. During interspecific compared with intraspecific competition, nematode inoculation decreased nodulation on M. lupulina, increased nodulation on Trifolium repens and had no effect on nodulation on Chamaecrista fasciculata. We found no support for hypothesised direct effects of nematode load on competitive outcomes and strong but idiosyncratic indirect effects of nematode inoculation on rhizobium abundance.

Can Native Plants Mitigate Climate-related Forage Dearth for Honey Bees (Hymenoptera: Apidae)?

Extreme weather events, like high temperatures and droughts, are predicted to become common with climate change, and may negatively impact plant growth. How honey bees (Apis mellifera L. [Hymenoptera: Apidae]) will respond to this challenge is unclear, especially when collecting pollen, their primary source of protein, lipids, and micro-nutrients. We explored this response with a data set from multiple research projects that measured pollen collected by honey bees during 2015–2017 in which above-average temperatures and a drought occurred in 2017. We summarized the abundance and diversity of pollen collected from July to September in replicated apiaries kept at commercial soybean and corn farms in Iowa, in the Midwestern USA. The most commonly collected pollen was from clover (Trifolium spp. [Fabales: Fabaceae]), which dramatically declined in absolute and relative abundance in July 2017 during a period of high temperatures and drought. Due to an apparent lack of clover, honey bees switched to the more drought-tolerant native species (e.g., Chamaecrista fasciculata [Michx.] Greene [Fabales: Fabaceae], Dalea purpurea Vent. [Fabales: Fabaceae], Solidago spp. [Asterales: Asteraceae]), and several species of Asteraceae. This was especially noticeable in August 2017 when C. fasciculata dominated (87%) and clover disappeared from bee-collected pollen. We discuss the potential implications of climate-induced forage dearth on honey bee nutritional health. We also compare these results to a growing body of literature on the use of native, perennial flowering plants found in Midwestern prairies for the conservation of beneficial insects. We discuss the potential for drought resistant-native plants to potentially promote resilience to climate change for the non-native, managed honey bee colonies in the United States.

Lifetime Fitness through Female and Male Function: Influences of Genetically Effective Population Size and Density.

AbstractAn individual's lifetime fitness and patterns of mating between individuals are interdependent features of sexual organisms. Mating systems (outcrossing vs. selfing or mating between close relatives) can affect the distribution of offspring fitness, which generally declines with inbreeding, which in turn is related to a population's genetically effective size (Ne). Fitness and mating patterns are also expected to vary with proximity of mates (i.e., population density). Consequently, density and Ne may influence demographic and genetic changes over generations and interact in their effects. Here, we report an experiment designed to assess the influence of these two population-level properties on mating system and lifetime fitness. In experimental arrays under quasi-natural conditions, we varied the density and Ne of the hermaphroditic annual legume Chamaecrista fasciculata. We recorded components of fitness for each individual and employed microsatellite markers to estimate outcrossing and assign paternity. We used aster analyses to estimate lifetime fitness for genetic families using female (seeds set) and male (seeds sired) reproduction as fitness measures. With estimates from these analyses, we assessed the evidence for a trade-off between fitness attained through female versus male function, but we found none. Lifetime fitness increased with density, especially under high Ne. Outcrossing rates increased with density under high Ne but declined modestly with density under low Ne. Our results show that density and Ne have strong direct effects on fitness and mating systems, with negative fitness effects of low Ne limiting the positive effects of increasing density. These findings highlight the importance of the interactive effects of density and Ne on lifetime fitness.

Dependence of Lifetime Fitness on Gene-by-Environment Interaction: Effects of Soil Salinity on an Annual Legume

Premise of research. Rapid environmental changes have raised questions about the capacity of plant populations to adapt to novel conditions. Salinity is increasing in both urban and rural areas because of irrigation and road deicing salt. While adaptation to salinity is found in some plant species, salt impairs plant fitness for the vast majority. Breeding to enhance adaptation to salinity has proved difficult, suggesting barriers to adaptation.Methodology. In this project, we assessed the capacity for adaptation to soil salinity. We planted an experimental population of Chamaecrista fasciculata (partridge pea, Fabaceae) in both roadside and greenhouse conditions. We assessed lifetime fitness as a composite of germination, survival, and the number of flowers or fruits produced. We estimated additive genetic variance for fitness in each greenhouse salinity treatment using aster models.Pivotal results. Significant additive genetic variance for fitness was detected in the control treatment in the greenhouse, in the low-salinity treatment in the greenhouse, and in the roadside experimental plot. Gene-by-environment interactions were also significant. This gene-by-environment interaction is caused by both differences in genetic variation among environments and a change in the ranks of the families. In the control and low-salinity treatments in the greenhouse experiment, the relative ranks of fitness among the paternal families visually demonstrate the gene-by-environment interaction.Conclusions. The findings of the roadside experiment demonstrate that this population has the potential to adapt to a salinized environment. This research found a gene-by-environment interaction that may alter the fitness of various families over small geographic scales, such as those found in a roadside. Reducing deicing salt usage may improve the health and quality of roadside ecosystems by enhancing the potential of some species to adapt.

Fine-Scale Patterns of Genetic Structure in the Host Plant Chamaecrista fasciculata (Fabaceae) and Its Nodulating Rhizobia Symbionts.

In natural plant populations, a fine-scale spatial genetic structure (SGS) can result from limited gene flow, selection pressures or spatial autocorrelation. However, limited gene flow is considered the predominant determinant in the establishment of SGS. With limited dispersal ability of bacterial cells in soil and host influence on their variety and abundance, spatial autocorrelation of bacterial communities associated with plants is expected. For this study, we collected genetic data from legume host plants, Chamaecrista fasciculata, their Bradyrhizobium symbionts and rhizosphere free-living bacteria at a small spatial scale to evaluate the extent to which symbiotic partners will have similar SGS and to understand how plant hosts choose among nodulating symbionts. We found SGS across all sampled plants for both the host plants and nodulating rhizobia, suggesting that both organisms are influenced by similar mechanisms structuring genetic diversity or shared habitat preferences by both plants and microbes. We also found that plant genetic identity and geographic distance might serve as predictors of nodulating rhizobia genetic identity. Bradyrhizobium elkanii was the only type of rhizobia found in nodules, which suggests some level of selection by the host plant.

Estimating the capacity of Chamaecrista fasciculata for adaptation to change in precipitation.

Adaptation through natural selection may be the only means by which small and fragmented plant populations will persist through present day environmental change. A population's additive genetic variance for fitness (VA (W)) represents its immediate capacity to adapt to the environment in which it exists. We evaluated this property for a population of the annual legume Chamaecrista fasciculata through a quantitative genetic experiment in the tallgrass prairie region of the Midwestern United States, where changing climate is predicted to include more variability in rainfall. To reduce incident rainfall, relative to controls receiving ambient rain, we deployed rain exclusion shelters. We found significant VA (W) in both treatments. We also detected a significant genotype-by-treatment interaction for fitness, which suggests that the genetic basis of the response to natural selection will differ depending on precipitation. For the trait-specific leaf area, we detected maladaptive phenotypic plasticity and an interaction between genotype and environment. Selection for thicker leaves was detected with increased precipitation. These results indicate capacity of this population of C. fasciculata to adapt in situ to environmental change.

Flowering Chamaecrista fasciculata borders enhance natural enemy populations and improve grain quality in field corn

Plants with floral resources are advocated to enhance natural enemy density and efficacy in conservation biological control systems. Field experiments were conducted to examine the ability of partridge pea (Chamaecrista fasciculata) planted along two borders of organic field corn (Zea mays) plots to attract natural enemies and enhance biological control, yield and profit. Partridge pea significantly increased natural enemy abundances, including parasitoid and predators; however, some key natural enemy and target pest abundances within field corn were unaffected. Crop damage was reduced, and grain quality improved significantly in corn adjacent to partridge pea compared with corn plots without partridge pea. Despite these benefits, there was no economic gain with respect to improved corn yields or increased profits.

Evolution in novel environments: Do restored prairie populations experience strong selection?

When populations colonize new habitats, they are likely to experience novel environmental conditions, and as a consequence may experience strong selection. While selection and the resulting evolutionary responses may have important implications for establishment success in colonizing populations, few studies have estimated selection in such scenarios. Here we examined evidence of selection in recently established plant populations in two prairie restorations in close proximity (<15km apart) using two approaches: (1) we tested for evidence of past selection on a suite of traits in two Chamaecrista fasciculata populations by comparing the restored populations to each other and their shared source population in common gardens to quantify evolutionary responses and (2) we measured selection in the field. We found evidence of past selection on flowering time, specific leaf area, and root nodule production in one of the populations, but detected contemporary selection on only one trait (plant height). Our findings demonstrate that while selection can occur in colonizing populations, resulting in significant trait differences between restored populations in fewer than six generations, evolutionary responses differ across even nearby populations sown with the same source population. Because contemporary measures of selection differed from evolutionary responses to past selection, our findings also suggest that selection likely differs over the early stages of succession that characterize young prairies.

Effects of the soil microbiome on the demography of two annual prairie plants.

Both mutualistic and pathogenic soil microbes are known to play important roles in shaping the fitness of plants, likely affecting plants at different life cycle stages.In order to investigate the differential effects of native soil mutualists and pathogens on plant fitness, we compared survival and reproduction of two annual tallgrass prairie plant species (Chamaecrista fasciculata and Coreopsis tinctoria) in a field study using 3 soil inocula treatments containing different compositions of microbes. The soil inocula types included fresh native whole soil taken from a remnant prairie containing both native mutualists and pathogens, soil enhanced with arbuscular mycorrhizal (AM) fungi derived from remnant prairies, and uninoculated controls.For both species, plants inoculated with native prairie AM fungi performed much better than those in uninoculated soil for all parts of the life cycle. Plants in the native whole prairie soil were either generally similar to plants in the uninoculated soil or had slightly higher survival or reproduction.Overall, these results suggest that native prairie AM fungi can have important positive effects on the fitness of early successional plants. As inclusion of prairie AM fungi and pathogens decreased plant fitness relative to prairie AM fungi alone, we expect that native pathogens also can have large effects on fitness of these annuals. Our findings support the use of AM fungi to enhance plant establishment in prairie restorations.

Phenotypic Variation of Partridge Pea (Chamaecrista fasciculata) from Mississippi Persists in a Common Garden

Intraspecific phenotypic variation occurs for many different reasons and understanding its basis has applications in taxonomy, ecology, and evolution. Chamaecrista fasciculata (partridge pea) is a widely distributed species with much phenotypic variation and varied interactions with other species in communities where it grows. Botanists have often noted that phenotypic variation in some traits of this species increases from north to south in the eastern United States. In this study, we grew seeds collected from five Mississippi populations in a common greenhouse environment to determine if the observed variation in leaf and stem traits is maintained in this environment. Interpopulation variation in the greenhouse-grown plants was not as extensive as that observed under natural conditions, but significant differences were detected in the number of stems and leaves and shoot height. The number of flowers and final shoot weight of plants did not differ, suggesting that there may be multiple growth strategies for this species to achieve equal fitness. Variation was detected in stem and leaflet trichome density. The population collected at the lowest latitude showed the most distinct morphology, producing shorter plants with many branched stems, more leaves, and a higher degree of leaflet pubescence. Trait variation that has so often been observed in natural populations of this species is maintained in a common environment, suggesting a genetic basis for the observed variation. Phenotypic variation observed in this species may reflect both responses to varied selective pressures from interacting species and adaptation to differing climatic factors.

Population‐ and community‐level rarity have opposing effects on pollinator visitation and seed set

Abstract When can small, isolated populations overcome the negative consequences of rarity? Despite considerable effort to understand threats to rare species, few studies consider how community context alters these threats. Plant–pollinator interactions offer the opportunity to test the effect of community context on rare species success, as plant–pollinator dynamics are thought to be influenced by neighbouring plants, both through competition for pollinators (reducing success in small populations) and attraction of potential pollinators (increasing success in small populations). Here, we test these predictions by experimentally decoupling community‐level rarity (relative abundance) from population‐level rarity (population size) in experimental two‐species fragments. We created experimental plant communities varying independently in population rarity (population size) and community rarity (relative abundance) of two annual plant species. We isolated plant roots to eliminate resource competition. We then compared the effects of population size versus relative abundance on pollinator visitation rates and an estimate of seed production. Both species had greatest pollinator visitation in large populations, but the negative effects of population rarity on visitation were partially offset when the neighbouring species was more abundant—community rarity offset the impacts of population rarity for the most common group of pollinators, solitary bees. These visitation trends impacted seed production for one species. When at low relative abundance, Polanisia dodecandra had higher seed set, matching increased visitation by solitary bees. Chamaecrista fasciculata showed no change in seed production with population‐ or community‐level rarity. Synthesis. Our results suggest that the surrounding community can offset the negative effects of low absolute abundance on fitness when neighbouring species are more abundant, and may ultimately maintain diversity even in fragmented ecological communities.

A Greenhouse Study of Concrete Grinding Residue Influences on Seedling Emergence and Early Growth of Selected Prairie Species

Concrete grinding residue (CGR) is a byproduct of diamond grinding, a road surface maintenance technique. Direct deposition of CGR along roadsides may influence plant growth, which has not been fully studied. Particularly, systematic experiments of CGR effects on selected common prairie species growth under controlled environments are rarely reported. Thus, in this study, a greenhouse experiment was performed to determine CGR effects on seedling emergence and aboveground biomass for four roadside prairie species: Indian grass, Canada wild rye, partridge pea, and wild bergamot. Nicollet loam and Hanlon fine sandy loam were used, and CGR of 4 rates, 0, 2.24, 4.48, and 8.96 kg m−2, were applied in two ways, either mixed with the soil or applied on the soil surface. Multiple comparisons indicate that CGR produced mixed impacts on seedling emergence, depending on plant species, while aboveground biomass is not significantly influenced by CGR in general. ANOVA analysis with stepwise linear regression indicates that CGR had no uniform effects on seedling emergence, and CGR impacts should be studied for specific plant species and soil types. In conclusion, while CGR may lead to negative environmental issues on roadside plants depending on the plant species and soil types, if aboveground biomass is a major consideration, CGR effects are negligible. This study provides reference information for regulating CGR depositions along roadsides. Future studies may focus on investigating the relationship between CGR effects on seedling emergence and species succession in actual roadside environments.