Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 79 2024 PRAIRIE NATURALIST Special Issue 2:79–92 Restoring Grassland with Native Plants & Active Management Monica Polgar1,2, Breanna Kobiela2, and Edward DeKeyser2* Abstract – Kentucky Bluegrass (Poa pratensis L.) and Smooth Brome (Bromus inermis Leyss.) can homogenize Northern Great Plains grasslands, resulting in impaired plant community structure and function. We evaluated restoration strategies to improve plant composition and forage production of a plant community dominated by these 2 invasive species in southeastern North Dakota. We installed 5 restoration treatments (interseed; interseed and burn; interseed, burn, and herbicide; interseed and herbicide; control/no treatment) and adaptively managed the site after restoration by employing livestock grazing and periodic prescribed burning. Restoration treatments had higher mean native warm-season grass biomass and grass species richness, and lower Smooth Brome biomass compared to the control. Mean Kentucky Bluegrass biomass decreased in all restoration treatments except the interseed and herbicide treatment. Introduction Grasslands are at risk across the globe, facing increasing alterations away from their natural states (Burke et al. 2020, Grant et al. 2020, Liu et al. 2019, Wick et al. 2016). In the United States, Great Plains grasslands have faced the most impacts, primarily through conversion to agriculture due to the high productivity of grassland soils (Burke et al. 2020, Grant et al. 2020, Liu et al. 2019, Masters et al. 1996, Wick et al. 2016). An estimated 82% to 99% of native grasslands have been altered or converted to other uses (Samson and Knopf 1994) with pronounced regional differences. For example, the extent of tallgrass prairie has been reduced by an estimated 96.8% (Wick et al. 2016). In the northern Great Plains, estimates of grassland losses are roughly 70%, with land development and invasive species cited as the most substantial factors in this reduction (Samson et al. 2004). The remaining grasslands lack native plant diversity because of alterations to historic management regimes. Grassland plant diversity has been hindered due to increases in urban/ suburban sprawl, production agriculture, energy demand, introductions of invasive species, alterations of natural fire regimes, and poorly managed livestock (Blackburn et al. 2020, Grant et al. 2020, Masters et al 1996, Wick et al. 2016). Limitations to historic grazing and natural fire regimes have altered grasslands, creating favorable conditions for invasive species, specifically Poa pratensis L. (Kentucky Bluegrass) and Bromus inermis Leyss. (Smooth Brome) (Dornbusch et al. 2020, Grant et al. 2020, Palit et al. 2021). These invasions have decreased northern Great Plains native floristic diversity (DeKeyser et al. 2009, DeKeyser et al. 2013, Fink and Wilson 2011, Grant et al. 2020, Larson et al. 2001, Sinkins and Otfinowski 2012), and have resulted in corresponding declines in ecological processes and ecosystem services generated by native plant communities (Toledo et al. 2014). 1Coastal Fisheries Division, Texas Parks and Wildlife Department, 4200 Smith School Rd., Austin, Texas 78744-3218 USA. 2School of Natural Resource Sciences, North Dakota State University, Department 7680, P.O. Box 6050, Fargo, ND 58108-6050 USA. *Corresponding author: edward. dekeyser@ndsu.edu Associate Editor: Jennifer Larson, United States Forest Service Perennial Cool-Season Invasive Grasses of the Northern Great Plains Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 80 Kentucky Bluegrass has increased in ground coverage since 1978 (Dennhardt et al. 2021) and is a dominant invasive species within the northern Great Plains (Cully et al. 2003, DeKeyser et al. 2013, DeKeyser et al. 2015, Dennhardt et al. 2021, Grant et al. 2009, O’Brien 2014, Palit et al. 2021, Toledo et al. 2014). In North Dakota, Kentucky Bluegrass was found on well over 50% of assessed rangeland sites based on surveys performed for the National Resources Inventory (Toledo et al. 2014). The dominance of Kentucky Bluegrass can be attributed to its rapid reproduction and development, strong presence in soil seedbanks, ability to alter plant-soil feedbacks, and capacity to develop densely-rooted rhizomatous mats (Palit et al. 2021). Despite Kentucky Bluegrass being an invasive species, it is still commonly accepted by regional landowners due to its forage value for livestock. However, once native pastures are dominated by Kentucky Bluegrass, there are reductions and alterations away from complex plant community compositions (DeKeyser et al. 2015). Smooth Brome also has become dominant across many native prairies, largely due to its forage value and its ability to rapidly colonize (Hendrickson and Lund 2010, Salesman and Thomsen 2011, Slopek and Lamb 2017). Smooth Brome can take over native species’ niches through its quick establishment of close-knit rhizomes and its ability to alter feedback cycles through changes in litter accumulation and nitrogen conversion processes (Piper et al. 2015, Slopek and Lamb 2017, Vinton and Goergen 2006). Smooth Brome can reduce plant diversity by as much as 70%, with impacts commonly noted in highly disturbed areas (Piper et al. 2015). Monocultures formed by Smooth Brome can diminish available forage, reduce ecosystem services, and degrade habitat for fauna dependent on diverse grassland ecosystems (Hendrickson and Lund 2010, Salesman and Thomsen 2011); thus, prompting the need for restoration of plant diversity throughout the northern Great Plains (Hendrickson and Lund 2010, Piper et al. 2015, Salesman and Thomsen 2011). Efforts have been made over the years to restore the native plants on sites that were previously cropped and invaded by Smooth Brome and Kentucky Bluegrass. The goals of restoration projects often include increasing a site’s plant diversity and limiting invasive species (Corbin et al. 2004, Jackson 1999, Rook et al. 2011). Plant diversity plays an important role in ensuring ecosystem production, function, and resilience (Isbell et al. 2011, Tilman et al. 2006, Tilman et al. 2014). Plant diversity also influences the spread of plant seeds, pollination, control of weedy and pest species, nutrient cycling through living and non-living components, and soil properties (Diaz et al. 2006). Increasing plant diversity by reducing invasive species can be difficult because the invasive species may have altered sites to the point where feedback loops favor invasive species (Sheley et al. 2010, Vinton and Goergen 2006). Herbicide applications may aid in the preparation of sites prior to grassland restoration of sites dominated by invasive species (Endress et al. 2012, Jackson 1999, Samson and Moser 1982, Waller and Schmidt 1983). Bahm et al. (2011) and Ereth et al. (2017) found herbicides to be useful tools limiting the cover of both Smooth Brome and Kentucky Bluegrass, especially when paired with other treatments. In areas where desirable native plant species remain, interseeding native seeds into the existing plant community may increase the abundance of other desired native species; interseeding is less invasive to the existing plant community and soil than seeding methods which may require extensive site preparation and/or tillage (Bailey and Martin 2007, Dixon et al. 2017, Link et al. 2017, Rossiter et al. 2016). However, if competitive invasive species are present within the existing plant community, several years of management practices specifically targeting the invasive species may be necessary to prepare a site for potential enhancement through interseeding (Dixon et al. 2017). Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 81 Prescribed fire and grazing play key roles in the management of grassland systems, both before and after restoration. Historically, grazing and natural fire regimes were present throughout the Great Plains (Blackburn et al. 2020, Dornbusch et al. 2020, Gates et al. 2017, Grant et al. 2020, Masters et al. 1996). Historic fire and grazing were decreased in frequency and scale in the early 1900s when grasslands were converted to provide for growing agricultural demands (Grant et al. 2020). As a result, the survival and growth of native species adapted to historical disturbance regimes were hindered and the altered conditions promoted the establishment of highly competitive invasive species, such as Kentucky Bluegrass and Smooth Brome (Dixon et al. 2019, Grant et al. 2020, Wick et al. 2016). Grazing influences on grasslands can be predominately attributed to the frequency and intensity of the grazing (Launchbaugh 2003). Both resting and overgrazing native grasslands can result in the invasion of Kentucky Bluegrass and Smooth Brome (Grant et al. 2020, Launchbaugh 2003). Thus, when grazing is used as a restoration or management technique, a balance must be found between grazing too heavily and not grazing enough to support site plant diversity. Given the ability of Kentucky Bluegrass and Smooth Brome to initiate growth prior to native species, the timing of grazing has the potential to differentially impact these species (Dornbusch et al. 2020, Grant et al. 2020, Smart et al. 2013). Prescribed burning has the potential to support plant diversity while suppressing invasive species (Burke et al. 2020, Dornbusch et al. 2020, Jackson 1999). Control methods for Kentucky Bluegrass often incorporate prescribed burning to reduce the species’ spread; however, timing is a key element in the prescribed burn’s effectiveness (Dennhardt et al. 2021, Kral et al. 2018). Information about the frequency of prescribed burns has suggested a consistent burning pattern of 2-year increments (Li et al. 2013) although Kral et al. (2018) found that burning outside the active growing season resulted in reducing Kentucky Bluegrass spread for up to 3 years following the application. Due to the pervasiveness of Kentucky Bluegrass and Smooth Brome, and the complex ecological factors at play for any given site, there is a need to provide land managers, especially ranchers, with workable strategies for site restoration. The objective of this research was to assess the long-term impacts of various site preparation methods coupled with interseeding, and the influence post-management practices have toward increasing native plant biomass and overall species richness on a degraded grassland without compromising the use of the area for livestock. Methods This research is a continuation of a long-term study (Huffington 2011, Link 2014, Link et al 2017, Stallman 2020) originating in 2010. Re-sampling data from 2020 and 2021 are evaluated in this paper. The study was conducted on approximately 12 ha of restored grassland located on the Albert K. Ekre Grassland Preserve in Richland County, North Dakota (46°32’31.31”N, 97°8’34.92”W). The mean annual temperature of the study region was 5.67 °C (1991–2020), with the mean maximum temperate being 11.83°C, and the mean minimum temperature being -0.4 °C based on climatic readings from McLeod 3E station (NOAA 2021). Mean annual rainfall over the same period was 60.93 cm, with peak precipitation occurring during the summer in June. In early 2020, the northern Great Plains were largely free of drought, however drought conditions began to develop in the spring of 2020. The drought conditions intensified and persisted until a peak in late summer 2021 (Umphlett et al. 2022). During the 2020–2021 drought, North Dakota experienced 50–70% reductions in pasture, rangeland, and hay productions. The soils at this site are primarily loamy to fine Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 82 sands (USDA-NRCS 2014a) and moderately well drained. The prairie vegetation within the region typically includes Andropogon gerardii Vitman (Big Bluestem), Panicum virgatum L. (Switchgrass), Sorghastrum nutans (L.) Nash (Indiangrass), and Schizachyrium scoparium (Michx.) Nash (Little Bluestem) (USDA-NRCS 2014b). The study site was cultivated prior to the 1970s when the site was seeded with grasses (Huffington 2011, Link 2014, Link et al. 2017). The site was grazed by cattle from the 1970s through 2010 and the plant community was dominated by Kentucky Bluegrass and Smooth Brome. Site preparation and restoration began in 2010 when a study to assess the effectiveness of various restoration and management techniques was installed. The study site was divided into 30 40 x 100 m plots and 5 restoration treatments were installed in 6 blocks (Fig. 1). The treatments included: 1) control (no restoration treatment, therefore the current invasive grass-dominated vegetation); 2) interseeding (native seed was drilled into existing plant community without any measures to reduce competition during site preparation, henceforth “seed”); 3) spring burn prior to interseeding, henceforth “burn + seed”; 4) glyphosate application prior to interseeding, henceforth “seed + herbicide”; 5) spring burn and glyphosate application prior to interseeding , henceforth “burn + seed + herbicide”. All burning and herbicide applications took place 3 weeks before interseeding to decrease potential negative impacts to seed germination and seedling health. Herbicide appli- Figure 1. Study site showing the 30 40 x 100 m plots and five restoration treatments installed in six blocks. C = Control (no restoration treatment, therefore the current invasive grass-dominated vegetation); S = Seed (interseeded native seed drilled into existing plant community); BS = Burn + Seed (spring burn prior to interseeding); SH = Seed Herbicide (glyphosate application prior to interseeding); BSH = Burn + Seed + Herbicide (spring burn and glyphosate application prior to interseeding). Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 83 cations used glyphosate (RoundUp® Concentrate Plus:The Scotts Company LLC, Worldwide Rights Reserved) mixed at a 60:1 ratio with water. A boom sprayer set to a rate of 23 L/ha was used to apply treatments. Initial burn treatments were applied as strip burns leading to predominantly head fires. Interseeding was conducted in July of 2010, due to a wet spring, 3 weeks after glyphosate was applied. Interseeding used a FLEX II drill model FLXII-818 (Truax) set to a depth of 0.25–1.25 cm with 20 cm spacing. The seed mixture consisted of 13 native prairie grasses and 2 native clover species and was based on dominant species listed in ecological site descriptions for the area (Major Land Resource Area 56; USDA-NRCS 2014b) and seeded at rates intended to reflect the composition of historic plant communities (Table 1). Species were included in the seed mix to enhance the historic native component of the plant community and improve forage availability. Species were selected based on what was absent in the existing plant community (i.e., native species representative of tallgrass prairie communities) and able to provide suitable forage for livestock in a relatively short time; thus, the emphasis on grasses and inclusion of 2 native clovers. To protect native seed establishment, grazing was removed from the study site prior to the seeding application in 2010 and the site remained ungrazed until the following spring (2011). From 2010 through 2013, grazing was excluded from half the study area, with half the site being rotationally grazed, and half excluded from grazing using fencing. In 2013, Table 1. Species composition and seeding rates for native species included in the seed mix applied in 2010. Seeds were obtained from Millborn Seeds of Brookings, South Dakota. Seeding rates were intended to reflect the historic plant community composition of tallgrass prairies in southeastern North Dakota. Scientific Name Common Name & Variety Rate (kg/ha) Hesperostipa spartea Porcupinegrass – South Dakota Native Collection 0.11 Koeleria macrantha Prairie Junegrass 0.11 Spartina pectinata Prairie Cordgrass – Red River Germplasm 0.17 Bouteloua gracilis Blue Grama – Bad River 0.17 Dalea purpurea Purple Prairie Clover 0.28 Dalea candida White Prairie Clover 0.28 Sorghastrum nutans Indiangrass – Tomahawk 0.28 Nasella viridula Green Needlegrass – Lodorm 0.28 Andropogon hallii Sand Bluestem 0.34 Pascopyrum smithii Western Wheatgrass – Rodan 0.56 Panicum virgatum Switchgrass – Dakota 0.56 Schizachyrium scoparium Little Bluestem 0.56 Elymus canadensis Canada Wildrye – Mandan 0.56 Calamovilfa longifolia Prairie Sandreed – Goshen 1.12 Andropogon gerardii Big Bluestem – Bison 2.69 Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 84 there were no apparent differences attributable to grazing (Link 2014) and the entire study site has been grazed since 2014 using a twice over rotation. An additional prescribed burn occurred in April of 2020, over the complete study site area and was followed by twice over rotational grazing in the same growing season. Initial evaluations of the plant community began in 2012 with vegetation surveys conducted in 2012, 2013, 2014, 2015, 2019, 2020, and 2021 (reported by Huffington 2011, Link 2014, Link et al. 2017, Polgar 2022, and Stallman 2020). The current study reports on the restored tallgrass plant community as sampled in 2020 and 2021; the burn plots refer to those that received a burn as site preparation in 2010, rather than the prescribed burn in 2020. Biomass production and grass species richness were estimated through clipping 8 randomly stationed 0.25 m2 quadrats per treatment plot. Biomass was obtained for individual grass species, while forb, sedge, and shrub biomass were aggregated. Forb, sedge, and shrub biomass was aggregated because these species were not included in the seed mix are not as important as livestock forage as grasses. One of the original objectives of the restoration of this site was to enhance the native tallgrass species component (i.e., native warm season grasses) at this site because these species were absent and provide valuable forage to livestock. The aggregated forb, sedge, and shrub biomass contributed to estimates of total biomass but were not examined separately. Biomass samples were dried for a minimum of 72 hours at a temperature of 37.78°C prior to weighing. Native warm-season grass (NWG) biomass estimates were aggregated to examine the native tallgrass prairie component at our study site. In addition, the species richness of all grass species (including introduced species) was compared among restoration treatments. We used analysis of variance (ANOVA) with Tukey’s (honestly significant difference) test (SAS Enterprise Guide 7.1 (Copyright © 2017 by SAS Institute Inc. Cary, NC, USA)) to examine whether total biomass, NWG biomass, Smooth Brome biomass, Kentucky Bluegrass biomass, and grass species richness (including introduced species and cool-season native grasses) responded to the restoration treatments (including a blocking factor) or sampling year. A log transformation (log base 10) was applied to total biomass and Kentucky Bluegrass biomass to meet distributional assumptions. A log transformation was not applied to Smooth Brome biomass because its application increased skewness. Log transformations were not performed on NWG and species richness because these variables met distributional assumptions. Results ANOVA indicated (F14,45 = 7.48, P = < 0.0001) mean total biomass responded to restoration treatment (P = 0.0003) and sampling year (P = < 0.0001). Mean total biomass was highest in the seed + herbicide treatment (mean = 4,075.60 kg/ha) (Fig. 2A). Seed only, burn + seed, and burn + seed + herbicide treatments were not different from the control. Mean NWG biomass responded (F14,45 = 15.20, P = < 0.0001) to treatment (P = < 0.0001) and year (P = < 0.0001), with a significant interaction term (Treatment x Year, P = < 0.0001). Mean NWG biomass was higher in all treatment plots than control plots (Fig. 2B). Seed + herbicide plots had greater NWG mean biomass (mean = 2,606.60 kg/ha) than burn + seed plots (mean = 1,835.20 kg/ha) and seed only plots (mean = 1,765.30 kg/ha) (Fig. 2B). Mean total biomass was higher in 2020 (mean = 3,745.50 kg/ha) than 2021 (mean = 2,354.20 kg/ ha) (Fig. 3A). Mean NWG biomass was higher in 2020 (mean = 2,265.535 kg/ha) than 2021 (mean = 1,212.725 kg/ha) (Fig. 3B). Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 85 Figure 2. Average (± SD) aboveground biomass (A), native warm-season grass biomass (B), Smooth Brome biomass (C), and Kentucky Bluegrass biomass (D) by restoration treatment. Significant differences are indicated by different letters (P < 0.05). Figure 3. Average (± SD) total biomass (A) and native warm-season grass biomass (B) by year. Significant differences are indicated by different letters (P < 0.05). Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 86 Mean Smooth Brome biomass differed (F14,45 = 4.58, P = < 0.0001) by restoration treatment (P = < 0.0001) and block (P = 0.007). Smooth Brome biomass was higher in control plots (mean = 514.70 kg/ha) than all other treatments (Fig. 2C). Mean Smooth Brome biomass was higher in blocks 1 (mean = 344.30 kg/ha) and 2 (mean = 358.70 kg/ha) than in block 4 (mean = 125.40 kg/ha). Mean Kentucky Bluegrass biomass responded (F14,45 = 4.15, P = 0.0001) to restoration treatment (P = < 0.0001) and block (P = 0.0038). Kentucky Bluegrass biomass was higher in control plots (mean = 708.60 kg/ha) than seed only (mean = 359.20 kg/ha), burn + seed (mean = 393.10 kg/ha), and burn + seed + herbicide (mean = 218.40 kg/ha) plots (Fig. 2D). Mean Kentucky Bluegrass biomass was lower in the burn + seed + herbicide plots than control plots (mean = 708.60 kg/ha) and seed + herbicide (mean = 423.50 kg/ha) plots (Fig. 2D). Mean Kentucky Bluegrass biomass was also higher in block 1 (mean = 641.58 kg/ha) than blocks 3 (mean = 343.80 kg/ha) and 5 (mean = 253.56 kg/ha). Mean grass species richness responded (F14,45= 6.20, P = < 0.0001) to treatment (P = < 0.0001) and block (P = 0.0024). All restoration treatments had higher average grass species richness when compared to the control (Fig. 4). Mean grass species richness was not significantly different across restoration treatments. Blocks 3 (mean = 5.275 grass species) and 6 (mean = 5.025 grass species) were significantly different from block 1 (mean = 3.9875 grass species). Figure 4. Average (± SD) grass species richness by treatment. Significant differences are indicated by different letters (P < 0.05). Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 87 Discussion Our current results suggest there is potential to enhance the native plant community component of grasslands while preserving biomass by strategically employing site preparation, restoration, and management enhancement techniques, i.e., interseeding into the existing plant community and using grazing, herbicide applications, and/or prescribed burning. However, it can be difficult to draw firm conclusions about specific techniques due to the dynamic aspects of prairie plant communities and site-specific differences. Previous research at our study site indicated interseeding paired with herbicide applications (seed + herbicide) resulted in the highest production of NWG biomass and total biomass (Huffington 2011, Link et al. 2017, Stallman 2020). Our current results also showed the seed + herbicide treatment had higher total biomass and NWG biomass than the control and, thus, demonstrating an improvement in NWG composition without compromising overall forage production for cattle. Smooth Brome biomass was reduced under the seed + herbicide treatment, although there was no apparent impact on Kentucky Bluegrass biomass. The combination of interseeding with a spring burn and glyphosate application (burn + seed + herbicide) was found to have the lowest biomass of both target invasive species while also producing a similar amount of NWG biomass as the seed + herbicide treatment. The single application of glyphosate as site preparation in 2010 seems to have resulted in a meaningful impact on invasive species control 10 years later by allowing the interseeded species to establish. The inclusion of an additional prescribed burn (in 2020) followed by rotational grazing may have aided in the reduction of both invasive species observed in our study. Likewise, findings from multiple other studies have indicated the value of prescribed burns and grazing applications for invasive species control (Ahlering et al. 2020, Dornbusch et al. 2020, Gasch et al. 2020). Our current study contributes to a body of research demonstrating that combining a variety of measures to control invasive species can result in more success than employing a single method (Collins et al. 1998, Sheley et al. 2010, Taylor et al. 2013). The pairing of prescribed burning with herbicide applications and interseeding followed by active management was successful in reducing the prevalence of Kentucky Bluegrass and Smooth Brome, despite many studies documenting the difficulty of finding restoration methods that are successful in controlling both invasive species at once (DeKeyser et al. 2013, DeKeyser et al. 2015, Hendrickson and Lund 2010, Link et al. 2017, Murphy and Grant 2005). Further, our control plots had higher Kentucky Bluegrass and Smooth Brome biomass and lower NWG biomass and mean grass species richness, validating the utility of our treatments toward enhancing working grasslands. Similarly, Bakker et al. (2003) and Leahy et al. (2020) found invasive species control measures utilizing interseeding treatments had the most positive impact when employed in conjunction with other treatment methods. Endress et al. (2012) and Taylor et al. (2013) also reported on the successful use of herbicide in conjunction with interseeding for the reduction of invasive species. Ecosystem services (erosion control, filtration, carbon sequestration, etc.) respond differently to management strategies (seeding rates, seed mix composition, burns, grazing, etc.) and prevalent weather conditions making it important to reduce response uncertainties through applying an adaptive management approach (Delaney et al. 2016, Grant et al. 2020, Palit et al. 2021). The drought experienced in the northern Great Plains during the years included in our current study influenced total biomass production and NWG biomass production within the study site, resulting in a decline between 2020 and 2021. These results echo points considered by Guo et al. (2012), Knapp (1984), Knapp et al. (2015), and Dennhardt et al. (2021), detailing the impact increased precipitation, as was the case at our study site in Prairie Naturalist M. Polgar, B. Kobiela, and E. DeKeyser 2024 Special Issue 2 88 2020, can have on the production of grassland vegetation, with periods of drought producing declines in vegetation cover (Heitschmidt et al. 2005). Increased precipitation within the northern Great Plains can result in alterations to plant community compositions (Dennhardt et al. 2021), with some studies connecting increases in Kentucky Bluegrass to higher precipitation (Nie et al. 1992, Patton et al. 2007, Weaver 1954). Grasslands affected by prolonged periods of low rainfall tend to see declines in plant diversity (Harrison et al. 2015), with the potential to experience plant community shifts towards greater invasive species dominance (Moran et al. 2014). Within the northern Great Plains, where cyclical periods of drought and high precipitation are historically present (van der Valk 2005), native grassland species are adapted to these fluctuations and may prevail over invasive plants (Dennhardt et al. 2021, Weaver 1954). Clark et al. (2002) and Heitschmidt et al. (2005) found forage biomass declines following extended droughts, with Heitschmidt et al. (2005) indicating biomass was reduced by 20–40% with the most declines in perennial C3 grasses following spring drought. Restoration of native grasslands can result in increased biomass during times of low precipitation because many NWG species are better equipped to withstand decreased moisture availability (Jackson 1999). Sites with higher plant diversity are able to utilize resources within a variety of different niches, supporting their ability to maintain a greater consistency of production during times of stress (Hooper 1998, Hooper et al. 2005, Tilman et al. 2006). Kentucky Bluegrass maintains palatability during the majority of the year, however, in months with limited moisture and above average temperatures, the forage quality of Kentucky Bluegrass can decline in comparison to native species (Gasch et al. 2020, Jackson 1999). Native warm season grasses can better utilize stored soil moisture because of their rooting depth and mass, increasing their survival (Biondini 2007, Daigh et al. 2014) and maintaining production. Ecological communities high in plant diversity have improved yields (Biondini 2007, Tilman et al. 1996), carbon capture levels (Yang et al. 2019), tolerance to disturbance (Biondini 2007), and resistance to species (Biondini 2007, Tilman et al. 2014). The results of this grassland restoration project demonstrate restoration efforts have a positive impact on vegetation production and species richness, both of which are valuable assets to producers and society as a whole. Further research is needed to evaluate the impact post-management prescribed burns and grazing regimes have on biomass production, species richness, and the continued control of Kentucky Bluegrass and Smooth Brome throughout the northern Great Plains. 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