Invasive Species Change Plant Community Composition of Preserved Prairie Pothole Wetlands

Abstract

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

Climate and Land Use Driven Ecosystem Homogenization in the Prairie Pothole Region

“…The rise of invasive cattails and reed canary grass in shallow-marsh and wet-meadow zones has been observed in other studies within the region as well [94,104]. Jones, 2022, [74]) found that for many wetlands restored in North Dakota where heavily invaded by non-native cool season grasses, this was likely attributed to weak, natural wetland seed banks and mechanically seeding the upland areas to cool season gasses that make up dense nesting cover. While the observed loss of vegetation structure and native species and increases in invasive species in prairie-pothole wetland plant communities appears to be a common pattern, the response of aquatic animal communities to habitat simplification has been less predictable [54], although shifts in aquatic plant communities would affect other organisms within these wetlands [119,120].…”

“…Non-native grasses, primarily smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis), have invaded many remaining grasslands in the region [71][72][73]. Even in areas where wetlands and grasslands are restored, the revegetation of wetlands is limited to occurring seedbanks and the seeding of upland grass seed mixes [74]. In North Dakota, the absence of wetland-specific seed mixes during restoration has likely facilitated the replacement of native vegetation with non-native cool season grasses and other invasive species [74].…”

“…Homogenization of other prairie-pothole ecosystem attributes threaten their important landscape functions and the societal benefits they provide. The increased presence of more monotypic stands of non-native vegetative communities in the wetland marsh zones has been attributed to a decline in native wetland plant communities [74,95,112] and has been found to limit the abundance of certain secretive marsh bird densities [138,139]. However, the impacts of homogenized plant communities dominated by invasive plant species and other land-use related effects on wetland aquatic animal species (e.g., aquatic invertebrates and amphibians) are relatively unknown.…”

Development of genomic resources for cattails (Typha), a globally important macrophyte genus

“…The markers that differentiate T. angustifolia from T. latifolia will have important applications in North America, where the two species interbreed across a large area and produce an invasive interspecific hybrid (T. × glauca) that dominates wetlands, alters nutrient cycling, and reduces biodiversity across the Great Lakes Region (Bansal et al, 2019); additionally, this hybrid is expanding throughout the Prairie Pothole Region, causing native plant diversity to decrease in invaded potholes (Jones et al, 2023), and may impact essential habitat for millions of breeding and migratory waterfowl species (Tangen et al, 2022). Until now, molecular resources to differentiate T. angustifolia, T. latifolia, and T. × glauca were limited to sets of relatively few individual markers that have produced important insights: RAPDs, chloroplast DNA sequences, and codominant SSR loci have contributed to exposing the sexual fertility of first-generation hybrids (F1) (Snow et al, 2010), asymmetric hybridization (with T. angustifolia being mainly the maternal parent) (Ball & Freeland, 2013;Kuehn et al, 1999;Pieper et al, 2017), overall comparable levels of sexual and clonal reproduction in parents and F1s (Pieper et al, 2020;Travis et al, 2011), heterosis in F1s (Bunbury-Blanchette et al, 2015Travis et al, 2010;Zapfe & Freeland, 2015), a high frequency of F1s in natural populations (Kirk et al, 2011;Travis et al, 2010), and partial sterility of F1s coupled with hybrid breakdown of F2s and advanced-generation hybrids (Bhargav et al, 2022;Pieper et al, 2017).…”

Development of genomic resources for cattails (Typha), a globally important macrophyte genus

“…Furthermore, T. domingensis is increasingly invading regions in Nigeria (Ringim et al, 2016), Costa Rica (Trama et al, 2017) and North America, potentially expanding its range across the latter (Spencer & Vincent, 2013;Zhang et al, 2008). However, the taxonomic identity of these plants is unclear--Are they hybrids, non-native lineages, native lineages responding to environmental change, or misidentified T. angustifolia (Bansal et al, 2019) The markers that differentiate T. angustifolia from T. latifolia will have important applications in North America, where the two species interbreed across a large area and produce an invasive interspecific hybrid (T. × glauca) that dominates wetlands, alters nutrient cycling and reduces biodiversity across the Great Lakes Region (Bansal et al, 2019); additionally, this hybrid is expanding throughout the Prairie Pothole Region, causing native plant diversity to decrease in invaded potholes (Jones et al, 2023), and may impact essential habitat for millions of breeding and migratory waterfowl species (Tangen et al, 2022). Until now, molecular resources to characterise T. angustifolia, T. latifolia and T. × glauca were limited to sets of relatively few individual markers that have produced important insights:…”