Are we close enough? Comparing prairie reconstruction chronosequences to remnants following two site preparation methods in Missouri, U.S.A.

Abstract

Prairie reconstruction has become a common method for reestablishing tallgrass prairie communities in the central United States. With the objective of creating plant communities that approximate remnant (reference) prairies, managers are interested in identifying: (1) best methods for reconstructing reference community conditions; (2) the rate of change in plant communities through time following reconstruction; and (3) species present in remnant communities but missing from reconstructed communities. This information is important in the development of adaptive management strategies during active reconstruction. We used a chronosequence approach to assess the success of two reconstruction methods in emulating local, reference remnant prairie plant communities. We compared broadcast dormant seeding following two types of site preparation, agricultural cropping (Crop) or herbicide control in existing grass assemblages (Grass), and remnant communities. The Crop site preparation method resulted in a rapid increase in richness shortly following seeding. Although more similar to remnant assemblages initially, the Grass method took longer for mean coefficient of conservatism and floristic quality index to approach conditions of the reference communities. However, neither method resulted in plant community compositions that converged with the reference through time. Further, indicator species analysis identified a diverse assemblage of species lacking from the reconstructed prairies. These results suggest the need to develop management strategies for establishing the “missing” species during reconstruction and provide further support for protection and conservation of existing remnant prairies.

Evidence for local‐scale community assembly processes from long‐term observations of biodiversity in a grassland chronosequence

“…The overall increase in C cwm is encouraging from the standpoint of successful reconstruction of a high-quality prairie community. Cvalues increased quickly in the first 6-8 years after prairie plantings in Iowa (Carter & Blair, 2012) and Missouri (Newbold et al, 2020).…”

“…The overall increase in C cwm is encouraging from the standpoint of successful reconstruction of a high‐quality prairie community. C ‐values increased quickly in the first 6–8 years after prairie plantings in Iowa (Carter & Blair, 2012) and Missouri (Newbold et al, 2020). However, over a longer time more comparable to our study, Hansen and Gibson (2014) found that mean C ‐values decreased over a 20‐year chronosequence of prairie restorations at Nachusa Grasslands in Illinois.…”

A chronosequence of soil health under tallgrass prairie reconstruction

“…In contrast, the older PFCA sites (9 to 13-yr) were previously under long-term cultivation for more than 20 yr (personal communication with Jeff Demand, site historical manager). The prairie reconstruction at PFCA employs a variety of management strategies and techniques, including: (1) site preparation; (2) seeding native plants collected from nearby native prairies (<75 km) including Tucker Prairie; and (3) mowing, prescribed fire, and exotic species control for establishment and maintenance of the natural plant communities (Newbold et al, 2019). Site preparation included two treatments to remove undesirable species: (1) 3-, 4-, 6-, 9-, 13-yr PFCA were prepared using notill cropping of glyphosate-resistant crops (e.g., soybeans or corn) for ≥3 yr prior to seeding prairie species; and (2) 2-, 10-, 11-, 12-yr sites were prepared using nonnative and native grass planting followed by 1-2 yr of herbicide applications.…”

“…In many ecosystem reconstruction projects, parameters increase rapidly during the first several years then level off in late successional conditions (Brown, 1991;Baer et al, 2002). A plant community study conducted at PFCA in July 2017 found that native plant community indices (floristic quality and species richness) initially increased with prairie reconstruction, but plateaued after 4-yr and did not decline (Newbold et al, 2019). Other studies have reported declines in older reconstruction sites (Sluis, 2002;Camill et al, 2004;Hansen and Gibson, 2014).…”

Milkweed Establishment in Restored Central Missouri Prairie

“…Greater than 180 species of grasses and forbs were established in the reconstructed prairies on PFCA, including many species with high coefficients of conservatism (Ladd and Thomas 2015, Newbold et al 2019). However, as a result of grass competition, milkweeds and other forbs were not as abundant as desired.…”