Dominance of warm-season grasses modulates tallgrass prairie ecosystem structure (e.g., community composition) and function (e.g., net primary production). Reintroduction of these grasses is a widespread practice to conserve soil, improve water quality, and restore tallgrass prairie ecosystems degraded from human land use changes such as agriculture. Seed sources for re-introduction of dominant prairie grass species include non-cultivar (collected from local remnant prairie) and selected (cultivar) populations. The overall objective of this study was to quantify whether intraspecific variation in developing root systems exists between population sources (non-cultivar and cultivar) of three dominant grasses used in restorations: Andropogon gerardii (big bluestem), Sorghastrum nutans (Indiangrass), and Schizachyrium scoparium (little bluestem). Non-cultivar and cultivar population sources of each species were isolated and grown in 7.62-cm diameter x 20 cm depth PVC cores inserted in a newly established experimental tallgrass prairie restoration at the Konza Prairie Biological Station (KPBS), Manhattan, KS. Non-cultivar source population seeds were collected from local remnant ecotypes at KPBS and recommended cultivar seeds were acquired from the USDA. I measured above- and below-ground net primary production (ANPP and BNPP), root architecture (root length, surface area, and volume), root tissue quality, and plant available inorganic nitrogen in each core at the end of the first growing season. Cultivars tended to have greater root length, surface area, and volume than non-cultivars for both S. nutans and S. scoparium . Two important soil resources, available inorganic N and water, were present in lower amounts in soil proximal to roots of cultivars than non-cultivars. Additionally, soil nitrate was negatively correlated with root volume in S. nutans and A. gerardii cultivars. Conversely, there were no correlations between soil N and root architecture among non-cultivars. While cultivars had greater below-ground net primary productivity (BNPP) than non-cultivars, this was not reflected above-ground, where ANPP was not different between cultivars and non-cultivars. There were no intraspecific differences in percent N, resulting in no difference in root tissue quality among species or sources. Overall, my results suggest there are some differences between cultivar and non-cultivar sources of the dominant prairie grasses used in restoration. These phenotypic differences may scale up to affect community and ecosystem properties, and consequently should be taken into consideration in the context of setting restoration goals and objectives.

More than forty percent of our country was once open prairie, grassland that extended from Missouri to Montana. Taking a critical look at this little-understood biome, award-winning journalist Richard Manning urges the reclamation of this land, showing how the grass is not only our last connection to the natural world, but also a vital link to our own prehistoric roots, our history, and our culture. Framing his book with the story of the remarkable elk, whose mysterious wanderings seem to reclaim his ancestral plains, Manning traces the expansion of America into what was then viewed as the American desert and considers our attempts over the last two hundred years to control unpredictable land through plowing, grazing, and landscaping. He introduces botanists and biologists who are restoring native grasses, literally follows the first herd of buffalo restored to the wild prairie, and even visits Ted Turner's progressive--and controversial--Montana ranch. In an exploration of the grasslands that is both sweeping and intimate, Manning shows us how we can successfully inhabit this and all landscapes.

Ecological restoration aims to augment and steer the composition and contribution of propagules for community regeneration in degraded environments. Three studies were conducted to elucidate the role of regeneration dynamics and dominant species on community assembly during tallgrass prairie restoration. In the first study, patterns in the abundance, richness, and diversity of seed and bud banks were quantified across an 11-year chronosequence of restored prairies and in prairie remnants to elucidate the degree to which the germinable seed bank, emerged seedlings, belowground buds, and emerged ramets were related to community regeneration. There were no directional patterns in the abundance, richness, or diversity of the germinable seed bank across the chronosequence. Emerged seedling abundance of sown species decreased during restoration, whereas richness and diversity of all emerged seedlings and non-sown emerged seedling species decreased across the chronosequence. Conversely, abundance and richness of belowground buds increased with restoration age and belowground bud diversity of sown species increased across the chronosequence. Numbers of emerged ramets also increased across the chronosequence and was driven primarily by the number of graminoid ramets. There were no temporal changes in abundance and richness of sown and non-sown emerged ramets, but diversity of sown emerged ramets increased across the chronosequence. This study demonstrates that after initial seeding, plant community structure in restored prairies increasingly reflects the composition of the bud bank. In the second study, abundance and richness of ramets, emerged seedlings, seed rain, and the soil seed bank were measured in a restoration experiment consisting of a split plot design with population source of dominant grasses (cultivar vs. local ecotype) and sown subordinate species (three unique pools of non-dominant species) as the subplot factor, respectively. Different sown species pools were included to assess whether any observed differences in propagule abundance or richness between the dominant species sources was generalizable across varying interspecific interactions. Abundance of emerged ramets was similar between communities sown with cultivar and local ecotypes of the dominant grasses but differed among sown species pools in prairie restored with cultivars but not local ecotypes. Number of emerged seedlings also differed among species pools, but only in communities sown with local ecotypes of the dominant grasses. There was also higher seedling emergence in communities sown with local ecotypes relative to cultivars of the dominant grasses in one species pool. Richness of the seed rain was influenced by an interaction between dominant grass population source and sown species pool, resulting from (1) higher richness in prairie restored with local ecotypes than cultivars of the native grasses in one species pool and (2) differences in richness among species pools that occurred only in prairie restored with the local ecotype grass source. Abundance and richness of the seed bank was not affected dominant grass population source. This study addressed a poorly understood potential effect of using cultivars in ecological restoration, specifically on the abundance and supply of propagules for community assembly. These results suggest that if both local ecotype and cultivar sources are available for restoration, using local ecotypes could result in more seedling germination and richness in the seed rain. One of the central concepts of ecology is to understand the processes that influence species diversity, and how the resulting diversity affects ecosystem functioning. Diversity has been hypothesized to be responsible for long-term community stability, contrasted by the idea that dominant species regulate temporal stability (mass ratio hypothesis). In the third study, community metrics (total plant cover, forb cover, C4 grass cover, richness, and diversity) were measured in a restoration experiment consisting of a split plot design with sown dominant grasses (Andropogon gerardii, Schizachyrium scoparium, and Sorghastrum nutans) and subordinate species (three unique pools of non-dominant species) as the subplot factor, with treatment (control vs. suppression of dominant grasses) as the sub-subplot factor, respectively. Dominant grass suppression had little effect on forb cover, richness, and diversity, but influenced total and C4 grass cover. Propagule addition increased community richness and diversity in year of sowing and year after sowing, but contributed little to total cover. Dominant grass suppression had an effect on new species recruitment in one of two species pools, with suppression of all dominant grasses having the greatest influence on total cover and richness of new species. These results suggest that dominant species collectively are responsible for modulating stable species composition during community assembly and can act as a biotic filter to the recruitment of new species, but diverse subordinate species assemblages are more important for temporal stability.

This book is the most up to date and thorough account of the natural history of the plants that comprise the most important food crop on Earth, the grasses and grasslands.