Distribution and Abundance of Prairie Plant Species in the Loess Hills

The species composition of grassland and ecotonal communities throughout the Loess Hills was studies between 1990 and 1993. Information pertaining to the latitudinal distribution of species in the Loess Hills, the abundance of species among community types (i.e., habitats), species persistence under woody encroachment, species associations, and resource partitioning among species is provided for the majority of grassland species occurring in the Loess Hills. The most abundant species on extant prairie in the Loess Hills include Bouteloua curtipendula (side-oats grama), Schizachyrium scoparium (little bluestem), Andropogon gerardii (big bluestem), Cornus drummondii (rough-leaved dogwood), Aster ericoides (heath aster), Carex heliophila (sun-loving sedge), Sisyrinchium camppestre (blue-eyed grass), Dichanthelium oligosanthes (Scribner\u27s panic grass), Amorpha canescem (lead plant), and Asclepias verticillata (whorled milkweed)

Community Composition of Dry Prairie in Iowa and Southeast Nebraska

Results from quantitative research on the community composition of dry prairies across Iowa were consolidated from three different studies completed since 1983. Information is provided on the distribution and abundance of 204 dry prairie species. The most abundant species included little bluestem (Schizachyrium scoparium (Michx.) Nash), big bluestem (Andropogon gerardii Vitman), side-oats grama (Bouteloua curtipendula (Michx.) Torrey), prairie dropseed (Sporobolus heterolepis (Gray) Gray) and Kentucky bluegrass (Poa pratensis L.). Multivariate analyses were completed using two independent measures of species abundance-relative cover and community constancy. When relative cover was used to determine community composition, the abundance of graminoids (tallgrasses vs. mid-grasses) had a strong effect on community composition and variation was mostly influenced by soil moisture. When community constancy was used to determine community composition, forbs had a higher representation and plant biogeography had a strong effect on variation in community composition

Effects of Compost on Prairie Seedling Establishment and Seed Production

Compost is a commonly used soil amendment in horticultural and agricultural practices that is generally known to improve soil conditions and plant growth. We conducted a field experiment to investigate the application of compost to prairie production plots as a method to improve seedling establishment and growth and the seed production of established plants. We evaluated the effect of compost depth and tillage on the survivorship, growth, reproduction and ecophysiology of several prairie plant species commonly used in restoration. Results were mixed; for some species, transplants in compost–amended plots incurred lower survivorship and reduced growth compared to control plots. When compost was used for transplants, improved growth and reproduction were observed more often if compost was tilled into the soil. No benefit from compost was observed for flower and seed production in established prairie species. Compost can be useful in promoting better growth in prairie plots, but its application can produce negative outcomes under certain conditions

Natural History in Iowa: The Early Phases

Natural history in Iowa prior to the 20th Century can be conveniently arranged into 4 phases: Native American, before the Louisiana Purchase, between the Louisiana Purchase and about 1850, and after 1850. Native American natural history was extensive and had a distinctly spiritual character. Natural history was a component of European exploration up to the time of the Louisiana Purchase, but was not treated as a separate endeavor; the evidence from this period comes from the journals and diaries of early exploreres, fur traders and the like. Between the Louisiana Purchase and about 1850, natural history changed from its status as an adjunct to geographic exploration, for instance government sponsored expeditions along the rivers and Army excursions into the interior, to systematic research with natural history as the primary goal. During this period, descriptions of natural history moved from being parts of exploration narratives to reports on natural history itself. After 1850, natural history in Iowa encompassed organized, systematic efforts to record the geology, environment and biota of the state

Iowa\u27s Non-native Graminoids

Iowa\u27s non-native graminoids include 60 species of grasses and one species of bulrush. The exotic grass species comprise a large proportion (about 31%) of the total species richness of grasses in Iowa, which are second only to the Asteraceae in terms of total species. About half of the non-native graminoids (52%) occur sporadically and form sparse, non-invasive populations, while eighteen species (about 30%) are commonly encountered in large populations throughout the state. About 60% are annuals and a large majority (89%) has been introduced from either Europe or Asia. The C3 photosynthetic pathway is prevalent, occurring in approximately two-thirds of the species. Grass species introduced for use as forage or grain account for over 40% of these non-native species. Among the nine species that are most ubiquitous throughout the state, six are forage or grain species. Although considered problematic in rural communities, many of these species provide valuable grassland habitat in some areas of the state. Biological data concerning growth, life history traits, and habitat affinities are provided for many of the most common species. A review of the literature related to the control of non-native grasses is also presented. In general, herbicides showed the greatest probability of reducing the occurrence of non-native grasses (effective 65% of the rime), prescribed fire worked 47% of the rime, and mowing was least effective, reportedly working 27% of the time

The Seed Bank of a Reconstructed Prairie

Seed banks, the reserve of viable seeds dormant in the soil, function in several important roles in the population and community dynamics of plant communities. Identification of the seed bank can furnish information on the vegetation history of a habitat, predict the future composition of the plant community, and provide insight on the seed viability and biology of plant species. Although seed banks of prairie ecosystems have been well studied, very little information exists on seed banks of reconstructed prairie. Identification of seed bank populations of reconstructed prairie provides a means to evaluate the success of restorations and establishes baseline data to monitor the development of prairie over time. A seed bank study of reconstructed prairie in central Iowa was conducted from March 2000 to July 2002. Samples of the seed bank in the top 3 cm of soil were collected at 15 sites on the reconstruction at the beginning of its fifth growing season. A seedling assay was used to identify and count seeds. A total of 2,693 seedlings and 62 plant taxa were observed in the seed bank. Out of the 78 plant species seeded at the study sites, 15 species were observed in the seed bank. Three of these were non-native species seeded by mistake. Among the other 47 species observed, about half were native and half were exotic. The most abundant species in the seed bank included green carpetweed (Mollugo vertieillaw), common yellow oxalis (Oxalis striew), witchgrass (Panicum capillare), hairy white oldfield aster (Symphyotrichum pilosum), and amaranth (Amaranthus rudis). Total seed densities ranged from 293 seeds/m2 /3 cm to 12,247 seeds/m2/3 cm. An ordination of the seed bank samples with the vegetation in 1999 and 2000 clearly shows a high dissimilarity between vegetation and seed bank as well as much greater variation in the seed bank composition than in the vegetation

Effects of Compost on Prairie Seedling Establishment and Seed Production

Compost is a commonly used soil amendment in horticultural and agricultural practices that is generally known to improve soil conditions and plant growth. We conducted a field experiment to investigate the application of compost to prairie production plots as a method to improve seedling establishment and growth and the seed production of established plants. We evaluated the effect of compost depth and tillage on the survivorship, growth, reproduction and ecophysiology of several prairie plant species commonly used in restoration. Results were mixed; for some species, transplants in compost–amended plots incurred lower survivorship and reduced growth compared to control plots. When compost was used for transplants, improved growth and reproduction were observed more often if compost was tilled into the soil. No benefit from compost was observed for flower and seed production in established prairie species. Compost can be useful in promoting better growth in prairie plots, but its application can produce negative outcomes under certain conditions