Proceedings of the North American Prairie Conferences

Growth and Reproduction of Local Ecotype and Cultivated Varieties of Panicum virgatum and Coreopsis palmata Grown in Common Gardens

D. W. Williams et al. — Mon, 14 Feb 2011 14:31:29 PST

Many practitioners prefer to plant seed from multiple remnant sources within the same region of the planting site. It is believed that this seed has improved fitness (survivorship, growth, and viability) over seed from outside the region. We tested this assumption by establishing two common gardens in northern and southern Iowa. Four varieties of switchgrass (Panicum virgatum) from prairie remnants in northern and southern Iowa and two cultivated varieties from Nebraska and South Dakota}, and stiff tickseed (Coreopsis palmata) from prairie remnants in northern and southern Iowa, were established in a greenhouse and transplanted into each common garden in May 2002. We hypothesized that plants grown near their origin would have improved fitness over those from distant origin. Stiff tickseed showed a trend of more shoots in regional populations vs. distant populations, though no significant differences in any of the measures of fitness between Northern and Southern Iowa populations were found. Iowa remnant populations of switchgrass had significantly (P < 0.05) more shoots per plant compared to at least one cultivar in both common garden sites in 2002 and 2003. Nebraska 28 cultivar of switchgrass experienced greater mortality than Iowa remnant populations. However, seed viability was not significantly (P < 0.05) different for the cultivated varieties of switchgrass and Northern populations; but was significantly lower for Southern Iowa populations in 2002. A decrease in fitness was measured when switchgrass seed from distant sources was planted in Iowa. The results suggest that switchgrass from various Iowa prairie remnants can be planted throughout the state without a loss of fitness.

Abstracts for Poster Presentations

Mon, 14 Feb 2011 14:26:59 PST

Abstracts for Poster Presentations pp. 1-10

Abstracts for Other Oral Presentations

Mon, 14 Feb 2011 14:25:53 PST

Abstracts for Other Oral Presentations pp.1-26

Dwelling on Common Ground: Scientific and Family Narratives of Change in Natural Landscapes

Damian Craniak Ph.D. — Mon, 14 Feb 2011 14:21:05 PST

Can mapping past and current changes in prairie landscapes in relation to historical shifts in human culture suggest promising directions for efforts to restore the health of grasslands and other natural communities? During the last 20,000 years the Land shifted and altered; during the past 10,000 years Life moved and migrated; and during the past 5,000 years natural and human Law has been turned and twisted to produce changes unanticipated in the history of the world. In the past 500 years these changes have quickened as we have changed ourselves from foragers into fur traders, and then into farmers, foresters, financiers and finally into fun~seekers, overrunning the Land and other Life. As our contact and connection with the Land has become more specialized and more distant, as the balance and integrity of the Land continues to fragment, our own health and happiness declines as family life deteriorates. Is there a way to transform our current destructive use into efforts that are more creatively restorative? In the last few decades we have concerned ourselves with the basic problem of the unavoidable effects of human population density (e.g., habitat loss and global warming), the critical challenge of how we partner and to what we become attached (e.g., cars as opposed to walking), and an appreciation of the power of group consensus and action (preserving ecologies as opposed to oil exploration). Can we shift our perceptions in ways that benefit natural communities? Conceptual schemes used in the natural sciences to organize understanding of the relations among species and habitats have not been integrated with sophisticated conceptualizations used in the psychological and social sciences that might better define threats to natural communities posed by human motivations and activities. When human population densities, movements, and activities are considered in such an integrated manner, the social potential for restoration efforts may be enhanced in powerful ways. This paper explores change as disturbance by proposing a comprehensive mapping of conditions, connections, communities and contexts affecting both grasslands and families. It offers specific suggestions to counter the destruction of healthy grassland and family systems by strengthening their positive relations with one another. The primary proposition is that families are the basic unit of care and connection in our communities. If family life is the primary relational process that determines and transmits our most valued participations in natural communities across generations through children, then perhaps we must re-balance our efforts, shifting a substantial portion of our focus upon individuals and groups toward child, couple-centered, and family centered relations with the Land that are intergenerationally sustainable. Perhaps it is possible that connecting with and caring for the Land can uncover greater connection and caring for one another, especially within the context of family, school, and neighborhood life.

Spatial Patterns of Canopy and Sub-canopy in Managed and Unmanaged Oak Savanna

Joy J. Wolf — Mon, 14 Feb 2011 14:15:59 PST

The oak savanna in the Midwest was maintained historically in part by fire, topography, climate, and other factors. After agriculture, which left only large fencerow trees, park management of fire, mowing and other minor factors to restore clusters of oaks has proceeded at different frequencies at different sites since the 1960s. I asked how different management frequencies created a range of spatial patterns and composition in the canopy. I compared three 0.37-ha sites that were unmanaged, or managed with more or less frequency by spatially mapping all woody species to the nearest 25 m² The oak trees, dominated by bur oak species (Quercus macrocarpa Michx.) had the desired clumped distribution in the managed sites, as opposed to a random distribution and a lower oak density without management. In addition, the dominant canopy species shifted from bur oak in managed sites to shade-tolerant black cherry (Prunus seratioo Ehrh.) and box elder (Acer negundo L.) under closed canopy and shagbark hickory (Carya ovata (P.Mill.) K. Koch). However, habitat heterogeneity did not decrease with management intensity, as predicted. The less managed site had more spatial heterogeneity than the more managed or unmanaged sites. All sites had woody understory thickets, however, the location and number of patches depended on management. This study shows how spatial dynamics in the canopy is influenced by management frequency.

Contour Strips for Prairie Invasion on a Topsoil-Depleted Hilltop at Retzer Nature Center

J. A. Schwarzmeier — Mon, 14 Feb 2011 14:12:13 PST

In 1981, 20% of a 3.3-acre (1.3-ha) portion of an eroded Hochheim loam on the Retzer "Vista" hilltop, in southeastern Wisconsin, was planted in 12-ft (3.7-m) wide "source strips" so that intervening 48-ft (15-m) wide "invasion strips" resulted. A dry-mesic prairie seed mix was used in the two highest elevation source strips and a mesic prairie seed mix was used in three source strips on the lower, side-sloped portion of the hilltop. While the fanning-era loss of essentially all of the original topsoil made the site "drier," the associated bringing up of more and more of the subsoil, with time, also made the topsoil seedbed much more clayey. No seed or transplants were ever planted in the invasion strips. An alternating pattern of simulated burning/real burning/simulated burning, etc. was the only treatment done in the six invasion strips. In ten years, early stage forbs had invaded so well that they were found in every square meter of both types of invasion strip treatment. However, most late-stage forbs and all warm-season grasses invaded less than half of the invasion strips after 18 years. After 23 years, the results of belt transect surveys indicate that warm-season prairie grasses would now be found in 70% of the total invasion strip space.

Temporal Effects of Grazing Regimes on Non-Game Birds in North Dakota Grasslands

Eric D. Salo et al. — Mon, 14 Feb 2011 14:09:29 PST

Grazing occurred naturally in the northern Great Plains and influenced many natural processes in grassland ecosystems, including the habitat selection of breeding birds. Grazing, mainly for livestock production, is still an important land use practice and is one that impacts millions of hectares on both public and private land in the United States. To better understand how long-term grazing treatments affect non-game breeding birds, a study was conducted at the Central Grasslands Research Extension Center (CGREC) in south-central North Dakota during 2001 and 2002 and results were compared to two earlier studies, one in native prairie and the other in Conservation Reserve Program (CRP) grasslands. Season-long and twice-over grazing treatments were in place for 19 years on native prairie sites and 10 years on CRP sites. Bird surveys were conducted along permanent belt transects three times per year and vegetation structure was characterized from measurements taken parallel to each bird survey transect, twice per year for each treatment plot. Non-game bird densities and species richness during this study period were lower for all grazing treatments in native prairie and CRP grazing system grasslands when compared to earlier studies. Among grazing treatments, rotational grazing treatments supported more species and are probably more beneficial because they provide areas of undisturbed habitat during the breeding season. Results from this study suggest that some grazing practices on native or seeded grass land habitats can be applied for long-periods of time without negative effects on certain species of grassland non-game birds.

Grazing Intensity Effects on Vegetation, Livestock and Non-Game Birds in North Dakota Mixed-Grass Prairie

Eric D. Salo et al. — Mon, 14 Feb 2011 14:05:13 PST

We conducted studies in native prairie mixed-grass pastures in south~central North Dakota (U.S.A.) during 1989- 2003 to determine how different grazing intensities affected structural characteristics of vegetation, livestock production and the occurrence and density of grassland birds. Generally, as grazing treatment intensity increased from light to extreme, mean vegetation structural values decreased for visual obstruction readings, tallest plants of grasses, forbs, and shrubs, and litter depth. Nineteen species of non-game birds were detected during 2001 and 2002. Overall breeding bird densities were negatively affected by increasing levels of grazing intensity in mixed-grass prairie. Claycolored sparrows (Spizella pallida), grasshopper sparrows (Ammodramus savannarum) , and savannah sparrows (Passrculus sandwichensis) reached their highest densities in the light and moderate grazing intensity treatments whereas they occurred at very low densities or were absent from extreme grazing intensity treatments. In contrast, densities of chestnut-collared longspurs (Calcarius omatus), horned larks (Eremophila alpestris), upland sandpipers (Bartramia longicauda), marbled godwits (Limosa fedoa) , and willets (Catoptrophorus semipalmatus) were highest in the heavy and extreme grazing treatment plots. Livestock average daily weight gains and body condition scores decreased directly with increasing grazing intensity. In contrast, average red meat production gains per unit of pasture had a quadratic relationship to stocking rates, increasing with increased grazing intensity (more animals per unit of pasture) until it reached a peak and then declined. Results from this study suggest that management of grassland habitats can be manipulated under specific grazing intensities to provide predictable conditions of nesting habitat for grassland bird species of management concern. Collectively, our results support that stocking rates equal to or nearly equal to our light to moderate grazing intensity treatments would provide habitat for most species of non-game birds nesting in mixed-grass prairies and still enable ranchers to obtain a profit from livestock production.

Ecological Restoration-based Education Transforms Schoolgrounds and Education

Libby McCann et al. — Mon, 14 Feb 2011 13:59:14 PST

The University of Wisconsin- Madison Arboretum, home to the world's first prairie restoration, has a threefold mission to conserve and restore Arboretum lands, advance the science of restoration ecology, and foster the Land Ethic. Since 1991 , teams of teachers from more than 150 schools in Wisconsin have learned to incorporate ecological restoration into the curriculum through the Earth Partnership for Schools Program. This multi-disciplinary teacher professional development program emphasizes inquiry-based learning and multiple intelligences in a hands-on, collaborative setting. The majority of schools have focused their efforts on prairies. Recreating or restoring an ecological community on school grounds provides opportunities for students to study local history, map current site conditions, learn about species tolerances, conduct research, manage their restorations, and celebrate a new personal relationship with the land. A recent follow-up questionnaire sent to participants since 1994 indicates that 94% of the respondents make use of restoration sites that are on average five yea rs old, at least 2,500 square feet in size, and used by six teachers and 250 students per year.

Soil Chemistry Properties Under Two Different Management Practices: Clipped Saint Augustine Grass Lawn and Annually Burned Cajun Prairie

Domingo M. Jariel et al. — Mon, 14 Feb 2011 13:56:32 PST

Prescribed burning every two or more years is the recommended management practice to remove unnecessary invasive plants and to enhance the regrowth of desirable plants for the development of a fire-dependent plant community native to southwestern Louisiana. A portion of Saint Augustine grass lawn at Louisiana State University at Eunice (LSUE) was converted into a Cajun Prairie restoration plot in 1989. Since 1991, the adjacent lawn has been clipped weekly, whereas the prairie has been burned every January. The objective of this study was to determine the soil chemical properties of clipped lawn and burned prairie plots. Each plot (12 m x 104 m) had four blocks (replications). Soil samples from the 0-10 cm depth were taken from each block for each plot in December 2002, March 2003, and June 2003. They were analyzed in the laboratory for soil chemical properties: pH, organic carbon (OC), electrical conductivity (EC) as a measure of soluble salts, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn) and copper (Cu). Extractable soil P, Ca, Mg and Na were significantly greater in the burned prairie than in the clipped lawn. In the burned prairie from December to June, Fe increased, whereas pH, EC, P, K, Na, Cu, and Zn decreased. The results suggest that the annually burned restored Cajun Prairie provided greater nutrient deposition into the soil than the clipped Saint Augustine lawn.

Using Cattle to Reduce Oak Savanna Understory Shrub Abundance: Stocking Rates and Weight Gains

Janet L. Hedtcke et al. — Mon, 14 Feb 2011 13:52:45 PST

Oak (Quercus spp.) savanna, characterized by widely scattered oaks with an understory of prairie and other specialized species, is one of the most endangered native ecosystems in North America (Nuzzo 1986, Packard and MuteI 1997). The absence of grazing and burning along with the introduction of tillage agriculture are key factors for the loss of this ecosystem. Our objective was to determine the effectiveness of rotational grazing to reduce the shrub layer in degraded oak savannas. This study took place at three sites in southwestern Wisconsin. In this paper, we report on the results of the savanna grazing on the cattle. For two summers, cow/calf pairs or yearling Scottish Highland cattle (Bos taurus spp.) were placed on 1-acre (0.4-ha) treatment sites for two to three days per month with a rest on grass pasture for one day between replicates. Animal weight gain was satisfactory. During the study, cattle generally gained better in 2002 due to adjusted stocking densities from 2001. Cows that calved prior to the study typically maintained body weight similar to controls, while late~calving cows in both groups lost some weight. Dry cows, steers, and nursing calves also performed similar to the controls. Body condition scores (BCS) for all classes of cattle were similar between the treatment and control groups over the season, hovering around 5 and 6. Managed grazing with five to seven cow/calf pairs or 12 yearlings per acre, for two to three days per month two to four times per season reduced the shrub layer in oak savanna, while permitting adequate weight gains in the cattle.

Ecological Restoration as a Strategic Framework for Invasive Species Management Planning: The University of Wisconsin Experience

Steve Glass — Mon, 14 Feb 2011 13:48:58 PST

The UW-Madison Arboretum uses an evolving, strategic approach to invasive species management that aims to develop comprehensive, integrated protocols for removing pest plants and subsequently replacing them with appropriate native species. We seek to provide managers with the decision,making tools to develop appropriate tactics to encourage native plants and discourage pest plants. This approach relies upon: 1) a rigorous invasive species risk assessment that yields an action priority ranking matrix; and 2) invasive species management conducted within an ecological restoration framework; and 3) incorporation of research findings into management actions in an adaptive management feedback loop. I use Phalaris arundinacea (reed canarygrass) as an example of invasive species management problems in Arboretum prairies.

Oak Savanna Restoration: A Case Study

Thomas D. Brock et al. — Mon, 14 Feb 2011 13:46:42 PST

A degraded oak savanna in southwestern Wisconsin is being restored using intensive cutting of undesirable shrubs- buckthorn (Rhamnus cathartica), prickly ash (Zanthoxylum americanum), honeysuckle (Lonicera spp.)-and selective removal of trees that are crowding the open-grown bur (Quercus macrocarpa) and white (Q. alba) oaks. Land use records and historic aerial photographs have been used to guide the restoration process. Slippery elm (Ulmus rubra), black walnut (Juglans nigra), black cherry (Prunus serotina), and black oak (Q. velutina) are being removed by cutting and burning or by converting to lumber or firewood. Hundreds of aspen (Populus tremuloides and P. grandentata) have been killed by girdling with subsequent cutting and burning. Management involves controlled burns and extensive weed control. Removal of invasive shrubs and trees has exposed the ground layer to higher light intensities and stimulated the growth of savanna forbs and grasses. A number of typical herbaceous savanna species have reappeared after clearing or have been successfully introduced from local sources. However, control of brambles (Rubus spp.) and regrowth of buckthorn and honeysuckle remain principal problems. One savanna species endangered in Wisconsin-purple milkweed (Asclepias purpurascens)-was first seen in the savanna after a single controlled burn, and appears to be spreading. The redheaded woodpecker (Melanerpes erythrocephalus), a typical savanna bird, was first seen after shrub and canopy clearing in the savanna. Tree removal is a slow and expensive operation, and strategies for preventing damage to the groundlayer during tree removal had to be devised. About 70 acres (28 hectares) of savanna have been restored during nine years.

Will Tillage and Plant Growth Regulator Pretreatments Enhance Herbicide Effects on Reed Canarygrass?

Craig A. Annen — Mon, 14 Feb 2011 13:39:29 PST

Reed canarygrass (Phalaris arundinacea L.) is a dominant perennial grass species in many sedge meadows and wet prairies. Efforts to control and eradicate this species with herbicides have had limited short-term success. A system of correlative inhibition (apical dominance) may operate in reed canarygrass rhizomes, resulting in a persistent rhizome bud bank that must be depleted in order to restore function and diversity to reed canarygrass stands. Pretreatments that overcome correlative inhibition may predispose reed canarygrass rhizomes to more effective herbicidal control. I conducted a feasibility study to test the efficacy of pretreatment tillage and plant growth regulator (PGR) application for enhancing herbicidal effects of sethoxydim (Vantage) on reed canarygrass. Three treatments were tested: 1) Vantage application only (control), 2) tillage followed by Vantage application, and 3) PGR application followed by Vantage application. Species density, diversity, and non-reed canarygrass stem density were higher in tilled plots than PGR plots or Vantage only plots, although this outcome may have been an indirect effect of tillage removing litter. Plant growth regulator pretreatments led to higher species diversity than plots treated with Vantage alone, possibly due to increased lateral growth of desired species. All treatments suppressed reed canarygrass stem density to the same degree in the year they were administered. Treatment lags may exist while reed canarygrass bud banks become depleted, and the effects of pretreatments may not be immediately evident. This is an ongoing study, and collecting additional response data in upcoming growing seasons will clarify reed canarygrass responses to tillage and PGR application.

Protecting Pioneer Cemetery Prairies: Balancing the Need to Preserve Cultural and Natural Heritage Values

Angella K. Moorehouse et al. — Mon, 14 Feb 2011 13:35:53 PST

The protection and management of pioneer cemetery prairies is a daunting challenge. As the public has become accustomed to highly manicured grass in their backyard lawns, neighborhood parks and cemeteries, prairie cemeteries, with grasses three- to six-feet tall, are often thought to be abandoned or unkept even though the cemeteries retain their original vegetation. Caring for prairie plants, protecting cemetery stones, and providing public access need not be goals that stand in conflict. Working in conjunction, cemetery advocates, archaeologists, and plant biologists can reach satisfactory accommodations. This paper gives an overview of the protection status of pioneer cemetery prairies and savannas in Illinois and the issues faced by those managing for the natural vegetation within these cemeteries along with providing an approach on how to deal with potential conflicts arising between the need to preserve the cultural heritage of the cemetery and conduct management necessary to maintain the historic prairie and savanna communities.

Large-Scale Restoration of the Rice Lake Plains: A Landscape Conservation Approach

Todd Farrell et al. — Mon, 14 Feb 2011 13:32:35 PST

In Ontario, it is estimated the tallgrass prairie and savanna once covered 70,000 hectares (173,000 acres), of which approximately 3% (2,100 ha, 5,189 acres) remains today. Based on historical land surveys and from early botanical accounts, the easternmost extent of these unique habitats was along the eastern flank of the Oak Ridges Moraine in an area known as the Rice Lake Plains. This area covered an estimated 15,384 to 30,300 hectares (38,000- 74,131 acres) (Carling and others 1992). The Rice Lake Plains harboured numerous savanna indicator species such as the extirpated Karner blue butterfly (Lycaeides melissa samuelis). In 2002, the Nature Conservancy of Canada purchased 316 ha (780 acres) on the Rice Lake Plains and initiated restoration plans. Bringing together multiple partners, NCC is leading the Rice Lake Plains Joint Initiative. This goal of the partnership is to raise the awareness of, and restore, the globally rare and provincially significant ecological communities and the species associated with them. To date, three years of funding has been secured. The Initiative involves the large-scale restoration of NCC lands and the assessment of over 2,400 hectares (6,000 acres) of adjacent lands. Restoration will include the removal of non-native species and prescribed burns. In addition, mapping and field inventories will be conducted on private lands on the Rice Lake Plains. Educational and communication opportunities will highlight this area to naturalists, landowners and local citizens and raise awareness of this globally rare habitat. Management plans are being developed for properties and will be used to generate a landscape conservation plan for the Rice Lake Plains.

Conservation Efforts and Natural History of a Prairie Habitat at Jennings Environmental Education Center, Pennsylvania

Bruno Borsari et al. — Mon, 14 Feb 2011 13:28:26 PST

The habitat consideted in this study is a 19.8-acre (8.0-hectare) prairie relict, which is part of the 296-acre (120-hectare) park (Jennings Environmental Education Center), and it is located in northwest Pennsylvania (Butler County). This prairie remnant is one of the easternmost existing relicts of the once widespread post-glacial prairies. The focus of this paper is to present an overview of the natural history of the Jennings Prairie with emphasis on preservation practices that have occurred since its discovery, in 1905, and management approaches aimed at the conservation of this habitat. The maintenance of its 225 native plant species requires human intervention in order to avoid its succession into a forest ecosystem, which is typical for this bioregion. Pedologic data are presented briefly as a frame; work used to justify decision-making in common land management practices. The conservation of the Jennings Prairie (the only one remaining of a few prairies dislocated through the landscape of western Pennsylvania) remains a unique habitat unit to demonstrate ecosystem diversity in the region.

Prairie Fen Preserved in an Urban Environment

Tyler Bassett — Mon, 14 Feb 2011 13:23:49 PST

Prairie fens are a rare, fire-dependent wetland type found only in the glaciated Midwest in ice-contact topography along streams or lake boundaries that historically occurred adjacent to prairies and savannas. Due to a strong dependence on cool, alkaline groundwater seepage, they are extremely sensitive to hydrological alterations that result from urban development. While prairie fens are common in glacial interlobate regions, it was still surprising to discover one while conducting a botanical inventory in 2001 in an urban development in Kalamazoo, Michigan. The 295-acre planned unit development (PUD), known as Parkview Hills, is bordered by medium-density residential neighborhoods, a major federal highway, and open lands. Three state-listed plant species and two state-listed animals occur in the fen and calcareous seepage is active in many areas. However, the effects of fire suppress ion , urban development, and a millpond two miles upstream are apparent. Woody encroachment from invasive species, such as glossy buckthorn (Frangula alnus), is severe throughout much of the fen.

Freshwater Mussels (Bivalvia: Unionidae) in the Cajun Prairie Ecosystem in Southwestern Louisiana

Malcom F. Vidrine et al. — Mon, 14 Feb 2011 13:20:52 PST

Freshwater mussels (Bivalvia: Unionidae) once cobbled the stream bottoms in the Cajun Prairie ecosystem in south-western Louisiana. The development of canal systems for aboveground irrigation of rice fields during the last century provided additional habitat-often the canals were likewise cobbled with mussels that formed diverse communities. This paper introduces the 31 known species, their general ecology and their distributions. These mussels develop a 'reef'-like benthic community that is home to a variety of plants and animals as parasites and haptobenthos. Freshwater mussels are on the decline numerically as well as in diversity as a result of human activity, namely loss of seepage or spring-feeding (shallow groundwater discharge) by agricultural/urban compaction of soil, sedimentation from erosion, channeling of natural streams by dredging, and poisoning of waterways from urban and industrial runoff and dumping. The once-spring-fed streams flow intermittently functioning more as drainage canals as a result of the destruction of prairies by agriculture and urbanization. The return of prairies and forests reinitiates the spring-feeding by shallow groundwater discharge to streams and minimizes runoff of agrochemicals and urban chemicals, thus providing an opportunity for revitalizing freshwater mussel communities.

Adapting a Floral Biogeography Model to Prairie-Dependent Lepidoptera

Eric H. Metzler et al. — Mon, 14 Feb 2011 13:15:15 PST

Analysis of data collected for a study of prairie dependent Lepidoptera in the northern tallgrass prairies showed four distributional patterns. A logical distributional pattern links species' distribution, i.e. Catocala abbreviatella, to larval host plants. Absence of larval host plant data, which is the case for most species of moths, requires inference based on habitat data of known specimens, i.e. Tarachidia binocula, or in the case of infrequently encountered species, i.e. Crambus murellus, capture data for a limited number of specimens. A fourth distributional pattern, i. e. Atrytone arogos, can be explained by hypotheses which explain the immigration of native grassland species eastward into the Midwest before the last glacial maximum and northward into the Midwest and East Coast from Florida and the Gulf Coast following the last glacial maximum. The hypothesized distributional patterns can be used to predict the occurrence of species in yet,to,be discovered populations along the migration routes as well as explain their absence in other seemingly nearby localities. The widely disjunct distribution, i.e. East Coast and Midwest, of many species, including those not found in prairies, is easily explained by the hypotheses presented here.