Fire and grazing in a mesic tallgrass prairie: impacts on plant species and functional traits

Fire is a globally distributed disturbance that impacts terrestrial ecosystems and has been proposed to be a global “herbivore.” Fire, like herbivory, is a top-down driver that converts organic materials into inorganic products, alters community structure, and acts as an evolutionary agent. Though grazing and fire may have some comparable effects in grasslands, they do not have similar impacts on species composition and community structure. However, the concept of fire as a global herbivore implies that fire and herbivory may have similar effects on plant functional traits. Using 22 years of data from a mesic, native tallgrass prairie with a long evolutionary history of fire and grazing, we tested if trait composition between grazed and burned grassland communities would converge, and if the degree of convergence depended on fire frequency. Additionally, we tested if eliminating fire from frequently burned grasslands would result in a state similar to unburned grasslands, and if adding fire into a previously unburned grassland would cause composition to become more similar to that of frequently burned grasslands. We found that grazing and burning once every four years showed the most convergence in traits, suggesting that these communities operate under similar deterministic assembly rules and that fire and herbivory are similar disturbances to grasslands at the trait-group level of organization. Three years after reversal of the fire treatment we found that fire reversal had different effects depending on treatment. The formerly unburned community that was then burned annually became more similar to the annually burned community in trait composition suggesting that function may be rapidly restored if fire is reintroduced. Conversely, after fire was removed from the annually burned community trait composition developed along a unique trajectory indicating hysteresis, or a time lag for structure and function to return following a change in this disturbance regime. We conclude that functional traits and species-based metrics should be considered when determining and evaluating goals for fire management in mesic grassland ecosystems.

Review of The Elemental Prairie: Sixty Tallgrass Plants (Watercolors and introduction) by George Olson

The Elemental Prairie provides a general discussion of the Great Plains and the tallgrass prairie for the general reader. Its botanically accurate plant drawings render a beautiful and artistic view into prairie plants. George Olson writes a compelling introduction about "Prairie Elements," painting a graphic verbal description about his trip into the prairie with noted prairie author John Madson. The introduction draws readers into the book and prepares them for John Madson's essay "The Running Country," an eloquent portrayal of the history of the tallgrass prairie. We are led into the hearts and minds of the pioneers who crossed the immense expanse of the Great Plains. Madson's descriptions of prairie plants help us visualize how the Great Plains looked prior to settlement, stirring us to see not only the allure of the prairies, but also the solitude and sometimes the loneliness. Madson mixes his personal experiences with current scientific theory of the formation of the prairies across the region, offering a way of seeing how the present fits into the past.

Long-term grazing alters species composition and biomass of a shrub meadow on the Qinghai-Tibet Plateau

Livestock grazing has long been the most widespread land use on the Qinghai-Tibet Plateau, one of the world's highest ecosystems. However, there has been increasing concern during recent decades because of the rapid increase in livestock numbers. To assess the possible influences of grazing on the vast grassland, a long-term grazing experiment in a shrub meadow on the northern Qinghai-Tibet Plateau was carried out. The experiment included five treatments with different stocking rates and one non-grazing (N) treatment. After 17 years of grazing, treatment differences were clear. The species composition differed markedly between grazing intensities, with a decrease in palatable grass species and an increase in unpalatable forbs at higher grazing intensities. The species richness and species diversity, however, were not significantly different between treatments. Vegetation height decreased significantly at higher grazing intensities. Total above,ground biomass declined considerably and the biomass of forbs increased significantly under the higher grazing intensities. The amount of litter was significantly lower under the higher grazing intensities. The results suggest that long-term grazing alters the species composition, vegetation height and biomass production of the alpine grassland ecosystem without significantly changing species richness.

Ecology, stable isotopes, and management of grassland songbirds at National Park Service properties on the Great Plains

Grassland ecosystems have been severely reduced and grassland bird populations have experienced consistent declines. National Park Service (NPS) properties on the Great Plains provide breeding habitat for grassland songbirds, though little is known about the quality of this habitat. A short-term study on songbirds at three NPS properties complemented current monitoring, providing an among park comparison addressing grassland bird productivity and fidelity relative to NPS property size. During 2008-2009, I assessed avian species richness, and estimated bird density and grassland songbird nest success. Bird species richness was greatest at small and medium sites, while number of nesting obligate species was greatest at the large site. Species-specific densities varied among sites, with few grassland obligates occurring at all three sites. Nest success estimates for grassland obligates were highest at the small site and lower at the large site. Another method to quantify habitat quality is assessment of breeding site fidelity. Current extrinsic markers used in monitoring site fidelity are inadequate for small birds; stable isotope analyses provide an alternative. I compared two techniques for assigning stable isotope tissue origin and measured grassland songbird site fidelity. My method of assigning origin provided site-specific variances of expected stable isotope values, an improvement over the most commonly used method. Fidelity tended to be higher at the large site, which may indicate a more robust breeding community of grassland birds. The small size of two of my sites precluded large sample sizes and made strong inferences difficult. To quantify how scientists cope with weak inference, I conducted a literature review. Strong inference was rarely observed, and most authors of weak-inference papers provided specific management recommendations. I suggest that adaptive management is an ideal method to resolve uncertainty from weak inference. Managers should consider my results within the context of regional and global management and the extent to which their unit might aide songbird conservation.

Microlepidoptera of Illinois hill prairies

Among insects, which are the most diverse eukaryotic group on earth, Lepidoptera is one of four enormously diverse orders, with approximately 10,000 described species in North America. Within the order, Nearctic “microlepidoptera,” which represent an overwhelmingly large percentage of diversity within the order, remain poorly known despite their ecological importance in many plant communities. In this thesis, I undertook several studies of microlepidoptera diversity in a natural community type (hill prairie) and a managed community type (biofuel feedstock). In two Illinois hill prairies differing in size, latitude, and plant composition, alpha diversity of Pyraloidea and Tortricidae was similar, but the prairies were found to support different sets of species of these moth groups. It is concluded that the similarity in alpha diversity occurs because the larger prairie supports primarily a complement of moth species that feed as larvae on prairie plants (especially species of Asteraceae and Fabaceae), whereas the moths collected in the small prairie represent relatively few prairie-associated species, plus a large component of species that feed as larvae on deciduous trees that surround the prairie. This agrees with the finding of high beta diversity of moths between the sites, which reflects a high level of larval hostplant specificity in most species of Pyraloidea and Tortricidae. Based on published information plus observations made on microlepidoptera collected during the course of this study, 31 families of basal microlepidoptera were reviewed with an aim toward evaluating the likelihood of their including species that are dependent on tallgrass prairie. Of these families, 12 were evaluated as possible, and two as likely or certain, to include prairie-dependent species. In a comparison of moth diversity in light-trap samples from corn, miscanthus, switchgrass, and native prairie, alpha diversity was highest in prairie and was higher in switchgrass than in the other two biofuel crops. Moth species complements generally were similar among the biofuel crops, and prairie shared higher species complementarity with switchgrass than with corn or miscanthus. These findings suggest that large-scale conversion of land to biofuel crops may, to a substantial degree, detrimentally affect arthropod biodiversity, with a resulting loss of valuable arthropod-derived ecosystem services both within the cropping systems and in the surrounding landscape. During the course of this study, rearing efforts yielded two species of moths of the family Gelechiidae, both of which are monophagous leaf feeders on leadplant, Amorpha canescens (Fabaceae). Because these moths are restricted to tallgrass prairie, they are likely to be of interest to conservation biologists. In the interest of naming the moths to facilitate communication regarding them, and to augment our taxonomic knowledge of their respective genera, the moths are described, and diagnoses are provided to differentiate them from similar, related species.

Decomposition of emergent macrophyte roots and rhizomes in a northern prairie marsh

Dry mass, nitrogen and phosphorus content in belowground litter of four emergent macrophytes (Typha glauca Godr., Phragmites australis (Cav.) Trin., Scolochloa festucacea (Willd.) Link and Scirpus lacustris L.) were followed for 1.2 years in a series of experimental marshes, Delta Marsh, Manitoba. Litter bags containing roots and rhizome materials of each species were buried in unflooded soil, or soil flooded at three water depths (1–30, 31–60, > 60 cm). There were few differences in dry mass loss in unflooded or flooded soils, and depth of flooding also had little effect on decomposition rates. In the flooded sites, Scolochloa and Phragmites roots lost more mass (48.9–63.8% and 59.2–85.5%, respectively) after 112 days than Typha and Scirpus (36.3–43.6 and 37.0–47.2%, respectively). These differences continued through to the end of the study, except in the shallow sites where Scirpus roots lost more mass and had comparable mass remaining as Scolochloa and Phragmites. In the unflooded sites, there was little difference between species. All litters lost nitrogen (22.9–90.0%) and phosphorus (46.3–92.7%) during the first 112 days, then levels tended to remain constant. Decay rates for our belowground root and rhizome litters were comparable to published literature values for aboveground shoot litter of the same species, except for Phragmites roots and rhizomes which decomposed at a faster rate (−k = 0.0014−0.0032) than shoots (−k = 0.0003−0.0007, [van der Valk, A.G., Rhymer, J.M., Murkin, H.R., 1991. Flooding and the decomposition of litter of four emergent plant species in a prairie wetland. Wetlands 11, 1–16]).

Biomass?Diversity Responses and Spatial Dependencies in Disturbed Tallgrass Prairies

Javier G. P. Gamarra and Ricard V. Sole (2002). Biomass-diversity responses and spatial dependencies in disturbed tallgrass prairies. Journal of Theoretical Biology, 215 (4) pp.469-480 RAE2008

Across the prairie in a motor caravan; a 3,000 mile tour by two Englishwomen on behalf of religious education,

http://www.archive.org/details/acrosstheprairie00haseuoft

Genetic evaluation of a proposed introduction: the case of the greater prairie chicken and the extinct heath hen.

Population introduction is an important tool for ecosystem restoration. However, before introductions should be conducted, it is important to evaluate the genetic, phenotypic and ecological suitability of possible replacement populations. Careful genetic analysis is particularly important if it is suspected that the extirpated population was unique or genetically divergent. On the island of Martha's Vineyard, Massachusetts, the introduction of greater prairie chickens (Tympanuchus cupido pinnatus) to replace the extinct heath hen (T. cupido cupido) is being considered as part of an ecosystem restoration project. Martha's Vineyard was home to the last remaining heath hen population until its extinction in 1932. We conducted this study to aid in determining the suitability of greater prairie chickens as a possible replacement for the heath hen. We examined mitochondrial control region sequences from extant populations of all prairie grouse species (Tympanuchus) and from museum skin heath hen specimens. Our data suggest that the Martha's Vineyard heath hen population represents a divergent mitochondrial lineage. This result is attributable either to a long period of geographical isolation from other prairie grouse populations or to a population bottleneck resulting from human disturbance. The mtDNA diagnosability of the heath hen contrasts with the network of mtDNA haplotypes of other prairie grouse (T. cupido attwateri, T. pallidicinctus and T. phasianellus), which do not form distinguishable mtDNA groupings. Our findings suggest that the Martha's Vineyard heath hen was more genetically isolated than are current populations of prairie grouse and place the emphasis for future research on examining prairie grouse adaptations to different habitat types to assess ecological exchangeability between heath hens and greater prairie chickens.

Lukas Foss's The Prairie (1942): Building Community through Music

Lukas Foss's The Prairie, a seven-movement cantata for SATB soloists, mixed chorus, and orchestra, is a well-crafted and audience-friendly setting of the poem of the same name by Carl Sandburg. Acclaimed at its 1944 premiere, The Prairie has not enjoyed a robust performance history due in large part to numerous inconsistencies between the score and parts which render the work challenging to perform. Heretofore, each conductor has individually located these inconsistencies and made the necessary adjustments for performances. In this document, resources have been assembled which identify and correct many of the inconsistencies, thus facilitating more performances in the future. The Prairie is an ideal vehicle for a project-based chorus, which is itself an opportunity to create a new community. A correlation may exist between "community" and "vulnerability;" that is, when a choral singer feels comfortably connected to fellow singers, he or she may be more likely to open up to new ways of making sounds for the ultimate service of the music. Results are inconclusive, but the project points to a successful strategy for creating an affirming new community and to positive musical and nonmusical results of intentional community-building.