148 research outputs found
Featured Herbarium: BUT—The Friesner Herbarium of Butler University
Feature written by Rebecca Dolan on the BUT—The Friesner Herbarium of Butler University in the Vasculum
Bacon\u27s Swamp- Ghost of a Central Indiana Natural Area Past
Bacon’s Swamp was identified in the 1920s as a ca. 12 ha glacial kettle lake bog system at the southernmost limits of these habitats in Indiana. Located just 9.6 km from the center of Indianapolis, the site was all but destroyed in the mid-20th century by urban expansion. Prior to habitat conversion at the site, Bacon’s Swamp was a frequent location for Butler University ecology class field trips and student research projects. Herbarium specimens and published inventory records allow for analysis of the historical vegetation of Bacon’s Swamp using modern techniques. Floristic Quality Assessment applied to these historical records reveals Bacon’s Swamp was a regionally significant natural area, with a native Floristic Quality Index (FQI) value of 60 and a mean native Conservation Coefficient value of 4.2. Little of this unusual, high-quality habitat remains. A 2010 botanical inventory at the site documents decline in habitat with the loss of species that have a fidelity to high-quality habitat, with a corresponding drop in FQI to 20 and the addition of invasive non-native plants. Re-analysis of Bacon’s Swamp historical flora supports the view that it was a significant wetland natural area and floristically unique in Central Indiana
Population dynamics of \u3cem\u3eLudwigia leptocarpa\u3c/em\u3e (Onagraceae) and some factors affecting size hierarchies in a natural population
Germination cohorts of Ludwigia leptocarpa, a semi-aquatic annual plant were marked in the field at time of establishment and followed through the 1981 and 1982 growing seasons at a site in southern South Carolina.
Data from each cohort were pooled to determine demographic characteristics of the population as a whole, then analyzed separately to determine the effect of time on germination on survivorship, relative growth rate, and adult size.
Changes in numbers of L. leptocarpa fit a Deevey Type II survivorship curve. This and other characteristics of the species classify it as ‘r-selected’. Aspects of the life history may reflect a ‘bet-hedging’ stratagem that ensures establishment.
Differences in the time of germination are not responsible for differences in adult size, even when early-germinating plants have as many as 35 days more for growth than late germinators. This, and the fact that differences occur even within single cohorts, implies that factors other than time of germination must influence plant size
Demographic viability of populations of \u3cem\u3eSilene regis\u3c/em\u3e in midwestern prairies: relationships with fire management, genetic variation, geographic location, population size and isolation
We studied the demographic viability of populations of a long-lived iteroparous prairie perennial, Silene regia, in relation to management regimes, population sizes, geographical region (Ohio and Indiana vs. Missouri and Arkansas), degree of isolation and amount of genetic variation. Demographic data were collected from 16 populations for up to 7 years.
This species has high survivorship, slow growth, frequent flowering and episodic seedling recruitment. Matrix projection methods were used to summarize population performance with and without recruitment. Median finite rates of increase by population varied from 0.57 to 1.82 and from 0.44 to 0.99, respectively.
Populations with the highest rates of increase had been burned. Six of eight populations, for which stochastic modelling predicted persistence for 1000 years, included fire in their management. None of the five populations with predicted 100-year extinction probabilities of 100% was managed for conservation or burned. An intermediate group of three populations with at least 10% probability of extinction between 100 and 1000 years was not managed, but was none the less kept open by mowing and herbicide application.
Analysis of composite elasticities showed that growth and fecundity terms were higher for growing (vs. declining) populations and that growth elasticity was higher in burned than unburned populations. Lack of burning shifts the elasticity spectrum from that typical of open habitat herbs (higher growth and fecundity elasticities) to values usually found for closed habitat herbs (higher survival elasticities).
In multivariate analyses predicting finite rates of increase (with and without recruitment), fire management and region were the strongest predictors, followed by genetic variation, population size, isolation and interactions of population size and fire, and region and fire. Populations with the highest rates of increase were burned, eastern, more genetically diverse, larger and less isolated. Discrimination of populations with different extinction risks (three classes) was related mainly to fire, genetic variation and region.
Most of these conclusions support conservation biology predictions that population viability will be highest in larger, less-isolated, more genetically diverse populations. However, management and geographic trends have overriding roles affecting demographic viability. Habitat fragmentation and genetic depletion have the potential to threaten residual prairie populations of S. regia, but lack of fire management appears to be the primary short-term threat
Taxonomy of \u3cem\u3eStreptanthus\u3c/em\u3e sect. \u3cem\u3eBiennes\u3c/em\u3e, the \u3cem\u3eStreptanthus morrisonii\u3c/em\u3e complex (Brassicaceae)
The Streptanthus morrisonii complex is a six-taxon group of closely related serpentine rock outcrop endemics from Lake, Napa, and Sonoma counties of California, USA. Two new subspecies (S. morrisonii subsp. kruckebergii and S. brachiatus subsp. hoffmanii) from Lake County, California, are described. The relationship of these taxa to others in the section is reviewed and descriptions and a key are provided
Floristic Inventory of Woollen’s Gardens Nature Preserve, Indianapolis, Marion County, Indiana, USA, With Quantitative Vegetation Sampling of Permanent Plots in 2003 and 2016
Urban forest fragments face challenges to habitat quality due to small size, isolation from larger natural areas, and close association with anthropogenic disturbance. Monitoring changes in vegetation can inform management practices targeted at preserving biodiversity in the face of these threats. Woollen’s Gardens is a high-quality mesic upland forest preserve in the city of Indianapolis, Indiana, USA, with a beechmaple older-growth forest and a significant display of showy spring wildflowers. The entire preserve was inventoried and quantitative vegetation analysis along seven 100 m transects was conducted in 2003 and again in 2016 to track changes. Data from both years document a high-quality flora with few non-native plants. Floristic Quality Index values for native species, derived from Floristic Quality Assessment, were 50.2 in 2003 and 47.3 in 2016. Native mean C-values of 4.5 and 4.3 for each year support that the site is comparable to the highest quality natural areas in central Indiana. Values declined little when non-natives were included, indicating non-natives are having little negative impact on the flora. Although non-natives comprised less than 10% of the flora, 11 of the 16 species are considered invasive in Indiana. In 2003, invasive Amur honeysuckle (Lonicera maackii) was among species in plots with the highest relative importance value. In 2016, invasive wintercreeper (Euonymus fortunei) was among these species. Limited public access to Woollen’s Gardens minimizes human disturbance, but invasive species are a threat to vegetation quality. Continuation of eradication efforts is strongly recommended before populations of these non-natives become more difficult to control
A new species of \u3cem\u3eStreptanthus\u3c/em\u3e (Brassicaceae) from Three Peaks in Lake County, California
Streptanlhus vernalis is a newly described species inhabiting serpentine rock outcrops in the Three Peaks area in Lake County, California. Morphological and allozyme data indicate that this taxon is related to the S. morrisonii complex
Five-Year Response of Spontaneous Vegetation to Removal of Invasive Amur Bush Honeysuckle Along an Urban Creek
Non-native invasive species have major impacts on landscapes worldwide, but their effects in urban areas are not well documented. We quantified the response of naturally regenerating vegetation along an urban creek to removal of the invasive shrub Lonicera maackii (Amur Bush Honeysuckle). Over the 5-year study, species richness more than doubled. Most new plants were native, disturbance-adapted, early successional species. Trend analysis of function traits revealed annuals that rely on seed dispersal by wind or externally on animals were significantly overrepresented among new plants in comparison to their proportion in the countywide species pool. Increased species richness did not result in improved habitat quality, as indicated by Floristic Quality Assessment. Eight new invasive species appeared over the course of the study. Active management of this site may be needed in perpetuit
Effects of a Prescribed Burn on Tree- and Herb-layer Vegetation in a Post Oak (Quercus Stellata) Dominated Flatwoods
Post oak flatwoods are an unusual plant community type dominated by even-aged and uniformly sized post oaks (Quercus stellata) growing along level terraces of the Ohio River. Historical evidence exists that fire may play a role in the maintenance of the open canopy and poorly-developed understory characteristic of this community type (Dolan and Menges. 1989). The results of summer vegetation surveys taken yearly from 1989 to 1992 in a post oak flatwoods in southwestern Indiana that was subjected to a prescribed bum in the spring of 1989 are reported in this paper. The objective of the study was to determine the effects of the burn on tree-and herb-layer vegetation. The fire killed or top-killed more than half the trees but did not markedly shift the rank order of species importance values. Mortality was greatest among small tree species, such as winged elm and shingle-bark oak, and least among post oak. Composition of the herb-layer did not change greatly following the fire. but several new species were found that did not occur in unburned control plots. The results indicate that fire contributes to the unusual species composition and community structure of post oak flatwoods
The Royal Catchfly (Silene Regia; Caryophyllaceae) in Indiana
Botanist Thomas Nuttall called the royal catchfly, Silene regia, one of the most splendid species in existence. This red-flowered, hummingbird-pollinated member of the Caryophyllaceae is a perennial herb of prairies and glades. Because of the conversion of much of its former habitat to agriculture, the royal catchfly is considered threatened in Indiana. The species\u27 historical and present-day distribution in the State, documenting the current status of all known locations, including population sizes and co-occurring species, are reported in this paper. Only 8 of the documented 23 historical locations still support the plant. No populations occur in dedicated nature preserves or other protected areas. However, the Division of Nature Preserves of the Indiana Department of Natural Resources does manage the site containing the largest and most genetically variable population in the State. Active management to promote prairie vegetation at the site may be the key to maintaining this high-quality population
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