Research & scholarly achievements, July 1, 1981 - June 30, 1982

Annual summary of scholarly activities at UCF for the period from July 1, 1981 to June 30, 1982. This report highlights the contributions to scholarship by the Faculty during this period, including books and monographs, articles, creative works, presentations, grants and contracts

Historical fire regimes in southeasern pine savannas

Southeastern coastal plain pine savannas lack direct evidence of past fire regimes. As a result, uncertainty exists regarding the range of variation in frequency and seasonal timing of past fire regimes and the relative importance of anthropogenic and lightning-ignited fires. Characterization of past fire regimes is needed for effective restoration and management of these high-biodiversity ecosystems. I used dendrochronologically dated fire scars from stumps of old growth longleaf pines in a large coastal, mainland pine savanna and from dead slash pines on a small, coastal barrier island in north Florida to explore past fire regimes. In the mainland savanna, 71 different fires occurred from 1592-1883, based on a composite record of 109 fire scars from six fire-scarred trees. Almost all (95%) scars occurred during the middle growing season. Only three fires, all in the 1800s after European settlement of the local area, occurred during the dormant season. There was a 2-3 year fire return interval between 1679 and 1868. Variability in fire return intervals was low, with 92% of all fires occurring at \u3c 5 yr intervals. On the barrier island 159 fire scars occurred in 21 separate years from 1864-2000, based on a record of 52 pines scarred during turpentine operations. Two periods of no fire scars corresponded to times of active pine resin extraction on the island (1911-1918, 1948-1958). Mean fire return intervals averaged four years from 1864-1910 and 1919-1947. A longer nine-year fire return interval occurred from 1959-2000. Most (86%) fires recorded in scars occurred during the growing season. The very high frequencies of growing season fires recorded in annual rings of these trees indicate that fire regimes were primarily driven by synoptic climatic conditions rather than by cultural burning practices. Both sites recorded frequent, growing season fires, suggesting that lightning fires were occurring frequently both before and after settlement despite differences in size and landscape context. This direct evidence of fire history in southeastern pine savannas can resolve some outstanding questions regarding ecological fire management. Fire managers now have direct evidence that supports frequent, growing season fires in pine savanna

Research & scholarly achievements, July 1, 1983 - June 30, 1984

Annual summary of scholarly activities at UCF for the period from July 1, 1983 to June 30, 1984. This report highlights the contributions to scholarship by the Faculty during this period, including books and monographs, articles, creative works, presentations, grants and contracts

COMPARING MECHANICAL MASTICATION, HERBICIDE APPLICATION, AND PRESCRIBED FIRE WITHIN AN ESTABLISHED LONGLEAF PINE (PINUS PALUSTRIS MILL.) ECOSYSTEM

Longleaf pine (Pinus palustris Mill.) forests once dominated the landscape throughout the Southeast and much of its success could be attributed to ecological disturbances such as fire. However, the use of fire as a management tool may be at risk due to a growing human population, negative impacts resulting from smoke production, and the imposition of restrictive federal and state laws, policies, and standards. This study was designed to determine whether alternative silviculture treatments such as herbicide or mechanical mastication can be used as surrogates to prescribed fire. We applied three commonly used silviculture treatments (prescribed burning, mechanical mastication, and herbicide) one time in May 2008 to eighteen approximately equal sized treatment units (0.405 ha) at the Aiken Gopher Tortoise Heritage Preserve, which is located in Aiken County, South Carolina. The firing techniques used during the prescribed fire consisted of a mix of backing, flanking, and head fires. The herbicide used was the granular form of hexazinone [3-cyclohexyl=6-(dimethylamino)-1-methy-1,5-triazine-2,4(1H,3H)-dione] also known as DupontTM Velpar ULW®, which was broadcast evenly at a rate of 1.26 kg a.i./ha. A Bobcat T-300 with a forestry cutter head and hand tools were used for mechanical mastication; these tools were used to masticate any midstory vegetation (i.e. Quercus spp.). Additional treatments were applied in a split-plot design, including rake and non-rake subplots within each of the herbicide and mechanical mastication treatment units. We monitored the response of the understory herbaceous layer (P. palustris Mill.). We also measured the litter depth of the forest floor, monitored the foliar cover of Aristida stricta, tracked the recruitment of Aristida stricta seedlings, and evaluated which treatment provided the maximum usage forage (medium = M, high = H, and very high = VH) for gopher tortoises pre- and post-treatment. No significant differences were determined between the species richness, species diversity, and evenness following treatments for two consecutive growing seasons. Both prescribed fire and mechanical mastication promoted species richness and diversity values that exceeded pre-treatment levels by the end of the second growing season. Prescribed fire treatments generated the highest relative increases in the evenness values, followed by mechanical mastication, and then herbicide. Mechanical mastication and herbicide treatments generated higher longleaf pine seedling survivorship while prescribed fire negatively affected the longleaf pine seedling survivorship. While the broadcast application of hexazinone caused initial decreases in species richness and diversity, the understory plants gradually began to recover the ensuing year. Prescribed fire positively influenced the Aristida stricta foliar cover throughout the study. Initial Aristida stricta foliar cover declines were observed following both the herbicide and mechanical mastication treatments; however, it began to recover the following year. Litter depths were not significantly influenced by any of the study treatments. Prescribed fire generated the greatest initial litter depth reduction (54%) and maintained the slowest litter recovery throughout the study. However, initial (2010) litter depth reductions were also observed each post-treatment year within the herbicide (38%) and mechanical mastication (39%) units. Aristida stricta seedling counts were not significantly different across the herbicide and mechanical mastication treatment units. However, the rake subplots promoted non-significantly higher A. stricta seedling counts and relative differences following initial treatments versus non-rake subplots. The rake subplots yielded the highest initial increases and maintained the highest relative difference each post-treatment year. No significant differences were determined between treatment types for the VH or M ranking gopher tortoise forage values. Significant treatment differences were determined for the H value forage in both post-treatment years. While there were mixed results across each treatment, no significant differences were observed for the prescribed fire treatment units throughout the study. The prescribed fire units yielded positive increases across all preferred gopher tortoise forage initially following treatment and maintained positive gains for the VH and M usage flora species throughout the study. Mechanical mastication produced some gains for the VH and M species initially following treatment; however, these were short-lived and quickly fell below pre-treatment levels by the end of the second post-treatment growing season. The herbicide treatment caused significant decreases for the VH and H gopher tortoise forage species during both post-treatment years. Based on results from this study, prescribed fire is the preferred silviculture tool that provides the maximum benefit to a xeric sandhills mature longleaf pine community by suppressing woody species, encouraging a diverse herbaceous understory, promoting an overall higher usage forage for gopher tortoises, and reducing litter layer accumulation. However, in areas that the use of fire may be limited or restricted, our study suggests that the use of herbicide and/or mechanical mastication treatments can be used to gain the desired structure and appearance and allow for regeneration of longleaf pine, but these alternative silviculture tools may not promote the desired understory herbaceous layer for target species such as the gopher tortoise. Caution should be made when applying these modern silviculture treatments, since impacts to the ecosystem resilience has not been documented long-term. These modern tools may be the next perturbation that will mimic stochastic events like fire and hurricanes. However, the longleaf pine ecosystem evolved under a fire regime and shifts may result from the new disturbance; consequently, close monitoring should occur following their use

Forested Wetlands of the Southern United States: A Bibliography

The term forested wetland covers a variety of forest types including mangroves, cypress/tupelo swamps, bottomland hardwoods, pocosins and Carolina bays, flatwoods, and mountain fens. These forests are dominated by woody species that have morphological features, physiological adaptations, and/or reproductive strategies enabling them to achieve maturity and reproduce in an environment where the soils within the rooting zone may be inundated or saturated for various periods during the growing season. Although alluvial floodplains occur along most streams of the United States, they are most extensive in the Atlantic Coastal Plain, Gulf Coastal Plain, and Mississippi Alluvial Plain. Only about half of the original floodplain forests remained by the 1930s, and conversion to agriculture continued at an accelerated pace during the 1960s and 1970s.The purpose of this bibliography is to provide a detailed listing of references for students and researchers of the varied studies conducted in these forest types

Coastal Habitat Integrated Mapping and Monitoring Program report for the State of Florida

Mangrove swamps and salt marshes provide valuable ecological services to coastal ecosystems in Florida. Coastal wetlands are an important nursery for many ecologically and commercially important fish and invertebrates. The vegetation stabilizes shorelines, protecting the coast from wave energy, storm surge, and erosion. Coastal wetlands are also able to filter surface water runoff, removing excess nutrients and many pollutants. Peat deposits sequester large amounts of carbon, making coastal wetlands a key sink in global carbon cycles. Mangroves and salt marshes, however, are vulnerable to both direct and indirect threats from human development. Current threats include continued habitat loss, hydrologic alteration of surface and groundwater, sea-level rise, and invasive vegetation. ... Coastal wetland monitoring programs are often short-lived and vary widely in methodology. Monitoring most commonly occurs on protected public lands or at wetland mitigation or restoration sites. These monitoring projects are rarely long-term due to a lack of funding; restoration sites are generally monitored for only a few years. Although long-term funding is difficult to secure, monitoring over long time scales is increasingly important due to regional uncertainties as to how coastal wetland vegetation and substrate accretion will respond to sea-level rise, altered freshwater hydrology, and other disturbances. While periodic land cover mapping programs can capture large-scale changes in habitat extent, smaller-scale species shifts among mangrove and salt marsh vegetation are best captured by on-the-ground monitoring. The chapters in this report summarize recent mapping and monitoring programs in each region of Florida. Content of each chapter includes a general introduction to the region, location-specific threats to salt marshes and mangroves, a summary of selected mapping and monitoring programs, and recommendations for protection, management, and monitoring. Land cover maps in this report generally use data from the most recent water management district land use/land cover (LULC) maps

The President\u27s Column

Column by Crystal Gates

Southeastern Librarian 70(4) Winter 2023 (Full Issue)

Complete issue of The Southeastern Librarian Volume 70 Number 4, Centennial Commemorative Issu

Dendroclimatological Analysis and Fire History of Longleaf Pine (\u3cem\u3ePinus Palustris\u3c/em\u3e Mill.) in the Atlantic and Gulf Coastal Plain

The purpose of this research was to use longleaf pine trees at three major sites in the Southeastern Coastal Plain to: (1) determine how longleaf pine trees respond to climate, (2) reconstruct past climate conditions using long tree-ring chronologies, (3) determine the effects of atmospheric teleconnections on longleaf pine growth, and ( 4) reconstruct fire history from fire-scar data. The native range of longleaf pine and its associated communities extends from southeastern Virginia south and westward to the Trinity River in eastern Texas. I collected samples from living and remnant longleaf pine wood in coastal South Carolina, Eglin Air Force Base in the Florida panhandle, and the Big Thicket National Preserve of Texas. In the climate response analysis, the Palmer Drought Severity Index (PDSI) and Palmer Hydrological Drought Index (PHDI) had the highest correlation with longleaf pine growth. The strongest relationships between longleaf pine growth and the Palmer indices occur between the months of July and November. Precipitation in the spring and summer was also positively related to growth at all sites. The relationship between temperature and growth was the weakest among all climate variables, but warm summer temperatures had a consistent, negative relationship with longleaf pine growth. The climate signal in the latewood was generally more robust than those in total ring width and earlywood width. developed chronologies for total ring width at all sites and for earlywood and latewood widths in Texas and South Carolina. The master chronologies for each site spanned the years from 1629-2003 in Texas, 1503-2003 in Florida, and 1455-2003 in South Carolina. I reconstructed September PHDI at all sites using a transfer function with tree-ring indices as the independent variable. For all reconstructions, the most widespread and intense year of drought since 1700 was 1925. The driest five-year period common to all reconstructions was 1951-1955. At decadal scales, extremely wet periods were often followed immediately by extremely dry periods. My reconstructions showed evidence for several historic disturbances, including the Charleston earthquake of 1886 and the arctic outbreak of 1835. Spectral analysis showed no significant spectral signatures in any of the reconstructions. Atmospheric teleconnnections such as El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO) significantly affected longleaf pine growth at all sites, but the strength of the teleconnections varied through time. ENSO in the summer and fall correlated significantly with tree growth in Texas and South Carolina. The PDO in the year prior to growth was generally directly related to longleaf pine growth, while PDO in the current year usually showed an inverse association. The NAO from August of the previous year and May of the current year were generally negatively related to longleaf pine growth. The AMO was generally positively associated with longleaf pine growth in all months of the year. The reconstruction of fire history revealed that fire was frequent at all sites prior to the advent of fire suppression in the 20th century. The nature of the fire regime varied according to site conditions, such as the size of fire compartments and soil types. Fire frequency and seasonality of fires were also variable over time, reflecting the combined influence of climatic conditions and anthropogenic ignitions. Fire-scarred samples were not particularly abundant at any of the sites, and most scars were embedded deep inside the tree rather than on obvious, fire-scarred surfaces. Trauma rings that are abundant at the root-stem interface may be useful indicators of injury from fire, but more samples will be required to verify this hypothesis

Desmognathus monticola

Number of pages=60Geological SciencesIntegrative Biolog