Social and Behavioral Sciences Commons^™

Reconstructing Late Holocene Fire, Agriculture, And Climate From Sediment Records In Costa Rica And The Dominican Republic, Erik Nicholas Johanson

Doctoral Dissertations

We use multiple proxies from sediment cores to identify periods of climate stress during the late Holocene across the circum-Caribbean region and to determine how fire activity and signals of Pre-Columbian agriculture coincide with these arid periods. We examine evidence of aridity from stable carbon isotope ratios and shifts in elemental composition, along with pollen and microscopic charcoal, at Bao Bog in the highlands of Hispaniola. We infer two major periods of aridity (3600–2300 and 1040–850 cal yr BP), with the later period associated with the late phase of the Terminal Classic Drought. A third, less marked interval of aridity …

Incendios En Los Pinares De Las Zonas Montañosas De La República Dominicana: La Visión De Fondo, Sally P Horn

Geography Publications and Other Works

Fire in Highland Pine Forests of the Dominican Republic―The Long View

Large forest fires in Valle Nuevo National Park in 2014 and 2015 have increased interest in fire as an ecological force in montane pine forests of the Dominican Republic. Geographer Dr. José Ramón Martínez Batlle estimated using Landsat imagery and GIS that some 4700 ha burned in July 2014 (http://www.geografiafisica.org/2014/07/29/superficie-quemada-incendio-valle-nuevo/), and an additional 1600 ha burned in late April 2015 (http://www.geografiafisica.org/2015/09/25/superficie-quemada-en-valle-nuevo-finales-de-abril-principios-de-mayo-2015/).

Since 1995, when I first visited what is today Valle Nuevo National Park (then, Valle Nuevo Scientific Reserve), as a guest of the Moscoso …

Using Spatial Analysis To Evaluate Fire Activity In A Pine Rockland Ecosystem, Big Pine Key, Florida, Usa, Lauren Ashley Stachowiak

Doctoral Dissertations

Pine rocklands are fire-prone ecosystems with limited spatial extent, and have experienced reduced area in the previous decades through habitat conversion and urbanization. The purpose of this dissertation research was to evaluate the historical range of variability of fire activity and spatial patterns of fires in a pine rockland ecosystem in the National Key Deer Refuge (NKDR) on Big Pine Key in the Lower Florida Keys. To investigate the temporal and spatial patterns in fire activity, I (1) evaluated the temporal patterns for fires in my study area in the NKDR, (2) analyzed differences in standard fire history metrics since …

Climate Drivers Of Wildfire Activity In The Magdalena Mountains Of New Mexico, U.S.A., Elizabeth Anne Schneider

Masters Theses

In recent years, crown fires have raged through mixed-conifer forests in the American Southwest that historically experienced frequent, low-severity wildfires. Land management agencies now wish to restore wildfires to their historical range of variability, but this requires information on fire regimes before Euro-American disturbance took place. We characterized the historical fire regime of a high elevation, mixed-conifer forest in the Magdalena Mountains, New Mexico. This research evaluated the different climate drivers, represented by the Palmer Drought Severity Index (PDSI), the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO), that influence the occurrence of …

Methods For The Study Of Soil Charcoal As An Indicator Of Fire And Forest History In The Appalachian Region, U.S.A., Sally P Horn, Christopher A. Underwood

Geography Publications and Other Works

Charcoal particles in soils and sediments of the Appalachian region provide evidence of long-term fire history relevant to resource management and to studies of paleoclimate, vegetation history, and the effects of prehistoric and historic humans on the environment. Charcoal records of fire history are of low resolution in comparison to dendrochronological records, but reach well beyond the oldest trees in most areas, providing evidence of fires thousands or tens of thousands of years ago. We focus here on fire history reconstruction from soil charcoal, which provides site-specific evidence of past fires and potentially forest composition. Charcoal > 2 mm may be …

Late Pleistocene Climate, Vegetation, And Fire History From A Southern Appalachian Bog, Whiteoak Bottoms, Nantahala National Forest, North Carolina, U.S.A., Mathew Stephen Boehm

Masters Theses

I examined loss-on-ignition, pollen, and charcoal evidence of climate, vegetation, and fire history at Whiteoak Bottoms (35º04’44”N, 83º31’50”W; 1032 m elevation), a peat-forming wetland located along the Nantahala River in western North Carolina. Previous research by J. McDonald and D. Leigh revealed that this wetland formed in a paleochannel of the Nantahala River between 15,000 and 14,000 cal yr BP. I obtained additional AMS radiocarbon dates, carried out high-resolution loss-on-ignition analysis, and examined pollen and microscopic charcoal assemblages in a 157-cm sediment core from the previous study. Radiocarbon dates and stratigraphic analyses indicate that much of the Holocene is missing …

Dinámica De La Vegetación Después De Fuegos Recientes En Los Páramos De Buenavista Y Chirripó, Costa Rica (Vegetation Dynamics Following Recent Fires In The Buenavista And Chirripó Páramos Of Costa Rica), Sally P Horn

Geography Publications and Other Works

Field studies following fires in the Buenavista (La Muerte Massif) and Chirripó páramos demonstrate that woody species show varying responses to fire. The bamboo Chusquea subtessellata and the ericaceous shrubs Vaccinium consanguineum and Pernettya prostrata typically resprout vigorously after fire, but rarely if ever recolonize burn sites by seeding. The shrub Hypericum irazuense, in contrast, generally suffers high mortality in páramo fires, but successfully reestablishes by seed following all but the largest fires. Preexisting vegetation, fire characteristics, and site differences both before and after burning likely affect rates of shrub and herb survival, colonization, and growth in páramo burn …

Registros De Sedimentos Lacustres De La Vegetación Del Holoceno Y Historia Del Fuego En El Páramo De Costa Rica. (Lake-Sediment Records Of Holocene Vegetation And Fire History In The Costa Rican Páramos), Sally P Horn, Brandon L. League

Geography Publications and Other Works

We examined pollen, pteridophyte (ferns and fern-allies) spores, and charcoal in a 5.6 m long sediment core from Lago de las Morrenas 1, and charcoal in a 1.1 m long sediment core from Lago Chirripó, to reconstruct postglacial vegetation and fire history in the Chirripó páramo. Lago de las Morrenas 1, the largest lake in the Valle de las Morrenas of Chirripó National Park, is presently surrounded by treeless páramo vegetation and has apparently been so since deglaciation approximately 10,000 radiocarbon years ago. Pollen spectra suggest no pronounced changes in vegetation since ice retreat. Pollen percentages for Gramineae and other …