The long term patterns of fire-climate interactions and forest recovery processes in subalpine forests are poorly understood. This study used a suite of dendrochronological techniques to identify tree growth-climate relationships, assess the interactions of fire with interannual climate variability, and reconstruct summer temperature in subalpine forests of the Selway-Bitterroot Wilderness Area on the border of Idaho and Montana, USA. Comparison of ring-width chronologies from whitebark pine (Pinus albicaulis Engelm.) and subalpine larch (Larix lyallii Parl.) with modern climate data indicated that summer temperatures were most limiting to growth in these conifers. Warm summers were generally conducive to radial growth. However, the temporal stability of the climate-tree growth relationship weakens from the early to later periods of the record. Alterations to growing season length, possibly modified by snow pack, may be related to the reduction in climate-growth relationships. A 748-year reconstruction of average summer temperature was developed that explains ≈36% of the variance of the instrumental record. Positive values of the coefficient of efficiency and reduction of error verification statistics indicated that the reconstruction was of good quality. Warm and cool periods in the reconstruction include a warm decade around the 1650s and prolonged cooling around 1700. Peaks in variance in reconstructed average summer temperature occurred at 87, 15, and 2 years. More than 2000 fire scar and age structure samples were used to evaluate fire-climate relationships. Comparison of widespread fire events to climate variables indicated dry conditions both during the fire year and one year before a fire. Multiple spatial patterns of drought and El Nino were related to widespread fire occurrence. Forest recovery following fires generally proceeds from lodgepole pine (Pinus contorta var. latifolia Dougl.) toward spruce-fir forests (Picea engelmannii Parry- Abies lasiocarpa (Hook) Nutt.). Two successional pathways occur, one beginning with an initial lodgepole pine stage, the other a spruce-fir stage. Initial composition was related to the presence of overstory lodgepole pine at the time of fire occurrence as well as the intervals between successive fires. Collectively, these results suggest a strong multi-year drought linkage between climate and fire, and dependence on fire intervals for structuring forest communities.

I used two sampling techniques, visual line transects and pitfall traps, to compare the numbers and species richness of lizards in four vegetative communities representative of the Sonoran Desert region: exotic grasslands, native grasslands, oak woodlands and desertscrub. I found similar numbers of lizards and species richness in three of the four communities, but I detected more lizards using transects than pitfall traps in the oak woodland community. On a per area basis, I detected significantly more lizards with transects than with pitfall traps in all four communities (P = 0.018). I compared capture success using three different pitfall traps. Overall, I found no differences between capture success in black and white plastic 19-1 buckets (Chi square = 0.58, df = 1, P > 0.05) or between white buckets and number 10 cans stacked three deep (Chi square = 0.60, df = 1, P > 0.05). I did find that one species (Sceloporus magister) was captured more often in black buckets than in white buckets (Chi square = 5.33, df = 1, P < 0.05). Pitfall traps were significantly more expensive (P = 0.02) than transects in terms of materials, installation and data collection. I did not obtain sufficient recaptures of any species in the pitfall traps to generate population or survivorship estimates using the programs RELEASE, SURGE, or JOLLY. I calculated the effort necessary to obtain sufficient recaptures to make those estimates using pitfall traps. I also calculated the effort needed to obtain similar estimates using transects in each vegetative community. Recommendations for sampling days for the two methods varied considerably depending on the species and the vegetative community. If managers need mark-recapture data or detailed information on individual lizards, pitfall traps should be used. However, if managers do not need detailed information, I recommend using transects to sample lizard populations because they are less expensive, less time-consuming, and provide similar information on the relative abundance and species richness of lizard populations.

During 1980-1995, 42 cohorts of free-living juvenile female Antrozous pallidus and Eptesicus fuscus were banded and recaptured at three bridge roosts in Chihuahuan desertscrub in southeastern Arizona. Surviving female colony members returned each Spring to rear young. Life tables from known-age cohorts provided comparison of survivorship within and between populations sharing similar macro-environmental conditions at these maternity roosts. Mean first-year survivorship varied between and within species and roosts and was higher for E. fuscus than for A. pallidus. First-year survivorship was affected by weather, by age of mothers through indirect influence on neonate size with number of young in the litter, and by human activity. Disease, predation, inclement weather, and human vandalism caused mortality. Second and third-year survivorship was higher than juvenile year for both species. Eptesicus fuscus had higher adult survivorship than A. pallidus. Compared to A. pallidus, female E. fuscus had lower mortality rates, and females decreased their reproductive effort by litter size reduction and deferred age of first reproduction. While A. pallidus females began reproducing at yearling age, 54% of E. fuscus females deferred their first reproduction until age two. Fifty-five percent of age two A. pallidus and up to 100% of older females produced twins. By contrast, only 9% of age two E. fuscus had twins, and 28% of older females produced twins. Lower annual productivity by E. fuscus females was apparently balanced by longer life. While no more than 10% of A. pallidus reached five years of age, at least 10% of E. fuscus attained eight years. Thus, these species have evolved a life history that allows reproductive replacement with low fecundity and high survivorship. Western populations of E. f. pallidus produced smaller litters, deferred first reproduction, and had higher juvenile and adult survivorship than reported for E. f. fuscus, demonstrating intraspecific geographical differences in life history. Maximum life-span records for A. pallidus were a 10-year old male and a female that was at least 11 years old. The oldest E. fuscus were two females that were at least 14 and 15 years old.

Forest fire policies are changing. Managers now face conflicting imperatives to re-establish pre-suppression fire regimes, while simultaneously preventing resource destruction. They must, therefore, understand the spatial patterns of fires. Geographers can facilitate this understanding by developing new techniques for mapping fire behavior. This dissertation develops such techniques for mapping recent fires and using these maps to calibrate models of potential fire hazards. In so doing, it features techniques that strive to address the inherent complexity of modeling the combinations of variables found in most ecological systems. Image processing techniques were used to stratify the elements of terrain, slope, elevation, and aspect. These stratification images were used to assure sample placement considered the role of terrain in fire behavior. Examination of multiple stratification images indicated samples were placed representatively across a controlled range of scales. The incorporation of terrain data also improved preliminary fire hazard classification accuracy by 40%, compared with remotely sensed data alone. A Kauth-Thomas transformation (KT) of pre-fire and post-fire Thematic Mapper (TM) remotely sensed data produced brightness, greenness, and wetness images. Image subtraction indicated fire induced change in brightness, greenness, and wetness. Field data guided a fuzzy classification of these change images. Because fuzzy classification can characterize a continuum of a phenomena where discrete classification may produce artificial borders, fuzzy classification was found to offer a range of fire severity information unavailable with discrete classification. These mapped fire patterns were used to calibrate a model of fire hazards for the entire mountain range. Pre-fire TM, and a digital elevation model produced a set of co-registered images. Training statistics were developed from 30 polygons associated with the previously mapped fire severity. Fuzzy classifications of potential burn patterns were produced from these images. Observed field data values were displayed over the hazard imagery to indicate the effectiveness of the model. Areas that burned without suppression during maximum fire severity are predicted best. Areas with widely spaced trees and grassy understory appear to be misrepresented, perhaps as a consequence of inaccuracies in the initial fire mapping.

Outdoor recreation and eco-tourism are areas of increasing interest to land management agencies worldwide. As commodity extraction values decline, and the demand for nature based recreation rises, there is a commensurate shift in the goals and management of undeveloped environments. Paralleling this rapid expansion of recreation uses is a concern for managing its future growth and its environmental impacts. Due to the complexity of the relationship between recreational use and impacts on both environmental resources and the quality of visitor experience, researchers and recreation managers have employed a number of simplifying assumptions. Impacts are typically represented by average values over large areas and/or over widely differing recreation experiences. This geographic homogenization is both theoretically inadequate and impractical. Recreation experiences must be understood as the result of specific activities carried out in specific environmental settings, and effective recreation management, integrated with other environmental resource concerns, requires geo-spatial representation. This study investigates the effectiveness of coupling computer based Geographical Information System (GIS) approaches with traditional social sciences survey methods to improve assessments of nature-based recreation activities and experiences, and their environmental impacts. Secondary analyses of preexisting data collected in the East Huachuca Mountain recreation area in Coronado National Forest, Arizona provided measures of spatial distributions of the number of users, and of social, managerial and environmental detractors from the quality of recreation experiences. GIS analysis identified the most likely locations for specific activities (e.g. hiking, camping, hunting), for negative social encounters (e.g. hikers meeting with mountain bikers), for managerial and environmental detractors from recreation quality (e.g. inadequate trail signage, presence of litter and trash, soil erosion). Thus, although respondents in general reported they had overall positive experiences, spatial analysis revealed consistently negative experiences in some specific sites. GIS analysis methods provide new opportunities to improve upon recreation theory by better addressing the naturally spatial character of recreation experience. More precisely geo-referenced recreation survey and assessment methods enable more effective integration of recreation values and impacts into the inherently geo spatial ecosystem management framework.

Croton fantzianus Seymour (Euphorbiaceae), is a structurally important tree in the tropical deciduous forest of the Municipality of Alamos in southern Sonora. It has become important as a non-timber forest product within the last thirty-five years, harvested for stakes (vara blanca ) for the agricultural fields in Sonora, Sinaloa and Baja California. A study was carried out on ecology of the species, macroeconomics and household economics to determine sustainability of current patterns of use. During a study on the ecology of the tree the species was identified from specimens collected and found to be a disjunct population known previously from Nicaragua. It was determined that vegetative and reproductive phenologies are driven by water availability with responses along a water gradient varying among study sites. Rapid development of silver mining precipitated woodcutting for timber and fuel at unprecedented rates in the late 17th century. The original tropical deciduous forest was transformed to secondary forest by this extraction. Closure of the mines in the early 20th century began economic isolation of the Municipality that persists today. The economy of Alamos is depressed in response to national and state economy, people are under- or un-employed. Many cut vara blanca. Economic strategies in the Municipality include exploitation of non-timber forest products, the most important is vara blanca. There are three levels of organization for vara extraction: cutters, middlemen truckers, and large truckers. Income generated by each level is significantly larger than the daily minimum wage. Financial records indicate that nine of eleven respondents rely on the resource for all or part of their incomes. A study of the population ecology of the species indicates it is the most important component of the forest community at all study sites. Population structure and composition are variable and may be related to prior harvest history. Loss of reproductive capacity was recorded on a recently harvested area. The tree may be a successional species and does well in disturbed areas. Government records and informant interviews indicate intensification of extraction has depleted the population. It is questionable if extraction at recent rates can be sustained.

The toppling of trees forms mounds of disturbed sediment and pits from which the mound removes sediment, rocks, and organic matter. Sites of uprooted trees in Puerto Rico and Colorado were examined (1) to compare areas and volumes of mounds and pits relative to tree size, (2) to compare areas and volumes of mounds and pits formed during catastrophic events at the landscape scale, and (3) to consider decay of mounds and pits after formation. For a given basal area, the analyses found no difference among sites in area and volume of freshly formed individual mounds and pits. For landscape-level catastrophic uprooting, the percent of toppled trees in a plot can explain 85% and 87% of the areas and volumes, respectively, of the quantity of soil uplifted. Exponential decay coefficients developed by monitoring mound/pit complexes indicate that mounds and pits at the humid tropical site in Puerto Rico decay in about 74% and 57% of the time, respectively, of mounds and pits at a temperate Colorado site. Decay coefficients developed for the Colorado site indicate that mounds and pits are reduced to 10% of their original volume within 30 and 78 years, respectively. Coefficients for Puerto Rico suggest that a similar reduction in volume requires 17 years, whereas pits generally fill within a decade.

The dissertation investigates communal forest use and management in the municipio (county) of La Campa, Honduras, and the multi-leveled interrelationships that influence ongoing transformations in the forests. The work takes a political ecology perspective, thus it evaluates the interrelationships between local, national and international processes that have shaped historical and current forest and land use patterns in the municipio. State policies have constituted an important factor in encouraging forms of forest management; the communitarian tradition imposed on Lenca Indian communities by the Spaniards following the Conquest provided a context which the people adapted to their own situation and propagated into recent years. Low population density, a relatively homogeneous populace, the pattern of subsistence agriculture, limited state interference and minimal interaction with national markets apparently contributed to the viability of common property management and the survival of forests into the present. The local context has changed in recent decades with a growing population, increased market involvement, socioeconomic differentiation, and state policies that undermine communal forms of forest management. Domination by the state forestry development institution (COHDEFOR) during the 1970s and 1980s led to logging, forest degradation, and disruption of traditional forms of forest management. A majority of the population eventually organized to oust COHDEFOR and prohibit market-oriented timber exploitation within the municipio, but communal forest management has suffered a number of shortcomings in the aftermath of COHDEFOR's departure. At present, the situation indicates an unsustainable level of forest exploitation and a gradual transformation of communal forests into private holdings. New national legislation regarding agriculture and forestry encourages the privatization of communal lands, while international market forces and economic development initiatives favor the production of agricultural export crops, such as coffee. The analysis considers the factors and interrelationships that inhibit sustainable use of communal forests in La Campa; it also recognizes the benefits and difficulties that relate to common property forest management within the current context.

I investigated the effects of winter prescribed burning on relative abundance and species richness of birds in mesquite (Prosopis glandulosa)-grassland at the Welder Wildlife Foundation Refuge, Texas, from June 1995 to August 1996. Relative abundance (P=0.246) and species richness (P=0.622) of breeding birds were not different, but mourning doves (Zendaida macroura) (P=0.058) and great-tailed grackles (Quiscalus mexicanus) (P=0.084) increased, and black-bellied whistling ducks (Dendrocygna autumnalis) (P=0.040) declined in burned treatments. Relative abundance of wintering birds was greater (P=0.002) in burned treatments, but species richness was not different (P=0.602). Mourning doves (P < 0.001) and savannah sparrows (Passerculus sandwichensis) (P=0.001) increased, but grasshopper sparrows (Ammondramus savannarum) (P=0.009), Le Conte's sparrows (Ammondramus leconteii) (P=0.001), and sedge wrens (Cistothorus platensis) (P=0.001) declined in burned treatments in winter.

Public land agencies are mandated to incorporate Ecosystem Management practices into forest planning and management. The human dimensions of Ecosystem Management, including recreation and amenity uses of forest lands constitute a critical component associated with management decisions. Recently, research has extended the Recreation Opportunity Spectrum (ROS) concept of experience based management, to one of Benefits Based Management (BBM). This Research presents results of a study on the Dixie National Forest to examine and test some components of the BBM concept as a means of improving recreation planning and management. This study utilized an on-site survey targeted to capture visitors knowledge about beneficial outcomes: expectations, desirability, acquisition and maintenance. Results of this study reveal that visitors could articulate these types of beneficial outcomes; indicating this type of research can assist in formulating design and management strategies for forest lands through the objectives incorporated in the human dimension of Ecosystem Management.