<p> Identifying species occurrence in ecosystems of high conservation concern is especially important in the context of modern landscapes. This study investigated how stand-scale and landscape-scale factors affect priority birds associated with longleaf pine (<i>Pinus palutris</i>) ecosystems. Herein, I compared priority bird occupancy among 12 stand types throughout the historic range of longleaf pine. I found open pine stands positively influenced red-cockaded woodpecker (<i>Picoides borealis</i>) and Bachman&rsquo;s sparrow (<i>Peucaea aestivalis</i>) occupancy, but were not significantly linked to northern bobwhite (<i>Colinus virginianus</i>) and brown-headed nuthatch (<i>Sitta pusilla</i>) occurrence. Landscape- and stand-scale factors affected red-cockaded woodpecker, Bachman&rsquo;s sparrow, and brown-headed nuthatch occupancy. Northern bobwhite occupancy was influenced solely by landscape-scale factors. Red-cockaded woodpecker and Bachman&rsquo;s sparrow were positively influenced by metrics associated with longleaf pine ecosystems suggesting they are effective indicator species. My analysis indicates that using this multi-scale approach is valuable to identifying areas on the landscape of conservation and restoration priority.</p>

Expanding urbanization into undisturbed Sonoran Desert vegetation has led to public concern over the removal and destruction of large saguaro cacti (Carnegia gigantea). Development mitigation plans were established requiring transplantation, salvage and replacement of saguaros in certain development sites. However, no research has assessed whether native birds use transplanted saguaros at the same rate as non-transplanted cacti. The objective of this study was to determine the effects of saguaro transplantation on nest use. In Tucson, Arizona, 87 transplanted and 28 non-transplanted saguaros on a developed site and 26 non-transplanted saguaros on an undisturbed site were selected for observation of bird nesting activity during the breeding seasons of 1997 and 1998. Birds showed a preference for saguaros, transplanted or non-transplanted, which were surrounded by native vegetation and in areas with low human activity. I suggest that guidelines be revised for development mitigation standards and saguaro transplanting.

Ponderosa pine (Pinus ponderosa Laws.) forests have changed considerably during the past century, partly because recurrent fires have been absent for a century or more. In dense stands of ponderosa pine in the Black Hills of South Dakota, a layer of pine needles has replaced understory vegetation. I examined the disturbance history, soil seed bank, and effects of prescribed burning and overstory reduction on understory vegetation in a ponderosa pine stand in the northern Black Hills. Cessation of fires, prolific ponderosa pine regeneration, and logging led to a dense, even-aged stand with very little understory vegetation and few viable seeds in the soil seed bank. Understory vegetation did not respond to restoration treatments the first growing season, but did respond the second growing season. Paucity of viable seeds in the soil seed bank does not appear to constrain recruitment of understory vegetation in dense ponderosa pine forests of South Dakota.

I studied bat activity at 13 artificial and 4 natural water sources in southern Arizona from May 1995 through August 1996 using mist-nets and ultrasonic detectors. I used 2 indices of bat activity, capture rates, calculated from mist-netting data, and bat passes/30 minutes, calculated from ultrasound data. Both methods provided similar information on temporal patterns of bat activity. Indices of bat activity were highest during the reproductive season (May through August) compared to the non-reproductive season (September through April). Bat activity did not differ between any of the 2-week time periods within the reproductive season. During the reproductive season, bat activity was bimodal with peaks during the first 2 hours after sunset and the 2 hours preceding sunrise. During the non-reproductive season, bat activity was unimodal, with the majority of activity occurred within 2 hours of sunset. I captured six bat species within the study area. Sex ratios tended to be male biased during the non-reproductive season but close to 1:1 during the reproductive season. Sex ratios did not differ between natural and artificial water sources for any of the bat species compared. Age ratios did differ significantly between natural and artificial water sites. A higher percentage of the total captures at natural water sources were juveniles compared to artificial water sources, possibly indicating higher reproductive output in areas surrounding natural sites. Indices of activity during the reproductive season were significantly higher at natural compared to artificial water sources. However, this difference was not due to higher insect biomass at natural water sources. I developed stepwise multiple regression models to explain variation in bat activity and species richness at water sources. Elevation, type of water source and distance to the nearest cliff or rock outcrop were significant variables in explaining variation in overall capture rates at water sources. Type of water source was the only significant variable explaining variation in ultrasonic activity (passes/30 min), while distance to the nearest source of permanent water and size of the water source explained 33% of the variation in species richness.

Fire scar analysis to identify fire events and stand age structure analysis to identify fire effects on survivorship of trees were used to reconstruct surface and crown fire regimes in upper elevation forests of the Gila Wilderness, NM. Fire regimes varied across forest type, but not necessarily across elevation. Prior to the twentieth century, (from 1706 to 1904), the mean return interval for large fires was 8 years. During the twentieth century, (from 1904 to 1995), the mean fire return interval for large fires was 46 years. The virtual end of historically frequent fire regimes due to livestock grazing and fire suppression since the turn of the century has affected successional pathways of forest types across elevations, favoring later successional forest species and structures.

<p> Wildfire and subsequent timber salvage harvests are forecasted to increase in the Alaska boreal forest, creating the need to evaluate the effectiveness of forest regeneration practices in light of these interacting disturbances. Silvicultural practices such as site preparation and assisted regeneration are carried out shortly after disturbance in order to ensure satisfactory reforestation. Thirty years after a stand-replacing wildfire and salvage, we sampled an operational-scale (26.7 ha) white spruce (<i>Picea glauca </i> Moench [Voss]) regeneration trial established in a productive upland forest. Regeneration treatments were applied in a split-split plot experimental design on two landform types (LF), four ground scarification treatments (GST) plus a non-scarified control, and five artificial white spruce regeneration treatments (WSRT) plus a natural seedfall control. We analyzed total biomass as well as stand density and basal area for all species, seeking to evaluate the persistence of regeneration silvicultural treatment effects 28 growing seasons after installation. Our results indicate GST had no significant effect on white spruce basal area or stem density. </p><p> However, compared to natural seedfall control plots, white spruce basal area was six times higher in planted seedling plots, and white spruce stem density (dbh &ge; 1.0 cm) was nearly three times greater in broadcast seeding plots. White spruce stem density from natural seedfall averaged 944 stems ha^-1, but density was dependent on both topographic position and distance to wind-dispersed seed sources. Scarification nearly doubled Alaska birch (<i>Betula neoalaskana</i> Sarg.) stem density and basal area compared to non-scarified control plots. Planted white spruce plots supported 19% less birch basal area, except in the most intensive scarification treatments in which birch basal area did not differ. Although quaking aspen (<i>Populus tremuloides</i> Michx.) density and basal area were generally unaffected by the regeneration silvicultural practices in this study, intensive scarification reduced basal area by half on slope plots. These results confirm that regeneration silvicultural practices continue to influence stand development beyond the stem initiation stage, but practices that promote one species may reduce others.</p>

The problem addressed is the public's lack of awareness of the contributions of landscape architects and other natural resource professionals to the practices of land stewardship. One solution is a travel guide to be developed using marketing and interpretive principles. The research question is: what should be the content of the travel guide such that it would increase public awareness about landscape architecture and related natural resource professions and their role in land stewardship? The scope included research for planning the guide: it excluded collection of specific project information. A questionnaire was administered to landscape architects at two professional meetings. The major findings include which topics best explain the profession, and the types of projects that should be selected. These findings are valuable to natural resource professional societies and to publishing industry marketers, and for use in pursuing grant funding to continue the guide's development.

<p> Deforestation in the Congo Basin is altering the natural functioning and services of the ecosystem and adversely impacting highly vulnerable human populations who rely on their proper functioning. There is currently no framework that comprehensively addresses the historical and cultural complexities that are persistent in Central African societies and that also include, from a micro scale, the detailed voices of local communities. Without such a holistic framework, it is difficult to evaluate the effectiveness or harmfulness associated with current management strategies in responding to deforestation at the various levels. This transdisciplinary mixed method study determined the most salient indirect and direct causes of forest loss, the impacts resulting from an altered state, and the effectiveness of current management responses by assessing changes in forest cover, forest provisions, and trends in forest management. Because forests are common goods, the elasticity of forests are dependent on a multitude of human activities and attitudes. Therefore, data collected via survey tools were used to evaluate the role of multiple stakeholders in the state of the Congo Forest using the Driver-Pressure-State-Impact- Response (DPSIR) framework, a structured analytical tool created by the European Environmental Agency for better understanding of Integrated Environmental Assessments. To best explore local to international perspectives on the effectiveness of current strategies in sustaining forests for livelihoods and ecosystem services, research methods included conducting remote sensing analysis of Landsat satellite images, interviewing over 325 individuals living in 25 communities in the Lake T&eacute;l&eacute;-Lake Tumba Landscape of northwestern Democratic Republic of Congo and 20 individuals working on forest management, conservation, and funding, and a climate analysis using 40 years of weather data collected from a scientific reserve located within the landscape. Results highlight that local populations are highly environmentally literate and their knowledge is a useful tool for qualifying environmental changes, such as reduced lake health, animal health, and plant health. Remote sensing results show the forest is in a state of decline and climate findings confirm the ecological health of the landscape has been reduced demonstrated by major shifts in the traditional agricultural calendars and the effects are having adverse public health impacts on local communities. The process of this research itself interfaces science and policy and thus recommendations focus on how to make effective payments to communities for supporting alternative livelihoods in order to prevent deforestation while next steps should focus on the implications of forest loss and the promotion of a One Health approach at the landscape level.</p>

Red-tailed hawks (Buteo jamaicensis), Swainson's hawks (Buteo swainsoni), great horned owls (Bubo virginiaus), and ravens (Covus corax and C. cryptoleucus) occur sympatrically in desert grasslands in Arizona. Desert grasslands have been invaded by trees since Anglo-American settlement. They may also be subject to greater human disturbance than historically, because of recent increases in illegal immigration along the U.S.-Mexico border. These changes may affect the abundance, diversity, competitive interactions, and reproductive success of raptors and corvids in desert grasslands. I studied raptors and corvids on the Santa Rita Experimental Range (SRER) and Buenos Aires National Wildlife Refuge (BANWR) in southern Arizona. My objectives were to (1) assess how spatial relationships among nesting raptors and corvids affect reproductive success, (2) identify characteristics of the environment selected by members of the assemblage for nest sites and home ranges, (3) identify similarities and differences in nest site and home-range characteristics among species, and (4) investigate how anthropogenic changes in desert grasslands have affected raptors and corvids. Productivity (x̄ [95% CI]) was high for red-tailed hawks on the SRER (1.82 [1.41, 2.23] young per breeding pair [YPB]), but low for all species on the BANWR (great horned owls: 0.96 [0.54, 1.38] YPB; ravens: 1.75 [1.39, 2.10]; red-tailed hawks: 1.04[0.83, 1.24]; Swainson's hawks: 0.91 [0.67, 1.16]) relative to range-wide averages (great horned owls: 1.42 [1.27, 1.56]; ravens: 2.39 [2.70, 3.07]; red-tailed hawks: 1.35 [1.20, 1.50]; Swainson's hawks: 1.34 [1.23, 1.45]). All species on both sites selected nest sites with taller nest trees and greater tree volume than available at random. Swainson's hawks selected home ranges with greater grass volume than available on BANWR. Overlap in habitat use was high among all species, exceeding 54% for nest trees, 80% for nest sites, and 90% for home ranges. Mesquite-dominated desert grasslands seemed to provide high quality habitat for red-tailed hawks on the SRER, but reproductive success for assemblage members on BANWR was poor. We suggest that competition, resulting from high habitat overlap, and human disturbance by illegal immigrants, has depressed raptor and corvid reproductive success on the BANWR.

I used archives of wildfire perimeters (fire atlases) within a geographic information system (GIS) to describe and evaluate fire frequency patterns for the 20th century in the 486,673-ha Gila/Aldo Leopold Wilderness Complex (GALWC), New Mexico and the 785,090-ha Selway-Bitterroot Wilderness Complex (SBWC) in Idaho and Montana. I addressed questions about changing 20th century fire frequencies and landscape-scale controls of fire frequency by analyzing fire atlases along with data for topography, vegetation, and climate. Similarities and differences in comparisons between study areas highlight important aspects of fire regimes and strengthen my interpretation and inference. In the GALWC, fire rotations were shortest during the recent wildfire use period (1975-1993) and longest during the pre-modern suppression period (1909-1946). In the SBWC, fire rotations were shortest during the pre-modern suppression period (1880-1934) and longest during the modern suppression period (1935-1975). Elevations with the highest fire frequencies differed between study areas. However, forest types found at these elevations are characterized by similar overstory tree species. Steeper northeastern slopes in the GALWC and southwestern slopes in the SBWC burned most frequently. I assert that, in the GALWC, horizontal fuel continuity is a main factor determining fire frequency. In the SBWC, fuel moisture status limits fire frequency. Fires are most frequent in areas where ignitions occur and neither fuel continuity nor fuel moisture are likely to limit fire spread. Three statistical modeling approaches were used to produce maps of reburn probabilities. Log-likelihood modeling provided the most satisfactory results, while logistic regression and classification and regression trees yielded statistically insignificant models. Empirical models contributed to the assertion that fuel continuity limits fire frequency in the GALWC while fuel moisture limits fire frequency in the SBWC. Mapped fire perimeters provide a valuable source of spatial historical information for describing the role of large fires over broad areas. This dissertation enhances scientific knowledge about broad scale changes in fire regimes. Comparisons between areas facilitate identification of unique versus general patterns. Results provide a contemporary baseline for comparison with estimates of Pre-EuroAmerican fire frequencies, and a historical, spatial context for modeling and managing future fire regimes.