<p> Invasive ants are one of the largest threats to Pacific island ecosystem conservation. I investigated effective ant control options by examining the relative attractiveness of five commercial ant baits to yellow crazy ants (<i>Anoplolepis gracilipes</i>). The results were used to select three baits whose efficacy at reducing <i>A. gracilipes</i> abundance was then tested in experimental treatment plots. The trials failed to identify an obvious preference for any of the baits and none of experimental treatments resulted in decreases in <i>A. gracilipes</i> abundance that differed from untreated plots. Additionally, the impact of <i>A. gracilipes</i> on nest initiation rates of Red-tailed Tropicbirds (<i>Phaethon rubricauda </i>) was explored. The survey found 90% fewer nest occurred in plots containing <i>A. gracilipes.</i> These results demonstrate the negative impacts invasive ants can have on ground-nesting seabirds and suggest that commercial ant baits may be ineffective against controlling <i> A. gracilipes</i> supercolonies.</p>

<p> Over the last three decades, collaboration has come to the fore as a way to address natural resource management problems that are often complex and contentious. As such, a new way of doing business has emerged for the United State Forest Service (USFS) as it engages community members in collaborative governance arrangements created to address forest management issues. USFS field-level personnel and the community stakeholders involved in collaborative governance arrangements expend valuable and limited resources to obtain collaborative outcomes. Field observations suggest that in order for collaborative outcomes to be durable and maintain longevity, changes must occur at the organizational level. However, few existing studies that document organizational changes made by natural resource land management agencies as a result of the agency&rsquo;s engagement in collaborative governance arrangements with community stakeholders. This dissertation provides theoretical and practical insights into the organizational changes occurring at three USFS field offices.</p><p> This exploratory, qualitative study employs a case study approach and semi-structured interviews were conducted with agency personnel and non-agency stakeholders. Document analysis of meeting minutes and personal observation data were also conducted. The data yielded the richest results when interpreted through three overarching theoretical lenses: organizational change, public administration, and collaborative governance. The results revealed that organizational changes are occurring at the field-level as a result of the actions of individual actors as they cross organizational boundaries. The outcomes of these changes can be beneficial to the agency, but a cautionary tale is presented suggesting that collaborative processes may impede, if not derailed, by power imbalances. The role of trust, or more accurately, the lack thereof, and its ability to change organizational boundaries and create power imbalances in the shared decision-making arena emerged as finding of importance to land managers and collaborative governance theory.</p><p> This dissertation advances the scholarly and practical knowledge of organizational change by presenting empirical evidence of the impact of community collaboration on federal natural resource agencies. It is necessary for the leadership of the USFS to understand their role in the collaborative process and to understand how and why these changes are taking place if they are to be sensitive to the added pressures and tensions that collaboration brings to their individual staff members. Managers in the USFS will need to be cognizant of the attributes of trust and should encourage their staff to build trust with stakeholders if they wish to maintain equitable power positions in the shared decision-making process. Future research that provides evidence of the linkage between organizational change, trust, and power would be useful in further understanding how the collaborative process and the collaborative behavior of individuals in natural resource management links to the outcomes of collaboration. </p>

<p> Tallgrass prairie once extended from Manitoba south to Texas and southeast to Indiana covering 100 million hectares prior to European settlement. Today less than 0.1% remains in Illinois, Indiana, Iowa, and Wisconsin. Tallgrass prairie is a diverse ecosystem with small remnants (1&ndash;2 ha) containing a large number of plant species (> 100). With most of the ecosystem lost, active efforts to replant tallgrass prairie began in the 1930s. Unfortunately, even the oldest restorations do not have plant communities similar to native prairies. My research attempts to understand the factors limiting successful restoration of native plant diversity by focusing on intensive surveys of three native and two restored prairies in Iowa. In each prairie, I sampled seven 0.5 m² plots using a frame with 49 grid points 10 cm apart and resurveyed these plots across successive years. I also collected soil cores and biomass and litter measurements in each plot. I analyzed plant community composition with a nonmetric multidimensional scaling ordination and fine-scale community structure with point richness and similarity metrics. Native prairies differed from restorations in plant community composition and had higher total carbon, nitrogen, and phosphorous, while restorations had higher plant available phosphorous. Native prairies also had higher richness from plot to point scales and lower similarity of neighboring plants at distances of centimeters. Restorations differ from native prairies at coarse and fine scales, and there was no indication that these restorations became more similar to native prairies over time. My work is the first to document fine-scale structure of plant diversity in native and restored prairies. By identifying that contemporary restoration practices do not result in plant communities that develop toward native prairies in composition, my work highlights our current limited understanding of the elements structuring plant communities and our ability to recreate this structure.</p><p>

<p> Land managers and researchers are currently concerned with expanding populations of invasive species across North America. Invasive species are non-native species, introduced intentionally or unintentionally to an environment, which have the potential to cause economic or ecological damage through modifications of biodiversity and structure of the resident community that it invades. While a great deal of attention has been given to the negative effects of non-natives, research regarding the community-level effects in native Illinois natural areas is limited at best. We address the issue of invasive species at the plant community level by assessing the impact that Eurasian native <i> Alliaria petiolata</i> (M. Bieb) Cavara and Grande (Brassicaceae) has on pine plantation understory communities at Sand Ridge State Forest (Mason County, IL). <i>Alliaria petiolata</i> is a biennial species possessing a multitude of characteristics that promote its success as an invasive plant across much of the United States. To properly evaluate the community-level response of Sand Ridge State Forest to invasion by garlic mustard, we experimentally invaded 72 plots with <i>A. petiolata</i> seeds or rosette transplants and subjected plots to different mineral nutrient amendments and management techniques. <i>Alliaria petiolata</i> population density was monitored over a 5-year period to evaluate the susceptibility of Sand Ridge State Forest to invasion, and a vegetative census was conducted to assess the effects of <i>A. petiolata</i> invasions on native understory plant communities using species richness (S), equitability (J), and the Shannon diversity index (H&rsquo;) as indicators. We present evidence that <i>A. petiolata</i> densities significantly increased over time, and that altering nutrient availability or management practices do not differentially affect the success of invasive <i>A. petiolata</i> at Sand Ridge State Forest. Additionally, we found that <i>A. petiolata </i> invasions do result in reduced diversity in this system, however nitrogen availability and management practices can modulate diversity losses. </p><p>

<p> Over the past century in the western United States, warming has produced larger and more severe wildfires than previously recorded. General circulation models and their ensembles project continued increases in temperature and the proportion of precipitation falling as rain. Warmer and wetter conditions may change forest successional trajectories by modifying rates of vegetation establishment, competition, growth, reproduction, and mortality. Many questions remain regarding how these changes will occur across landscapes and how disturbances, such as wildfire, may interact with changes to climate and vegetation. Forest management is used to proactively modify forest structure and composition to improve fire resilience. Yet, research is needed to assess how to best utilize mechanical fuel reduction and prescribed fire at the landscape scale. Human communities also exist within these landscapes, and decisions regarding how to manage forests must carefully consider how management will affect such communities. </p><p> In this work, I analyzed three aspects of forest management at large spatiotemporal scales: (1) climate effects on forest composition and wildfire activity; (2) efficacy of fuel management strategies toward reducing wildfire spread and severity; and, (3) local resident perspectives on forest management. Using a forest landscape model, simulations of forest dynamics were used to investigate relationships among climate, wildfire, and topography with long-term changes in biomass for a fire-prone dry-conifer landscape in eastern Oregon, United States. I compared the effectiveness of fuel treatment strategies for reducing wildfire under both contemporary and extreme weather. Fuel treatment scenarios included &ldquo;business as usual&rdquo; and strategies that increased the area treated with harvest and prescribed fire, and all strategies were compared by distributing them across the landscape and by concentrating them in areas at the greatest risk for high-severity wildfire. To investigate local community preferences for forest management, I used focus groups, interviews, and questionnaires. Through open-ended questions and a public participation geographic information systems (PPGIS) mapping exercise, local residents expressed their views on fuels reduction treatments by commercial and non-commercial harvest and prescribed fire. Emergent themes were used to inform alternative management scenarios to explore the usefulness of using PPGIS to generate modeling inputs. Scenarios ranged from restoration-only treatments to short-rotation commercial harvest. </p><p> Under climate change, wildfire was more frequent, more expansive, and more severe, and ponderosa pine expanded its range into existing shrublands and high-elevation zones. There was a near-complete loss of native high-elevation tree species, such as Engelmann spruce and whitebark pine. Loss of these species were most strongly linked to burn frequency; this effect was greatest at high elevations and on steep slopes. </p><p> Fuel reduction was effective at reducing wildfire spread and severity compared to unmanaged landscapes. Spatially optimizing mechanical removal of trees in areas at risk for high-severity wildfire was equally effective as distributing tree removal across the landscape. Tripling the annual area of prescribed burns was needed to affect landscape-level wildfire spread and severity, and distributing prescribed burns across the study area was more effective than concentrating fires in high-risk areas. </p><p> Focus group participants generally approved of all types of forest management and agreed that all areas should be managed with the &ldquo;appropriate&rdquo; type of treatment for each forest stand, and that decisions about management should be made by &ldquo;experts.&rdquo; However, there was disagreement related to who the &ldquo;experts&rdquo; are and how much public input should be included in the decision making process. Degree of trust in land management agencies contributed to polarized views about who the primary decision makers and what the focus of management should be. While most participants agreed that prescribed fire was a useful tool for preventing wildfire spread and severity, many expressed reservations about its use. </p><p> I conclude that forest management can be used to reduce wildfire activity in dry-mixed conifer forests and that spatially optimizing mechanical treatments in high-risk areas can be a useful tool for reducing the cost and ecological impact associated with harvest operations. While reducing the severity and spread of wildfire may slow some long-term species shifts, high sub-alpine tree mortality occurred under all climate and fuel treatment scenarios. Thus, while forest management may prolong the existence of sub-alpine forests, shifts in temperature, precipitation, and wildfire may overtake management within this century. The use of PPGIS was useful for delineating the range of forest management preferences within the local community, for identifying areas of agreement among residents who have otherwise polarized views, and for generating modeling inputs that reflect views that may not be obtained through extant official channels for public participation. Because the local community has concerns about the use of prescribed fire, more education and outreach is needed. This may increase public acceptance of the amounts of prescribed fire needed to modify wildfire trajectories under future climate conditions.</p><p>

<p> Natural mortality, <i>M</i>, has historically been a difficult parameter to estimate in conjunction with other stock assessment parameters. Time-varying <i>M</i>, while likely to be experienced by a population, is a particularly difficult process to estimate with the data and methods currently available to most stock assessments. Although auxiliary information in the form of a covariate to <i>M</i> has been shown to improve model fit for some stocks, such data are rarely available. Meanwhile, hierarchical models continue to be utilized in capturing processes that vary in time and space. I tested both the covariate and hierarchical methods in their ability to estimate time-varying <i>M</i>. I attempted to fit hierarchical models by two different methods: penalized likelihood and the integrated likelihood approach associated with mixed effects models. Mixed effects models performed poorly in comparison to penalized likelihood. Including a covariate to natural mortality aided the estimability of time-varying <i>M</i>, regardless of the observation error associated with the covariate. Estimating a constant value of <i>M</i> resulted in biased estimates when <i>M</i> was time-varying in the simulated population. I showed that the Akaike information criterion (AIC) is a useful metric for comparing models although it does not necessarily align with the accuracy of estimates that are of most interest to managers, such as terminal year spawning stock biomass. In addition to showing empirically that incorporating a covariate is a robust approach to estimating time-varying <i>M</i>, I conclude that this approach is also advantageous to stock assessment on theoretical grounds, as it is more amenable than hierarchical models to making predictions.</p><p>

Eastern box turtles are declining throughout their range as a result of habitat loss and fragmentation, associated road mortality, collection for the pet trade, and other localized threats such as incidental collection, disease, mowing, and fire. We evaluated the geomorphic habitat suitability for Eastern box turtles in Massachusetts using a Mahalanobis distance modeling approach. To evaluate habitat use, home range size, and box turtle population status in the Connecticut River Valley, Massachusetts, we conducted a four year mark-recapture and radio-telemetry effort. We surveyed over 30 sites, captured 191 animals and radio-tracked 91 animals at eight sites for 1-4 years for a total of 217 turtle-years. Estimated population sizes at these sites ranged from a summer high of 3.8 to a winter low of 0.3 turtles/ha. Home range size ranged from 140–2145 m straight line and 0.5–136 ha. These densities are much lower and home range sizes much larger than reported throughout the rest of the species range. Conservation efforts based on data from previous studies elsewhere in the species range would have underestimated habitat requirements and space needs, highlighting the need for local and regional information when planning for rare species conservation. We evaluated over-wintering habitat at multiple levels of habitat selection and spatial scales using logistic regression and classification trees in conjunction with remotely sensed geomorphic and land-use variables. We also conducted a micro-habitat assessment of over-wintering sites using variables measured in the field. Microtopography proved important, with 59% of transmitting turtles over-wintering in depressions (typically behind tip-up mounds of fallen trees). Other variables distinguishable between turtle and random locations were high basal areas of hardwood trees and abundant downed wood and mountain laurel. These results can be used to inform management practices and focus future survey efforts. We evaluated the influence of landscape composition and structure on the movements of box turtles using mixed effects linear regression models. Eastern box turtles have smaller home ranges in more urbanized landscapes and move further in more forested, less fragmented areas. The relationship varies significantly by site, underscoring the importance of evaluating effects across multiple sites, and suggesting that single-site studies may not be generalizable throughout regions. Population density estimates from five of the sites suggest a unimodal rather than linear relationship with urbanization. The highest-density site had a moderate level of fragmentation, suggesting that low levels of urbanization may be compatible with Eastern box turtle conservation, but that high levels of fragmentation may be detrimental to box turtle populations. Early successional habitat comprised more than 50% of June locations, suggesting these habitat features are important and may be limited on the landscape. We evaluated whether habitat management to create such areas could be effective by using utility distribution volume and a randomization approach to assess habitat use before and after forest was cleared at two sites. Use of the treatment areas increased significantly after clearing. Our results suggest that Eastern box turtles are willing to incorporate newly cleared areas into their home range within one year, and that it may be possible to improve habitat and minimize movement distance through active management. We also characterized seasonal movement and activity patterns, nesting habitat and reproductive parameters, and adult mortality rates. We suspect that mortality rates are much higher statewide and that habitat loss is likely the largest cause of mortality. Using our observed clutch size, nest success rate, and adult mortality rate and a deterministic population model, we estimated that hatchling and juvenile survival rates must exceed 77.6% annually in order to maintain a stable population in the absence of stochastic events. This survival rate is unrealistically high, particularly since the model does not account for variability and we suspect that our adult survival rate was artificially inflated, suggesting that populations may be declining in the Connecticut River Valley, even at protected sites. (Abstract shortened by UMI.)

This study sought to connect two bodies of knowledge—integrative complexity and attribution theory. Integrative complexity is a term that indicates the simplicity vs. complexity of a person's mental frame and perceptual skill. A person who perceives nuance and subtle differences typically scores higher on an integrative complexity measure. Attribution theories are concerned with how individuals perceive causation for various events. The limited research into the linkages between perceived causation for an event and how complexly a person thinks about the domain of that event, coupled with the dearth of attribution research in the natural resource management literature, inspired this research. Florida Keys coral reef users were sent a mail questionnaire between July 2009 and March 2010. Integrative complexity level was determined using an index that was developed for this research. Based on attributional and cognitive complexity literature, it was hypothesized that people who score lower in integrative complexity would exhibit an "external" attribution pattern. Integrative complexity was also proposed to influence: attitude and value extremity; number of perceived problem causes; and use of mediated communication. Finally, it was hypothesized that individuals will assign more blame to other groups than to their own. Six of the study's seven null hypotheses were rejected: (1) a significant relationship was found between integrative complexity level and the number of causes that respondents recorded for the decline of the Florida Keys reef ecosystem, (2) significant differences were observed in attitude extremity according to integrative complexity, (3) significant differences were observed in value orientation according to integrative complexity, (4) significant differences were observed in value extremity according to integrative complexity level, (5) significant differences were observed in mediated communication according to integrative complexity level, and (6) significant differences were observed in blame pattern according to group affiliation. Only one null hypothesis was not rejected: no support was found for a connection between integrative complexity and attribution style. These results indicate support for the integrative complexity index, though work to refine the measure seems in order. Additional recommendations for future research include investigating new approaches to examining the relationship between integrative complexity and attribution style.

No description available.

No description available.