Natural frequency and damping ratio were measured for ten forest grown northern red oak trees with co-dominant trunks. Steels support cables were installed in the canopies of five of the sample trees prior to measurement. Free vibration testing was performed during periods when leaves were and were not present. An accelerometer mounted at the base of the co-dominant union measured the acceleration time history during the free vibration testing. Natural frequency was determined from the acceleration time history using power spectral density analysis. Damping ratios were calculated from the power spectral density plots using the half power bandwidth method. Trees with steel support cables had higher natural frequencies than trees without steel support cables. Sample trees had higher natural frequencies in the leaf off condition than the leaf on condition. The increase in natural frequency associated with the steel support cable was less pronounced in the leaf on condition. There was no difference between the damping ratios of cabled and non-cabled trees. Trees in the leaf on condition had significantly higher damping ratios than trees in the leaf off condition.

These chapters were written as three separate papers for publication. After the island fox (Urocyon littoralis) underwent a period of severe population decline, the National Park Service began a captive breeding program to increase their numbers. Here, I identify the factors influencing the breeding success of pairs in captivity to formulate strategies that could increase productivity. I compiled a database of variables including litter size, reproductive success, distance to nearest occupied pen, subspecies, exposure, female age, male age, age difference, female and male origin (wild vs. captive born), years paired, previous reproductive success by the pair, previous reproductive success by the female, mate aggression related injuries reported, and previous involvement in an aggressive pair. I performed linear multiple regression to identify factors related to litter size, and logistic regression to predict the probability of reproductive success. A larger interpen distance, higher male age, less exposure, and a smaller intra-pair age difference positively affected litter size. The probabilities of reproductive success increased with interpen distance, lower female age, fewer years paired, and less exposure. Comparatively, pairs with wild born females (vs. captive born females), previously successful pairs (vs. previously unsuccessful and new pairs), and pairs with a previously unsuccessful female (vs. untried and previously successful females) were most likely to be successful. These results suggest that the ideal situation and pairing would be to pair young wild-caught females with older males in sheltered pens that are as far from other pens as possible, while maintaining successful pairs and repairing unsuccessful pairs.

Vitellogenin (VTG) is widely used as a biomarker for environmental estrogens and reproductive disruption in fish. Vitellogenesis is the process by which yolk is formed. The endpoint is most sensitive in male fish where vitellogenesis is an abnormal process. Research examining effects of environmental mixtures of chemicals (e.g. creosote) on vitellogenesis is limited. This study examines plasma VTG expression in both male and female mummichog, Fundulus heteroclitus, collected from a creosote-contaminated site and two reference sites in lower Chesapeake Bay, USA, and in wild-caught male reference fish exposed in the laboratory to creosote-contaminated sediment. Further, this study uses tissue somatic indices (gonadosomatic index, hepatosomatic index, and condition factor) as organ-level indicators of reproductive status and creosote exposure. Western blotting with an anti-vitellogenin monoclonal antibody (FY 10- 9) was used to identify an abundant (approx. 218 kDa) protein in F. heteroclitus plasma samples. Vitellogenin was not observed in any male fish collected from any of the field sites. No sitespecific differences were observed in plasma VTG of females from these sites. Overall, fish from the creosote-contaminated site appear resilient and reproductively fit. After seven days of exposure, reference fish exposed to sediment from the creosote-contaminated site suffered extensive mortality (approx. 25% ), but displayed no expression of VTG and had no alterations in other measured indices except for increased hepatosomatic index and induction of the biotransformation enzyme, cytochrome P4501A (CYPlA). Lack of response in Atlantic Wood fish could be due to: (1) physiological adaptation of the population from the creosotecontaminated site to creosote exposure (2) species-specific sensitivity (3) creosote not exerting estrogenic effects and regulating vitellogenesis. Thus, while VTG has been used successfully as a practical and reliable screening method for wildlife toxicity, results herein do not support use of this biomarker for F. heteroclitus from creosote-contaminated sites. This study does reaffirm constituents of creosote binding to the aryl hydrocarbon receptor resulting in induction of CYP IA. More attention needs to be given to developing alternative biomarkers not sensitive to aryl hydrocarbon-mediated antiestrogens if detection of weak estrogens and reproductive disruption in creosote and other complex mixtures is to be achieved.

The multiple-objective exploratory study investigates effects of various silvicultural management regimes commonly applied to coast redwood (Sequoia sempervirens [D. Don] Endl.) forests in Santa Cruz and San Mateo Counties, California, USA. A temporary forest inventory was installed in 24 harvest origin stands and 4 natural origin stands throughout the study area (sample area = 1189 acres). Data from the systematic sample of 233 one-quarter acre nested cluster plots (sample intensity = 4.9%) rendered overall forest descriptions in terms of species composition, density, and structure. The common forestry measures of trees per acre (TPA), basal area per acre (BA), and quadratic mean diameter (QMD) were calculated from the "snapshot" data and stratified by species groups and diameter ranges/canopy layers. Forest components were derived from the dataset by selecting specific groups within the forest as defined by the California Forest Practice Rules, literature, and common forestry groups (refer to the table below). An example of a forest component would be TPA of conifers from 2.1-14.0 inches DBH. In all, 162 forest components were analyzed through three research objectives: (1) general forest components, (2) small stem density and distribution, and (3) large stem density. The driving question behind the analysis is whether forest management is creating significantly different forest structure. If so, in which components of forest composition, density, and structure do those differences reside? A mixed-effects linear model tested overall significance and Fisher's Least Significant Difference (LSD) method tested pairwise comparisons among the six management regimes. Each model was tested with a significance level of alpha = 0.05 (pairwise and experimentwise). A fourth objective compared two methods of late successional forest (LSF) classification based on QMD measures of canopy layers and diameter ranges. The methods were compared via a paired-sample t-test. The two methods are significantly different, but the investigation of LSF classification led to an examination of the validity of current LSF policy. It is suggested that the minimum overstory QMD for LSF classification be increased from 24.0 to at least 30.0 inches DBH. Furthermore, it is recommended that landowner incentives should be implemented by the State of California to encourage promotion of LSF and its functional elements. An underlying theme of all research objectives in this study is an examination of forest restoration management. Restoration management is intentional treatments that begin or accelerate recovery of a degraded ecosystem in regards to its integrity and sustainability relative to a reference condition, often defined culturally, historically, or ecologically (Society for Ecological Restoration 2004, Hobbs 2004, Hobbs and Norton 1996, Stanturf 2005). Results and conclusions were synthesized to discuss current restoration efforts in the redwoods. Recommendations for target stand densities and silvicultural methods are presented.

Agriculture has diminished shorebirds’ natural habitat in the Mississippi Alluvial Valley. Remaining natural stopover sites are supplemented with agricultural fields during the fall and winter. This study evaluates the impact of 4 different post-harvest water management strategies on shorebird food abundance and potential agrochemical biomagnification. Chironomid samples estimated abundance, biomass, and chironomid agrochemical concentration in each field. A risk assessment of agrochemical biomagnification to shorebirds was made across all treatments. Of treatments represented on all study sites, winter treatment had greatest chironomid abundance and biomass. Models indicated that days since flood initiation, start date, and temperature are significant predictors of chironomid abundance and biomass. Risk assessment results indicate low risk to shorebirds across all treatments for agrochemicals measured in this study. This study shows that flood timing is more important to providing shorebird resources than trends in abundance and biomass of chironomids, and shorebird risk from agrochemicals measured was minimal.

In Ecuador, there is a grave socioeconomic nutritional problem, and it is seen clearest in Imbabura province in the communities of Cuambo and La Rinconada. One of the biggest problems is inadequate food, due principally to the poor food storage and conservation habits. Considering this problem, it is necessary to deepen the knowledge of improved traditional techniques for storing and conserving food, through which families can store and manage their product better, controlling and avoiding losses due to insects, rodents, and climate, and guaranteeing conservation of the same. The investigation was oriented to implement alternative, improved storage and conservation technologies for the most-produced foods in the aforementioned communities. The alternative conservation technologies applied in the investigative process, with the active participation of the communities' families, were: a) GRANARY: A simple wooden structure constructed from local materials that permits storing corn on the cob, thus retaining its physical and organoleptic qualities while avoiding losses from insects and rodents. b) METAL SILO: A cylindrical, metal structure with a capacity up to 4 quintales [184 kg], used to store grains such as beans and corn, and cured with ash to avoid diseases such as weevils. c) CLAY JARS: A technique used anciently and in this study that has been used to store beans, corn, and peas. These containers are recommendable because they have thermoisolating characteristics and are resistant to insects and rodents. The cost of making clay jars is relatively small because customs, traditional methods of creation, and limited usage are still conserved. d) REED BASKETS: Receptacles used to store grains, principally beans and corn. This storage technique has been used more frequently in Cuambo, due to which in this study it was necessary to make use of them and increase their coverage in the community of La Rinconada. e) TUBER STORAGE: For this, the techniques used were: 1) Greening silo, which consists of an open wooden structure with a tile roof and with posts attached to the ground for seed potato storage beds, and 2) Pœsha, which consists of making a hole in the soil in order to keep potatoes and yucca in good condition. f) HOME REFRIDGERATOR: This consists of a wooden structure covered in cloth, rubber, and oxidation-resistant mesh. Its works simply: water is put in an upper receptacle. Water is absorbed through the cloth and passed to the lower chamber, keeping the inside of the refrigerator cold. This permits storage and conservation of fruit, vegetables, milk, etc. The refrigerator was used in the two communities in this project, with which it validity and effectiveness were proven. The refrigeration temperatures in La Rinconada and Cuambo were 12°C and 20°C, respectively. The study's results allowed rescuing and strengthening of the knowledge of home techniques for food storage and conservation. They were accepted and applied by the different families in the project, thus allowing sustainable family development.

In the face of unprecedented anthropogenic change, we increasingly turn to emergent technologies and extensive data sets for solutions that complement much needed systemic changes in our societies. These technological solutions, however, must be approached with care. We must recognize and address biases in the way data has been accumulated. In demographic studies, dormant life stages, such as seed banks, and other cryptic factors have often been neglected. The potential consequences of these omissions have been extensively described in the literature. In the first chapter, I analyze patterns of seed bank omissions in demographic models, finding unjustified omissions are widespread across ecoregions, growth forms, and taxonomic groups. More importantly, studies with longer duration and accounting for a greater range of conditions were less likely to neglect the seed bank. Unfortunately, most demographic studies are conducted for relatively short periods and are limited to one or a few sites. In addition, modeling tools often focus on mean behavior and do not properly characterize variability. In the second chapter, I explore the use of Bayesian generalized linear mixed models to characterize vital rates and compare their variation across growing conditions. Using wild and translocated populations of Dicerandra christmanii,this study tests the ability of this approach to evaluate early translocation success and site suitability.In chapter 3, I expand the demographic analysis of Dicerandra christmaniiand provide an example of the use of Bayesian-fitted Integral Projection Models (IPMs) to combine data sources and incorporate seed dynamics into demographic models. By propagating uncertainty from vital rates to derived population metrics, this study illustrates the consequences of accounting for the seed bank stage and site condition to our assessment of population viability. In the final part of this work, I present potential routes to expand field and modeling tools to help address the inclusion of dormant and cryptic life stages into demographic studies. Among these, I recommend exploring more complex sampling schemes, informed priors, and expanded IPMs.

The Nambiti Private Game Reserve in KwaZulu-Natal, South Africa is a nature reserve that aids in the conservation of some of the world’s most renown species. This includes members of the "Big Five," which is comprised of the African lion (Panthera leo), the African elephant (Loxidonta africana), the Cape buffalo (Syncerus caffer), the black & white rhinoceroses (Diceros bicornis and Ceratotherium simum, respectively), and the African leopard (Panthera pardus pardus). These animals represent the top five African animals desired by trophy hunters and by tourists hoping to view wildlife (Caro & Riggio, 2014). While studies concerning the African leopard population status have been completed on surrounding game reserves (Balme et al., 2009; Chapman & Balme, 2010), there have not been any studies done investigating the African leopard population on Nambiti. It is important that the population on Nambiti be identified since conservation management of leopards is largely influenced by their population numbers. For example, southern African countries rely on population estimates to establish trophy hunting quotas (Balme et al., 2010). Furthermore, knowledge on the reserve's leopard population can also lead to ecotourism benefits by attracting tourists to visit areas of known leopard activity (Lindsey et al., 2007). This case study investigated baited camera trapping footage, obtained by Nambiti rangers between May 2015 – May 2017, to determine the African leopard population on Nambiti. Camera footage results revealed that there were four leopards identified in six different locations on the reserve between May 2015 – May 2017. Baited Location J in the Western region of the reserve showed the greatest amount of leopard activity, indicating that it is the baited location most likely to provide ecotourism benefits. Furthermore, 23 non-target species were identified from the camera trapping footage, providing insight into the reserve's biodiversity, prey availability, and competition among predators.

This thesis explores how the COVID-19 pandemic has impacted wildlife rangers with an emphasis on the influences of tourism rates. Two sets of data are used: one is a survey of rangers around the world and the other looks at global governmental tourism data. While coming from a routine activities perspective, the problem of decreased capable guardianship becomes apparent in the form of massively decreased tourism arrivals and troubling ranger perceptions. This data allows for the establishment of tourism trends and changes during COVID. The findings of this thesis link the downturn in tourism with impacts on formal and informal guardianship within protected areas. Recommendations and discussions include potential ways to preserve guardianship in future pandemic settings.

Spatial information about invasive species abundance is critical for estimating impact and understanding risk to ecosystems and economies. Unfortunately, at landscape and regional scales, most distribution datasets provide limited information about abundance. However, national and regional invasive plant occurrence datasets are increasingly available and spatially extensive. We aim to test whether the frequency of these point occurrences can be used as a proxy for abundance of invasive plants. We compiled both occurrence and abundance data for nine regionally important invasive plants in the northeast US using a combination of herbarium records, surveys of expert knowledge, and various invasive species spatial databases. We integrated all available abundance information based on infested area, percent cover, or qualitative descriptions into abundance rankings ranging from 0 (absent) to 4 (highly abundant). Within equal area grid cells of 800 m, we counted numbers of occurrence points and used an ordinal regression to test whether higher numbers of occurrence points were positively correlated with abundance rankings. We compiled a total 49,341 occurrence points in 18,533 cells, of which 12,183 points (25%) within 4,278 cells (32%) had associated abundance information. In six of nine study species we found slight but significant positive overall relationships between abundance rank and occurrence frequency at high abundance ranks. However, at low abundance rankings the relationship tended to be negative and the magnitude of the overall difference in occurrence frequency was too small to be relevant to management. My results suggest that currently available occurrence datasets are unlikely to serve as effective proxies for abundance, and models derived from invasive plant occurrence datasets should not be interpreted as indicative of plant abundance and associated impact. Increased efforts to collect and report invasive species abundance information, and/or higher densities of occurrence points in heavily infested areas are strongly needed for regional scale assessments of potential abundance and associated impact.