Nonnative species are reshaping global ecosystems. The success of a nonnative species hinges on both biological and cultural variables. Primates represent a minority of nonnative species but warrant research to understand ecological implications and management solutions. The Florida Fish and Wildlife Conservation Commission recognizes three species of nonnative primates in Florida that include populations of rhesus macaques (Macaca mulatta) in Marion County, squirrel monkeys (Saimiri spp.) in Broward County, and green monkeys (Chlorocebus sabaeus) in Broward County. This study focused on the Dania Beach C. sabaeus population. The goals of this study were to: 1) determine the geographical origins and species of the monkeys, 2) record demographics and determine population growth rate, 3) assess the public’s perception of monkeys, and 4) understand the influence of human provisioning on the population’s behavior and biology. Public surveys and direct field observations of social groups provided baseline data to show that unlike other introduced primates (e.g., macaques in Marion County and green monkeys in the Caribbean), the Dania Beach monkey population has strong public support and is at risk of extinction within the next 100 years. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

The introduction of exotic species is one of the greatest threats to freshwater biodiversity. Brown trout are native to Eurasia, but have been introduced to much of the rest of the world, including the United States. In other parts of their introduced range, brown trout have caused substantial negative effects to native species‟ abundances and distributions, and have altered the structure of some aquatic communities. In the United States, studies of some streams and watersheds have shown that brown trout can negatively affect native species, but I found no study that considers the effect of brown trout across a large portion of their introduced range. For this study, I examined if (1) the abundance and distribution of two ecologically different native fish taxa (sculpins and speckled dace) and (2) the structure of entire stream vertebrate assemblages were negatively associated with the presence and abundance of brown trout. I based my analyses on existing, standardized survey data collected across streams of the western United States. I found no relationship between brown trout and the abundance, presence-absence, or probability of detection of sculpins or speckled dace. I also found that brown trout were not associated with the structure of native stream vertebrate assemblages. My results imply that native stream vertebrates in western US streams are able to coexist with brown trout across the western United States, despite the negative effects brown trout can have on some taxa in individual watersheds or rivers.

Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.

Roadsides in Sweden offer suitable habitats for species that naturally occur in the old agricultural landscape, a habitat that is less common today. These species are favored by small-scale disturbance such as of mowing which is to some extent applied in roadsides for management of the road surface. The Swedish Transport Administration has worked according to the environmental directives for sustainable populations of threatened species that occur along roadsides. Roadsides with threatened species and species that represent the old agriculture landscape have been located and described. Such roadsides have been named species rich roadsides (artrik vägkant) and can be found in different environments spread across the country. The Swedish Transport Administration has developed recommendations for special management to support species of old agricultural landscape in roadsides. Previous studies have shown a negative development of the species rich roadsides, with reduced numbers of species rich roadsides.  This project has analyzed whether there is a relationship between the management of species rich roadsides and the negative development of species rich roadsides, and also make recommendations for improving management methods needed for improving the development of species rich roadsides. Data have been used from previous inventories of species rich roadsides, the study area restricted to Region Mitt.  The present management of species rich roadsides has a significant negative effect of the development of species rich roadsides. To improve the development of species rich roadsides, management must be adapted to the environment the roadside is located to.

Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.

Many ecologists are struggling to quantify the species richness in a particular landscape or region. The number of species increases with sample area. Species-area relationship is often used to estimate species richness of a particular region. This study used species-log (area) curves, corrected with Jaccard¡¦s coefficients for within-vegetation type heterogeneity, to estimate species richness and to describe vascular plant species composition in Taiwan Forestry research Institute Tai-Ma-Lee Experimental Forest. In the study area, the author recorded 748 plant species, including 98 endemic species, 21 rare species and 36 naturalized species. There are estimation of 701 species (95¢H CI¡×651~758 species) in the 583-ha natural forest area, 819 species (95¢H CI¡×744~889 species) in the 291-ha plantation area, 560 species (95¢H CI¡×508~641 species) in 8.1-ha forest road. As plantation area is not well-sampled, the total species number in the 947-ha study area could not be estimated. When use 0.1 Modified-Whittaker sampling techniques to assess plant diversity, it is possible to use elevation division, instead of vegetation type, to estimate species richness.

Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As species invasions continue to rise, it is important to understand how to mitigate this threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti) on rates of food removal within the range of the critically endangered Mount Graham red squirrel (Tamiasciurus hudsonicus grahamensis). In the presence of Abert's squirrels, the time until 50% of cones were removed was 5.55 days faster than when Abert's squirrels were excluded (95% confidence interval 2.25 to 11.63 days). The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Eradication of established non-native populations is rare. Management targeted at specific mechanisms by which non-natives cause endangerment is an essential tool for conservation.

A major trend in invasion biology is the development of models to accurately predict and define invasive species and the stages of their invasions. These models focus on a given species with an assumed set of traits. By doing so, they fail to consider the potential for differential success among different source populations. This study looked at the inland invasion of Rhithropanopeus harrisii in the context of a current invasion model. This species has been introduced worldwide, but has only invaded freshwater reservoirs within the state of Texas (United States) indicating a potential difference amongst source populations. Previous studies indicate that this species should not be capable of invading inland reservoirs due to physiological constraints in the larvae. A more recent study gives evidence to the contrary. To investigate whether the inland populations are in fact successfully established, I attempted to answer the following questions: Can inland populations successfully reproduce in the inland reservoirs and rivers? If so, what factors in the native environment could have led to the evolution of this ability? What are the impacts of this species in the inland reservoirs and what is its potential spread? I combined a larval developmental study, conspecific and heterospecific crab competition trials, field collections, gut content analysis, shelter competition trials with crayfish, and larval and adult dispersal study to answer these questions. I showed that Rhithropanopeus harrisii is established in the inland reservoirs and capable of spreading. I demonstrated that in the native populations along the Gulf coast of the United States, this species is the least aggressive and is therefore likely excluded into lower salinity waters during reproductive periods. This likely led to a lowered salinity tolerance in the larval stages, which predispose these populations to successful introductions in inland freshwater bodies. I showed that the crabs are capable of outcompeting juvenile crayfish for shelter at high densities and therefore warrant management in order to reduce their effect. This study indicates a need for the invasion models to take the source population into account in order to ensure effective and prudent management strategies.

No description available.

Habitat fragmentation is one of the most important factors affecting species extinction and biodiversity loss, Species habitat response expects to differ with habitat feature at different spatial scales and this study was to identify how bat diversity and individual bat species respond to different habitat amounts. The local bat species richness was observed in 156 different locations in Östergötland and the proportion of different habitats were calculated for circular areas with diameters ranging from 400 m. to 12 km. from each location. Although we found that the individual bat species responded differently to the amount of each habitat at different spatial scales, the bat species richness showed a decreasing response with increasing spatial scale. The strongest response of bat species richness to habitat characteristics was at a scale of 939 m.