This project examined the role of functional diversity of bacterial prey organisms on a mixotrophic flagellate’s function. The concept of functional diversity and its role for ecosystem functioning is a subject of ongoing research and controversially discussed. Mixotrophy is the combination of different modes of nutrition in one organism. In the case of this project’s organism, Ochromonas tuberculata, the combination of phototrophy and heterotrophy or phagotrophy. Mixotrophs can have a severe impact on nutrient cycling or carbon fixation in aquatic ecosystems, therefore it is important to investigate what drives their ecological functioning. For this project, two sets of bacterial prey traits were investigated and their effect on the flagellate’s growth rate. The first experiments involved the addition of heat-killed bacterial prey with heterotrophic mode of nutrition (Escherichia coli) and phototrophic mode of nutrition (Synechocystis sp.) on their own and in conjunction to generate a functional diversity. The last experiment investigated heat-killed Gram-negative (Escherichia coli) and Gram-positive bacterial prey (Staphylococcus aureus and Bacillus subtilis) each on their own and in conjunction. The acclimated O. tuberculata cultures in this project were non-axenic and flagellate cell densities were recorded daily over five days after the addition of the prey in each experiment. The results showed that prey with a phototrophic mode of nutrition resulted in a significantly higher growth rate over the course of the experiments than heterotrophic prey or a mix of both under the experimental conditions. For the second set of bacterial functions tested, the results showed no clear effect of the different bacterial functions on the flagellate’s growth rate. This was attributed to the heat-killing method used. The heat-killing method is assumed to have harmed the bacteria structurally and therefore negate the effect of the differences in cell wall properties. Therefore, this question could not be fully investigated. Overall, the experimental setup was not ideal to tackle the research question, nevertheless the results can provide ideas for possible improvements of the experimental setup.

Shellfish aquaculture is a developing industry along northeast Pacific coastlines and represents another potential stressor to already impacted nearshore ecosystems. The industry is particularly prominent in Baynes Sound, British Columbia (BC), Canada. The region hosts the operations which account for approximately 35% of all clams and 50% of all oysters produced in BC. Concurrently, it represents one of the most ecologically valuable areas in the northeast Pacific. In this study, I examined the interactions of benthic intertidal shellfish aquaculture with nearshore fish communities using abundance, biodiversity (species richness, diversity, and evenness), and functional diversity (Rao’s quadratic entropy and functional evenness) metrics. Also, I measured habitat complexity, as defined by a contour distance:linear distance ratio, at all fish sampling sites because it has often been identified as a driver of community variation. Fish abundance, biodiversity, and functional diversity did not vary between aquaculture and non-aquaculture sites. Additionally, habitat complexity, while on average was 1.2x greater at aquaculture beaches compared to non-aquaculture reference beaches, was not a strong driver of these indicators. Fish communities in Baynes Sound are relatively homogenous on a small scale and are highly functionally redundant, meaning that there is considerable overlap of species’ roles in the ecosystem. In summary, the presence of shellfish aquaculture in Baynes Sound is not associated with either a positive or negative response of fish communities. Furthermore, these communities are functionally redundant and therefore are likely resilient to ecosystem disturbances. / Graduate

A riqueza de espécies de organismos no Cerrado é a maior entre as savanas do mundo, sendo superior a 7.000 espécies, com alto nível de endemismo e sendo considerado um dos 25 hotspots de conservação mundial. O presente faz uma análise da diversidade funcional com 1044 espécies da avifauna em 42 áreas do domínio do Cerrado por meio de dados extensivamente compilados da literatura. Os valores dos índices de Diversidade Funcional Total (FDt) das áreas foram altos nas áreas de transição ou muito próximas a outras formações vegetais. A análise simulou perdas das espécies fortemente vinculadas às fisionomias abertas de cerrado e daquelas consideradas sensíveis e ameaçadas. A primeira simulação causou um forte declínio nos índices de FDt de todas as áreas (média de 33% de perda). Já a eliminação das espécies consideradas sensíveis e ameaçadas resultou em uma perda média menor de 6%. Uma randomização foi realizada para cada simulação. Os valores de FDt foram menores em 43% das áreas na simulação de perda de áreas abertas e em 0% das áreas na simulação de perda de espécies sensíveis e ameaçadas. Simultâneamente foi realizado um estudo sobre o \"turnover\" de espécies entre as comunidades. Os resultados obtidos foram de 12% de perda média da similaridade das áreas quando espécies aquáticas e florestais foram removidas das comunidades, corroborando a sugestão de CAVALCANTI (1999) quanto à influência destas na renovação das comunidades de aves de cerrado. Este estudo evidencia a necessidade de se manter a qualidade dos recursos disponibilizados pelo ecossistema onde as espécies estão inseridas, ressaltando a importância da preservação das áreas abertas para as comunidades de aves de Cerrado. Além disso, evidenciou a necessidade de monitorando de espécies florestais e aquáticas para preservação do intercâmbio biológico entre áreas de domínio de Cerrado. / The biodiversity in the Cerrado Region is the largest among the savannas of the world, with more than 7,000 species, presenting high levels of endemism, and being considered one of the 25 global hotspots for conservation. This study performs an analysis of Functional Diversity with 1044 bird species from 42 areas of Cerrado by an extensive data compilation from the literature. The Total Functional Diversity Index (FDt) was higher in the vegetation transition areas or close to other vegetations. Simulations of the loss of open savanna areas species and loss of bird species considered sensitive and/or endangered were conducted. The first simulation caused a large decrease in the FDt rates of all areas (33% of avarage loss). The elimination of sensitive and endangared species resulted in an average loss of 6%. A randomization was perfomed for each simulation. The resulting FDt values were minor in 43% of the areas in the simulation of open areas loss and 0% in the simulation of sensitive/endangered species loss. Simultaneously, an analysis on the turnover of species between communities was conducted. The results were an average 12% of the areas similarity loss when aquatic and forest species were removed, supporting CAVALCANTI (1999) proposition regarding the influence on the renewal of the cerrado species in the communities. This study highlights the need for maintaining the quality of the resources provided by the ecosystem where the species are found, emphasizing the importance of open areas preservation for the Cerrado communities. Furthermore, this study shows the need of monitoring forest and aquatic species to conservate the biological exchange between Cerrado domain areas.

As alterações no uso do solo decorrentes das atividades humanas modificam as condições ambientais, o que pode levar a mudanças na estrutura de comunidades locais. A expansão da silvicultura ao redor do mundo tem causado uma crescente preocupação em termos de conservação da biodiversidade. Isto por que ela resulta em uma simplificação e homogeneização do habitat originalmente nativo. Este estudo avaliou a estrutura da assembleia de aves em áreas de silvicultura e em floresta nativa, sendo que os principais objetivos foram: 1) avaliar o possível impacto da silvicultura sobre a riqueza, abundância e composição de espécies de aves, considerando diferentes idades de plantio; 2) avaliar se as espécies de aves registradas em áreas de silvicultura representam um subconjunto daquela registrada na floresta nativa; 3) analisar as respostas da diversidade funcional e dos atributos funcionais morfológicos e comportamentais das espécies de aves. Foram amostrados plantios de eucalipto de quatro idades de cultivo assim como áreas de floresta nativa num total de 150 pontos de escuta. A riqueza, a abundância de espécies de aves e a diversidade funcional foram significativamente maiores na floresta nativa. A composição de espécies também apresentou diferença significativa entre a floresta e os plantios de diferentes idades. Entretanto apesar da diferença na composição, as espécies que ocorrem nos plantios de eucalipto representam subconjuntos daquelas encontradas na floresta nativa, com um elevado índice de aninhamento para os plantios de idade mais avançada. Os resultados deste estudo indicam a ação de um filtro ambiental imposto pela silvicultura, selecionando espécies com requerimentos de habitat e atributos similares, assim como um maior número de espécies generalistas de habitat. Pode-se inferir então que áreas de silvicultura oferecem um habitat pouco complexo para a avifauna com um nível limitado de recursos e com isso, uma perda de funções ecológicas essenciais ao ambiente, como a dispersão de sementes. / Changes in land use resulting from human activities modify the environmental conditions, which can lead to changes in the structure of local communities. The expansion of silviculture around the world has caused a growing concern for biodiversity conservation. This is because it results in a simplification and homogenization of originally native habitat. This study evaluated the structure of the assembly of birds in areas of native forest and silviculture, and the main objectives were : 1) to evaluate the possible impact of silviculture on the richness, abundance and composition of bird species, with different ages of planting and 2) assess whether the bird species recorded in areas of silviculture represent a subset that recorded in native forest, 3) analyze the responses of functional diversity and functional morphological and behavioral traits of birds species. Eucalyptus plantations four ages of cultivation as well as areas of native forest in a total of 150 point counts were sampled. The richness, abundance of bird species and functional diversity were significantly higher in the native forest. The species composition also showed a significant difference between the forest and plantations of different ages. However despite the difference in composition, species that occur in eucalyptus plantations represent subsets of those found in the native forest, with a high level of nestedness for plantations older age. The results of this study indicate the action of an environmental filter arising for silviculture, selecting species with similar habitat requirements and traits, as well as a greater number of generalist species habitat. It can be inferred then that silviculture areas offer a bit complex habitat for birdlife with a limited amount of resources and thus, a loss of ecological functions essential to the environment, such as seed dispersal.

As alterações no uso do solo decorrentes das atividades humanas modificam as condições ambientais, o que pode levar a mudanças na estrutura de comunidades locais. A expansão da silvicultura ao redor do mundo tem causado uma crescente preocupação em termos de conservação da biodiversidade. Isto por que ela resulta em uma simplificação e homogeneização do habitat originalmente nativo. Este estudo avaliou a estrutura da assembleia de aves em áreas de silvicultura e em floresta nativa, sendo que os principais objetivos foram: 1) avaliar o possível impacto da silvicultura sobre a riqueza, abundância e composição de espécies de aves, considerando diferentes idades de plantio; 2) avaliar se as espécies de aves registradas em áreas de silvicultura representam um subconjunto daquela registrada na floresta nativa; 3) analisar as respostas da diversidade funcional e dos atributos funcionais morfológicos e comportamentais das espécies de aves. Foram amostrados plantios de eucalipto de quatro idades de cultivo assim como áreas de floresta nativa num total de 150 pontos de escuta. A riqueza, a abundância de espécies de aves e a diversidade funcional foram significativamente maiores na floresta nativa. A composição de espécies também apresentou diferença significativa entre a floresta e os plantios de diferentes idades. Entretanto apesar da diferença na composição, as espécies que ocorrem nos plantios de eucalipto representam subconjuntos daquelas encontradas na floresta nativa, com um elevado índice de aninhamento para os plantios de idade mais avançada. Os resultados deste estudo indicam a ação de um filtro ambiental imposto pela silvicultura, selecionando espécies com requerimentos de habitat e atributos similares, assim como um maior número de espécies generalistas de habitat. Pode-se inferir então que áreas de silvicultura oferecem um habitat pouco complexo para a avifauna com um nível limitado de recursos e com isso, uma perda de funções ecológicas essenciais ao ambiente, como a dispersão de sementes. / Changes in land use resulting from human activities modify the environmental conditions, which can lead to changes in the structure of local communities. The expansion of silviculture around the world has caused a growing concern for biodiversity conservation. This is because it results in a simplification and homogenization of originally native habitat. This study evaluated the structure of the assembly of birds in areas of native forest and silviculture, and the main objectives were : 1) to evaluate the possible impact of silviculture on the richness, abundance and composition of bird species, with different ages of planting and 2) assess whether the bird species recorded in areas of silviculture represent a subset that recorded in native forest, 3) analyze the responses of functional diversity and functional morphological and behavioral traits of birds species. Eucalyptus plantations four ages of cultivation as well as areas of native forest in a total of 150 point counts were sampled. The richness, abundance of bird species and functional diversity were significantly higher in the native forest. The species composition also showed a significant difference between the forest and plantations of different ages. However despite the difference in composition, species that occur in eucalyptus plantations represent subsets of those found in the native forest, with a high level of nestedness for plantations older age. The results of this study indicate the action of an environmental filter arising for silviculture, selecting species with similar habitat requirements and traits, as well as a greater number of generalist species habitat. It can be inferred then that silviculture areas offer a bit complex habitat for birdlife with a limited amount of resources and thus, a loss of ecological functions essential to the environment, such as seed dispersal.

A riqueza de espécies de organismos no Cerrado é a maior entre as savanas do mundo, sendo superior a 7.000 espécies, com alto nível de endemismo e sendo considerado um dos 25 hotspots de conservação mundial. O presente faz uma análise da diversidade funcional com 1044 espécies da avifauna em 42 áreas do domínio do Cerrado por meio de dados extensivamente compilados da literatura. Os valores dos índices de Diversidade Funcional Total (FDt) das áreas foram altos nas áreas de transição ou muito próximas a outras formações vegetais. A análise simulou perdas das espécies fortemente vinculadas às fisionomias abertas de cerrado e daquelas consideradas sensíveis e ameaçadas. A primeira simulação causou um forte declínio nos índices de FDt de todas as áreas (média de 33% de perda). Já a eliminação das espécies consideradas sensíveis e ameaçadas resultou em uma perda média menor de 6%. Uma randomização foi realizada para cada simulação. Os valores de FDt foram menores em 43% das áreas na simulação de perda de áreas abertas e em 0% das áreas na simulação de perda de espécies sensíveis e ameaçadas. Simultâneamente foi realizado um estudo sobre o \"turnover\" de espécies entre as comunidades. Os resultados obtidos foram de 12% de perda média da similaridade das áreas quando espécies aquáticas e florestais foram removidas das comunidades, corroborando a sugestão de CAVALCANTI (1999) quanto à influência destas na renovação das comunidades de aves de cerrado. Este estudo evidencia a necessidade de se manter a qualidade dos recursos disponibilizados pelo ecossistema onde as espécies estão inseridas, ressaltando a importância da preservação das áreas abertas para as comunidades de aves de Cerrado. Além disso, evidenciou a necessidade de monitorando de espécies florestais e aquáticas para preservação do intercâmbio biológico entre áreas de domínio de Cerrado. / The biodiversity in the Cerrado Region is the largest among the savannas of the world, with more than 7,000 species, presenting high levels of endemism, and being considered one of the 25 global hotspots for conservation. This study performs an analysis of Functional Diversity with 1044 bird species from 42 areas of Cerrado by an extensive data compilation from the literature. The Total Functional Diversity Index (FDt) was higher in the vegetation transition areas or close to other vegetations. Simulations of the loss of open savanna areas species and loss of bird species considered sensitive and/or endangered were conducted. The first simulation caused a large decrease in the FDt rates of all areas (33% of avarage loss). The elimination of sensitive and endangared species resulted in an average loss of 6%. A randomization was perfomed for each simulation. The resulting FDt values were minor in 43% of the areas in the simulation of open areas loss and 0% in the simulation of sensitive/endangered species loss. Simultaneously, an analysis on the turnover of species between communities was conducted. The results were an average 12% of the areas similarity loss when aquatic and forest species were removed, supporting CAVALCANTI (1999) proposition regarding the influence on the renewal of the cerrado species in the communities. This study highlights the need for maintaining the quality of the resources provided by the ecosystem where the species are found, emphasizing the importance of open areas preservation for the Cerrado communities. Furthermore, this study shows the need of monitoring forest and aquatic species to conservate the biological exchange between Cerrado domain areas.

Marine ecosystems contain both highly abundant and diverse communities of vertebrates and invertebrates; however anthropogenic activity has drastically altered the species composition and diversity of these ecosystems. Specifically, human activity has targeted high trophic level species and degraded much of the biogenic habitat that faunal communities rely upon. These alterations have resulted in the loss of many marine predators and overall declines of marine biodiversity. To investigate the consequences of marine predator loss and community level species decline, I use a combination of large-scale data synthesis and in situ field observations of marine fish communities. I first use a meta-analysis approach to synthesize the consequences of marine predator loss in benthic marine ecosystems worldwide. From this synthesis, I was able to determine some of the biotic and abiotic factors that regulate the response of marine herbivores and primary producers to predator loss. Specifically, I show that marine predators have the strongest effect on populations of marine herbivores when predators and herbivores were similar in size and when larger herbivores were involved. Conversely the factors that best explained the response of the primary producer populations were related to the abiotic environment. The results show that primary producers respond the most positively to the presence of predators in high nutrient environments. While I found no link between the magnitude of change in the herbivore population and the magnitude of change in the producer population, I was able to demonstrate that primary producers are under the strongest top-down controls when nutrient concentrations are high, sea surface temperatures are low, and when the predator is larger in size than the herbivore. Finally, I use the data related to marine reserves to show that reserves are an effective tool to help reverse the trophic consequences of marine predator loss and that they are most effective when they are older in age. The third chapter examines the links between community diversity and community biomass within fish communities in eelgrass ecosystems in Northern British Columbia. After controlling for environmental variation, I found that it was the dominance of certain species within a community that resulted in the highest ecosystem function. This finding was demonstrated by both the taxonomic and functional metrics of diversity used. While previous work on this topic has shown that richness is positively correlated to function, my results are to the contrary, and suggest that further investigation into which aspects of community diversity drive ecosystem function is required. In conclusion, my results provide a new synthesis of the consequences of marine predator loss across the world and show how species diversity is linked to ecosystem function in local eelgrass fish communities. / Graduate / 2018-12-17

As alterações no uso do solo decorrentes das atividades humanas modificam as condições ambientais, o que pode levar a mudanças na estrutura de comunidades locais. A expansão da silvicultura ao redor do mundo tem causado uma crescente preocupação em termos de conservação da biodiversidade. Isto por que ela resulta em uma simplificação e homogeneização do habitat originalmente nativo. Este estudo avaliou a estrutura da assembleia de aves em áreas de silvicultura e em floresta nativa, sendo que os principais objetivos foram: 1) avaliar o possível impacto da silvicultura sobre a riqueza, abundância e composição de espécies de aves, considerando diferentes idades de plantio; 2) avaliar se as espécies de aves registradas em áreas de silvicultura representam um subconjunto daquela registrada na floresta nativa; 3) analisar as respostas da diversidade funcional e dos atributos funcionais morfológicos e comportamentais das espécies de aves. Foram amostrados plantios de eucalipto de quatro idades de cultivo assim como áreas de floresta nativa num total de 150 pontos de escuta. A riqueza, a abundância de espécies de aves e a diversidade funcional foram significativamente maiores na floresta nativa. A composição de espécies também apresentou diferença significativa entre a floresta e os plantios de diferentes idades. Entretanto apesar da diferença na composição, as espécies que ocorrem nos plantios de eucalipto representam subconjuntos daquelas encontradas na floresta nativa, com um elevado índice de aninhamento para os plantios de idade mais avançada. Os resultados deste estudo indicam a ação de um filtro ambiental imposto pela silvicultura, selecionando espécies com requerimentos de habitat e atributos similares, assim como um maior número de espécies generalistas de habitat. Pode-se inferir então que áreas de silvicultura oferecem um habitat pouco complexo para a avifauna com um nível limitado de recursos e com isso, uma perda de funções ecológicas essenciais ao ambiente, como a dispersão de sementes. / Changes in land use resulting from human activities modify the environmental conditions, which can lead to changes in the structure of local communities. The expansion of silviculture around the world has caused a growing concern for biodiversity conservation. This is because it results in a simplification and homogenization of originally native habitat. This study evaluated the structure of the assembly of birds in areas of native forest and silviculture, and the main objectives were : 1) to evaluate the possible impact of silviculture on the richness, abundance and composition of bird species, with different ages of planting and 2) assess whether the bird species recorded in areas of silviculture represent a subset that recorded in native forest, 3) analyze the responses of functional diversity and functional morphological and behavioral traits of birds species. Eucalyptus plantations four ages of cultivation as well as areas of native forest in a total of 150 point counts were sampled. The richness, abundance of bird species and functional diversity were significantly higher in the native forest. The species composition also showed a significant difference between the forest and plantations of different ages. However despite the difference in composition, species that occur in eucalyptus plantations represent subsets of those found in the native forest, with a high level of nestedness for plantations older age. The results of this study indicate the action of an environmental filter arising for silviculture, selecting species with similar habitat requirements and traits, as well as a greater number of generalist species habitat. It can be inferred then that silviculture areas offer a bit complex habitat for birdlife with a limited amount of resources and thus, a loss of ecological functions essential to the environment, such as seed dispersal.

As a part of Saudi Arabia’s Vision 2030, the Al Wajh Bank will soon undergo major coastal development to be transformed into a sustainable luxury tourist destination, with goals to safeguard the marine and coastal habitats in order to achieve a net conservation benefit of 30%. To realize these objectives, it is essential to establish baseline data on the marine communities to gauge the success of conservation goals. In this study, we evaluated and compared the taxonomic and functional diversity of reef fish assemblages between two areas in the Al Wajh Bank, sites inside the lagoon and those outside of it, in order to establish differences in fish communities across environmental gradients. Conditions within the lagoon, such as temperature and salinity, have been shown to differ from most other Red Sea areas and are thought to result in unique fish assemblages. Underwater assessments of fish communities and benthic composition were conducted throughout the Al Wajh Bank during cruises in 2016 and 2017. We found that of the 168 fish species recorded, 75 species were exclusive outside the lagoon, 22 were exclusive inside the lagoon, and 71 species were shared between inside and outside. Sites within the lagoon had significantly less species richness as well as lower abundances. While taxonomic composition differed between the two areas, functionally they were very similar. Two functional metrics (functional richness and functional dispersion) indicated different levels of functional diversity, while two other metrics (functional evenness and functional specialization) showed no differences in functional diversity. The outside had five groups comprising eleven species with functional redundancy; in contrast, the inside had two species which were functionally redundant. This study was able to establish that the inside and outside habitats are different and have dissimilar species compositions, yet the functional characterization of fish assemblages in conserved. These results advocate for the use of functional diversity metrics as a way to evaluate changes to community composition, and is an initial assessment towards tracking changes in the fish communities as coastal development progresses

No description available.