Habitat temperature is a major determinant of performance and activity in fish. I examined the relationships between thermal response metrics describing growth (optimal growth temperature [OGT] and final temperature preferendum [FTP]), survival (upper incipient lethal temperature [UILT] and critical thermal maximum [CTMax]), and reproduction (optimum spawning [OS] and optimum egg development temperature [OE]) for 173 North American freshwater fish species. All metrics were highly correlated and associated with thermal preference class, reproductive guild and spawning season. Controlling for phylogeny resulted in an overall decrease in correlation strength, varying with metric pair relationship. ANCOVA and Bayesian hierarchical models were utilized to assess the influence of phylogeny on metric pair relationships. For both methods, FTP based metric pairs were weakly correlated within taxonomic family. Strong within family associations were found for reproduction metrics OS-OE. These results suggest that evolutionary history plays an important role in determining species thermal response to their environment.

Competition plays a fundamental role in structuring ecological communities, and is a particularly important interaction for sessile organisms such as plants (Goldberg & Fleetwood 1987; Tilman 1994). To mitigate the negative effects of competition on fitness, plants can alter their phenotypes and reproductive traits through plastic responses. For example, decreases in the red to far-red ratio of light signal the presence of competitors, inducing a suite of responses known as shade avoidance syndrome (Franklin 2008). My thesis examines the impact of the competitive environment on reproductive output, the phenotypes Impatiens capensis produce and natural selection acting on shade avoidance responses. I found that heterospecific competitors affect both the phenotypes of I. capensis, and selection on shade avoidance traits. I also found evidence of population differentiation in hypocotyl lengths and flowering time. My thesis elucidates the influence of competition on the evolution of phenotypic plasticity in Impatiens capensis.

Phylogenetic structure measures patterns of evolutionary history within communities – are some communities composed of species more distantly or closely related than expected by chance? Due to common descent, closely related species are more ecologically similar, and so degrees of relatedness in a community may be good predictors of its ecology, more so than the number of species. Whether we are speaking of how phylogenetic structure arises as a consequence of ecological processes, or how phylogenetic structure affects the functioning of communities, the role of consumer organisms has received less attention than the role of resources. In this thesis, I ask what are the consequences and causes of phylogenetic structure of a potentially multi-level community, focusing on the underappreciated effects of consumer-resource interactions. In Chapter 2, I show how phylogenetic diversity of plant communities predicts the diversity and abundance of arthropods captured in a long-running biodiversity experiment better than species richness alone. In Chapter 3, I show how phylogenetic diversity and species richness interact to explain herbivore damage at a whole community level. In Chapter 4, I explore how phylogenetic structure of old field plant communities differs in plots of contrasting disturbance history, and speculate as to what factors – such as herbivory – may have contributed to these differences. In Chapter 5, I present a model which incorporates competition – through both resources and consumers of a focal trophic level – and environmental filtering, two factors which are thought to impact phylogenetic structure through their influence on ecological similarity. I show that environmental filtering interacts with competition to determine the coexistence of similar species, and that consumers may have different effects than do resources. My dissertation provides new insight into the importance of consumers in ecological communities, both through their effect on, and through their response to, patterns of evolutionary history in their prey.

Phylogenetic structure measures patterns of evolutionary history within communities – are some communities composed of species more distantly or closely related than expected by chance? Due to common descent, closely related species are more ecologically similar, and so degrees of relatedness in a community may be good predictors of its ecology, more so than the number of species. Whether we are speaking of how phylogenetic structure arises as a consequence of ecological processes, or how phylogenetic structure affects the functioning of communities, the role of consumer organisms has received less attention than the role of resources. In this thesis, I ask what are the consequences and causes of phylogenetic structure of a potentially multi-level community, focusing on the underappreciated effects of consumer-resource interactions. In Chapter 2, I show how phylogenetic diversity of plant communities predicts the diversity and abundance of arthropods captured in a long-running biodiversity experiment better than species richness alone. In Chapter 3, I show how phylogenetic diversity and species richness interact to explain herbivore damage at a whole community level. In Chapter 4, I explore how phylogenetic structure of old field plant communities differs in plots of contrasting disturbance history, and speculate as to what factors – such as herbivory – may have contributed to these differences. In Chapter 5, I present a model which incorporates competition – through both resources and consumers of a focal trophic level – and environmental filtering, two factors which are thought to impact phylogenetic structure through their influence on ecological similarity. I show that environmental filtering interacts with competition to determine the coexistence of similar species, and that consumers may have different effects than do resources. My dissertation provides new insight into the importance of consumers in ecological communities, both through their effect on, and through their response to, patterns of evolutionary history in their prey.

Phylogenetic structure measures patterns of evolutionary history within communities – are some communities composed of species more distantly or closely related than expected by chance? Due to common descent, closely related species are more ecologically similar, and so degrees of relatedness in a community may be good predictors of its ecology, more so than the number of species. Whether we are speaking of how phylogenetic structure arises as a consequence of ecological processes, or how phylogenetic structure affects the functioning of communities, the role of consumer organisms has received less attention than the role of resources. In this thesis, I ask what are the consequences and causes of phylogenetic structure of a potentially multi-level community, focusing on the underappreciated effects of consumer-resource interactions. In Chapter 2, I show how phylogenetic diversity of plant communities predicts the diversity and abundance of arthropods captured in a long-running biodiversity experiment better than species richness alone. In Chapter 3, I show how phylogenetic diversity and species richness interact to explain herbivore damage at a whole community level. In Chapter 4, I explore how phylogenetic structure of old field plant communities differs in plots of contrasting disturbance history, and speculate as to what factors – such as herbivory – may have contributed to these differences. In Chapter 5, I present a model which incorporates competition – through both resources and consumers of a focal trophic level – and environmental filtering, two factors which are thought to impact phylogenetic structure through their influence on ecological similarity. I show that environmental filtering interacts with competition to determine the coexistence of similar species, and that consumers may have different effects than do resources. My dissertation provides new insight into the importance of consumers in ecological communities, both through their effect on, and through their response to, patterns of evolutionary history in their prey.

Phylogenetic structure measures patterns of evolutionary history within communities – are some communities composed of species more distantly or closely related than expected by chance? Due to common descent, closely related species are more ecologically similar, and so degrees of relatedness in a community may be good predictors of its ecology, more so than the number of species. Whether we are speaking of how phylogenetic structure arises as a consequence of ecological processes, or how phylogenetic structure affects the functioning of communities, the role of consumer organisms has received less attention than the role of resources. In this thesis, I ask what are the consequences and causes of phylogenetic structure of a potentially multi-level community, focusing on the underappreciated effects of consumer-resource interactions. In Chapter 2, I show how phylogenetic diversity of plant communities predicts the diversity and abundance of arthropods captured in a long-running biodiversity experiment better than species richness alone. In Chapter 3, I show how phylogenetic diversity and species richness interact to explain herbivore damage at a whole community level. In Chapter 4, I explore how phylogenetic structure of old field plant communities differs in plots of contrasting disturbance history, and speculate as to what factors – such as herbivory – may have contributed to these differences. In Chapter 5, I present a model which incorporates competition – through both resources and consumers of a focal trophic level – and environmental filtering, two factors which are thought to impact phylogenetic structure through their influence on ecological similarity. I show that environmental filtering interacts with competition to determine the coexistence of similar species, and that consumers may have different effects than do resources. My dissertation provides new insight into the importance of consumers in ecological communities, both through their effect on, and through their response to, patterns of evolutionary history in their prey.

Conserving biodiversity in human-dominated landscapes requires protecting networks of ecological reserves and managing the intervening matrix to maintain the potential for species to move among them. This dissertation provides original insights towards (1) identifying areas for protection in reserves that are critical to maintain biodiversity and (2) assessing the potential for species' movements among habitat patches in a reserve network. I develop and test methods that will facilitate conservation planning to promote viable, resilient populations through time. The first part of this dissertation tests and develops reserve selection strategies that protect either a single focal species in a dynamic landscape or multiple interacting species in a static landscape. Using a simulation model of boreal forest dynamics, I test the effectiveness of static and dynamic reserves to maintain spatial habitat requirements of a focal species, American Marten (Martes americana). Dynamic reserves improved upon static reserves but re-locating reserves was constrained by fragmentation of the matrix. Management of the spatial and temporal distribution of land-uses in the matrix will therefore be essential to retain options for re-locating reserves in the future. Additionally, to include essential consumer-resource interactions into reserve selection, a new algorithm is presented for American marten and its two primary prey species. The inclusion of their interaction had the benefit t of producing spatially aggregated reserves based on functional species requirements. The second part of this dissertation evaluates and synthesizes the network-theoretic approach to quantify connectivity among habitat patches or reserves embedded within spatially heterogeneous landscapes. I conduct a sensitivity analysis of network-theoretic connectivity analyses that derive least-cost movement behavior from the underlying cost surface which describes the relative ecological costs of dispersing through different landcover types. Landscape structure is shown to aff ect how sensitive least-cost graph connectivity assessments are to the quality (relative cost values) of landcover types. I develop a conceptual framework to classify network connectivity statistics based on the component of habitat connectivity that they quantify and the level within the network to which they can be applied. Together, the combination of reserve design and network connectivity analyses provide complementary insights to inform spatial planning decisions for conservation.

Doctor of Philosophy / Department of Biology / Walter K. Dodds / Much of the North American tallgrass prairie ecosystem has been converted to cropland or urbanized. One threat to the remaining prairie ecosystems, and the streams within, is woody vegetation encroachment. Stream productivity, measured as metabolism, is a fundamental process comprised of gross primary production (GPP) and (CR) community respiration. Understanding GPP and CR is important because these processes are vital to ecosystem function and can be impacted by a change in canopy cover. First, I investigated improvements in existing methods for estimating whole-stream metabolism as estimated from diel patterns of oxygen (O2). I compared measured and modeled O2 and aeration (a physical parameter required for measurement of metabolism) rates to determine if direct measurement of aeration is necessary and the importance of temperature correction of metabolism. Modeling was moderately successful in determining aeration rates, and temperature correction of GPP and CR substantially improved model fits. Second, effects of woody vegetation encroachment on prairie stream function were investigated. Stream metabolism was measured for four years in duplicate reaches with varying canopy cover (closed canopy, naturally open canopy, and vegetation removal reaches). The removal reaches had closed canopy for the first two years and open canopy for the last two years. Canopy cover increased CR rates and had minimal effects on GPP. Third, the same experiment was used to determine the effects of woody vegetation encroachment on prairie stream ecosystem structure and food web interactions. Chlorophyll a and filamentous algal biomass were greater in naturally open and vegetation removal reaches, although the effects were stronger on filamentous algal biomass. As canopy cover decreased, the filamentous algal biomass to chlorophyll ratio increased, indicating a shift in algal community structure. Stable isotope analysis indicated some shift in pathways of nitrogen and carbon flux into the food web related to degree of canopy cover, but overlap in the signature of food sources made distinct food sources difficult to identify. The data indicate that riparian encroachment can influence ecosystem structure and function in prairie streams and restoration to remove woody riparian cover may restore some ecosystem features of naturally open canopy streams.

Master of Science / Department of Biology / Kimberly A. With / Organisms exist within complex landscapes, and landscape features may influence multiple aspects of a species’ distribution within the landscape, including patch occupancy, abundance within patches, and population genetic diversity at a local or regional scale. We took two approaches to identify the relative importance of landscape context for populations of the Eastern Collared Lizard (Crotaphytus collaris collaris) in the northern Flint Hills of Kansas. First, we conducted surveys at limestone outcrops in experimental watersheds managed under different burning and grazing practices. Habitat occupancy and lizard abundance were estimated by constructing models that incorporated aspects of the environment at multiple scales. Both abundance and occupancy were higher on rock ledges that had more crevices, greater complexity in vegetation, covered a larger area, and were more prominent than available habitat. Abundance and occupancy were also higher in watersheds that were burned frequently (1–2 year intervals), but grazing only had a significant effect in less frequently burned (four–year burn interval) watersheds. Our second approach was to measure genetic diversity and population genetic differentiation and relate these measures to differences in landscape context. We sampled collared lizard DNA at four locations (sample sites < 45 km apart) and analyzed trends in 10 polymorphic microsatellite loci. We found evidence for low genetic variability and moderate population differentiation among our sample sites relative to estimates reported in the literature at the core of the species’ range. Differences in migration rates and ancestry among sampling locations also appear to correspond to differences in landscape resistance based on land cover and rock availability. Thus, it appears that habitat management may influence the suitability of habitat patches at the local scale, and that differences in land cover and rock availability may influence the connectivity of populations at the landscape scale.

The evolution of wind pollination (anemophily) has occurred at least 65 times in the flowering plants and over 10% of angiosperm species are wind pollinated. However the pollination and mating of anemophily species is poorly understood, particularly in comparison with animal-pollinated species. My thesis employs a range of approaches and tools to examine the evolution and ecology of wind pollination. These include comparative analyses, theoretical modeling, field and glasshouse experiments, the use of genetic markers and quantitative genetics. Experimental studies on diverse taxa were used to address questions concerned with the efficacy of outcrossing mechanisms, the ecological and demographic context of pollination and mating, and the plasticity of sex allocation. Comparative analyses indicated that wind pollination is correlated with unisexual flowers, reduced ovule number, small unshowy flowers, an absence of nectar, and open habitats. These analyses also demonstrated that anemophily originates more often in lineages with unisexual flowers. This suggests that wind pollination evolves in diclinous taxa as a mechanism of reproductive assurance because autonomous selfing is mechanically precluded. Empirical data on stigmatic pollen loads in 19 anemophilous species challenge the widespread assumption that anemophilous plants commonly have uniovulate flowers because they capture few pollen grains. Further, a model based on floral costs and the aerodynamics of pollen capture demonstrated that when flowers are inexpensive it is optimal to produce many flowers each with few ovules, because this allows more efficient sampling of the airstream. Manipulative field experiments on seven Carex species indicated that neither monoecy nor protogyny, two putative outcrossing mechanisms, are effective at limiting selfing. Based on these results I suggest that geitonogamy can provide reproductive assurance in anemophilous species with unisexual flowers. Field experiments and the application of sex-specific markers in Rumex nivalis revealed that the local neighbourhood of maternal plants affects pollination intensity and progeny sex ratios. Finally, I demonstrated that plant density in Ambrosia artemisiifolia affects stigmatic pollen loads but not outcrossing rates. Through a quantitative genetics experiment in A. artemisiifolia, I detected significant genetic variation for plasticity in sex allocation, potentially enabling adaptive adjustment of sex allocation to local environmental conditions.