This thesis elucidates patterns and drivers of invertebrate herbivory, herbivore diversity, and community-level biomass along elevational and land use gradients at Mt. Kilimanjaro, Tanzania. Chapter I provides background information on the response and predictor variables, study system, and the study design. First, I give an overview of the elevational patterns of species diversity/richness and herbivory published in the literature. The overview illuminates existing debates on elevational patterns of species diversity/richness and herbivory. In connection to these patterns, I also introduce several hypotheses and mechanisms put forward to explain macroecological patterns of species richness. Furthermore, I explain the main variables used to test hypotheses. Finally, I describe the study system and the study design used. Chapter II explores the patterns of invertebrate herbivory and their underlying drivers along extensive elevational and land use gradients on the southern slopes of Mt. Kilimanjaro. I recorded standing leaf herbivory from leaf chewers, leaf miners and gall-inducing insects on 55 study sites located in natural and anthropogenic habitats distributed from 866 to 3060 meters above sea level (m asl) on Mt. Kilimanjaro. Standing leaf herbivory was related to climatic variables [mean annual temperature - (MAT) and mean annual precipitation - (MAP)], net primary productivity (NPP) and plant functional traits (leaf traits) [specific leaf area (SLA), carbon to nitrogen ratio (CN), and nitrogen to phosphorous ratio (NP)]. Results revealed an unimodal pattern of total leaf herbivory along the elevation gradient in natural habitats. Findings also revealed differences in the levels and patterns of herbivory among feeding guilds and between anthropogenic and natural habitats. Changes in NP and CN ratios which were closely linked to NPP were the strongest predictors of leaf herbivory. Our study uncovers the role of leaf nutrient stoichiometry and its linkages to climate in explaining the variation in leaf herbivory along climatic gradients. Chapter III presents patterns and unravels direct and indirect effects of resource (food) abundance (NPP), resource (food) diversity [Functional Dispersion (FDis)], resource quality (SLA, NP, and CN rations), and climate variables (MAT and MAP) on species diversity of phytophagous beetles. Data were collected from 65 study sites located in natural and anthropogenic habitats distributed from 866 to 4550 m asl on the southern slopes of Mt. Kilimanjaro. Sweep net and beating methods were used to collect a total of 3,186 phytophagous beetles representing 21 families and 304 morphospecies. Two groups, weevils (Curculionidae) and leaf beetles (Chrysomelidae) were the largest and most diverse families represented with 898 and 1566 individuals, respectively. Results revealed complex (bimodal) and dissimilar patterns of Chao1-estimated species richness (hereafter referred to as species diversity) along elevation and land use gradients. Results from path analysis showed that temperature and climate-mediated changes in NPP had a significant positive direct and indirect effect on species diversity of phytophagous beetles, respectively. The results also revealed that the effect of NPP (via beetles abundance and diversity of food resources) on species diversity is stronger than that of temperature. Since we found that factors affecting species diversity were intimately linked to climate, I concluded that predicted climatic changes over the coming decades will likely alter the species diversity patterns which we observe today. Chapter IV presents patterns and unravels the direct and indirect effects of climate, NPP and anthropogenic disturbances on species richness and community-level biomass of wild large mammals which represent endothermic organisms and the most important group of vertebrate herbivores. Data were collected from 66 study sites located in natural and anthropogenic habitats distributed from 870 to 4550 m asl on the southern slopes of Mt. Kilimanjaro. Mammals were collected using camera traps and used path analysis to disentangle the direct and indirect effects of climatic variables, NPP, land use, land area, levels of habitat protection and occurrence of domesticated mammals on the patterns of richness and community-level biomass of wild mammals, respectively. Results showed unimodal patterns for species richness and community-level biomass of wild mammals along elevation gradients and that the patterns differed depending on the type of feeding guild. Findings from path analysis showed that net primary productivity and levels of habitat protection had a strong direct effect on species richness and community-level biomass of wild mammals whereas temperature had an insignificant direct effect. Findings show the importance of climate-mediated food resources in determining patterns of species richness of large mammals. While temperature is among key predictors of species richness in several ectotherms, its direct influence in determining species richness of wild mammals was insignificant. Findings show the sensitivity of wild mammals to anthropogenic influences and underscore the importance of protected areas in conserving biodiversity. In conclusion, despite a multitude of data sets on species diversity and ecosystem functions along broad climatic gradients, there is little mechanistic understanding of the underlying causes. Findings obtained in the three studies illustrate their contribution to the scientific debates on the mechanisms underlying patterns of herbivory and diversity along elevation gradients. Results present strong evidence that plant functional traits play a key role in determining invertebrate herbivory and species diversity along elevation gradients and that, their strong interdependence with climate and anthropogenic activities will shape these patterns in future. Additionally, findings from path analysis demonstrated that herbivore diversity, community-level biomass, and herbivory are strongly influenced by climate (either directly or indirectly). Therefore, the predicted climatic changes are expected to dictate ecological patterns, biotic interactions, and energy and nutrient fluxes in terrestrial ecosystems in the coming decades with stronger impacts probably occurring in natural ecosystems. Furthermore, findings demonstrated the significance of land use effects in shaping ecological patterns. As anthropogenic pressure is advancing towards more pristine higher elevations, I advocate conservation measures which are responsive to and incorporate human dimensions to curb the situation. Although our findings emanate from observational studies which have to take several confounding factors into account, we have managed to demonstrate global change responses in real ecosystems and fully established organisms with a wide range of interactions which are unlikely to be captured in artificial experiments. Nonetheless, I recommend additional experimental studies addressing the effect of top-down control by natural enemies on herbivore diversity and invertebrate herbivory in order to deepen our understanding of the mechanisms driving macroecological patterns along elevation gradients. / In dieser Dissertation werden Muster und Determinanten von Herbivorendiversität, von Herbivorieraten durch Invertebraten sowie die Diversität und Gesamtbiomasse von Säugetieren entlang von Höhen- und Landnutzungsgradienten am Kilimandscharo (Tansania) untersucht. Kapitel I liefert Hintergrundinformationen zu den betrachteten Variablen, dem Untersuchungssystem und dem generellen Studiendesign: Zuerst fasse ich den aktuellen Kenntnisstand über die Muster des Artenreichtums und der Herbivorie entlang von Höhengradienten zusammen und erläutere in diesem Zusammenhang verschiedene Hypothesen, die zur Erklärung von Gradienten des Artenreichtum herangezogen werden. Ich erkläutere verschiedene Variablen, die zum Testen dieser Hypothesen erhoben wurden und stelle dar, wie diese den Artenreichtum, die Herbivorieraten und die Biomasse beeinflussen könnten. Anschließend beschreibe ich das Untersuchungssystem, sowie das generelle Design der Studie. In Kapitel II werden die Muster und Determinanten der Invertebratenherbivorie entlang von Höhen- und Landnutzungsgradienten an den südlichen Hängen des Kilimandscharos präsentiert. Auf insgesamt 55 Untersuchungsflächen, die sowohl natürliche als auch anthropogen genutzte Habitate am Kilimandscharo in Höhenlagen zwischen 866 und 3060 Meter über Normalnull (m ü. NN) umfassten, wurden die Herbivorieraten ektophager, minierender und gallbildener Insekten an Blättern erfasst. Die Blattherbivorie war sowohl mit klimatischen Variablen [Jahresmitteltemperatur und mittlere Jahresniederschlagsmenge], der Nettoprimärproduktivität (NPP) und mit funktionellen Blattmerkmalen von Pflanzen [spezifische Blattfläche (SLA), Kohlenstoff (C) / Stickstoff (N)-Verhältnis, sowie N / Phosphor (P)-Verhältnis] assoziiert. Die Gesamtherbivorie zeigte eine unimodale Verteilung über den Höhengradienten, wurde aber sowohl von der Herbivorengilde, als auch vom Habitattyp (natürlich versus anthropogen) beeinflusst. Das C/N-Verhältnis von Blättern war die stärkste Determinante der Blattherbivorie und wurde selbst stark durch die NPP bestimmt. Herbivorieraten sanken mit steigendem C/N-Verhältnis. Das C/N Verhältnis nahm mit steigender NPP zu.- Letztere konnte fast vollständig durch Änderungen der mittleren Jahrestemperatur (MAT) und des Jahresniederschlags (MAP) entlang des Höhengradienten erklärt werden. Damit zeigt unsere Studie, dass sich durch klimatische Faktoren und Energie, welche ihrerseits die Blattchemie beeinflussen und so Variationen in der Blattherbivorie entlang großer Klimagradienten ergeben. In Kapitel III werden die Muster im Artenreichtum phytophager Käfer entlang der Höhen- und Landnutzungsgradienten untersucht und die direkten und indirekten Effekte von klimatischen Faktoren (MAT, MAP), NPP und funktionellen Pflanzenmerkmalen (funktionelle Dispersion, SLA, C/N - und N/P - Verhältnisse) auf diese Muster analysiert. Die entsprechenden Daten wurden auf 65 Untersuchungsflächen, die sowohl natürliche als auch anthropogene Habitate entlang eines Höhengradienten am Kilimandscharo von 866 bis 4550 m ü. NN abdeckten, erhoben. Mittels Kescher wurden insgesamt 3186 phytophage Käfer aus 21 Familien gesammelt und in 304 Morphospezies eingeteilt. Der Artenreichtum phytophager Käfer zeigte eine komplexe, zweigipflige Verteilung entlang der Höhen- und Landnutzungsgradienten. Eine Pfadanalyse ergab, dass sowohl die MAT, als auch NPP positiven direkte bzw. indirekte Effekt auf die Artendiversität phytophager Käfer hatte. Die NPP war positiv mit der funktionellen Dispersion von Blattmerkmalen, ein Maß für die Diversität der Nahrungsressourcen, korreliert. Letztere hatte einen positiven Effekt auf die Diversität der Käfer. Die starken direkten und indirekten Effekte von Klima auf die Diversität und Abundanz von phytophagen Käfern, lassen vermuten dass der Klimawandel in den nächsten Dekaden großen Änderungen der Struktur von phytophagen Käfergemeinschaften bewirken wird. In Kapitel IV untersuchen wir den Effekt von Klima, NPP und anthropogener Störung auf den Artenreichtum und die Gesamtbiomasse von Großwild. Dazu wurden auf 66 Untersuchungsflächen, welche natürliche und anthropogene Habitate in Höhenstufen zwischen 870 und 4550m ü. NN umfassten, Daten zum Artenreichtum un der Abundanz von Großwild mittels Kamerafallen erfasst. Mittels einer Pfadanalyse wurden die direkten und indirekten Effekte von klimatischen Variablen, NPP, Landnutzung, Größe und Schutzstatus der Flächen, sowie der Präsenz von domestizierten Säugetieren auf den Artenreichtum und die Biomasse von Großwild untersucht. Artenreichtum und Gesamtbiomasse dieser endothermen Organismen zeigten eine unimodale Verteilung über den Höhengradienten. Verschiedene Nahrungsgilden zeigten unterschiedliche Muster. Es konnte gezeigt werden, dass NPP und der Schutzstatus der Fläche, aber nicht die Temperatur einen direkten, positiven Einfluss auf den Artenreichtum und die Gesamtbiomasse des Großwildes hatte. Die vom Klima abhängige Nahrungsressourcenverfügbarkeit ist also eine wichtige Determinante im Artenreichtum von Großwild. Die Temperatur hingegen, die den Artenreichtum verschiedener ektothermer Organismen entscheidend prägt, hatte keinen direkten Einfluss auf den Artenreichtum des Großwildes Dafür reagiert das Großwild besonders sensibel auf anthropogene Einflüsse, was wiederum die Wichtigkeit von Schutzgebieten unterstreicht. Obwohl die Muster im Artenreichtum und in Ökosystemfunktionen entlang großer klimatischer Gradienten bereits gut dokumentiert sind, ist das Wissen über die zu Grunde liegenden Prozesse nach wie vor unzureichend. Mit meinen drei Studien über die Muster und Determinanten der Herbivorendiversität, der Herbivorieraten und der Großwildbiomasse trage ich somit zur Verbesserung des mechanistischen Verständnisses solcher makroökologischer Muster bei. Wie die Pfadanalysen zeigten, wurden sowohl der Artenreichtum die Biomasse als auch ökologische Prozesse direkt oder indirekt vom Klima beeinflusst. Es ist somit zu erwarten, dass der vorhergesagte Klimawandel ökologische Muster, biotische Interaktionen, Energie- und Nährstoffkreisläufe in terrestrischen Ökosystemen wesentlich umstrukturieren wird, wobei natürliche Systeme wahrscheinlich besonders sensibel auf den Klimawandel reagieren werden. Meine Ergebnisse demonstrieren auch den Einfluss von Landnutzung auf Artenreichtum und ökologische Prozesse. Da der anthropogene Druck auf die natürlichen Ökosysteme des Kilimandscharos immer weiter zunimmt, sollten objektive Biodiversitätsmaße implementiert werden mit denen man Veränderungen in den Ökosystemen und in Ökosystemldienstleistungen schnell detektieren kann. Meine Ergebnisse basieren auf Beobachtungsdaten, die von bestimmten Nebenfaktoren im Feld beeinflusst werden können. Dennoch ist es mir gelungen mit korrelativen Methoden, Organismen in ihrem biotischen und abiotischen Interaktionsumfeld zu untersuchen – ein Szenario, welches in einem rein experimentellen Aufbau in dieser Form wahrscheinlich nicht geschaffen werden kann. Über weiterführende Experimente könnte jedoch zum Beispiel der Einfluss von Prädatoren auf die Herbivorendiversität und Herbivorieraten quantifiziert werden, welches unser Verständnis über die Determinanten makroökologischer Muster noch vertiefen würde.

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For this dissertation, I measured how plant communities in Appalachian forests responded to disturbances caused by forest management activities. I had two primary objectives including (1) testing theories of biological diversity and invasions by nonnative species; and (2) providing empirical data that will help guide the sustainable use of forest resources. This work is part of the Southern Appalachian Silviculture and Biodiversity (SASAB) experiment that was established in the early 1990s to investigate ecosystem responses to a gradient of timber harvesting disturbances. Ranging from undisturbed controls to silvicultural clearcuts, the disturbance gradient is replicated at sites located throughout the Appalachian mountains of Virginia and West Virginia. The plant community was sampled across a wide range of spatial scales (2 hectares to 1 m2) using a nested sampling design and was also sampled at three times including pre-disturbance, one year post-disturbance, and ten year post-disturbance. For one element of the study I tested modern theories of biological invasions and investigated how the forest disturbance gradient interacted with species diversity to influence invasion by nonnative species (Chapter 2). Contrary to popular ecological theories of biotic resistance, the most diverse sites tended to be more easily invaded following intense canopy disturbance. Interestingly, none of the sites in this study were dominated by invasive plants, which led me to ask whether dominant tree species in forests provided resistance to nonnative plant establishment and growth through the quality of the litter they produce. I also asked how might animals that are known to alter litter layers interact with dominant tree species to influence plant invasions. Therefore, I conducted an experiment investigating how changes in litter from dominant tree species and invasions by nonnative earthworms might influence invasibility of forests using forest floor mesocosms (Chapter 3). I found that plant invasion was inhibited by native oak litter even when earthworms were present, suggesting that oak forests may resist plant invasions via oak tree litter. In contrast, plant invasion was greater under invasive tree litter and earthworm activity tended to facilitate invasive plant success only under invasive tree litter. I was also interested in understanding how disturbance might alter relationships between local and regional diversity. The long-term data of the forest disturbance experiment allowed me to investigate how local species richness is mediated by regional species richness after disturbance and during forest community development (Chapter 4). Local richness depended strongly on regional richness only after disturbance via colonization of species, but this relationship changed during forest aggradation. These results suggest that regional species pools are important to maintain local diversity following disturbance, but that local interactions (through canopy closure of dominant trees) exert control over species diversity during community reorganization. Lastly, I tested current theories on how diversity influences compositional stability after disturbance (Chapter 5). Disturbance consistently resulted in decreased compositional stability, but diversity was associated with stability in complex ways, which depended on how stability was measured and at what scale. Species-rich areas were in some instances less stable; in other instances areas with intermediate levels of diversity were more stable. These results suggest that disturbance causes shifts in species composition via colonization, but the ways in which diversity of sites influences compositional stability is complex and depends on methods used and the scales of observation. Taken together, these results suggest that disturbance influences invasibility, species saturation, and compositional stability of ecological communities. These properties change immediately following disturbance, and during forest development and canopy closure. Data from this project were useful in testing existing theories of community ecology, and may ultimately prove useful for forest managers as they decide how to protect biodiversity while planning for other uses of forest resources. Overall, these results suggest that colonization of species is the primary process driving plant community patterns in Appalachian forests following disturbance. / Ph. D.

Island biogeography theory predicts that the patterns and distributions of spatially isolated populations are governed by large scale processes. The high elevations forests in the Southern Appalachians represent a series of naturally fragmented islands that harbor many isolated populations of species at the southern limits of their range. Understanding the governing forces of population dynamics in this region will enhance the probability of species persistence in the face of threats such as global warming and human development. We surveyed bird populations across multiple elevations in Virginia and combined this with a multi-scale habitat analysis to determine influences of species presence and species richness. We detected 101 species across the elevation gradient, including 12 species with special conservation status and ten species whose presence increased with increasing elevation. These ten elevation sensitive species responded to habitat variables at both the microhabitat and landscape scale, with species-specific patterns of habitat variable correlation emerging. Habitat type was least effective in predicting species presence for any elevation sensitive species. Species richness declined over the elevation gradient until the highest elevations, where this trend reversed and richness began to increase. This pattern was driven by an increase in short-distance migrants beginning at mid-elevations, which ultimately overpowered a corresponding decrease in long-distance migrants beginning at similar elevations. Habitat analysis linked these patterns to a preference of short-distance migrants for smaller, more isolated non-forested patches, and a historical lack of persistence for long-distance migrants. Conservation and management decisions for the region should focus on a multi-scale approach that preserves all habitat types for continued species presence and high species richness, although the persistence of particular elevation sensitive species is compounded by unique species-habitat relationships and the perception of islands as species-specific. Continued monitoring of these fragmented populations in light of both short- and long-term threats which span multiple scales of influence will maintain high species richness and ensure the persistence of crucial breeding habitat. / Master of Science

The present state of forestry post mining land uses has prompted concern among researchers, landowners, and the public. Surface mines reclaimed to forests under the provision of the Surface Mining Control and Reclamation Act (SMCRA) may not achieve site productivity levels required by the law. Anecdotal evidence suggests that many pre-law reforested mined sites are growing productive forests. The purpose of this study was to characterize these forests and the mine soils in which they are growing, and use them to benchmark forest development on mined land. Using 14 mined and 8 non-mined sites in the midwestern and eastern coalfields research to address the following objectives was undertaken: (i) characterize the development, composition, and diversity of woody species on pre-SMCRA, forested surface mined land; (ii) estimate forest and site productivity on surface mined land and determine the soil and site properties most influencing forest growth; (iii) estimate projected rotation-age timber product value; (iv) quantify current carbon sequestration pools associated with the developing woody plant biomass, the forest floor, and developing soil medium; (v) compare the diversity, forest and site productivity, commercial value, and carbon capture of reclaimed mined sites to that of regional non-mined forest systems. Species richness between non-mined and mined sites was about the same within each region with 14 to 15 tree species in the canopy. Canopy richness of eastern mined sites was less than that on midwestern mined sites (12 species compared to 17 species, respectively). Species richness of the understory and woody ground layer were similar between sites planted to pines versus hardwoods. White pine (Pinus strobus) monocultures, planted on many sites in the eastern region, caused species unevenness throughout all forest strata. Midwestern mined sites and eastern sites planted to hardwoods closely approximated non-mined sites in commercial species composition. Planted species represented the majority of canopy layer dominance and abundance (82% relative dominance and 56% relative abundance). Site productivity between non-mined sites and 12 of the 14 mined sites was similar. Regression analysis identified the five most influential soil properties affecting site quality, which included soil profile base saturation, total coarse fragments, total available water, C horizon total porosity, and soil profile electrical conductivity. These five properties explained 52 % of the variation in tree growth. Forest productivity of these mined sites was equal to or greater than that of non-mined forests, ranging between 3.3 m3ha-1yr-1 and 12.1 m3ha-1yr-1. Management activities such as planting pine and valuable hardwood species increased the stumpage value of forests on reclaimed mine sites. Rotation-age stumpage values on mined study sites ranged between $3,064 ha-1 and $19,528 ha-1 and were commonly greater than stumpage values on non-mined reference sites. After 20 to 55 years, total site carbon levels on mined study sites averaged 217 Mg ha-1, while total carbon amounts on natural sites averaged 285 Mg ha-1. The amounts of carbon captured within the plant biomass and litter layer were the same on mined and natural sites. However, the soil carbon content of mined sites averaged 39 % lower than natural soils. The amount of carbon captured across mined sites was largely a function of forest stand age. Pre-SMCRA forests growing on mined sites with productivity levels similar to non-mined sites are capable of developing forest attributes comparable to or greater than those found on non-mined land within a period of 60 years, the length of a commercial hardwood rotation. These mature forests can serve as benchmarks for forest development on mined lands being reclaimed under current state and federal regulations. / Master of Science

vegetation and soil carbon-and nitrogen cycles in a grazing area through food selection, consumption, fertilization, and trampling. There have been discussions on how reindeer grazing, plant communities, and different ecosystems relate to each other and how the management of protected areas should proceed based on various laws, recommendations, and perspectives. The purpose of this study is to examine the impact of reindeer grazing on biodiversity in northern Scandinavia and thus be able to support these discussions. Inventory data was collected in 1995 on both sides of the fence that demarcates Norway from Malla National Park in Finland. At the time of the inventory, reindeer husbandry had been prohibited on the Finnish side of the fence for several decades, creating a difference in grazing pressure between the inventory areas. A statistical comparison was made between the number of plant species for six different functional plant groups divided into four different soil moisture types between the two countries, as well as a comparison of the number of reindeer droppings per study area in each country to quantify the difference in grazing pressure. The results show that there were more grass species in meadow areas and more reindeer droppings on the Norwegian side. I found no significant difference for the other functional plant groups or for the grasses in the other soil moisture types. Based on these results, I conclude that reindeer may increase the number of grass species in meadow areas.

Biodiversity is a complex concept encapsulating the variation that occurs within and among levels of biological organization. It is positively linked to ecosystem persistence, adaptability, and function. Biodiversity loss, driven by global change and human activities, is one of the most prominent threats to ecosystems. Characterizing the variation of and processes driving biodiversity is a critical step in understanding the causes, consequences, and magnitude of biodiversity loss. However, characterizing biodiversity comprehensively requires understanding multiple dimensions, or types, of diversity, such as genetic, taxonomic, phylogenetic, and life history diversity, that encompass both ecological and evolutionary processes varying across space and time. In this dissertation, I investigate spatial and temporal variation in frog and toad (order Anura) biodiversity to understand the effects of how diversity is measured on biodiversity characterization and the underlying processes driving biodiversity. In my first chapter, I examined the spatial and temporal variation of genetic diversity and other population genetic metrics to understand the effects of multi-year sampling on population genetic inference in an anuran metapopulation (Arizona treefrog, Hyla (Dryophytes) wrightorum). I found that a single sample year captures global, but not local, population genetic dynamics, as there is considerable temporal variation in genetic metrics within individual populations. In my second chapter, I developed a tool to improve the characterization of anuran life history diversity using species traits. Traits are the measurable attributes of species, and a suite of species traits is used to distinguish ecological strategies found among species. I collated trait data from 411 primary and secondary sources for 106 anuran species found in the United States to develop an anuran traits database for use in conservation, management, and research. In my third chapter, I investigated spatial variation within and among taxonomic, phylogenetic, and life history anuran diversity in the United States and examined the abiotic relationships behind observed patterns. To do this, I developed species distribution models at a 1 km2 resolution for the majority of the native US anurans. I identified relationships among diversity metrics for improved, comprehensive biodiversity characterization and potential ecological and evolutionary processes underlying biodiversity. Spatial variation in multidimensional relationships highlights regional needs for multiple metrics of diversity to comprehensively characterize biodiversity. This spatial variation is driven by temperature, elevation, and water availability, likely related to the biological limits for anurans. Collectively, these chapters highlight the considerable variation that exists within and among species of a broad and diverse biological. Furthermore, these chapters call attention to the importance of measuring multiple biodiversity dimensions for effective conservation in a rapidly changing world. / Doctor of Philosophy / Biodiversity loss, from global change and human activities, is one of the biggest threats to the Earth's ecosystems. Biodiversity is the similarities and differences in organismal characteristics, such as their genetics, evolutionary history, and ecology. Biodiversity is often linked to how well an ecosystem will persist and adapt to global change. To understand the causes and consequences of biodiversity loss, it is important to first measure diversity and what shapes it. However, there are many types of diversity and ways to measure them, such as the number of species in a system, or species richness, the span of evolutionary lineages in a system, or phylogenetic diversity, the number of roles species fill in a system, or life history diversity, and the genetic relationships within individuals and populations, or genetic diversity. In this dissertation, I investigate how our understanding of biodiversity is affected by the ways it can be measured and the relationship among those metrics. To do this, I studied diversity in three ways for frogs and toads of the United States. First, I investigated whether sampling across multiple years is necessary to adequately characterize genetic diversity in a frog species (Arizona treefrog: Hyla (Dryophytes) wrightorum) with populations that fluctuate in size over time. Here, I found that multiple sample years are necessary to capture the genetic variation within individual populations over time, but unnecessary to capture the average genetic variation among all populations over space and time. Second, I developed a tool to improve our ability to measure anuran life history diversity using traits. Traits are measurable attributes of species, and multiple species traits can be used to define the role of a species in an ecosystem. I collected trait data from 411 sources for 106 frog and toad species found in the United States to develop a traits database for use in conservation, management, and research. Third, I investigated the similarities in multiple diversity metrics across the United States using species richness, phylogenetic diversity, and life history diversity. Species richness is highest in the eastern US, phylogenetic diversity is highest in the western US, and life history diversity is clustered around eastern US mountains. These regional relationships among metrics coincided with regional water availability, temperature, and elevation. These results collectively call attention to changes over space and time in frog and toad diversity and how the relationships within and among diversity types relate to our understanding of frog and toad biodiversity. Considering how, where, and when to measure biodiversity can lead to more effect biodiversity conservation in a rapidly changing world.

Exotic invasive plants have become a significant issue in the Southeastern United States for private landowners. These plants possess characteristics that allow for rapid growth and easy adaptation to many growing conditions, often outcompeting native vegetation and altering wildlife habitat, especially in disturbed areas. Disturbance, including access roads, trails, harvest sites, powerline corridors, and fence rows, is common on private land. Private landowners are often left to combat these problems without many monetary or expertise resources that are available to federal lands. Three field sites, each in a different physiographic province in Virginia, were surveyed for exotic invasive populations and sampled with nested overstory, understory, and regeneration plots and wildlife point intercept transects using paired plots during the summers of 2006 and 2007. Species richness of the overstory and understory did differ, but native percent understory cover and sapling density remained unchanged. Tree density and forest basal area were reduced with presence of exotic invasive plants. Regeneration diversity and density decreased in areas of exotic plant invasion. Eastern cottontail habitat suitability increased with the presence of exotic invasive plants. Suitability of habitat for the gray squirrel, downy woodpecker food, black-capped chickadee reproduction, and eastern wild turkey cover declined with the occurrence of exotic invasive plants. Twenty three of thirty seven total invasive plots were within twenty feet of a disturbance area. Continual assessment of impacts will help provide a better understanding of the nature of exotic invasive plants to landowners and may help them to manage and prevent plant invasions. / Master of Science