<p>  </p> <p>Bats serve important ecological and economic roles in their communities. However, due to anthropogenic land use and human-introduced disease, bat populations in North America are facing unprecedented declines. To better inform conservation efforts for bat species in northeastern Indiana, I studied two aspects of bat ecology: (1) the effects of urbanization and agriculture on bat community composition in northeastern Indiana and (2) the roosting behavior of a population of state endangered/federally threatened northern long-eared bats (<em>Myotis septentrionalis</em>; hereafter northern myotis) in a restored mesic forest adjacent to a moderately sized city (Fort Wayne, IN). To study the first aspect, I deployed acoustic detectors in green spaces throughout Fort Wayne and the surrounding rural areas of Allen County. For each detector site, I compared species occupancy rates with site-specific characteristics at the plot scale (e.g., % canopy cover, midstory density) and at multiple landscape scales (e.g., % impervious cover within 1 km). Across 429 survey nights, acoustic detectors recorded calls from eight unique bat species, of which six species were abundant enough to conduct occupancy modeling. In four of the six species, measures of the amount of forest and forest edge in the landscape were included in one or more of the top models. The top models for the two other bat species, tricolored bats (<em>Perimyotis subflavus</em>) and silver-haired bats (<em>Lasionycteris noctivagans</em>), included measures of urban land cover and revealed a negative relationship between probability of occupancy and the proportion of high-density urban land in the area. The effect of habitat scale also differed between species. For example, models in the confidence set for eastern red bats (<em>Lasiurus borealis</em>) included variables associated with the plots surrounding detectors and with landscape features within 100 m of detectors. In contrast, the top models for hoary bats (<em>Lasiurus cinereus</em>) included landscape features at larger scales, within 500m and 1 km of detector sites. These findings suggest that both generalist and forest-obligate bat species in this study area selected spaces with greater levels of forested habitat. Furthermore, heavily urbanized areas were less likely to support the same levels of bat diversity as areas with forests and other green space.</p> <p>To accomplish the second aspect of my project, I captured bats in Fox Island County Park (Fort Wayne, IN) using mist-nets and affixed temperature-sensitive radio transmitters to four northern myotis individuals. I tracked these individuals back to day roosts, where I recorded roost characteristics (e.g., tree height, # of roost trees within 0.1 ha) and monitored bat skin temperatures (Tsk). I compared the characteristics of selected roosts to those of randomly assigned available trees in the same landscape to determine trends in roost selection preferences. Northern myotis in this study strongly preferred standing dead trees within a 31-ha patch of flooded forest on the northern border of Fox Island. These trees were highly exposed to solar radiation and were consistently warmer than ambient weather conditions, which suggests they may provide important thermoregulatory benefits to reproductive females and other members of the population.</p> <p>My research offers valuable information regarding resource use by bat communities in a landscape dominated by anthropogenic development. Urban areas containing large stretches of forests with trees in various stages of decay will be more likely to meet the needs of bats that would otherwise struggle in developed landscapes. The results of this study can be used to inform conservation efforts aimed at protecting populations of bats throughout Indiana and the Midwestern United States.</p>

<p dir="ltr">Mammalian mesocarnivores contribute greatly to a proper functioning ecosystem by exerting top-down population control on prey species. While many of these species can be legally trapped or hunted in Indiana, given their responsibilities in the ecosystem, continuous monitoring of Gray fox (Urocyon cinereoargenteus) and Long-tailed weasel (Neogale frenata) by researchers is important to identify potential signs of decline and produce specific management plans. Both U. cinereoargenteus and N. frenata populations are suspected to be declining based on reduced frequencies of observations and harvest. However, each species displays cryptic behaviors that can make observation and effective surveying difficult, which may make the development of accurate assessments of population health unfeasible. To enable better monitoring of populations of these species, I developed a model for potential U. cinereoargenteus habitat and build upon camera trapping survey methods for N. frenata in this project. I used community surveying tools in a presence-only software (e.g., MaxEnt) to develop a consensus model for U. cinereoargenteus potential habitat. I identified five landscape-based covariates (distance to mixed and evergreen forest, distance to low urban cover, distance to shrub/scrub cover, and percent total forest cover per km2 ) that contributed the greatest to predicting the presence of the species. The top models in my project indicated a positive relationship between predicted U. cinereoargenteus presence and forested land cover. Additionally, predicted presence was high when the distance to low urban and shrub/scrub cover was low. In the Southern portion of Indiana predicted areas of presence occurred where larger forest patches exist. This differed from the Central and Northern portions of the state where smaller fragmented forest patches exist. In these areas, predicted areas of presence predominantly occurred near shrub/scrub or low urban cover. These findings will allow researchers to target specific areas for effective surveying and develop species conservation strategies. I also evaluated the ability of three enclosed camera trapping systems (AHDriFT system, Mostela system, and MoHDriFT system) to detect N. frenata. These camera systems have been designed to detect N. frenata and potential prey items, doing so successfully in past studies. I deployed trapping systems in three sites throughout Northeast Indiana from February to November 2023. Camera systems collected data during the project period during unbaited and baited (using sardines) survey periods. During my project, I observed three unique detections of N. frenata, all 9 of which were in the AHDriFT system during unbaited survey periods (P = 0.99; Z = -0.005). During these survey periods when N. frenata were detected, the AHDriFT system accounted for greater prey visitation and prey species abundance than the other two trapping systems (P < 0.01; F = 12). The ability to attract large amounts of prey species while successfully detecting N. frenata in this project may point to the AHDriFT system as the best camara trapping system suited for monitoring this cryptic species. The results from my project provide researchers and state agencies with input for monitoring these two cryptic species. With both species in suspected declines, the research conducted in the two chapters can contribute to portions of future species management plans. By targeting specific areas with predicted suitable habitat for U. cinereoargenteus, agencies can better allocate funds and conduct more extensive species research in Indiana. Likewise, by deploying the AHDriFT system, researchers in Indiana can cost-effectively monitor, not only N. frenata populations, but also small mammal and herp communities with ease. The research in this project provides researchers and state agencies in Indiana with new tools and insights in monitoring these cryptic species that are critical mesocarnivores in the state’s ecosystem.</p>

<p>Human society is presently beset by an array of anthropogenic social-ecological crises that threaten the sustainability of the social-ecological systems that sustain our livelihoods. While research alone will not rectify these issues, it can help to answer key questions that must be addressed to develop effective solutions. To address such questions in a cohesive, compelling manner, social-ecological research can be bounded, structured, and distilled through innumerable organizing principles or theoretical frameworks. For this dissertation, I focused on the geographic region of Tierra del Fuego and sought to draw from the array of disciplines and methods that use sound as a lens for biological, ecological, and/or social inquiry. I also endeavored to consider various temporal, spatial, and organizational scales while investigating a selection of topics with a) specific importance in the social-ecological systems of Tierra del Fuego and b) general relevance to global social-ecological challenges. Chapter 1 provides an introduction to the dissertation, and Chapter 6 serves as a conclusion.</p><p><br></p><p> </p><p>The objective of Chapter 2, “Biogeographical and analytical implications of temporal variability in geographically diverse soundscapes”, was to provide some guidance to passive acoustic monitoring (PAM) practitioners on how to design appropriate temporal sampling schemes based on the temporal variability of the sounds one wishes to measure and the power and storage limitations of acoustic recorders. We first quantified the temporal variability of several soundscape measurements and compared that variability across sites and times of day. We also simulated a wide range of temporal sampling schemes in order to model their representativeness relative to continuous sampling.</p><p><br></p><p> </p><p>For Chapter 3, “Sentinels for sentinels: passive acoustic and camera trap monitoring of sensitive penguin populations”, we tested the utility of PAM to monitor behavior and abundance of Magellanic (<i>Spheniscus magellanicus</i>) and southern rockhopper penguins (<i>Eudyptes chrysocome</i>) at different spatial and temporal scales. We conducted <i>in situ</i> observations of the acoustic behavior of each species, and we compared acoustic metrics with penguin counts from narrowly focused camera traps and larger-extent observations of colony density. </p><p><br></p><p> </p><p>Chapter 4, “Acoustic monitoring shows invasive beavers (<i>Castor canadensis</i>) increase avian diversity in Tierra del Fuego”, is focused on impacts of the invasive North American beaver (<i>Castor canadensis</i>) on Fuegian bird communities. We sought to determine how bird communities might differ between intact riparian forests, beaver ponds, and beaver meadows created by pond drainage. We conducted PAM and classic avian point counts under each of these conditions across seasons to test for differences between impact conditions and to compare the two methodologies.</p><p><br></p><p> </p>For Chapter 5, “Human-nature connection and soundscape perception: insights from Tierra del Fuego, Argentina”, we evaluated the relationship between soundscape perception and nature relatedness by conducting surveys and soliciting responses to soundscape audio prompts. We also examined the potential for any demographic influences on nature relatedness or soundscape perception in the context of local social tensions.

<p>Here, we seek to address the importance of biodiversity in plant ecosystems. We examined the productivity-diversity relationship through the lens of the modern coexistence theory, using a combination of both experimentation and mathematical simulation. We did this by tracking and comparing the productivity of mixed and monoculture plots, analyzing the growth responses of individual trees at forest plots (Chapter 1), confirming the productivity-diversity relationship in a greenhouse experiment using local herbaceous plants (Chapter 2), and finally simulating the productivity response of monoculture vs polyculture plantations to specialist enemy attack (Chapter 3).</p><p>It is no surprise that biodiversity has been decreasing at an exponential rate on the global scale because of effects such as habitat fragmentation, invasive species, spreading pathogens, and anthropogenic influences. Ecologists often found that plants in more species rich locations often exhibited higher productivity and stability in the face of stress. One such phenomenon is known as the productivity diversity relationship that implies biodiversity is key to sustaining ecosystems. Notably, while efforts are being put forth to address ecosystem destruction, much of the current tree planting strategy in the USA is based on timber profit rather than forest productivity and species coexistence with tree biology often being a secondary consideration. These thought processes are in opposition with historical experiments that indicate polyculture communities create more biomass making them significantly more productive than monocultures. However, we also acknowledge that it is not simply biodiversity that must be taken into consideration for a productive ecosystem but also species interaction through coexistence indicate whether or not a community will persevere. These interactions can be addressed using the modern coexistence theory which depends on these complementarity and fitness similarities for species to coexist through time. Here, we seek to address the importance of biodiversity in plant ecosystems. We examined the productivity-diversity relationship through the lens of the modern coexistence theory, using a combination of both experimentation and mathematical simulation. We did this by tracking and comparing the productivity of mixed and monoculture plots, analyzing the growth responses of individual trees at forest plots (Chapter 1), confirming the productivity-diversity relationship in a greenhouse experiment using local herbaceous plants (Chapter 2), and finally simulating the productivity response of monoculture vs polyculture plantations to specialist enemy attack (Chapter 3). Our research across the combination of approaches used found that species with overlapping niches and very different finesses will exclude one another due to high competition. Further, the productivity diversity correlation is necessary for ecosystem growth, but it is not sufficient for species coexistence. However, species can maintain this positive relationship despite a lack of coexistence if they maintain niche complementarity. Lastly, using a theoretic game model we were able to identify the impacts of a specialist pest on polyculture and monoculture forest. These results showed that a polyculture forest was more productive than that of a monoculture forest regardless of the presence of a specialist enemy. The results of the multiple threads of evidence found from these combined experiments indicate that while the productivity diversity correlation is important to ecosystems it is likely due to the impacts of niche complementarity that determine whether or not species will be productive within an ecosystem.</p>

<p>Eastern black walnut (<i>Juglans nigra</i> L.) ranks among the most highly valued timber species in the central hardwood forest and across the world. This valuable tree fills a critical role in native ecosystems as a mast bearing pioneer on mesic sites. Along with other <i>Juglans</i> spp. (Juglandaceae), <i>J. nigra</i> is threatened by thousand cankers disease (TCD), an insect-vectored disease first described in 2009. TCD is caused by the bark beetle <i>Pityophthorus juglandis</i> Blackman (Corthylini) and the phytopathogenic fungus <i>Geosmithia morbida</i> Kol. Free. Ut. & Tiss. (Bionectriaceae). Together, the <i>P. juglandis</i>-<i>G. morbida</i> complex has expanded from its historical range in southwest North America throughout the western United States (U.S.) and Europe. This range expansion has led to widespread mortality among naïve hosts <i>J. nigra</i> and <i>J. regia</i> planted outside their native distributions.</p> <p> The severity of TCD was previously observed to be highest in urban and plantation environments and outside of the host native range. Therefore, the objective of this work was to provide information on biotic and abiotic environmental factors that influence the severity and impact of TCD across the native and non-native range of <i>J. nigra</i> and across different climatic and management regimes. This knowledge would enable a better assessment of the risk posed by TCD and a basis for developing management activities that impart resilience to natural systems. Through a series of greenhouse-, laboratory- and field-based experiments, environmental factors that affect the pathogenicity and/or survival of <i>G. morbida</i> in <i>J. nigra</i> were identified, with a focus on the microbiome, climate, and opportunistic pathogens. A number of potentially important interactions among host, vector, pathogen and the rest of the holobiont of TCD were characterized. The <i>holobiont</i> is defined as the whole multitrophic community of organisms—including <i>J. nigra</i>, microinvertebrates, fungi and bacteria—that interact with one another and with the host.</p> <p>Our findings indicate that interactions among host, vector, pathogen, secondary pathogens, novel microbial communities, and novel abiotic environments modulate the severity of TCD in native, non-native, and managed and unmanaged contexts. Prevailing climatic conditions favor reproduction and spread of <i>G. morbida</i> in the western United States due to the effect of wood moisture content on fungal competition. The microbiome of soils, roots, and stems of trees and seedlings grown outside the host native range harbor distinct, lower-diversity communities of bacteria and fungi compared to the native range, including different communities of beneficial or pathogenic functional groups of fungi. The pathogen <i>G. morbida</i> was also associated with a distinct community of microbes in stems compared to <i>G. morbida</i>-negative trees. The soil microbiome from intensively-managed plantations facilitated positive feedback between <i>G. morbida</i> and a disease-promomting endophytic <i>Fusarium solani</i> species complex sp. in roots of <i>J. nigra</i> seedlings. Finally, the nematode species <i>Bursaphelenchus juglandis</i> associated with <i>P. juglandis</i> synergizes with <i>G. morbida</i> to cause foliar symptoms in seedlings in a shadehouse; conversely, experiments and observations indicated that the nematode species <i>Panagrolaimus</i> sp. and cf. <i>Ektaphelenchus</i> sp. could suppress WTB populations and/or TCD outbreaks.</p> <p>In conclusion, the composition, function, and interactions within the <i>P. juglandis</i> and <i>J. nigra</i> holobiont play important roles in the TCD pathosystem. Managers and conservationists should be aware that novel associations outside the host native range, or in monocultures, intensive nursery production, and urban and low-humidity environments may favor progression of the disease through the effects of associated phytobiomes, nematodes, and climatic conditions on disease etiology. Trees in higher diversity, less intensively managed growing environments within their native range may be more resilient to disease. Moreover, expatriated, susceptible host species (<i>i.e.</i>, <i>J. nigra</i>) growing in environments that are favorable to novel pests or pest complexes (<i>i.e.</i>, the western U.S.) may provide connectivity between emergent forest health threats (<i>i.e.</i>, TCD) and native host populations (<i>i.e.</i>, <i>J. nigra</i> in its native range).</p>