Understanding the effects of fire on the Sonoran Desert is of critical importance as rising temperatures and changing weather patterns increase the frequency and size of wildfires. Seed banks are an important component in post-fire landscape recovery as the seeds that remain in the soil are an indicator of a landscape’s future trajectory. The purpose of this study is to determine the lasting impacts of fire on the soil seed bank of the Sonoran Desert and to identify potential concerns affecting post-fire recovery and restoration. The study site was located in the Arizona Upland division of the Sonoran Desert, Arizona, United States. Soil samples were collected from five burned sites with increasing time since fire, and five nearby unburned sites used as a control. A seedling emergence test was conducted to investigate the density and richness of the seed bank of burned and unburned sites. Seed densities and species richness for sites were calculated using germination results. Findings were analyzed using non-parametric analyses comparing changes in burned and unburned sites over time. Results found that burn status and time since fire had no significant impact on seed density. Graminoid and forb densities were statistically consistent across burn status and time since fire. While species richness was consistent across both plot types, burned samples typically had fewer species than unburned samples. Burned and unburned plots revealed a dominance of annual species with limited presence of woody perennials. While seed densities and species richness are relatively unchanged across burned and unburned sites over time, the lack of woody perennials in the seed bank raises concerns about landscape recovery trajectories in burned sites. These results suggest that restoration efforts focused on maintaining the presence of woody trees and shrubs in the landscape may have the most impact.

Urban wetland ecosystems provide myriad ecosystem services and are shaped by diverse social and ecological factors. In rapidly urbanizing parts of the desert Southwest, wetlands are especially vital. Across less than 60 km as it enters the Phoenix area, the Salt River is dammed, diverted, re-filled, clear-cut, restored, and ignored. This study documents how animal and plant communities in three perennially inundated reaches of the river changed over a decade under different social-ecological pressures. One wetland in the urban core is restored, another formed accidentally by human infrastructure, and the last is managed on the urban periphery. Surveys conducted since 2012 used point-count surveys to assess bird communities and visual encounter surveys to assess reptiles and amphibians. Plant communities were surveyed in 2012 and 2022 using cover classes. Between 2012 and 2022, accidental and restored wetlands close to the urban core displayed an increase in plant abundance, largely consisting of introduced species. While all sites saw an increase in plant species considered invasive by land management groups, both urban wetlands saw an increase in regionally native species, including plants that are culturally significant to local Indigenous groups. Reptile communities declined in richness and abundance in both urban sites, but birds grew in abundance and richness at the urban restored site while not changing at the urban accidental wetland. The non-urban site saw stable populations of both birds and herpetofauna. These trends in biotic communities reveal ecological tradeoffs under different management strategies for urban wetlands. These findings also create a portrait of wetland communities along a rapidly urbanizing arid river. As the Salt River watershed becomes more urbanized, it is important to establish a more empathetic and informed relationship between its plant and animal—including human—residents. To this end, these data were incorporated in a series of handmade paper artworks, crafted from the most abundant wetland plant species found at the study sites, harvested alongside local land management efforts. These artworks examine the potential of four common cosmopolitan wetland plants for papermaking, revealing the potential to align ecosystem management efforts with both materials production and fine arts. By using relief printmaking to visualize long-term ecological data, I explored an alternative, more creative and embodied way to engage with and visualize urban wetland communities. This alternate mode of engagement can complement ecological management and research to diversify disciplines and participants engaged with understanding and living alongside urban wetlands.

The nests of the Curve-billed Thrasher (Toxostoma curvirostre) were studied across the greater Phoenix area from 2020-2022 in order to assess any significant relationships between their composition and the composition of their environment. Nests were collected and measured, and the vegetation was surveyed to 100 m for potential nest material type. In the lab, nests were separated by material type and tallied. The dense cores of the nests received a 100-piece sampling, with the first hundred pieces plucked from the structure, sorted by type, and massed. Ordinary least squares (OLS) and binomial regression analyses were performed on the body tallies and their corresponding site tallies. Core material weights and their corresponding site tallies only received OLS regression analyses. Beta regression analyses were also performed on the mass proportions of core samples and their corresponding environmental tallies. OLS regression yielded a significant relationship between the spiny body material tally and its site tallies at 25 and 100 m. While failing the assumption of normality, the tally of barrel cactus in a nest body yielded significant p-values in OLS and binomial regression, as well as the Spearman’s correlation test, supporting a strong correlation with the 100m site tally. The tally of anthropogenic materials and the distance to the nearest man-made structure failed the test of normality, but yielded significant p-values in binomial regression and the Spearman’s correlation test. OLS regression of log anthropogenic tally and log distance to nearest structure failed normality but yielded a significant p-value as well. In beta regression analyses, only the spiny core mass proportion yielded a significant relationship at the 100 m site tally.

Bouteloua eriopoda (Torr.) Torr., also known as black grama, is a perennial bunchgrass native to arid and semiarid ecosystems in the southwestern region of North America. As a result of anthropogenic climate change, this region is predicted to increase in aridity and experience more frequent extreme drought and extreme wet years. This change in precipitation will no doubt affect black grama; however, few studies have investigated how the specific structural components of this grass will respond. The purpose of this study was to examine the effects of years since start of treatment and annual precipitation amount on tiller and stolon densities, and to test for interaction between the two predictor variables. Additionally, the effects of annual precipitation on ramets and axillary buds were investigated. By using 36 experimental plots that have been receiving drought, irrigated, or control treatments since 2007, tiller density was the most responsive component to both annual precipitation amount and years since start of treatment. Years since start of treatment and annual precipitation amount also had a statistically significant interaction, meaning the effect of precipitation amount on tiller density differs depending on how many years have passed since treatments began. Stolon density was the second-most responsive component; the predictor variables were found to have no statistically significant interaction, meaning their effects on stolon density are independent of one another. Ramet density, ramets per stolon, and axillary bud metabolic activity and density were found to be independent of annual precipitation amount for 2021. The results indicate that multiple-year extreme wet and multiple-year extreme dry conditions in the Southwest will both likely reduce tiller and stolon densities in black grama patches. Prolonged drought conditions reduced tiller and stolon production in black grama because of negative legacies from previous years. Reduced production during prolonged wet conditions could be due to increased competition between adjacent plants.

In the Spring of 2021, I had an internship with Butterfly Wonderland, where I worked in their conservatory and learned about the ecological relationship between butterflies and plants. As part of my internship, I encouraged guests to learn more about gardening for pollinators. That experience inspired me to complete a creative project in which I would design a butterfly garden of my own that would highlight wildlife benefits and be accessible to people like myself, who do not have their own gardens and don’t have hundreds of dollars to spend on gardening supplies. In collaboration with Dr. Gwen Iacona and Liz Makings (director and second committee member respectively), I planted accessible gardens. By “accessible”, I mean that the gardens were affordable (less than $100 total), included free/upcycled materials wherever possible, and are easily replicable. For my project, I made ‘prototypes’ of the gardens by using freely available seeds and soil sources, germinating those seeds in the ASU Greenhouses, and documenting my process so that it could be shared. Freely available seeds and other materials came from a variety of places including the ASU seed library, local Free Little Libraries, donations, as well as purchases from on campus fundraisers. The germination and growth of seeds in the ASU greenhouse took place over the course of several months in the fall and winter. That documentation has taken on several forms, including an informational pamphlet about wildlife gardening and flyers specific to locally available plant seeds. I find this to be very important because my end goal was to create something that other students or people in our community can use in a practical way. I wanted to create something that will bring gardening into the homes of people who didn’t think they were able to participate in it.

The Phoenix Zoo, also known as the Arizona Center for Nature Conservation (PZ), is an Association of Zoos and Aquariums (AZA) accredited zoological institution and among largest-nonprofit, privately-owned zoos in the United States (Smith, 2020). Located within Papago Park in Phoenix (Maricopa County), Arizona, adjacent to the Desert Botanical Garden (DES), the two combine to bring environmental awareness to the Phoenix Metropolitan Region. While the DES specializes in botanical presentation, the ACNC focuses on zoological education. Whereas the flora of DES is well known, that of ACNC has yet to be completely documented. Given its role as a center for public engagement and education, documenting and mapping the floristic diversity of the Phoenix Zoo provides updated botanical information and occurrence records, an important component of understanding biodiversity for the Phoenix area. Between the fall of 2017 and the Spring of 2021, the grounds of the ACNC were walked within the 2-mile perimeter and surrounding exterior within Papago Park. Plant specimens and photographs were collected and archived for later identification using various botanical keys. Species names were verified through updated botanical databases such as Tropicos.org and worldfloraonline.org and compiled into a checklist. A total of 706 species have been identified, and of those 548 specimens have been collected as specimen vouchers. Of these, 120 are of taxa known to be native to the Phoenix Salt River Valley. While approximately 79 of those previously listed taxa native to Papago Park were either not found during this study or were extirpated from the grounds of the ACNC during urbanization of the region. There are 586 exotic taxa, some are common cultivars, while others are new to the region. Data for this survey is publicly available on SEINet, a regional network of North America herbaria (https://swbiodiversity.org/seinet/), as georeferenced voucher specimens, human observations, and photographs. Data is also partially duplicated through the iNaturalist platform (iNaturalist.com).

Echinomastus erectocentrus (J.M. Coulter) Britton & Rose var. acunensis (W.T. Marshall) Bravo, the Acuña cactus, is a small, single-stemmed spherical cactus with a restricted distribution across the Sonoran Desert in southern Arizona and into northern Sonora, Mexico. Populations of E. erectocentrus var. acunensis are threatened by loss of habitat, climate change, predation, and border related impacts. Due to the severity of these threats and shrinking population sizes, E. erectocentrus var. acunensis was federally listed as endangered by the United States Fish and Wildlife Service in 2013. The varieties of Echinomastus erectocentrus, E. erectocentrus var. acunensis and E. erectocentrus var. erectocentrus (J.M. Coulter) Britton & Rose, share many morphological characteristics that make them difficult to distinguish from one another. Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter, a presumed closely related species, also has a high level of morphological overlap that further complicates our understanding of species boundaries and detailed morphological data for these three taxa indicate a geographical cline. The goal of this project is to document the genetic diversity within and among populations of E. erectocentrus var. acunensis, and its close relatives E. erectocentrus var. erectocentrus and E. johnsonii. To accomplish this, populations of E. erectocentrus var. acunensis, E. erectocentrus var. erectocentrus, E. johnsonii and the outgroup Echinomastus intertextus (Engelm.) Britton & Rose were sampled. Deoxyribonucleic acid (DNA) was extracted, and data were collected for nine microsatellite regions developed specifically for these taxa, and two microsatellite regions developed for Sclerocactus, a closely related genus. Standard population genetic measures were used to determine genetic variation and structure, and this observed genetic differentiation was then compared to the current morphological understanding of the group. These analyses help improve the knowledge of the genetic structure of E. erectocentrus var. acunensis and inform the understanding of species boundaries and evolutionary relationships within the group by revealing genetic distinctiveness between all four taxa and hybrid populations between the two varieties. This information also reveals patterns of gene flow and population locations that have the highest conservation priority, which can be incorporated into efforts to conserve and protect this endangered species.

Las Cienegas National Conservation Area (LCNCA), located in southeastern Arizona, is a place of ecological and historical value. It is host to rare native, threatened and endangered fauna and flora. as well as the site of the oldest operating ranch in the state. The first chapter of this thesis provides a preliminary flora of vascular plants at LCNCA assembled from field collections, photographs and herbarium specimens, and published through the online database SEINet. This preliminary flora of LCNCA identified 403 species in 76 families. Less than 6% of the flora is non-native, perennial forbs and grasses are the most abundant groups, and over a third of species in the checklist are associated with wetlands. LCNCA has been the target of adaptive management and conservation strategies to preserve its biotic diversity, and results from this study will help inform actions to preserve its rare habitats including cottonwood willow forests, mesquite bosques, sacaton grasslands, and cienegas. The second chapter investigates poorly understood aspects of the life history of the endangered Huachuca Water Umbel (Lilaeopsis schaffneriana subsp. recurva. Apiaceae) (hereafter HWU). This wetland species occurs in scattered cienegas and streams in southeastern Arizona and northern Sonora, Mexico. Three studies were conducted in a greenhouse to investigate seed bank establishment, seed longevity, and drought tolerance. A fourth study compared the reproductive phenology of populations transplanted at LCNCA to populations transplanted at urban sites like the Phoenix Zoo Conservation Center and the Desert Botanical Garden (DBG). Results from the greenhouse studies showed that HWU seeds were capable of germinating 15 years in a dormant state and that HWU seeds are present in the seed banks at sites where populations have been transplanted. Also, greenhouse experiments indicated that colonies of HWU can tolerate up to 3 weeks without flowing water, and up to 2 weeks in dry substrate. Transplanted populations at LCNCA monitored in the fourth study produced a higher abundance of flowers and fruit relative to urban sites (i.e. DBG) suggesting that in-situ conservation efforts may be more favorable for the recovery of HWU populations. Findings from these studies aim to inform gaps in knowledge highlighted in USFWS recovery plan for this species.

Urbanization has global impacts on ecosystems and transforms landscapes into man-made constructs. As urbanization continues to encroach on landscapes it is important to understand its effects on biodiversity and the long term health of our planet. In terms of species numbers, urban floras can actually be more diverse than their native surroundings and I am specifically interested in the species that have been introduced into these settings, their provenance, and the historical circumstances of how they were established. I collected plants in the alleys of Tempe, Arizona over a 5 month period to get a baseline understanding of the local diversity; then collected data from herbarium records using SEINet http://swbiodiversity.org/seinet/ to trace the origin of the introduced species and the first record of their appearance. I also used on-line information from the City of Tempe to investigate the relationship of land use change, development, and population growth to the introductions of some non-native plants. Finally, I used SIENet records to investigate the relationship of collection intensity throughout the decades to the introductions of some non-native plants. A total of 130 specimen were collected representing 83 different species from 32 different families. Most of the introduced species were from climates similar to Arizona. New occurrence records were spread out over the decades that Tempe has been around, and I was only able to weakly link them to the historical and collection intensity data. Knowing the biodiversity of an area can give clues into the ecosystem services that biodiversity provides, as well as management implications. Additionally, knowing the history of what is out there may give insights into what the biodiversity of the future may look like.