Cheadle Center for Biodiversity and Ecological Restoration

Bee body size affects their ability to forage, carry pollen, and adapt to environmental conditions. Body size is influenced by environmental factors such as food availability and temperature. As these conditions continue to change, it is crucial to accurately measure body size and determine whether particular body measurements can predict size variation across and within species. Measuring body size is challenging as bees are often small and may be missing body parts. In this study, we examined ten different bee species across three different families. We compared body and wing measurements as proxies for dry weight for both damaged and non-damaged bees. We used fitted vs. residuals and QQ plots to test for normality and linearity, along with performing simple linear regression using R version 4.4.0. We determined that intertegular distance (ITD) and head width to be the most significant predictors of dry weight across species and within most species, suggesting that these measurements may be used to accurately estimate dry weight. We also found that intertegular distance significantly predicted dry mass even in specimens missing body parts, suggesting that this measurement is somewhat robust to specimen damage. These findings contribute to the understanding of the relationship between dry weight and body measurements and provide guidelines for accurately estimating body size within and across species, for a range of applications in ecological research and conservation efforts. Presented at UC Santa Barbara CSEP Summer Colloquium

This study investigates the impact of anthropogenic land use on the body size of bees across 18 different species. Adult bee body size, primarily influenced by developmental nutrition, is significantly affected by the availability of floral resources. Developed land often has reduced floral diversity and density is hypothesized to produce smaller bees due to limited food resources. Specimens from the UCSB Invertebrate Zoology Collection were categorized based on their collection sites into three land use types: developed, agricultural, and forest using USGS National Land Cover Database. Measurements of head width, intertegular distance (ITD), and dry mass were taken to assess body size. A body size index was calculated as the average of these measurements. Analysis of Variance (ANOVA) were done in Python version 3.12.4. Results indicate that bees from agricultural habitats are significantly larger than those from developed and forest habitats across all metrics (head width, ITD, dry mass, and body size index). These findings highlight the influence of landscape changes on bee functional traits, providing essential insights into the ecological consequences of land use on bee health.

This poster was presented at the UCSB CSEP summer colloquium 2024.

This project aims to mitigate the critical decline in bee populations, essential for crop pollination and food security. With a shortage of taxonomic specialists to identify the vast array of bee species, the project's goal is to enhance the monitoring of population changes through an automated classification system. Utilizing a dataset of bee wing images, the project aims to develop a computational pipeline to identify species based on their unique wing vein patterns. This approach not only supports bee conservation efforts but also expands our understanding of complex geometric variations in nature, offering wider applications in biological research.

This poster was presented at the UCSB Data Science Capstone showcase in 2024.

This poster was presented at the California Invasive Plant Council 2023 Symposium, the Merced Vernal Pool and Grassland Reserve 10th Anniversary Symposium, and the 2024 California Society for Ecological Restoration conference.

The California Rapid Assessment Method (CRAM) is a level 2 landscape quality surveying method. Wetlands are rated on their buffer/landscape context, hydrology, physical structure, and biotic structure. Certified practitioners are trained and calibrated such that CRAM scores are standardized throughout the state. This allows for state-wide comparisons and analysis of wetlands across sites, projects, and managers. Here, we present comparisons of CRAM scores for natural and restored vernal pool wetlands across the state. This allows us to assess how restoration projects compare to natural ecosystems, and also allows us to target specific regions or landscape metrics for future restoration.

Species-level identification of insects is often difficult and can limit ecological studies, particularly those assessing insect biodiversity. Wing venation characteristics are fundamental for defining and classifying insects. Bees (Hymenoptera: Apoidea) have relatively conserved wing characteristics at the family, genus, and species level, but the patterns between groups remain poorly understood. In this study, we employed geometric morphometrics to assess variation in wing venation across bees taxa. Geometric morphometrics allows for detailed shape analysis of wing structure, which may provide insights into evolutionary relationships. By digitally landmarking nine homologous wing vein characters of a diverse sample of bees, we quantified and compared phenotypic variation across several recognized species, genera, and families in order to assess whether the resulting morphological clusters reflect evolutionary divergence. Preliminary results demonstrate the ability to differentiate species within a genus and even among populations, testifying to a high level of precision. We are currently investigating the extent to which our groupings based on morphometric data aligns with established phylogeny and the practical implications. This study assesses the potential of geometric morphometrics to infer the phylogenetic placement of indeterminate bee species based solely on wing vein patterns and provides an effective pathway for species identification. This classification method could accelerate research in pollinator conservation and ecology by offering an accessible alternative means for bee identification and ecological morphotype hypotheses.

This poster was presented at the UCSB Undergraduate Research Colloqium- 2024

The disparate global range of Plethodontid salamanders in the Batrachoseps subgenus Plethopsis is unique, and implicates perplexing historical biogeographic scenarios.  Using uncorrelated relaxed molecular clock methods and fossil-calibrated divergence estimates from Shen et al. (2016), we present a time-scaled phylogeny for the genus Batrachoseps in order to test hypotheses concerning the diversification of the subgenus Plethopsis.  Our estimated divergence time intervals detract support from a hypothesis that Batrachoseps robustus diverged as the flow of the Owens river changed course at ca. 3.2 Ma, as evidenced by sediment deposits at Searles Lake (Phillips, 2008).  Instead, our estimates support that diversification of the known Plethopsis species began earlier, in the late Miocene to early Pliocene, as extensional activity formed the proto-Owens Valley and led to ensuing hydrological and climatic changes, driving vicariance between populations in the proto-southern Sierra Nevada and Inyo Mountains.  Moreover, our estimates support a scenario wherein B. campi and B. wrighti diverged in the Pliocene as ancestral populations of B. wrighti expanded northward to Oregon via a corridor of relatively mesic habitat in the western Great Basin.

North Campus Open Space (NCOS) is a large-scale restored habitat in the historic Devereaux slough in Goleta, California. Forty-four plywood cover boards measuring 3’ x 4’ were dispersed across NCOS in four distinct habitats (grassland, woodland, coast sage scrubland, and marshland). For over 4 years, researchers have tracked the presence of animals under these coverboards, mostly small rodents and herpetofauna, following the area’s habitat restoration. Patterns of their distribution are increasingly understood as surveys continue; however, little is known about the patterns of invertebrate distribution and the factors influencing them. Invertebrates provide essential ecosystem functions as they break down organic matter, recycling nutrients back into the ecosystem, and they can serve as insightful bioindicators of ecosystem health. Previous studies documented that in agricultural systems, mean annual precipitation and soil pH are the largest predictors of soil invertebrate richness. In this study, we test whether these variables accurately predict patterns of invertebrate richness in a restored ecosystem. We focused on two diverse macroinvertebrate taxa, Coleoptera (beetles) and Arachnida (spiders). By collecting, curating, and identifying beetles and spiders under each coverboard we were able to establish what species reside in the various habitats. We took measurements of the soil pH under each board as well as the humidity in the interspace between the soil and the board as a proxy for mean annual precipitation. Our preliminary data suggest that soil pH and relative humidity partially contribute to the distribution of macroinvertebrates within habitats. However, other factors such as cohabitation, soil type, adjacent vegetation, or other factors involved in nutrient cycling, could have larger effects on the distribution patterns of these taxa.

This poster was presented at the UCSB undergraduate research colloquium 2024.

This poster was presented at the UCSB EEMB research symposium in 2024.

Seed predation by granivores limits plant survival and recruitment of new germinates, especially of rare species limited by small populations and increasing pressure from nonnative invasives. The relationship between granivores and native flora at the Dune Protected Area in Callandar, CA is currently shifting away from historic patterns; Nipomo  mesa lupine (L. nipomensis) and other dune stabilizing plant species have been impacted by the habitat-wide colonization by the invasive perennial veldt grass (Ehrharta calycina). Current veldt management practices prevent the use of herbicide to control the grass within a 15-foot buffer of extant lupine populations. Understanding how dense stands of veldt grass may support increased populations of L. nipomensis seed predators can inform the management of veldt grass and the recovery of the endangered lupine. This study assessed seed predation through low profile boxes baited with L. nipomensis seeds and camera traps capturing both video and still images to compare seed predation rates relative to dense stands of veldt grass. Conservation implications were further assessed by considering the role of cages (fencing) in reducing seed predation.  We found that increased proximity to veldt grass modestly increased seed predation, and that uncaged bait stations lost the most seeds (~70% loss rates compared to ~15% in caged plots). The most common seed predators captured on camera were Heermann’s kangaroo rats, Dipodomys heermanni (found outside of cages and away from veldt grass), Deer mice, Peromyscus maniculatus (found outside of cages and adjacent to veldt grass), and California towhees (found within cages and away from veldt grass). Our results establish patterns of seed predation consistent with predicted results and emphasize potential vulnerability to seed predation in areas near veldt or areas unprotected by caging.

This poster was presented at the 2024 UCSB EEMB Research symposium.

Algae plays a crucial role in aquatic ecosystems, serving as both a primary producer through photosynthesis and a food source and habitat for macroinvertebrates, which in turn supports larger organisms. The abundance and composition of algae and macroinvertebrates are influenced by environmental factors such as salinity, temperature, pH, and dissolved oxygen.

This ongoing study investigates the dynamics of a temporary open-closed estuary in the North Campus Open Space Devereux Slough. Monthly water quality data and algae samples are collected from three sites to assess the types of algae present and variations in macroinvertebrate abundance. Preliminary findings reveal several genera of algae, including but not limited to Tribomena, Phormidium, Ulva, and Oscillatoria. Tribomena exhibits the highest abundance of macroinvertebrates and species diversity. 

These findings have enabled a more targeted exploration into local microalgal salinity tolerance, primarily through measurements of algal cell wall density, extent of motion, and color in response to regularly increasing salt concentration. Algae samples were collected from Phelps Bridge and introduced to a controlled aquarium environment in which oxygen and temperature levels were kept relatively constant, while 0.25 ppt of salt was introduced to the system every three days over the course of seven weeks. After each addition, the cell structures and behavior of the algae were examined with microscopy. This yielded results aligning with expectations of algal health deterioration with higher salinity. This research highlights the complex interactions between algae, macroinvertebrates, and environmental factors in estuarine ecosystems.

Wing venation characteristics are fundamental for defining and classifying insects. In bees these characteristics are relatively conserved, but the patterns between groups remain poorly understood. We employed geometric morphometrics to assess variation in wing venation across bees taxa. Geometric morphometrics allows for detailed shape analysis of wing structure, which may provide insights into evolutionary relationships. By digitally landmarking homologous wing vein characters of a diverse sample of bees, we quantified and compared phenotypic variation in order to assess whether the resulting morphological clusters reflect evolutionary divergence and align with established phylogeny. This study assesses the potential of geometric morphometrics to infer the phylogenetic placement of indeterminate bee species based solely on wing vein patterns and provides an effective pathway for species identification.

Presented at the UCSB EEMB Undergraduate Research Symposium 2024