Many widespread species show morphological variation across the unique habitats and climates they inhabit. For reptiles these morphological adaptations such as limb length or body depth are often correlated with habitat use and substrate types. Additionally, body size trends and the degree of pigmentation of reptiles, driven by thermoregulatory requirements, can correspond with the elevation and climate of populations. The blue ventral coloration of Western Fence Lizards (Sceloporus occidentalis) is a social signaling device and can also be a byproduct of increased melanism in response to thermally challenging environments. I used handheld and photo analysis methods to obtain head, body, and limb measurements in addition to quantifying belly and throat coloration from S. occidentalis in Washington State at a high elevation creek canyon population, a low elevation forest population, and a coastal beach population. I found that high elevation creek canyon lizards used rock perches 69% of the time, low elevation forest lizards used trees 67% of the time, and beach lizards perched on driftwood 97% of the time. Given this distinct substrate use, my morphological data suggests adaptations between populations. Rock lizards had the longest front fore-limbs which could result in increased running speed to optimally navigate their open rocky habitat. Forest lizards had the shortest front fore-limbs possibly due to reduced running reliance, as they specialized in arboreal perches. Driftwood lizards had the skinniest body condition that could optimize them for cracks in driftwood logs they relied on. Beach lizards had bluer and darker bellies than high elevation lizards, and bluer throat patches than the other two sites. My study suggests morphological and signalling adaptations among populations of S. occidentalis at the species’ geographic extreme, and demonstrates how habitat and climate selection pressures create intraspecific variation between populations of widespread species.

Trait-based plant ecology can serve as a means to better understand shifts in ecological strategies within plant communities, and how that affects greater ecosystem processes, such as productivity, before, during, and after a period of major climate change. Apart from modern anthropogenic activity regarding greenhouse gases, the most recent major global warming event was the Middle Miocene Climatic Optimum (MMCO). 17 14 million years ago, this event was a short aberration to a long-term cooling trend that lasted over the last 53 million years, with global temperature averages during the MMCO estimated to be about 8°C warmer than preindustrial averages. Through statistical analysis of leaf functional trait measurements such as leaf area, leaf perimeter, tooth count, and petiole width, we seek to help document an example of how global warming affected vegetation in Earth’s past by comparing changes in leaf traits across the MMCO to modern leaves. While studying Miocene fossil leaves, we are creating a modern leaf database to better interpret trait trends analyzed from samples. This is building off of a previous study’s global dataset to create a model that can be used as an analog for categorizing fossil plant assemblages into different vegetation types using functional trait distributions, as well as assist in trait trend interpretation. At this point in time, we have analyzed enough modern samples to be prepared to interpret trait trends preserved in MMCO leaf fossils. Our objective during the 2021-2022 school year will be to collect enough MMCO trait trend data to make stronger predictions about how modern plant communities will be affected by climate change.

California spot prawns (Pandalus platyceros) are an essential crustacean that supports fisheries along the West Coast. Very little is known about how climate change or food availability will impact their natural population in the Pacific Northwest. In this study we analyzed the mortality rate of prawns by Dungeness crabs (Metacarcinus magister) under different environmental conditions, including different water temperatures and food availability. These treatment groups included an increase in 2℉ from the water collected around San Juan island and food options included sponges (Ircinia strobilina), small native shrimp (Pandalus hypsinotis and Pandalus borealis), and a combination of sponges and shrimp, or starved. To implement these treatment groups, we used 6 water tanks containing 9 prawns and 3 crabs per tank and used an open water system. The experiment took place at the Friday Harbor Labs (San Juan Island, WA) for over a week. We found that Dungeness crabs primarily preyed on starved prawns, and prawns that fed on a combination of sponge and shrimp had the higher survival rate. We did not observe a significant effect of water temperature in any of the experimental groups. The research shows that prawn’s survivability depended on food availability and the variation of food. As the ocean changes due to climate change, the supply and variety of food will fluctuate every year and as a result, we can expect that the population of prawns will follow that trend in the Pacific Northwest.

The Serrasalmidae are a family of Neotropical freshwater fishes that includes carnivorous piranhas as well as their herbivorous relatives, the pacus. Pacu diets consist of leaves, stems, fruits, seeds, and algae, as well as insects, benthic invertebrates, plankton. Likewise, some piranha species are actually more omnivorous than carnivorous, feeding on fruits and seeds in particular and only to a lesser degree the fins and scales of other fishes. These diverse prey materials appear concomitant with diverse jaws and dentitions in both pacus and piranhas, suggesting that some species are ecomorphologically specialized for feeding on certain prey. We investigated how the pattern and tempo of feeding morphological specialization in herbivorous serrasalmids reflects the ecological diversity of their food resources. Pacu and piranha species were first categorized as either algivores, frugivores, folivores, phytophages, planktivores, or omnivores based on a meta-analysis of published gut content data. We used computed tomography (CT) scanning and morphometrics to describe the primary morphological axes of jaw and dental variation and any correlates these phenotypes may have with each species’ primary prey. We found significant differences in the occlusional offset, mechanical advantage, size and shape of the lower jaw among different diet guilds. Phytophages tended to have scissor-like dental occlusion, resembling piranhas more than other pacus. We also found significant differences in the rate of morphological evolution among different diet guilds, notably folivores had morphological rates over 40 times faster than that of planktivores, suggesting different selective regimes acting on each dietary guild.

Seed dispersal is an important component in the lifecycle of plants and aids in establishment of successive generations. Flowering plants have developed multiple ways of dispersing their progeny, including via wind, a strategy known as anemochory. In this presentation, I evaluate and compare wind dispersal potential of ecologically dominant grasses of the tropical savannas of Venezuela, Cerrado region in Brazil, and Serengeti region in Tanzania. Due to increased canopy cover in regions of the Cerrado and Venezuelan savannah relative to the Serengeti, I predict that conditions in the Serengeti would favor wind dispersal. Dispersal structures, known as diaspores, were sampled from specimens obtained from various herbaria. I measured falling velocity as a proxy for wind dispersal ability. I dropped diaspores from a chute and recorded them on high-speed video, which I analyzed to determine the speed of the falling specimen. My data analysis so far has consisted of obtaining and comparing average falling velocity for communities. Contrary to my original prediction, preliminary data suggest that wind dispersal is favored in the Cerrado. This may be due in part to the relative abundance of megafauna in the Serengeti, which would allow for seed dispersal via animal adhesion (epizoochory) or consumption (endozoochory). Diaspores using these dispersal mechanisms may not be as likely to have low falling velocities associated with anemochory. To further evaluate epizoochorous and endozoochorous potential, I am currently analyzing surface roughness using photographs of dispersal units.

It is commonly known that climate has shaped the photosynthesis type, height, and leaves of plants. However, it’s less commonly considered how plants affect climate. Major forest loss events have occurred due to deforestation and tree die off over the past decade. Prior research has shown that which types of plants grow where, and how those plants function, can impact climate both nearby and across larger spatial scales. Because this prior research has focused on theoretical simulations, it remains an open question if the impact of changes in plants can be seen in the real and very noisy climate system. We have compiled maps of actual forest loss as observed by satellites, to create initial conditions for simulation experiments in order to test if the impact of plants can be identified in observations of the atmosphere during the satellite era. We are assessing differences between simulations with and without forest loss to identify how that forest loss impacted the atmosphere. Using these identified impacts we will analyze if these same patterns are found in observed environmental conditions. This project aims to advance our understanding of the effect of forest loss on global climate, atmospheric circulation, and energy balances. Better understanding of this will help us to coordinate efforts to mitigate climate change by planting forests, while minimizing unwanted impacts. Additionally, this allows us to further predict and understand the impact of forest loss.