Speaker: Dr. Thomas Lee, UHH Geology Department
Title: Understanding Legacy Data and Developing Methods for Its Modern Usage
Abstract: Microseism are a ubiquitous feature recorded in seismic data, and exist on records going back for over a century. The main source of microseism is oceanic wave activity, and thus these seismic signals are sensitive to climate-sensitive phenomena such as increases in near-coastal wave-state and changes in the behavior of oceanic storms. The use of modern tools to rescue and digitize old seismic data allows modern quantitative analyses to be performed on them. Such analyses cast valuable light on the oceanic climate of the pre-satellite era. In particular, rescued legacy seismic data for 1936 through 1940 from Harvard, MA, are digitized into usable time series, and instrument corrections derived from earthquake doublets are applied to make comparisons to modern data. For historical and modern data, spectrograms are calculated, instrument responses removed, and microseism signals are extracted. The results are consistent with changes to tropical cyclone behavior in the North Atlantic for the last century; comparison of these results to those using only modern data illustrate the additional information that obtained from historical data. Extraction of such oceanic information from legacy seismic data provides valuable and irreplaceable quantitative data for future climate modeling and verification of hindcasts.
Speaker: Dr. Rebecca “Becky” Ostertag, UHH Biology Department
Title: Using plant functional traits to design forest restoration: an example of hybrid ecosystem restoration in an invaded Hawaiian lowland wet forest
Abstract: Plant functional recently have been suggested to be useful for restoration planning. The Liko Nā Pilina hybrid ecosystem experiment in Hilo, Hawaii, USA employed functional traits to design and test the suitability of different species combinations, using native and introduced (but non-invasive) species to meet the objectives of increased carbon storage, native biodiversity regeneration, and invasion resistance. In this case, restoration to a previous reference condition was not feasible. After several years of forest development, we evaluated community-level outcomes related to nutrient cycling: carbon, nitrogen, and phosphorus via litterfall, litter decomposition, outplant productivity, rates of invasion, and leaf litter arthropod species composition. We found that regardless of treatment, the experimental communities had low rates of nutrient cycling through litterfall relative to the invaded forest. In addition, which treatment did “best” depends on the metric being assessed. And we found that several surprises have altered ecological trajectories. This seminar will include a discussion of how hybrid ecosystems represent a paradigm shift, how potential metrics of belonging within an ecosystem may be developed, how new policies can support these efforts, and how the technique can be applied in other ecosystems. Although challenges remain, this study provides evidence that functional trait-based restoration approaches to carefully select species and to assess ecosystem functioning can achieve management goals.
Speakers: Dr. Karla McDermid and Dr. Grady Weyenberg, UHH Marine Science Department and UHH Math/Data Science Departments
Title: Not Always Slow and Steady: Hawaiian Green Turtles, a New Four-Parameter Bayesian Growth Model, and the Primitive Reptilian Condition
Abstract: Growth rates, essential for understanding the demographics of sea turtle populations, vary regionally because of variability in habitat quality, food availability, turtle density, environmental conditions, and genotype. In past decades, declining green turtle (Chelonia mydas) growth rates within the Hawaiian Archipelago raised concerns about long-term population stability. From 1976 to 2018, at Punalu‘u, Hawai‘i Island, a key foraging ground, green turtles were captured, measured for straight carapace length (SCL) and mass, and released. Recaptured individuals were monitored to assess growth rates and body condition index. Of 319 turtles captured, 186 were captured at least twice during the 42 years, and 127 were captured three or more times. The average annual growth rate was 1.16 ± 0.05 cm/year based on 178 individuals. A four-parameter Bayesian growth model predicts population asymptotes at 68.6 cm SCL, and that individuals will achieve close to their final size approximately 15 years after reaching 50 cm SCL. Punalu‘u green turtles displayed a size-specific sigmoidal growth rate function characteristic of the “primitive reptilian condition” seen in extant species of alligators, crocodiles, snakes, lizards, and land tortoises, as well as extinct non-avian dinosaurs. Growth trend analyses help develop management strategies and provide comparisons with green turtle populations locally and globally.
Speaker: Dr. Matthew L. Knope, UH Manoa School of Life Sciences
Title: Can combining genomics, geology, and ecology inform us about the predictability of evolution in Hawaiʻi?
Abstract: Patterns of convergent evolution demonstrate that organisms that live in similar environments often evolve similar traits, making evolutionary trajectories potentially predictable under certain conditions. In fact, evolution is so often deterministic on islands that the general suite of repeated outcomes in island phenotypes (compared to mainland relatives) has been termed the “Island Syndrome” and is well documented in both plant and animal lineages. However, random genetic mutations and chance historical events can introduce unpredictability, and it is not yet clear when and where evolution should be predictable, and when and where it should not. In addition to the island syndrome, one of the most most powerful hypotheses for the predictability of evolution in Hawaiʻi, and other oceanic island archipelagos around the world with a linear age progression of island formation, comes from the so-called “Progression Rule” which predicts a priori that dispersal, colonization, and speciation patterns will follow the age progression of the islands and is largely deterministic based on the geological history of the archipelago. In this seminar, I will ask if we can combine state-of-the-art genomic tools, with a well-constrained geologic history, and the study of eco-morphological variation in relation to habitat affinity to determine to what extend evolution in native Hawaiian plants is predictable? I will first present evidence from our recent reviews of global patterns in island evolution and then I will focus on our results from study of endemic Hawaiian Koʻokoʻolau plants (genus Bidens, family Asteraceae) and argue that both biogeographic and trait evolution patterns can be largely predictable, but that these insights are only made possible by the combination of fields that are often viewed as disparate. Lastly, I will conclude with some vision for the future and some acknowledgments for the 8.5 years I spent as a member of the UH Hilo ʻohana with the Biology Department and the TCBES graduate program.
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Speaker: Dr. Norman Arancon, UHH College of Agriculture, Forestry & Natural Resource Management
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Speaker: Sage Constantinou, UH Institute for Astronomy
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Speaker: Angela Bridges, Physics and Astronomy Department
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Speaker: Raymond Adams, Geology Department
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Speaker 1: Atlas Quarles, Physics and Astronomy Department
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Speaker 2: Raven Kromer, Physics and Astronomy Department
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