Innovation in California Herbaria and Specimen Records Use
Friday, October 21 at 8:00-9:40 am, Donner Room
*note alternate instance of this session – Thursday at 10am
Session Description: This session is intended to include an array of presentations around the transformation of herbaria in the digital age, such as: new research conducted using specimen data, educational and outreach innovations undertaken by herbaria around digitization projects, progress made on the ethical, technical challenges presented by the digital age.
Session Chairs: Alison Colwell (UC Davis Center for Plant Diversity, Davis, CA, USA) and Jenn Yost (California Polytechnic State University, San Luis Obispo, San Luis Obispo, CA, USA)
11.1 Harnessing the power of inadvertent collecting
Alison Colwell (UC Davis Center for Plant Diversity Herbarium, Davis, CA, USA), Prof. Emily Meineke (Dept. of Entomology, Davis, CA, USA), David Eng (Dept. of Entomology, Davis, CA, USA)
Massive digitization efforts have brought attention to the potential of herbarium specimens as repositories of unique, large-scale datasets demonstrating plant interactions with commensals, symbionts, pathogens, and parasites. While herbarium specimens could powerfully enhance the study of changing insect interactions over decades to centuries, biases associated with collector and curator preferences need to be evaluated. Such biases may add noise to analyses derived from data collected from specimens, possibly introducing systematic biases across the very axes that researchers aim to investigate. As an example, herbarium specimens are increasingly harnessed for investigating the effects of climate on insect damage to plants. We tested for systemic biases in herbivory data gathered from herbarium specimens across two axes of interest to global change ecologists: taxa and time, using volunteers making collections in a controlled environment. We found that while collectors uniformly try to minimize herbivory, herbarium specimens reliably capture herbivory differences between species and across phylogenetic groups. In a second survey, we revisited a historical set of herbarium specimen vouchers from study of herbivory on oaks collected by entomologist Ian Pearse, and found that herbarium specimens can indeed capture trajectories of herbivory over decades. This pair of studies adds to the pool of testing needed to make herbarium specimens into reliable sources of herbivory data for expanding our understanding of plant-insect interactions and how they respond to anthropogenic change.
11.2 Region-specific phenological responses to climate and climate change in Streptanthus tortuosus (Brassicaceae)
Natalie LR Love (California Polytechnic State University; University of California, Santa Barbara, Santa Barbara, CA, USA), Susan Mazer (University of California, Santa Barbara, Santa Barbara, CA, USA)
Forecasting how species will respond phenologically to future changes in climate is a major challenge. Many studies have focused on estimating species- and community-wide phenological sensitivities to climate to make such predictions, but sensitivities may vary within species, which could result in divergent phenological responses to climate change. We used 743 herbarium specimens of the mountain jewelflower (Streptanthus tortuosus, Brassicaceae) collected over 112 years to investigate whether individuals sampled from relatively warm vs. cool regions differ in their sensitivity to climate and whether this difference has resulted in divergent phenological shifts in response to climate warming. During the past century, individuals sampled from warm regions exhibited a 20-day advancement in flowering date; individuals in cool regions showed no evidence of a shift. We evaluated two potential drivers of these divergent responses: differences between regions in (1) the degree of phenological sensitivity to climate and (2) the magnitude of climate change experienced by plants, or (3) both. Plants sampled from warm regions were more sensitive to temperature-related variables and were subjected to a greater degree of climate warming than those from cool regions; thus our results suggest that the greater temporal shift in flowering date in warm regions is driven by both of these factors. Our results are among the first to demonstrate that species exhibited intraspecific variation in sensitivity to climate and that this variation can contribute to divergent responses to climate change. Future studies attempting to forecast temporal shifts in phenology should consider intraspecific variation.
11.3 When do California plants flower and seed? Insights into plant phenology from new digital tools
Katie Pearson (California Polytechnic State University, San Luis Obispo, San Luis Obispo, CA; Arizona State University, Tempe, AZ, USA), Natalie Love (California Polytechnic State University, San Luis Obispo), Tadeo Ramirez Parada (University of California, Santa Barbara), Susan Mazer (University of California, Santa Barbara), Jenn Yost (California Polytechnic State University, San Luis Obispo)
The Consortium of California Herbaria’s CCH2 data portal is a publicly accessible, online database of specimens from herbaria in California and beyond. The portal provides foundational data on the spatiotemporal distributions of California plants, and it now includes tools for recording and searching phenological data (e.g., flowering or fruiting status) of its specimens. These tools enable users to discern and visualize when phenological events occur for certain taxa and how this may differ across the range of a taxon. Phenological data are critical for the timing of inventories, restoration activities, and seed collection, and understanding patterns of phenological events can provide insight into ecological and evolutionary processes that may be impacted by climate change. Here we demonstrate how and where these tools and their data can be accessed, and we summarize how these tools have already empowered novel research on the effects of climate change on California plants using a recent case study of the California poppy (Eschscholzia californica Cham.).
11.4 A morphometric analysis of western sword fern (Polystichum munitum) pinnae and pinnae scales across the coast redwood forest ecological gradient
Lacey Benson (San Jose State University, San Jose, CA, USA)
Ferns are an integral component of biodiversity and productivity in the coast redwood understory and canopy. Given that summer fog is expected to decrease and winter precipitation patterns are predicted to change it is vital to understand the role of microclimates and adaptation strategies utilized by ferns in the coast redwood ecosystem in order to gauge how the distribution, community dynamics, and reproductive success of ferns will be affected in the coming decades. Researchers have found ferns display signs of shifting climate patterns through leaf traits such as number of fronds, size of fronds, foliar uptake capacity and leaf water retention. By studying morphological and physiological changes to ferns scientists can get a more rapid understanding of how community dynamics and slower growing species such as the coast redwood will be affected by future changes to climate. The aims of this study are (1) to compare western sword fern (Polystichum munitum or POMU) pinnae size traits (length, width, and length:width ratio) to environmental variables such as precipitation, fog frequency, and temperature; (2) to quantify pinnae scale density to compare with in situ climate data; and lastly (3) to collect, mount, and enter POMU specimens and redwood associate species into the Carl W. Sharsmith Herbarium at SJSU. To achieve these objectives, we will utilize digitized herbarium accessions as well as personal collections to measure pinnae in ImageJ and count scales on both pinna surfaces. Data will then be compared to latitude and in situ environmental variables. The results of this study will greatly inform our understanding of the landscape scale variety of morphological and physiological traits within POMU and add to previous research on POMU foliar water uptake capacity and leaf water retention abilities.
11.5 Herbaria contain a hidden treasure in aDNA for climate adaptation studies.
Lua Lopez (California State University, San Bernardino, San Bernardino, CA, USA), Patricia Lang (Stanford University, Stanford, CA, USA), Jesse Lasky (Pennsylvania State University, State College, PA, USA)When faced with environmental changes plant populations must migrate or adapt or they will go extinct. Thus, elucidating which features may confer adaptive potential is of great interest. In the actual climate change context, longstanding experiments tracking adaptive genetic changes are a pivotal element. However, these are almost non-existent because of the intrinsic challenge of maintaining a natural continuous long-term experiment. Inferences about past events are usually based on current patterns of genetic variation. However, these single time-point observations provide limited information on underlying evolutionary events because multiple processes can generate the same patterns. Plant historical records archived in herbaria offer a perfect alternative to carry out this type of study but obtaining DNA from ancient and/or historical specimens has proven to be, at best, challenging. Because of recent advances in ancient DNA retrieval techniques, aDNA genomics are experiencing an unprecedented attention allowing us the direct observation of past events and its evolution until present time. In this regard, my research focuses on what genetic changes have occurred in over 500 individuals collected from native populations of Arabidopsis thaliana during the last 250 years in response to climate changes and more specifically, to anthropogenic-caused environmental change. Additionally, I also investigate how those temporal genetic changes are associated with phenotypic traits scored from the herbarium vouchers. Although A. thaliana is not native to California, the research I have done with this model species has led to a new library preparation protocol for whole genome sequencing that applies to any species preserved in herbaria as well as the bioinformatic protocol to study genetic changes over time associated with environmental change.
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