Alynn Martin - Botany 2010

Comparison of shrub and seed traits in two eastern California Sarcobatus populations. Co-authors: Rebecca E. Drenovsky and James Richards

Currently, taxonomic keys for California vegetation consider the genus Sarcobatus to be monospecific. However, some keys for other states or regions describe two species: Sarcobatus baileyi and Sarcobatus vermiculatus. We studied two populations of Sarcobatus; we hypothesize that one population represents S. vermiculatus and the other, S. baileyi. We compared shrub size (canopy volume and height) as well as fruit and seed traits (wing span, fruit length, fruit mass, fruit width, and percent of filled and unfilled fruit). Additionally, a subsample of the filled seeds was tested for germinability over a 20 day period. S. vermiculatus canopy height and volume were approximately 3 and 18.5-fold greater, respectively, than was observed for S. baileyi. In contrast, fruit and seed size for the S. baileyi population were much larger than for the S. vermiculatus population (as predicted based on species descriptions). S. baileyi fruits were, on average, 2-fold greater in mass than S. vermiculatus fruits. At the end of 20 days, 95.6% of S. vermiculatus seeds had germinated compared to 70.3% of S. baileyi. After 20 days 73% of S. vermiculatus seedlings were still alive, where as only 33.7% of S. baileyi seedlings survived. Our data on vegetative and reproductive traits suggest our populations match published species description for S. baileyi and S. vermiculatus, indicating a range expansion for S. baileyi into California. Additionally, germination and survivorship data suggest greater seed and seedling vigor in the S. vermiculatus population.

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Science & Technology

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• Alynn
• Martin
• Poster
• Botany
• 2010