Скачать или смотреть San Diego Botanic Garden July 2023 Science Seminar Series: Jim Bartel

Join us each month as plant science and conservation efforts are presented by San Diego Botanic Garden’s staff, research associates, colleagues, and guest speakers. This month we will feature Jim A. Bartel, who continues his more than 40 years of botanical research on the genetics, ecology, and taxonomy of western or New World cypresses (Hesperocyparis) and their close allies. In a follow-up to a molecular phylogenetic studies that identified two distinct genetic clades (Arizonica and Macrocarpa) within Hesperocyparis, Jim and a colleague began a study in the fall 2016 of more than 40 naturally occurring populations within the Macrocarpa clade and its 6 species. Apart from genetic sampling and photographic documentation, other observations were made simultaneously on the status and extent that the sampled groves had been affected by fire since 1900.

In this presentation, Jim will talk about the varying effects of increasing fire frequency and related climate change impacts to the studied cypress groves. The widespread Sargent cypress (Hesperocyparis sargentii) had only one of the sampled populations impacted by fire, the type locality by the 2018 River Fire, while the other sampled large stands have been fire free for decades (Cedar Mountain, Cypress Mountain, and Red Mountain in northern Mendocino County). Jim will explain that while the species that grow on the immediate coast have been unaffected recently by fire (H. goveniana, H. macrocarpa, and H. pygmaea), all five groves of the more interior Santa Cruz cypress (H. abramsiana) burned in whole or in part since 2008. Though a portion of the largest grove and another population of Piute cypress (H. nevadensis) have never burned in recorded history, the remaining sampled groves or grove portions have burned at least in part since 2010, including the Cane Creek grove in 2019.