Comparing cold and drought tolerance in Sequoia sempervirens and Sequoiadendron giganteum at The Butchart Gardens and University of Victoria
| dc.contributor.author | Wardell, Stephanie | |
| dc.date.accessioned | 2026-05-05T15:26:12Z | |
| dc.date.available | 2026-05-05T15:26:12Z | |
| dc.date.issued | 2026 | |
| dc.description.abstract | Drought and cold are important limiting factors for plant growth that can impact health and visual appeal. For show gardens that often plant non-native species, it is important to understand a species’ tolerance of the conditions in a foreign range. The Butchart Gardens (TBG) in Victoria, B.C. is a National Historic Site of Canada that features many prominent, nonnative species. The two Californian Sequoia sempervirens (D. Don) Endl. planted on the property are important focal points within the Gardens, but this species is known to have poor cold and drought tolerance. Comparatively, the Sequoiadendron giganteum (Lindl.) Buchh. is a related Californian species that is commonly planted as an ornamental tree. Due to its cold and dry native range, the S. giganteum is considered to have greater drought and cold tolerance. Drought and cold tolerance of individuals of both species at TBG and the University of Victoria (UVic) were compared from late summer to early winter in the context of irrigation regimes to understand what differences in care may improve stress tolerance and growth of these trees. Drought tolerance was assessed biweekly from July to November with a Scholander pressure chamber using shoot samples of S. sempervirens and S. giganteum individuals at UVic and TBG. The cold tolerance of shoot samples from the same individuals were assessed from September to January using a freeze-induced electrolyte leakage test. The S. giganteum individuals developed cold tolerance more rapidly than S. sempervirens in autumn, likely a result of the S. giganteum adaptation to colder native ranges. The S. giganteum showed greater variability in drought stress through the sample period, but responded rapidly to changing water availability, unlike the S. sempervirens. The S. sempervirens individuals at UVic that received high amounts of irrigation were less drought stressed, indicating a reliance on irrigation to minimize drought stress and that individuals at TBG would benefit from increased irrigation. The sampled S. giganteum individuals were more drought and cold tolerant than the S. sempervirens, indicating that S. giganteum is more tolerant of the climate and weather in Victoria, B.C. Supervisor: Dr. Barbara Hawkins Honours Advisor: Dr. Terri Lacourse | |
| dc.description.reviewstatus | Unreviewed | |
| dc.description.scholarlevel | Undergraduate | |
| dc.identifier.uri | https://hdl.handle.net/1828/23801 | |
| dc.language.iso | en | |
| dc.publisher | Univserity of Victoria | |
| dc.subject.department | Department of Biology | |
| dc.title | Comparing cold and drought tolerance in Sequoia sempervirens and Sequoiadendron giganteum at The Butchart Gardens and University of Victoria | |
| dc.type | Honours thesis |