Seasonal changes in tissue-water relations for eight species of ferns during historic drought in California
| Autor: | Amanda M. Burns, Nicole A. Nakamatsu, Kaitlyn E. Sauer, Jarmila Pittermann, Breahna M. Gillespie, Stephen D. Davis, Helen I. Holmlund, Victoria M. Lekson |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Frond Climate Change Plant Science 01 natural sciences California 03 medical and health sciences Species Specificity Genetics Desiccation Ecology Evolution Behavior and Systematics Ecosystem Riparian zone geography geography.geographical_feature_category biology Ecology Phenology Niche differentiation Water Evergreen biology.organism_classification Chaparral Droughts 030104 developmental biology Habitat Ferns Fern Seasons 010606 plant biology & botany |
| Zdroj: | American journal of botany. 103(9) |
| ISSN: | 1537-2197 |
| Popis: | PREMISE OF THE STUDY California experienced severe drought between 2012 and 2016. During this period, we compared seasonal changes in tissue-water relations among eight fern species in the Santa Monica Mountains of southern California to elucidate differential mechanisms of drought survival and physiological performance during extreme water deficits. METHODS We monitored seasonal changes in water potential (Ψmd) and dark-adapted chlorophyll fluorescence (Fv/Fm), assessed tissue-water relations including osmotic potential at saturation and the turgor loss point (Ψπ, sat and Ψπ, tlp), and measured, for two evergreen species, xylem-specific and leaf-specific hydraulic conductivity (Ks and Kl) and vulnerability of stem xylem to water stress-induced embolism (water potential at 50% loss hydraulic conductivity, Ψ50). KEY RESULTS Species grew in either riparian or chaparral understory. The five chaparral species had a wider range of seasonal water potentials, root depths, and frond phenological traits, including one evergreen, two summer-deciduous, and two desiccation-tolerant (resurrection) species. Evergreen species were especially diverse, with an evergreen riparian species maintaining seasonal water potentials above -1.3 MPa, while an evergreen chaparral species had seasonal water potentials below -8 MPa. In those two species the Ψ50 values were -2.5 MPa and -4.3 MPa, respectively. CONCLUSIONS Observed differences in physiological performance among eight fern species reflected niche partitioning in water utilization and habitat preference associated with distinct phenological traits. We predict differential survival among fern species as future drought events in California intensify, with desiccation-tolerant resurrection ferns being the most resistant. |
| Databáze: | OpenAIRE |
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