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dc.contributor.authorLiu, Shuangshuang
dc.contributor.authorBradford, Kent J
dc.contributor.authorHuang, Zhenying
dc.contributor.authorVenable, D Lawrence
dc.date.accessioned2020-02-04T19:56:20Z
dc.date.available2020-02-04T19:56:20Z
dc.date.issued2019-12-15
dc.identifier.citationLiu, S., Bradford, K. J., Huang, Z., & Venable, D. L. (2020). Hydrothermal sensitivities of seed populations underlie fluctuations of dormancy states in an annual plant community. Ecology. https://doi.org/10.1002/ecy.2958 ‌en_US
dc.identifier.issn0012-9658
dc.identifier.pmid31840254
dc.identifier.doi10.1002/ecy.2958
dc.identifier.urihttp://hdl.handle.net/10150/636909
dc.description.abstractPlant germination ecology involves continuous interactions between changing environmental conditions and the sensitivity of seed populations to respond to those conditions at a given time. Ecologically meaningful parameters characterizing germination capacity (or dormancy) are needed to advance our understanding of the evolution of germination strategies within plant communities. The germination traits commonly examined (e.g., maximum germination percentage under optimal conditions) may not adequately reflect the critical ecological differences in germination behavior across species, communities, and seasons. In particular, most seeds exhibit primary dormancy at dispersal that is alleviated by exposure to dry after-ripening or to hydrated chilling to enable germination in a subsequent favorable season. Population-based threshold (PBT) models of seed germination enable quantification of patterns of germination timing using parameters based on mechanistic assumptions about the underlying germination physiology. We applied the hydrothermal time (HTT) model, a type of PBT model that integrates environmental temperature and water availability, to study germination physiology in a guild of coexisting desert annual species whose seeds were after-ripened by dry storage under different conditions. We show that HTT assumptions are valid for describing germination physiology in these species, including loss of dormancy during after-ripening. Key HTT parameters, the hydrothermal time constant (θHT ) and base water potential distribution among seeds (Ψb (g)), were effective in describing changes in dormancy states and in clustering species exhibiting similar germination syndromes. θHT is an inherent species-specific trait relating to timing of germination that correlates well with long-term field germination fraction, while Ψb (g) shifts with depth of dormancy in response to after-ripening and seasonal environmental variation. Predictions based on variation among coexisting species in θHT and Ψb (g) in laboratory germination tests matched well with 25-yr observations of germination dates and fractions for the same species in natural field conditions. Seed dormancy and germination strategies, which are significant contributors to long-term species demographics under natural conditions, can be represented by readily measurable functional traits underlying variation in germination phenologies.en_US
dc.language.isoenen_US
dc.publisherWILEYen_US
dc.rightsCopyright © 2019 by the Ecological Society of America.en_US
dc.subjectafter-ripeningen_US
dc.subjectdormancyen_US
dc.subjectgermination nicheen_US
dc.subjectgermination phenologyen_US
dc.subjecthydrothermal time modelen_US
dc.subjectplant functional traiten_US
dc.titleHydrothermal sensitivities of seed populations underlie fluctuations of dormancy states in an annual plant communityen_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Dept Ecol & Evolutionary Biolen_US
dc.identifier.journalECOLOGYen_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.journaltitleEcology
dc.source.beginpagee02958
dc.source.endpage
refterms.dateFOA2020-02-04T19:56:20Z
dc.source.countryUnited States


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