Phenological responses to climate in the Alberta native flora: Herbarium specimens reveal differential responsiveness between species in mesic and xeric habitats
Date
2019-03-01
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Abstract
The field of phenology focuses on investigating the timing of biological events and phases of life cycles. In the face of projected and ongoing climate change, there is a growing interest in detecting the effects of climate change on plant phenology. This research focuses on using herbarium specimens to examine whether 14 native plant species in Alberta have adjusted to changes in temperature and precipitation over the past century. I hypothesize that the soil moisture to which plants are exposed might affect their phenological responses and investigate: if herbaria collections contain evidence of phenological responses to climate in species of the Alberta flora, and if the responses are dependent on the typical moisture regime of their habitat. Plants from mesic and xeric habitats are compared in terms of phenological responses to air temperature and precipitation. The taxonomic relationships between the species were taken into account, by selecting a total of 14 species representing seven different angiosperm orders (one pair of species for each order). For each selected species, the preserved specimens available at three major Albertan herbaria collections were included in the study, if showing more than 50% of flower buds in anthesis (defined as peak flowering). The peak flowering date of each specimen, combined with the average temperature (or total precipitation) of the species’ mean flowering month and the three months prior, allowed the use of a regression model for the estimation of a species’ phenological responsiveness. The linear multiple regression analysis has revealed a significant responsiveness to temperature for six species from xeric habitats and one species from mesic habitats. My results suggest that species from xeric habitats have an average phenological responsiveness to temperature significantly more pronounced than species from mesic habitats. This tendency might be explained by the thermal properties of mesic habitats. The results indicate that for some species there is a set of environmental cues, as opposed to only one parameter, that governs flowering timing. The elucidation of the ecological implications involving plants phenological responses is key for the development of effective ecosystem conservation programs in the context of global climate change.
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Keywords
Phenology, Alberta plants, Climate change, Herbarium
Citation
Porto, C. (2019). Phenological responses to climate in the Alberta native flora: Herbarium specimens reveal differential responsiveness between species in mesic and xeric habitats (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.