Class
Article
College
S.J. & Jessie E. Quinney College of Natural Resources
Department
Wildland Resources Department
Faculty Mentor
Kari Veblen
Presentation Type
Poster Presentation
Abstract
As the earth’s climate warms many plant species are experiencing phenological stages (the timing of their seasonal life cycle events) earlier than they previously have. Dangers of phenological stages occurring earlier in the year include a greater risk of frost kill and the possibility of the speciation of already small populations, both of which could make species more susceptible to extinction. This research focused on determining if meadow forb species within Utah State University’s TW Daniel Experimental Forest (TWDEF) have experienced earlier phenology -specifically, earlier flowering dates- over the past 52 years. Historical phenological data was obtained from journals kept by past USU professor Dr. Theodore Daniel who recorded data from ten meadow plots from 1968-1972 and 1990-1995. Current phenological data was collected in the summer of 2020, following Dr. Daniel’s study design of visiting these plots once a week and recording the phenological stages of leaves, buds, flowers, and fruits/seeds on the species present in each plot. Climatic variables are represented by the number of degree days > 5°C in the spring. Flowering dates were converted to Julian days (1-365). Regression analyses of 36 frequently recorded species resulted in all but three species having significant effects of spring degree days > 5°C on Julian day of flowering. However, only seven species resulted in R2 values > 60% showing that Julian day of flowering can only be confidently predicted for a few species. This implies that spring degree days may not be the strongest climate variable contributing to flowering time for the majority of forb species in the TWDEF and that each species may be individually sensitive to different climate conditions. Presentation Time: Wednesday, 1-2 p.m.
Location
Logan, UT
Start Date
4-12-2021 12:00 AM
Included in
Pheonolgy and Climate Change in the TW Daniel Experimental Forest Meadow
Logan, UT
As the earth’s climate warms many plant species are experiencing phenological stages (the timing of their seasonal life cycle events) earlier than they previously have. Dangers of phenological stages occurring earlier in the year include a greater risk of frost kill and the possibility of the speciation of already small populations, both of which could make species more susceptible to extinction. This research focused on determining if meadow forb species within Utah State University’s TW Daniel Experimental Forest (TWDEF) have experienced earlier phenology -specifically, earlier flowering dates- over the past 52 years. Historical phenological data was obtained from journals kept by past USU professor Dr. Theodore Daniel who recorded data from ten meadow plots from 1968-1972 and 1990-1995. Current phenological data was collected in the summer of 2020, following Dr. Daniel’s study design of visiting these plots once a week and recording the phenological stages of leaves, buds, flowers, and fruits/seeds on the species present in each plot. Climatic variables are represented by the number of degree days > 5°C in the spring. Flowering dates were converted to Julian days (1-365). Regression analyses of 36 frequently recorded species resulted in all but three species having significant effects of spring degree days > 5°C on Julian day of flowering. However, only seven species resulted in R2 values > 60% showing that Julian day of flowering can only be confidently predicted for a few species. This implies that spring degree days may not be the strongest climate variable contributing to flowering time for the majority of forb species in the TWDEF and that each species may be individually sensitive to different climate conditions. Presentation Time: Wednesday, 1-2 p.m.