The Effects of Extreme Heat Events on Tree Health Measurements
Start Date
4-4-2023 4:00 PM
End Date
4-4-2023 6:00 PM
Abstract
As the climate continues to warm, the pacific northwest is experiencing more frequent extreme heat events, or more than 3 consecutive days with average temperatures above 35℃. Many assessments of tree health are performed during the summer and, due to the large sample size of these assessments, tree health data from the beginning of the summer and the end are often grouped together without consideration of the part of the season in which they were collected. It is hypothesized that, in the wake of extreme heat events, trees will experience damage that will lead to significantly different health assessments than those taken before the extreme health events. To assess the impact of extreme heat events on tree health, we took water potential, CO2 absorbance, and light adapted fluorescence measurements at three points over the summer that all occurred within one week of an extreme heat event. These measurements were taken on selected trees of four different species: Acer macrophyllum, Acer platanoides, Calocedres decurrens, and Thuja plicats. We found that, between June and August, average predawn water potential decreased significantly for all four species while average delta water potential remained constant. Similarly, average light-adapted fluorescence was relatively stable over time for all four species. Average CO2 absorbance decreased for both Acer species, but not to a point of definitive statistical significance and requires further study. These results indicate that certain measures of tree health remain stable in the wake of extreme heat events while others need to be reassessed for accuracy.
Subjects
Climate Change, Plant ecology
Persistent Identifier
https://archives.pdx.edu/ds/psu/40473
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.
The Effects of Extreme Heat Events on Tree Health Measurements
As the climate continues to warm, the pacific northwest is experiencing more frequent extreme heat events, or more than 3 consecutive days with average temperatures above 35℃. Many assessments of tree health are performed during the summer and, due to the large sample size of these assessments, tree health data from the beginning of the summer and the end are often grouped together without consideration of the part of the season in which they were collected. It is hypothesized that, in the wake of extreme heat events, trees will experience damage that will lead to significantly different health assessments than those taken before the extreme health events. To assess the impact of extreme heat events on tree health, we took water potential, CO2 absorbance, and light adapted fluorescence measurements at three points over the summer that all occurred within one week of an extreme heat event. These measurements were taken on selected trees of four different species: Acer macrophyllum, Acer platanoides, Calocedres decurrens, and Thuja plicats. We found that, between June and August, average predawn water potential decreased significantly for all four species while average delta water potential remained constant. Similarly, average light-adapted fluorescence was relatively stable over time for all four species. Average CO2 absorbance decreased for both Acer species, but not to a point of definitive statistical significance and requires further study. These results indicate that certain measures of tree health remain stable in the wake of extreme heat events while others need to be reassessed for accuracy.