Phenology

Long-Term Ecological Monitoring
The Generation OneTree Long-Term Ecological Monitoring research plot is located along the trail system on the University of Alaska Fairbanks campus, in an area known as the T-Field (see map). A ten-foot high moose- and snowshoe hare-proof fence surrounds the plot to protect the  trees from munching critters. The saplings were grown during the winter of 2010-11 in a growth chamber in the Institute of Arctic Biology research greenhouse on campus from seed collected during harvest operations for a wood milling study. We know a fair bit about the eight maternal trees from which the 144 seedlings in the research plot arose: The characteristics of the progeny can tell us a lot about the genetic diversity and resilience of our local birch resource, because the seedlings were reared to simulate the lengthening growing season in Interior Alaska. The season lengths were: three months (pre-1976 mean length), four ('normal' current conditions)   and five-month growing seasons (four in the last 10 years). We tested this to see how the initial growing season length affects long-term tree growth.

The first results from the plot really surprised us. An Introductory Ecology class from UAF used the plot for a lab. They found that the saplings that were grown for three months in the growth chamber had a shrubby appearance: with multiple main stems and branching primarily within the bottom third of the sapling's overall height. In contrast, the group of seedlings grown for five months in the growth chamber looked like mature trees: the predominant branching occurred in the middle third of the tree, with the bottom branches having been shed. This correlates well with what we'd observed initially in the growth chamber: the five-month group completed two full growing seasons before being placed into the dormancy conditions that heralded the end of their first year of growth.

This summer OneTree was able to undertake an intensive phenology study to help understand the possible impacts of climate change and a lengthening growing season. Every other day over the course of the summer, we documented the length of the apical (leader) stem of 70 trees in the T-field. Relating these measurements to the ecological conditions like temperature, rainfall, and day length will help us understand how birch tree growth is affected at different times during the growing season.

After five years of growth, we are beginning to see trends, and are actively researching the birch trees. We will be recruiting volunteers to help us in summer 2016 to continue the phenology study. If you are interested, please contact us! As director Jan Dawe would say, "Each of these trees has a story to tell!"

Classroom Connection: "How do plants and animals tell time?"
STEAM Curriculum Unit coming soon!