Agata Buchwal-What Can Artic Shrub Tree Rings Tell Us?

Talk on 12/11/14

Agata Buchwal, a Fulbright Fellow from the University of Alaska in Anchorage wanted to know what can we learn from tree rings in Artic shrubs’ annual growth? She realized that the Artic is like a desert in that it has very little life and knowing what goes on there is crucial especially because the Artic has a great deal of control over the temperature due to it being one of the greatest sources of cold climate. The Artic is also a hotspot for global change and has evidence of site and species specific response to change. Both of these important phenomenon led her into researching her topic on annual growth patterns in Artic shrubs.

The Artic has “high resolution data and might be a proxy for validation and reconstruction on records”.  She noticed that from global warming, there has been an overall greening and warming effect which is affecting the flora, but how? In most cases, plants are active in growth only during the summer months due to more sunlight (for photosynthesis) and warmer temperature. She found that these dwarf shrubs are actually becoming more active in summer and winter months. She saw evidence of this in patterns in tree ring growth. Buchwal analyzed the tree rings of 10 shrubs, but noticed that she was getting little records from the rings and in fact, there were huge gaps in years with no growth. She decided to take a different approach to analyzing tree rings and instead dug deeper into the ground to analyze the rings under the surface, which is not standard procedure. When she analyzed those below surface rings, she found a more concrete story leading her to believe that dendrochronologist may be missing out on key information by not measuring and comparing above and below surface rings. Another main point she stressed in the talk was that the Artic needs to be explored further to get a better indication of climate change and how species and sites can adapt to change.

Agata still has many unanswered questions brought up while analyzing her results. How many observed shrubs actually have missing rings and how many are actually wedging rings? Due to current measurement methods, some rings may be misanalysed and counted as missing when they are really a wedge ring (partially missing ring). Are we measuring tree rings wrong and leaving out key data by not measuring rings from below the surface (roots)?

Up next on Agata’s academic journey is to look at our local Tundra in Alaska to see if there are similar tree rings results as found in Tundra of the Artic. She also wants to run experiments to see how plants will deal with a 2 degree Celsius increase in temperature (result of Global Warming). She suggests bringing many different diverse experts to help bring in different ideas to piece the story together. Buchwal also wants to know (in future research) how water is being dealt with based on the evidence from the tree rings, for example, can we see if the plants are using precipitation or melting permafrost more efficiently based on the ring evidence.