Researchers Forecast How Trees Will React to Rapid Climate Change by Studying Chilly Pocket Environment Near Glacier Snouts in Alaska

According to the authors of a new 120-year case study of a quickly advancing and receding glacier in Alaska, a cold pocket climate surrounding a glacier's snout might aid researchers in forecasting how forests will react to rapid climate change.

You may have experienced a chilly air pocket next to a snowbank when snowshoeing in the mountains or walking past a snowbank on the pavement.

A similar impact is seen by trees close to glaciers, which might hinder their growth.

As described in a recent study published in the AGU's Geophysical Research Letters, trees preserve the history of cooling in their annual growth rings.

Glacial microclimate mimicking climate change

(Photo : Paxson Woelber/Unsplash)

Temperature is one of several elements that affect tree ring development.

Many species experience slower development and narrower or denser rings as a result of colder, drier circumstances, as per ScienceDaily.

In an unparalleled close-up look at historical glacial microclimates, the study, directed by ecologist Ben Gaglioti, revealed this relationship between the La Perouse glacier and the neighboring Glacier Bay National Forest.

The study discovered the glacier rapidly advanced hundreds of meters during the late 1800s, fluctuated during the early 1900s, then started to recede around 1950 based on historical reports, tree cores, and aerial photographs.

The next step was to see if the trees had kept track of any changes in the microclimate during those times.

The researchers discovered a definite slowing in growth as the glacier advanced and an increase in growth rates as it retreated after accounting for regional temperatures and elevation.

In the summer, the glacier advance reduced the forest's temperature by over 4 degrees Celsius (or 7 degrees Fahrenheit).

Gaglioti and his colleagues made the discovery while looking at layers of trees that were once buried after being trampled by glaciers in the 19th century.

They observed squeezed development in the tree rings of rainforest trees along the edge of the glacier's footprint throughout the late 1800s as the glacier moved and pushed its bubble of icy air into the forest.

For three years, from July 2018 to July 2021, Gaglioti and his colleagues erected a network of temperature sensors around La Perouse Glacier that extended hundreds of meters.

The microclimate reached the furthest they have placed sensors, at least 600 meters, into the forest. Gaglioti believed it's difficult to determine where it truly ends without further sensors.

The discoveries also provided a crucial source of data for retracing the path taken by ancient glaciers and their impact on the local environment.

According to Gaglioti, if you look at trees that were trampled by ice, you can see the chilling impacts as the ice gets closer to them before they die.

Also Read: Alaska Declares Disaster Emergency Due to Flooding Caused by Ice Jam in Manley Hot Springs

Dramatic climate change in Alaska

(Photo : Paxson Woelber/Unsplash)

The hundreds of thousands of tourists who come to Alaska each year are in awe by its size, remoteness, and continued wildness, as per Climate.gov.

Alaska is larger than Texas, California, and Montana put together, with a total land area of more than 570,000 square miles and the longest coastline of any state.

It includes Denali, the tallest mountain in North America, as well as 17 of the country's 20 highest peaks.

There are said to be 100,000 glaciers there.

Because of its enormous natural landmarks, such as its mountains, tundras, glaciers, lakes, and oceans, the landscape might appear to be unchanging.

However, due to human-caused global warming, Alaska's climate is altering, with sometimes disastrous consequences.

The Alaska Center for Climate Assessment and Policy (an NOAA Climate Program Office RISA team), in collaboration with the International Arctic Research Center and the University of Alaska, Fairbanks, tells this tale in a recent study.

Every three years, the report, Alaska's Changing Environment, will be updated. The first part focuses mostly on the significant changes the state has gone through in the previous five years.

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