Tree rings help researchers decode climate change

A Sino-Kazakh research project initiated in 2016 has been using tree rings to gather information about changes in temperature, precipitation and glaciers.

Zhang Ruibo, a researcher with the China Meteorological Administration's Urumqi Desert Meteorological Institute, who participated in the expedition, told People's Daily in August that Kazakhstan's well-preserved environment enables experts to collect useful samples from old trees.

The Altai Mountains' foothills in the country's northeast are covered with Siberian pines, whose rings are sensitive to temperature differences over long time spans, People's Daily reported.

Ring density－namely, wood density measured by gram per cubic centimeter－is usually determined by cell size and cell wall thickness, which is influenced by the environment and climate.

Density variations may indicate changes in these conditions over time, according to the paper Advances in Tree-ring Density Study, published in the journal Quaternary Science in 2015 by an expert from the Chinese Academy of Sciences' Institute of Botany.

The research project explores new paths toward climate change adaptation and helps to protect Kazakhstan from weather disasters caused by melting glaciers.

Zhang said tree rings can be used to reconstruct previous mass balances of glaciers and snow cover over a century or even longer, providing basic climate-projection data.

In 2016, Urumqi Desert Meteorological Institute and the Kazakh Ministry of Agriculture's Forestry Research Institute's Almaty branch signed an agreement to cooperate on research related to tree rings and climate change, according to the China Meteorological Administration.

The agreement states that Chinese researchers use specific instruments and methods to study forest growth and regional climate change in Kazakhstan. The Central Asian nation, in turn, provides forest-distribution data and assistance in sample collection in specific areas. China then produces tree-ring data analyses and historical climate-change models.

The agreement was made after an exchange in which Chinese researchers learned the glaciers near Almaty had melted rapidly and meteorological disasters had occurred frequently.

However, monitoring of the region's glaciers and snow needs to be further improved to predict local disasters, People's Daily reported.

"Previously, there had been almost no research on changes in glacial mass over the past few centuries," Zhang was quoted as saying.

"So, every finding by the joint project qualifies as a breakthrough."

The two sides will cooperate on research, exchange information, pay mutual visits and build a shared laboratory on climate change and forest ecology.

They have maintained frequent exchanges since the 1980s and signed a meteorological science and technology cooperation agreement in 1995, the China Meteorological Administration said.