Photo/IllutrationThe Asahi Shimbun

  • Photo/Illustraion

A century from now, cold regions as far north as Hokkaido could become home to bamboo thickets--if global warming proceeds at its current pace.

Researchers studying the issue expressed alarm at such an eventuality, saying it could impact local ecosystems in many ways.

A team made up of experts from Tohoku University, the Japan Meteorological Agency and other institutes said bamboo groves would reach Wakkanai at the northern tip of Hokkaido if temperature levels continue to increase.

Bamboo primarily thrives in the country’s main island of Honshu.

If bamboo takes root in the Tohoku region and Hokkaido, other plants in local areas could be affected, said the researchers, whose findings were published in the online edition of the Ecology and Evolution journal on Oct. 18.

They said that 99 percent of bamboo in Japan is either of the "moso" or "madake" type, both of which are believed to be native to warmer regions.

Those species grow quickly and block out sunlight, thereby adversely affecting the growth of surrounding foliage.

This problem has been mainly limited to areas in western and eastern Japan, where temperatures are relatively high.

Around 35 percent of regions in eastern Japan were found to be conducive to the growth of bamboo between 1980 and 2000, according to a survey.

The ratio of favorable habitats is projected to rise to between 77 and 83 percent, covering Wakkanai, if the average temperature in Japan increases 4 degrees by the end of this century from pre-Industrial Revolution levels during the mid-18th century.

While a 1.5-degree temperature rise would likely raise the ratio to between 46 and 48 percent, the figure would increase to between 51 and 67 percent if temperatures went up by 2 to 3 degrees.

Although moso and madake bamboo are designated as an alien species that requires appropriate control, the number of bamboo thickets that are not properly managed is rising.