Home > Research > Research Results > Research Results 2019 > Alaskan black spruce forest soils reserving forest scents

Update:December 18, 2019

Main content starts here.

Alaskan black spruce forest soils reserving forest scents


Article title

Spatiotemporal variations of below-ground monoterpene concentrations in an upland black spruce stand in interior Alaska

Author (affiliation)

Tomoaki Morishita(a), Takafumi Miyama(b), Kyotaro Noguchi(a), Yojiro Matsuura(c), Kim Yongwon(d)

(a) Tohoku Research Center, FFPRI, Morioka, Iwate, Japan.

(b) Department of Disaster Prevention, Meteorology and Hydrology, FFPRI, Tsukuba, Ibaraki, Japan.

(c) Center for International Partnerships and Research on Climate Change, FFPRI, Tsukuba, Ibaraki, Japan.

(d) University of Alaska Fairbanks, Fairbanks, AK, 99775-7335, USA.

Publication Journal

Polar Science, 20(or 21), June (or September) 2019 DOI:10.1016/j.polar.2019.02.002( External link )

Content introduction

Forest scents, also known as phytoncides, have a relaxing effect on humans and/or exhibit a sterilizing effect on microorganisms, depending on the type of microorganisms. Meanwhile, there are indications that substances emitting forest scents may also be involved in producing atmospheric ozone and promoting global warming. It is known that such forest scents are released from the above-ground parts of trees, including leaves and trunks, but there is limited knowledge regarding substances emitting forest scents that are contained in the underground parts of trees, including the soil. In particular, limited information is present regarding forest scents from black spruce forests, which are widely distributed in the North American subarctic area and are likely to be susceptible to the effects of global warming.

Therefore, this study focused on measuring the concentrations of substances emitting forest scents in both the atmosphere in a black spruce forest and in the forest soil from spring to autumn in the inland region of Alaska. The findings showed that forest scent concentrations were several hundred times higher in the forest soil than in the forest atmosphere, with the highest concentrations being in the layer of organic matter deposited on the forest floor up to 10–30 cm deep. The study also showed that the major substance emitting forest scent was -pineneNote), which is also contained in cedars and other trees. The organic matter layer on the forest floor consists of mosses, lichens, fallen leaves, and rootlets of black spruce, which act as underground reserves of forest scent substances.

Substances emitting forest scents, which contribute to global warming, are likely to be released to the atmosphere from the soils. The clarification of the quantity of these substances released should help in obtaining more accurate assessments of the effects of forest ecosystems on global warming.


Note) a-pinene: Please refer “A scent component a-pinene derived from timber relaxes humans” introduced in our research achievements 2017 in our homepage, and “Spring with forest scents” in Shizen Tanbo (Nature Inquiry) of April 2018.


(A) appearance of the forest floor

(A) appearance of the forest floor and (B) appearance of a cross-section of the organic matter layer, in which mosses, lichens, fallen leaves, etc., are thickly deposited, in the study site of a black spruce forest in the inland region of Alaska, covered by various mosses and lichens. Such organic matter layers are particular reserves of substances emitting forest scents.