Evaluation of microelement contents in Clethra barbinervis as food for human and animals in contrasting geological areas
- 209 Downloads
The young leaves of Clethra barbinervis Sieb. et Zucc, which is a deciduous tree species found in secondary forests widely in Japan, are used in spring as a local traditional food by local populations, and the bark of this plant is also preferred by sika deer, Cervus nippon. However, C. barbinervis has been known to accumulate heavy metals in its leaves. Then, we aimed to clarify the characteristics of microelement contents in C. barbinervis and to discuss the value of this species as food for humans and animals through the analysis of seasonal changes and distribution in various organs of C. barbinervis growing under two different geological conditions. We found that C. barbinervis is an accumulating and tolerant plant for Ni, Co and Mn. It accumulates Ni from serpentine soil containing Ni at high concentration, and Co and Mn from acidic soils based on crystalline schist. The seasonal variation in element concentrations in leaves indicates that the young leaves contain Cu at high concentration and that eating them in spring season may be advantageous to humans, due to the associated increase in Cu intake. The high concentrations of Cu and Zn in the bark of C. barbinervis might explain why deer prefer to eat the bark of this species.
KeywordsClethra barbinervis Microelement Food Leaves Bark
We would like to thank Mr. Motowo Kobayashi and the members in the Aichi Prefectural Forestry Research Institute for many helps in the sampling operation.
- Brooks, R. R. (1998). Plants that hyperaccumulate heavy metals (p. 380). Oxon: CAB International.Google Scholar
- Baker, D. E., & Amacher, M. C. (1982). Nickel, copper, zinc and cadmium. In A. L. Page, R. H. Miller, & D. R. Keeney (Eds.), Methods of soil analysis, part 2 (2nd ed.). Madison, WI: ASA Inc. and SSSA Inc.Google Scholar
- Japan Meteorological Agency (2003–2010) Meteorological data. http://www.jma.go.jp/jma/indexe.html.
- Kabata-Pendias, A. (2011). Trace elements in soils and plants (4th ed., p. 520). Boca Raton: CRC Press.Google Scholar
- R Development Core Team. (2012). R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing. http://www.r-project.org/
- Taiz, L., & Zeiger, E. (2010). Plant physiology (5th ed., p. 782). Massachusetts: Sinauer Associates Inc.Google Scholar
- Tyler, G. (2005). Changes in the concentrations of major, minor and rare-earth elements during leaf senescence and decomposition in a Fagus sylvatica forest. Forest Ecology and Management, 206, 167–177. doi: 10.1016/j.foreco.2004.10.065.