CHANGES IN FATTY-ACID COMPOSITION WITH AGE AND ENVIRONMENT IN DIFFERENT TYPES OF PEAT PROFILES IN JAPAN

Fatty acid composition of the crude lipid fraction of pest was investi gated using several typical peat profiles in Japan, Fatty acid composi tion varied with the peat layers accumulated in a peat profile since 3 2,000 years BP, Deposition of long-range transported volcanic ash teph ras also affected the composition remarkably due to the acceleration o f decomposition, Fatty acid composition differed among high moor, tran sitional moor, and low moor peat profiles sampled in several locations in Hokkaido, Japan, The difference in the plants involved in the form ation of peat was considered to be a very important factor determining the fatty acid composition, For example, arachidic acid was considere d to be a good indicator for the presence of reed, while the percentag e of stearic acid tended to be high in the high moor pear profiles dom inated by sphagnum, As the fatty acids with a longer chain length were more stable than those with a shorter chain length, the percentage of longer fatty acids (C24 and C26) tended to increase and that of short er fatty acids (C14 and C16) to decrease in the lower peat profiles, T he drying of peatland also exerted a similar effect on the fatty acid composition.