The quantitative assessment of the carbon deposit in the basic blocks of the surface ground phytodetritus of the prevailing forest type groups is given in the article. The research is conducted in the zone of the discontinuous permafrost distribution of the Baikit forest district of the mountain middle-taiga forests. The analysis of the received data showed that over-mature dark-coniferous plantation contains carbon in the soil phytodetritus by 1,6 times and in the big woody debris by 4,5 times larger than the light-coniferous plantation of the same age.