Characterization of detritus profiles in some ecosystems of southern Sakhalin

Resumo

The typology of the detritus profiles for the main forest types in the southern part of Sakhalin is developed for the first time. It is shown that their mean thickness varies from 4 to 8 cm and regularly decreases with increasing proportion of deciduous plants in the ground cover. It is found that this parameter agrees closely with the habitat conditions and the highest diversity of detritus profiles is observed under semihydromorphic conditions typical of alder stands. For the first time, it is proposed to assess the environmental favorability for humus formation using the Shannon index, the coefficient that relates the diversity level of the detritus profiles to the thickness of the humus horizon and enables the composition of ecological series. It is shown that the most favorable conditions for humus accumulation are created in the series birch forest–mixed coniferous forest–mixed deciduous forest. The applicability of the classification developed on the basis of studies in the forests of Primorye and Southern Yakutia to the forest ecosystems of Southern Sakhalin is confirmed.