Mineral component part of litters in the bog birch forests: storage conditions and relationship with stand productivity
Tamara Timofeevna Efremova, Ada Fedorovna Avrova, Stanislav Petrovich Efremov, Nadejda Vasilievna Melentieva
Abstract
Strongly decomposed, moderately decomposed, rhizomatous, peaty, peat and рeatified litters develop on the gradient from tall-grass to sphagnum-litter (dead ground cover) birch forest types, objectively related to certain forest biotopes. Litter thickness and stock change accordingly: 5.7 sm (4.5 kg/m2) > 4.7 (3.7) > 3.6 (2.1) < 4.5 (2.5) < 6,1 (3,0) < 6.2 sm (3.2 kg/m2). Content of ash (mineral) substances in litter make on the average 12.5% and change from 4.6 to 22.2% and are characterized by high variability within the typological profile. Forest leaffall, ground vegetation, and silt deposit are, mainly, as sources of coming ash substances to the litter of studied bog birch forests. Their additive contribution to litter ash accumulation by litter is 56%. However, increase of mineral substances by one g/m2 due to the coming sources is accompanied by increase of ash content in litter by 0.76 g/m2 (within ash limits of: litter 179-1119, coming sources 111-1310 g/m2). Using the multiple regression analysis we found that ground vegetation and silt deposit are the best predictors. Contribution of forest leaffall is not authenticc. Forest leaffall forms, mainly, a certain mineral base of litters, against a background of which the influence of typological bog birch forest diversity and other hydrological factors, is shown. A pair regression analysis revealed a high reliable relationship of wood biomass and litter ash percentage.