Carbon pools in spruce forests of the Qilian Mountains (north-eastern Tibetan Plateau under the influence of global warming and land use

点击翻译按钮获取中文摘要

Mountain forests of spruce (Picea crassifolia), the forest community with largest extension on the north-eastern Tibetan Plateau, and their degradation stages resulting from forest pasture and logging are analyzed for their total carbon stocks. Estimates of the carbon pools are made for different fractions of the above-ground (trees, shrubs, deadwood, herbal layer) and below-ground biomass (living and dead fine roots) as well as for the soil organic carbon. The past role and future perspectives of the spruce forests to store carbon and to sequester carbon by stem wood growth under the influence of global warming are assessed with the help of tree-ring analyses, which also provide information on temporal trends in wood formation and forest regeneration. Climate-related trends are separated from responses to land use by (1) including stands with low land-use pressure in the analyses, (2) correlating tree-ring widths with instrumental climate data, and (3) the analysis of δ13C and δ18O signatures of individual tree-ring series.