Forest structures and carbon storage in managed and unmanaged forests along analtitudinal gradient in a central European low mountain range

摘要

Along an altitudinal gradient in the Bavarian Forest, a German low mountain range, forest structures on 144 sampling plots located in eight strict forest reserves and nearby managed forest stands were investigated. Live woody biomass volumes increased with decreasing altitude, whereas deadwood volumes did not show a dependency on elevation. Mean wood volumes were on average around 40 % higher in strict forest reserves than in managed forest stands, with decreasing discrepancies at higher altitudes. Silvicultural management had a strong impact on deadwood volumes, leading to higher mean deadwood volumes in the strict forest reserves than in managed forests. Probability of presence models for the main tree species indicated shifts of the curve maxima towards higher altitudes for beech and silver fir in the strict forest reserves, when data from 2009 and 2018 were compared. Total carbon stores in the strict forest reserves increased from the first survey in 2009 to 2018 in most cases, on average by around 40 to/ha. The two reserves at the highest altitudes (1,174 and 1,211 m a .s. l.), however, suffered from recent storm damages and severe spruce bark beetle outbreaks, which led to decreased above ground carbon stores but increased coarse woody debris carbon stores.