The Holocene History of a Subalpine Birch Forest Enclave: Subfossil Evidence from Central Sweden

摘要: Aspects of the Holocene history subalpine birch (Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman) forest belt in Scandes Mountains, Sweden, were analysed by radiocarbon dating subfossil wood remnants forming an enclave high above present-day limit. The population thrived continuously at site throughout period 8700-3400 years BP, suggesting absence major protracted coolings and mostly higher than present temperatures. Presumably, disappearance from study ca. 3400 reflects substantial cooling, which is corroborated independant proxy data. It inferred that during first few millennia Holocene, pine (Pinus sylvestris L.) formed uppermost pure stands restricted to small enclaves with excessive late-melting snow. Eventually, as climate cooled, these conditions became regionally ubiquitous could spread pockets favourable habitat form coniferous forest. In original too much snow accumulated there perished.