Vegetation, fire, and climate history during the last 18 500 cal a BP in south‐western Yunnan Province, China

Abstract

High-resolution pollen and charcoal records from Qinghai Lake in south-western China are presented. The records reveal variations in vegetation, fire and climate history since 18 500 cal a BP. The results show that seven significant vegetation changes are recorded, which are responses to climate changes and/or fire events. Frequent and intensive fires occurred during the periods 17 900-15 000, 13 000-11 500 and 4280-980 cal a BP, corresponding to relatively dry climatic conditions. Combined with the climatic record from Tiancai Lake, the regional climatic changes since 18 500 cal a BP in western Yunnan Province are reconstructed. Namely, the Heinrich Event 1, the Bølling-Allerød warm period and the Younger Dryas event during the last deglaciation are ubiquitous in western Yunnan Province. The start of the Holocene is recorded at 11 500 cal a BP. The Holocene climatic optimum occurred between 8450 and 4280 cal a BP. After 4280 cal a BP, the climate deteriorated, accompanied by evidence for human impact. Based on this study, we consider that vegetation and climatic changes since 18 500 cal a BP in south-western Yunnan Province are primarily driven by September and average summer solar insolation, with some associated influence from regional sea-surface temperature and sealevel rise.

Postglacial fire history and interactions with vegetation and climate in southwestern Yunnan Province of China

“…In our published pollen record from Qinghai Lake (Xiao et al, 2015), Alnus, evergreen oaks, and Lithocarpus/Castanopsis are dominant tree taxa. The proportion of tropical trees and shrubs comprised mainly of Altingia, Ficus, Pentaphylax, Schima, Symplocos, Camellia, Eurya, and Mallotus/Macaranga is relatively high in the forests.…”

“…1c). Most of the precipitation is concentrated in the rainy season from May to October, which is 85 % of the annual precipitation (Xiao et al, 2015).…”

“…The rate of forest loss in tropical rainforest and monsoon forest zones is, however, lower than that in the former two vegetation types (Chen et al, 2012). A low-resolution charcoal record from Qinghai Lake in southwestern Yunnan Province of China was briefly mentioned in Xiao et al (2015). Here, we presented a high-resolution and continuous macroscopic charcoal record spanning about 18.5 kyr from the same core, and specifically analysed the fire event history and fire regime dynamics through time in southwestern Yunnan Province based on the charcoal record.…”

“…Here, we presented a high-resolution and continuous macroscopic charcoal record spanning about 18.5 kyr from the same core, and specifically analysed the fire event history and fire regime dynamics through time in southwestern Yunnan Province based on the charcoal record. Combined with the climate records and vegetation histories since 18.5 ka, reconstructed in Xiao et al (2015), the main controlling factors of forest fire dynamics and the relationship between fire activity and vegetation were examined in this study. These results provide new evidences for studies on fire frequency variability and vegetation-fire-climate interactions in southwestern China, which is important for improving our predictions of the influence of climatic change on future fire activity and planning appropriate management policies for forest ecosystems.…”

Evolution of the Indian summer monsoon during the interval 32.7–11.4cal. ka BP: Evidence from the Baoxiu peat, Yunnan, southwest China

“…Highresolution paleoenvironmental records obtained from this region provide important information on the evolution and potential forcing mechanisms of the ISM. Existing studies are based mainly on lacustrine sediments with relatively low temporal resolution and covering relatively short time spans (Kramer et al, 2010;Cook et al, 2011Cook et al, , 2012Tareq et al, 2011;Xiao et al, 2014aXiao et al, , 2014bXiao et al, , 2015. Indeed, only a few lacustrine records cover the period since the Last Glacial Maximum (LGM).…”