Phenology and Climatic Regime Inferred from Airborne Pollen on the Northern Slope of the Qomolangma (Everest) Region

摘要

We present 3 years (2011-2013) of in situ airborne pollen monitoring data on the northern slope of the Qomolangma (Everest) region to better understand the connections among airborne pollen, vegetation and climate. The pollen assemblage dominated by local herb and shrub pollen can reflect mountain shrub steppe vegetation. Herb pollen behave differently from tree and shrub pollen, including their responses to temperature, humidity, and wind speed, the distribution in wind direction and the optimum climate range. Herb pollen are mainly influenced by temperature and humidity, but wind direction and wind speed are more important to tree and shrub pollen. The flowering phenology can be reflected by annual and seasonal pollen variations, which are influenced by temperature and precipitation. Arboreal pollen (AP) represent long-distance transported types during the westerly period and nonarboreal pollen (NAP) locally dominate in the monsoon season; thus, the AP/NAP ratio could be an indicator of atmospheric circulation, vegetation and climate change in the semiarid Tibetan Plateau (TP). Airborne pollen, as a record of biological and climatic events, provides insights into vegetation response to climate change and has significance for interpreting fossil pollen records on the TP.