Pollen-based temperature and precipitation records of the past 14,600 years in northern New Zealand (37°S) and their linkages with the Southern Hemisphere atmospheric circulation

Abstract

Regional vegetation, climate history, and local water table fluctuations for the past 14,600 years are reconstructed from pollen and charcoal records of an ombrogenous peatbog in northern New Zealand (38°S). A long-term warming trend between 14,600 and 10,000 cal. yr BP is punctuated by two brief plateaux between 14,200–13,800 and 13,500–12,000 cal. yr BP. Periods of relatively drier conditions are inferred between 14,000–13,400 and 12,000–10,000 cal. yr BP, while a long-term wet period is observed between 10,000 and 6000 cal. yr BP. The last 7000 years feature relatively stable temperatures, a long-term drying trend that culminates with persistent drier conditions over the last 3000 years and cyclical fluctuations in the bog’s water table and fires. Present-day climate controls and comparisons with other climate reconstructions from New Zealand, the Southern Hemisphere mid-latitudes and the tropical Pacific suggest that complex and temporally variable teleconnections exist between northern New Zealand and the Southern Hemisphere low- and high-latitude circulation.