STUDY ON RECORD OF SPORE-POLLEN IN HIGH MOOR PEAT AND DEVELOPMENT AND SUCCESSIVE PROCESS OF PEAT IN DA AND XIAO HINGGAN MOUNTAINS
Xia Yumei(Changchun Institute of Geography, Academia Sinica, Changchun 130021)
The author revealed the associate features of spore-pollen and successive process of vegetation and climate in Da Hinggan and Xiao Hinggan mountains since 5000 a and 2700 a B. P. based on data analysis of spore-pollen in 3 profiles of high moor peat. It was divided into 2 periods, one is the period (5000-3000 a B. P. ) of the broad-leaved forest with predominate Betula of the temperate climate, the other is the period 3000 a B. P. -updata of conifer and broad-leaved forest with predominate Pi-nus koroiensis, Picea and Abies of cool temperate climate in the north part Xiao Hinggan mountains. Then climate developed from temperate and slight dry to cool and moist.Since 2700 a B. P. there had been the mixed conifer and broad-leaved forest with predominate Pinus sylvcsteris. Pinus pumlia and a few Betula and Corylus in 2300-1800 a B. P. , and conifer forest of cool temperate climate consisted of Larix, Picea, Abies and Pinus sylvestris and so on in 1800 a B. P. -update, in the north part of Da Hinggan Mountains. The period was controlled by cool and moist climate, in which the period of 1800 - 1300 a B. P. was lowest time in the temperature and permafrost frozen soil was distributed to the south.It shows that development of the high noor peat in Da Higgan and Xiao Hinggan mountains passed 3 periods from the low moor pent, middle moor peat to high moor peat. It has greatly and continuously been formed and developed in Sphagnum leat since 1300 a in Da and Xiao Hinggan mountains, through confirmation of fossil record of spore-pollen and vertical change of plant residues from peat profiles.