Study of quantitative relationships between vegetation and pollen in surface samples in the eastern forest area of Northeast China Transect

The eastern forest stands of Northeast China Transect (NECT) were chosen to study the quantitative relationships between vegetation and pollen in surface samples. The indices of A (association index) O ( over-representation index), U (under-representation index), C (correlation coefficient) and R(representation coefficient) for each pollen type were calculated. The results indicated that the relationships between vegetation and pollen type in surface samples were significant and the correlation coefficients of 70% pollen types were more than 0.5 (alpha = 0.05); the similarity between pollen assemblage and plant community was good and coefficient of similarity was more than 50%. 69 pollen types found in the surface samples could be divided into four groups with TWINSPAN classification and PCA ordination according to A, O, U and C. The four groups reflected the pollination characteristic of plants and the state of pollen conserved in soil. Group 1 was the associative group which could accurately reflect the local vegetation; Group 2 was over-representative group which had high pollen percentage outproportional to vegetation; Group 3 was the under-representative group in which the pollen were hardly obtainable from the soil, and Group 4 was also an under-representative group, in which pollen were easily obtainable in soil where plants directly grow from. The study also showed that A was a parameter to rectify pollen data and it was easier to obtain than parameter R, The parameters A and R have close relation and their regression equation was: A = -0.042 1R(2) + 0,242 5R + 0.392 6(r(2) = 0.602 1). These groups and indices provide a solid foundation for using pollen data in accurately reinstating vegetation.