Modern pollen spectra from tropical South India and Sri Lanka: altitudinaldistribution

We analysed the pollen content of 106 surface soil samples from evergreen a nd deciduous tropical forests distributed between 6 degrees and 13 degrees of latitude north in South India and Sri Lanka. The samples were collected along altitudinal gradients, ranging from 50 to 2420 m, in five regions tha t experience different rainfall regimes. Original pollen data from tropical vegetation subjected to seasonal monsoon rains are presented along altitud e/temperature gradients. This paper includes a summarized description of th e vegetation types mapped in the area. The pollen results are presented in the form of quantitative pollen diagram s and correspondence analyses. They show clear distinct pollen assemblages and markers for all types of vegetation in deciduous and evergreen vegetati on. Forests are well identified by percentages of Arboreal Pollen greater t han 50%, despite the fact that Dipterocarpaceae and Lauraceae are hardly re corded by pollen. The pollen distinction between low, medium and high elevation evergreen for ests matches that established by ecologists. The botanical limits, respecti vely, placed at 900 m and 1500 m limits, correspond to the 20 degrees C and 15 degrees C-values of mean temperature of the coldest month. They appear clearly identified in the modern pollen record. This justifies further use of pollen data in Biome modelling.