A NEW POLLEN DIAGRAM FROM THE SANDYNALLAH SWAMPS (NILGIRI HILLS, SOUTH-WEST INDIA)

A new pollen diagram from the Sandynallah swamps (Nilgiri hills, South West India). This paper presents pollen data from the Nilgiri hills i n South-West India subjected to the summer monsoon climatic regime. Th e sequence comes from a new 9-m core (A2) collected in one of the Sand ynallah swamps (11 degrees 26'N, 76 degrees 38'E) at an elevation of 2 200 m. Forteen conventional radiocarbon dates have been obtained from nine bulk samples. They clearly indicate that the lower part was depos ited during the last glacial period and confirm previous information f rom this area. The oldest dates, 27,000 to 35,000 yr BP, measured at t he Laboratoire souterrain de Modane (France), present consistent resul ts. The lower part of the pollen sequence dates from the last glacial period (isotopic stage 3) before the last glacial maximum. The upper t hree metres were deposited during the last 5000 years. The record of t he lower Holocene is apparently missing. Pollen analysis was undertake n on 65 samples. The pollen flora appears to be strongly dominated by grasses and swamp plants accounting for more than 80 % of the total co unts. High counts were done which allow to recognize 95 distinct taxa among which 55 are attributed to tree forest elements. The glacial per iod is dominated by C-4 grasses associated with a significant signal o f Artemisia and Apiaceae. During the late Holocene a sharp peak of Mic helia, a semi-deciduous tree of the montane forest among the Magnoliac eae is dated at around 3800 yr BP. Its association with other forest c omponents such as Olea, Glochidion, Ilex and Rapanea favour the interp retation that a mosaic of grassland and forest existed in the Nilgiri hills since a few thousand years, well before human impact on forest.