Chatsee Trikanchanawattana. Palynological study at Ban Tham Lod and Ban Rai in Pang Mapha district, Mae Hong Son province, Northern Thailand. Master's Degree(Technology of Environmental Management). Mahidol University. : Mahidol University, 2005.
Palynological study at Ban Tham Lod and Ban Rai in Pang Mapha district, Mae Hong Son province, Northern Thailand
Abstract:
The objective of this research was to investigate the palaeovegetation and
palaeoenvironment of Ban Tham Lod and Ban Rai in Pang Mapha district, Mae Hong
Son Province, Northern Thailand. Soil samples were collected from archaeological
excavation sites and surrounding areas of Tham Lod rock shelter and Ban Rai rock
shelter. Additionally, charcoal samples were collected to determine the age of soil
sample layers by radiocarbon dating. Palynological samples were treated by chemical
processes and kept in silicone oil before slide preparation. Then identification and
counting of pollen and spores were done in order to obtain the pollen diagrams.
Interpretation of the pollen diagrams of samples collected from Ban Rai rock
shelter indicated that vegetation in the past was like the present, including tropical and
sub-tropical flora. However, the environment tended to be cooler than at present,
because of the reducing trend of sub-tropical plants as Pinus sp.. Moreover, decreases
of Circulisporites sp. and Concentricystes sp., which can suggest humid or flooding
conditions, and fern spores, together with an increase of grass pollen could indicate
dryness and increasing open space. This is consistent with the interpretation of pollen
diagrams of samples collected from Tham Lod rock shelter in that the climatic trend
may have been cooler than at present. Increases of pollen found in dry land forest or
secondary forest could suggest an increase of forest disturbance and dryness. These
changes may have been caused by human activities, which could show the existence of
humans in this area. It is probable that some characteristics of this area may have been
suitable for seasonal land use for a long time. Although pollen diagram could not be
constructed from samples from archaeological excavation sites at Tham Lod rock
shelter and Ban Rai rock shelter, it could show that the vegetation in the past was
similar to the present consisting of tropical and sub-tropical flora. The presence of
Pinus sp. pollen, sub-tropical plants, in every sample layer could suggest a cool
environment in the past. In addition, the results of palaeoenvironmental and
palynological study could success from areas that may not be in archaeological
excavation area. Therefore, it may be productive to study area around archaeological
sites.