Vegetation history and human impacts from Thong Pha Phum, western Thailand during the past 700 years

Palaeoecological analyses including pollen and charcoal analyses on a sediment core (NP3) collected from Nong Pling freshwater spring area in Thong Pha Phum, western Thailand are used to reconstruct past environmental change. The results demonstrate that there were changes in plant composition over the past 700 years resulting from interactions between hydrological conditions in relation to rainfall variability, and anthropogenic activity. Open vegetation such as grasses and lowland forest were established in Nong Pling freshwater spring forest from at least around ad 1300 suggesting drier conditions than present until around ad 1460. After that, decreased lowland forest and increased freshwater spring taxa together with the low charcoal contents indicate wetter conditions than during the former period, which allowed freshwater spring taxa to establish until around ad 1800. There were some fluctuations between freshwater spring taxa and lowland forest with open vegetation, probably due to rainfall fluctuations particularly after ad 1800 until the present. Moreover, recent increases in total charcoal accumulation, especially in large particles and the appearance of domesticated grass pollen may be related to recent human interaction within the ecosystems in Thong Pha Phum.