In 2001, the Authority for the Protection and Management of Angkor and the Region of Siem Reap (APSARA National Authority) and the National Research Institute for Cultural Properties, Tokyo, launched a joint research project for the conservation of stone monuments in the Ta Nei Temple. Ta nei Temple was built in the end of 12th century to the beginning of 13th century, and sandstone and laterite are used as building materials. This temple was selected as the site of research because several types of microorganisms that are typical to the Angkor area grow on the stone surfaces at the temple site.

We have been studying the methods for conservation of the stone surfaces, especially with regard to the characteristics of adhering lower plants and microorganisms, their influence on the stone, and ways to reduce their negative effects.

We have been doing the monitoring of the microclimate, studies of microorganisms (lichens and mosses) and analysis of the characteristics of sandstone such as hardness, susceptibility and so on.

Our research reveals that more work on the possibility of controlling the growth of these lower plants and microorganisms by regulating surrounding environmental conditions is necessary. For this purpose, we will investigate the optimal growth conditions for each species found in this area and collect environmental monitoring data. We will also continue the study of cause-and-effect relationships between the existence of lower plants and the deterioration of stone surfaces.

After the termination of the civil war, international teams has been conducting cooperative projects for the restoration of monuments in Angkor area, but there are a few teams which have been doing researches in the field of conservation science. Among these teams , we keep contact with Blaise Pascal University team working at the Ta Keo Temple.