Exploring ecological relationships in the biodeterioration patterns of angkor temples (Cambodia) along a forest canopy gradient.

Various biological communities colonize the Khmer temples in Angkor (Cambodia) which had lain abandoned for many centuries. These biodeterioration patterns change in response to different environmental conditions, and the aim of this study is to quantify their frequency and ecological characteristics according to a forest canopy gradient. The descriptive and multivariate statistical analysis applied to data collected from the four temples in the study identifies various biological communities along with a temple-specific ecological succession. The initial pioneer community is primarily composed of a reddish biofilm of the green alga Trentepohlia sp., and it occurs in xeric and shady environmental conditions, becoming dominant in forested areas. Cyanobacteria biofilm, consisting of species belonging to the genera Scytonema and Gloeocapsa, sometimes in combination with the lichen Endocarpon sp., prevails in xeric and sunny conditions. With the progressive increase of the availability of edaphic water, typical of forested areas, various lichen communities are able to establish themselves (dominated by Lepraria, Pyxine coralligera and Cryptothecia subnidulans respectively), followed by moss and higher plant communities. Understanding these relationships appears to be a very useful way of identifying the best microclimatic conditions for stone conservation.