Accelerated stone deterioration induced by forest clearance around the Angkor temples

Area of Science:

• Environmental Science
• Archaeology
• Geology

Background:

• Forest clearance significantly impacts cultural heritage sites, particularly sandstone structures.
• Ancient temples like Ta Keo at Angkor are susceptible to environmental degradation.

Purpose of the Study:

• To quantitatively assess the deteriorative impact of forest clearance on sandstone masonry.
• To understand the role of forest cover in protecting archaeological sites from weathering.

Main Methods:

• GIS-based analysis of historic imagery to determine stone loss rates.
• Comparative climate monitoring between cleared and forested temple sites.
• Visual assessment of mechanical weathering on decorative motifs using a 7-point scale.

Main Results:

• Stone loss rates increased ten-fold (0.2% vs. 0.02% per year) after forest clearance.
• Temperature and humidity ranges tripled post-clearance, increasing swelling-shrinking movements.
• 79% of decorative motifs remained largely intact in forested areas, versus only 7% at the cleared site.

Conclusions:

• Forest clearance exposes sandstone to extreme climatic stress, accelerating decay.
• Forest canopy provides a crucial bioprotective 'umbrella effect' for cultural heritage.
• This ecosystem service must be integrated into sustainable management strategies for heritage sites.