Subterranean sites such as caves and catacombs are generally characterized by limited air circulation, a limited variation in temperatures throughout the year, a high level of humidity, and at times, pronounced gradients of light [1]. Hypogea show similarities but also differences with caves due to their more limited size which leads to greater fragility also on the basis of the variability of materials used by human activities [2,3]. In fact, they were often embellished by wall paintings, stuccos, ceramics, bricks, and mosaics for decorative and augural purposes, as well as by statues, sarcophagi, and funerary objects which need to be preserved as the testimony of their cultural heritage [4,5]. Moreover, the tombs which often maintained an environment cut off from the exterior world for hundreds of years, undergo substantial environment changes after excavations and consequent weathering [6,7].

Literature on biological colonization in caves is becoming highly relevant, with hundreds of papers describing the microbial diversity and the relationship with environmental conditions, whereas much less is available for tombs. The most common inhabitants of subterranean sites are oligotrophs (bacteria, represented mainly by Actinobacteria, and fungi), accustomed to long periods of starvation, and,  phototrophs (cyanobacteria, green algae, diatoms, mosses, ferns) that have adapted to scarce light [4,5,6,8,9,10,11,12,13]. The current knowledge of the ecological succession of microbial communities in hypogea in relation to environmental factors, such as the efficiency or risks of different control methods seems insufficiently addressed. The peculiarities of hypogea, which vary according to different cultures also deserve special attention, as they give rise to distinct biodeterioration phenomena. This study is focused on the review of data on the Etruscan tombs in Italy and The Ancient Tombs of Baekje Dynasty in the Republic of Korea. In Italy the practice of building hypogea and decorating them with mural paintings was developed in several Etruscan from the 7th to the 3rd century BC. Our data set collected information on biodeterioration phenomena in 23 Etruscan tombs in Latium (in Tarquinia, Cerveteri, and Veio), and in Tuscany (Chiusi). Since 2004, both the Necropolises of Cerveteri and Tarquinia (Latium) have become UNESCO World Heritage sites in consideration of their painted tombs which have extraordinary importance as they reflect the daily life and burial practices of the Etruscans and bear witness to the achievements of their culture.

In the Republic of Korea during the Baekje Dynasty, three tomb styles developed: (1) a stone mound tomb,  (2) a brick chamber tomb,  (3) a corridor-style stone chamber tomb. In this study, the attention was focused on 

Ancient Tomb No. 6 in Songsan-ri, Gongju, a brick-chamber tomb, and Ancient Tomb No. 1 in Neungsan-ri (Buyeo), a corridor-style stone chamber tomb, in Baekje Dynasty, listed as UNESCO World Heritage Sites since 2004.

References