# Contributions of DNA Sequencing Technologies to the Integrative Monitoring of Karstic Caves
## 6 Contribution of NGS Assessments of Microorganisms to Cave Integrative Studies  
A majority of environmental studies only consider one disciplinary side of the question at stake (i.e., biology, geochemistry, or physics, etc.), with, consequently, (i) gaps in our understanding at the interface between disciplines, (ii) a disciplinary focus on specific scales or levels of organization, and (iii) the development of specific disciplinary lexicons and methods that are difficult for non-experts to understand [126; 127]. For a better understanding of the underground world, the use of an integrative approach through the interdisciplinarity of projects seems necessary. Interdisciplinary science is an integrated approach that synthesizes the perspectives of multiple individual disciplines during all phases of the research [128]. Thus, cave studies require a holistic, interdisciplinary approach that simultaneously considers the physical, chemical, and biological components of the underground environment (Figure 2) [126; 129]. One of the ultimate aims of integrative investigations is the development of a database that regroups information about water, air, rock surfaces, speleothems, microorganisms, fauna, etc. (Figure 2) [129]. Some caves suffer from an imbalance in their environment due to construction works, excessive presence of tourists, and/or chemical/biological treatments (Figure 2) [26; 50; 91]. This may induce rock wall alterations and complicates cave conservation, especially in Paleolithic caves. The lack of interface between disciplines constitutes a major issue for understanding ecosystem functioning and conservation of rock art in caves. Another aim of interdisciplinarity is to compile information on cave wall alterations, their characterization, methods of diagnosis, the mechanism of their formation and the parameters ruling their evolution, in order to better identify, prevent, or control them in painted caves [129].  
One of the first interdisciplinary cave studies was carried out in 1983, and included specialists in karstology, the micromorphology of walls, and underground climatology to understand how tourism activities were responsible for artwork wall alteration [130; 131]. This collaborative work determined the cause of artwork damage in the Black Salon of Niaux Cave, France. To make further progress, scientists established a laboratory cave in Vezere Valley (Dordogne, France) [129], which was set to conduct experiments for in situ analyses and obtaining samples to develop interdisciplinary approaches in caves. Using this pilot cave, [PERSON] et al. (2013) focused on microclimate analysis, showing that there are special conditions for large exchanges between the inside and outside of the cavity, and after a year of monitoring the cavity, a link between microbiology and microclimate could be made to understand the dynamics of microbial communities (Figure 2) [129]. Such interdisciplinary studies of caves have been performed in many countries, especially in Spain [132; 133].  
While interdisciplinary is powerful, challenges stem from disciplinary barriers, which including the challenge of competing and conflicting uses of scientific terms, but also institutional difficulties of organization and logistics [126; 128]. Integrating disparate disciplines with different paradigms, priorities, inherent questions, research methods, approaches, and metrics of success is a fundamental challenge in environmental science [126]. Consequently, the results of interdisciplinary efforts may be emergent as well. Ultimately, true collaboration is essential for successful interdisciplinary science and a better comprehension of the underground ecosystem.