Contradictory evidence from biogeomorphological studies has increased the debate on the extent of lichen contribution to differential rock surface weathering in both natural and cultural settings. This study, undertaken in Côa Valley Archaeological Park, aimed at evaluating the effect of rock surface orientation on the weathering ability of dominant lichens. Hyphal penetration and oxalate formation at the lichen‐rock interface were evaluated as proxies of physical and chemical weathering, respectively. A new protocol of pixel‐based supervised image classification for the analysis of periodic acid‐Schiff stained cross‐sections of colonized schist revealed that hyphal spread of individual species was not influenced by surface orientation. However, hyphal spread was significantly higher in species dominant on northwest facing surfaces. An apparently opposite effect was noticed in terms of calcium oxalate accumulation at the lichen‐rock interface; it was detected by Raman spectroscopy and complementary X‐ray microdiffraction on southeast facing surfaces only. These results suggest that lichen‐induced physical weathering may be most severe on northwest facing surfaces by means of an indirect effect of surface orientation on species abundance, and thus dependent on the species, whereas lichen‐induced chemical weathering is apparently higher on southeast facing surfaces and dependent on micro‐environmental conditions, giving only weak support to the hypothesis that lichens are responsible for the currently observed pattern of rock‐art distribution in Côa Valley. Assumptions about the drivers of open‐air rock‐art distribution patterns elsewhere should also consider the micro‐environmental controls of lichen‐induced weathering, to avoid biased measures of lichen contribution to rock‐art deterioration.

Wood and charcoal were key sources of energy during early industrialization in Europe (18th century), preceding the large-scale exploitation of fossil coal. Past timber harvesting implied land transformation and woodland resources management. Therefore, relict charcoal kilns and historical documents of forest management are important sources of information about past woodland composition and structure. However, ancient charcoal kilns are poorly documented in temperate woodlands in the lowlands of western Europe, especially combined with historical written sources. In this study, charcoal production was investigated in an area in NE France, by combining charcoal and historical sources analysis, along with innovative dating methodologies. Thus, by using both radiocarbon and optically-stimulated luminescence dating, we showed that the activity lasted until recent times (19th–early 20th centuries) and Carpinus was the dominant taxon in charcoal assemblage. Moreover, kiln attributes seemed to be independent of topographical variables. Woodlands in this area were subject to a coppice-with-standards management, where small diameter wood was preferred to produce charcoal and large diameter stems, mainly Quercus and Fagus, were traded as timber. The dominance of Carpinus is rather uncommon in charcoal studies but supports the importance of Carpinus as fuelwood since the Middle Ages, as confirmed by many written sources.

Lichens are frequently regarded as agents of biodeterioration on exposed rock surfaces and are commonly incorporated into conservation assessments of rock-hewn cultural heritage. However, whether lichen diversity and biodeteriorative potential are actually associated with conservation condition remains poorly evaluated. This study investigated relationships between lichen communities and the conservation status of 28 engraved schist outcrops in the Côa Valley, north-eastern Portugal, a UNESCO World Heritage Site since 1998.Conservation condition was assessed using the Intervention Urgency Scale (IUS), while lichen assemblages were characterised through species richness, diversity indices, estimated cover, community composition and the Lichen Potential Biodeteriorative Activity index (LPBA).The results revealed consistent negative relationships between lichen diversity and conservation condition, and little evidence linking estimated biodeteriorative potential to conservation condition. Topographic and physical weathering variables associated with outcrop stability explained parallel patterns in lichen diversity and conservation condition, while community composition analyses indicated continuous ecological turnover along the conservation condition gradient represented by the IUS rather than replacement by distinct assemblage types.These findings challenge the assumption that abundant lichen colonisation necessarily reflects poor conservation condition and instead suggest that lichen diversity provides complementary ecological information on the long-term geomorphological context of rock-art-bearing outcrops. More broadly, the study demonstrates that indices operating at different spatial scales capture distinct ecological processes, highlighting the need for hierarchical conservation assessment frameworks that integrate complementary ecological and geomorphological indicators.