Pastoral Stone Enclosures as Biological Cultural Heritage: Galician and Cornish Examples of Community Conservation

Towards Mobilizing Knowledge for Effective Decision-Making in Parks and Protected Areas

In November 2017, over 15,000 scientists issued a second letter to humanity that outlines how we are “jeopardizing our future” by failing to protect key ecological systems [...]

Impact of wildfire on granite outcrops in archaeological sites surrounded by different types of vegetation

The lack of scientific information about the effects of wildfire on prehistoric structures and rock art, such as dolmens and petroglyphs, impedes the development of conservation guidelines. In this study, the impact of a recent wildfire (late 2017) on granite outcrops in the San Salvador de Coruxo archaeological site (Vigo, SW Galicia) was evaluated. Samples of the same type of granite were obtained from three sites characterised by different types of vegetation (natural scrub, native deciduous oak and non-native pine-eucalypt forest) in order to determine how the vegetation influences the fire-caused damage to the rock. Three subsamples were taken from each of the granite samples at depths of 1 cm-3 cm to study how fire affects the rock at depth. In all sites, the temperature reached at the granite surface was below 380 °C. No mineralogical changes due to fire exposure were detected, and no physical changes that could be attributed to the effect of the fire on the fissure system of the granite were identified. However, aesthetic colour changes due to the deposition of organic and charred matter, which even penetrated the fissures, were detected. The existence of lignin-derived compounds, lipids and carbohydrates in the samples from the oakwood site indicates greater resistance to fire effects in this type of vegetation than in the other two types. Although preliminary, these findings suggest that oakwoods could act as protective belts around archaeological sites by reducing the wildfire severity, because of their greater resistance to being burnt, and that they could buffer the damaging effects of fire in natural areas where parietal art is found.

A review of the nature, role and control of lithobionts on stone cultural heritage: weighing-up and managing biodeterioration and bioprotection

Lithobionts (rock-dwelling organisms) have been recognized as agents of aesthetic and physico-chemical deterioration of stonework. In consequence, their removal from cultural heritage stone surfaces (CHSS) is widely considered a necessary step in conservation interventions. On the other hand, lithobiontic communities, including microbial biofilms ('biological patinas'), can help integrate CHSS with their environmental setting and enhance biodiversity. Moreover, in some cases bioprotective effects have been reported and even interpreted as potential biotechnological solutions for conservation. This paper reviews the plethora of traditional and innovative methodologies to characterize lithobionts on CHSS in terms of biodiversity, interaction with the stone substrate and impacts on durability. In order to develop the best management and conservation strategies for CHSS, such diagnosis should be acquired on a case-by-case basis, as generalized approaches are unlikely to be suitable for all lithobionts, lithologies, environmental and cultural contexts or types of stonework. Strategies to control biodeteriogenic lithobionts on CHSS should similarly be based on experimental evaluation of their efficacy, including long-term monitoring of the effects on bioreceptivity, and of their environmental safety. This review examines what is known about the efficacy of control methods based on traditional-commercial biocides, as well as those based on innovative application of substances of plant and microbial origin, and physical techniques. A framework for providing a balanced scientific assessment of the role of lithobionts on CHSS and integrating this knowledge into management and conservation decision-making is presented.