Deteriogenic flora of the Phlegraean Fields Archaeological Park: ecological analysis and management guidelines

Abstract

18 Biodeterioration, the alteration caused by living organisms, on historical buildings and stone 19 monuments is a well-known problem affecting two-thirds of the world's cultural heritage. The study 20 of the flora growing on wall surface is of particular importance for the assessment of the risk of 21 biodeterioration of stone artifacts by vascular plants, and for maintenance planning. In this study, we 22 investigate how rock type, exposure and inclination of the wall affect the biodeteriogenic flora at 13 23 sites of the Archaeological Park of the Phlegraean Fields located in the province of Naples, in 24 southern Italy. For each site, we analysed randomly selected square areas with 2 x 2 m size, 25 representing the different vegetation types in terms of vascular plant species cover. The total number 26 of plant species recorded was 129, belonging to 43 families. Erigeron sumatrensis, Sonchus 27 tenerrimus, and Parietaria judaica are the most commonly reported species, while Capparis 28 orientalis is the species with the highest average coverage. Substrate type, exposure and surface 29 inclination affect the floristic composition, with the average plant cover significantly higher on 30 vertical surfaces and at western and southern exposure. All the main biodeteriogenic vascular plant 31 species grow on more or less porous lythotype like yellow tufa, conglomerate and bricks. Finally, 32 woody plants eradications methods are proposed by the tree cutting and local application of 33 herbicides, to avoid stump and root sprouting and to minimize the dispersion of chemicals in the 34 surrounding environment. 2 35 36

Assessment of the potential effects of plants with their secreted biochemicals on the biodeterioration of archaeological stones

“…Vegetation becomes a hazard in the future if proper prevention is not applied to the sites [24]. Plant controlling is costly, complex, and difficult due to its dispersal, vegetation regeneration after mowing, and the ability to grow in high habitats; in addition, consideration must be given to the appropriate conservation of man-made structures, the environment, and the landscape [75,125]. The methods of control differ depending on the species of plant identified, building structure, state of conservation, and its location [11,15,25].…”

“…Relying on herbicides alone for weed management is unsustainable and will fail in the long term even when we use several herbicides with different mechanisms of action; resistant biotypes will be selected by either improving metabolism or stacking multiple resistance traits [136]. Selective herbicides in limited quantities can be suitable to avoid mechanical deterioration of the structure, and while using herbicides, it is necessary to prevent their spread to architectural parts and the environment [125,126].…”

“…Glyphosate is one of the most widely used herbicides at archeological sites [4,64,125,129]. Despite the use of glyphosate, it has been proven that it has disadvantages in some cases such as acidic degradation, the formation of salts, the discoloration of the stone surfaces, and it can expand the materials resulting in widening fissures [129,137].…”