Analysis of the biodeteriogenic vascular flora at the Royal Palace of Portici in southern Italy

A study was carried out on the biodeteriogenic vascular flora at the Royal Palace of Portici in southern Italy. In all, 160 species were found on the building, which represents approximately 35.5% of the flora found in the whole grounds (449 taxa). Ecological analysis of the plant population highlighted the decisive role of xeric climatic conditions, the lack of substrate, use of the site, and ordinary and restorative maintenance work. Therophytes (48.8%) broadly prevail over other biological forms. Most of the taxa censused (38.8%) may be considered ubiquitous and hence found at the same time on different types of substrate. Measured against the Hazard Index (HI), 62.5% of the species detected may be considered low-hazard (HI 0–3), 31.9% medium-hazard (HI 4–6), and 5.6% very hazardous (HI 7–10). Ailanthus altissima (Mill.) Swingle (HI 10), Ficus carica L. (HI 10), and Quercus ilex L. subsp. ilex (HI 9) were the species that had the most impact of the architectural structures in question.