The Monumental Olive Trees as Biocultural Heritage of Mediterranean Landscapes: The Case Study of Sicily

Abstract

Monumental olive trees, with their longevity and their remarkable size, represent an important information source for the comprehension of the territory where they grow and the human societies that have kept them through time. Across the centuries, olive trees are the only cultivated plants that tell the story of Mediterranean landscapes. The same as stone monuments, these green monuments represent a real Mediterranean natural and cultural heritage. The aim of this paper is to discuss the value of monumental trees as “biocultural heritage” elements and the role they play in the interpretation of the historical stratification of the landscape. We present the results of a survey of the most significant olive trees growing in Sicily. The selection was based on the “monumentality” aspects of trees, taking into account dendrometric parameters and environmental contexts. The collected dataset constitutes a heterogeneous sample of 367 specimens of considerable size that, in some cases, reach a circumference of about 19 m. Starting from the data presented here, the whole Sicilian territory shows a historical relationship between human and olive. The presence of these plant monuments is, therefore, evidence of long-term, often centennial, landscapes as a result of sustainable use of the territory.

Exploring Olive Genetic Diversity in the Maltese Islands

“…A separated genotyping of different tree parts, such as canopy and rootstock, showed the presence of at least two genotypes per plant, confirming the occurrence of grafting propagation in 29.6% of cases among total analyzed Grafting practice was developed almost 4000 years ago and was the key element in the domestication process [54]. This observation confirms what has been previously shown in other countries, such as Spain, Italy, Palestine/Israel, Cyprus and Turkey [9,11,17,55,56]: that majority of ancient trees were grafted. In some cases, grafting occurred between two distinct lineages, confirming a different maternal origin and, presumably, different phases of olive cultivation that occurred in Malta during the last millennia.…”

The Ancient Olive Trees (Olea europaea L.) of the Maltese Islands: A Rich and Unexplored Patrimony to Enhance Oliviculture

“…Considering the quantities and the different phenol fractions found, it can be stated that some Maltese genotypes have important radical scavenging, antioxidant and anti-inflammatory properties [ 42 , 43 , 44 , 45 , 46 ]. The main phenolic compounds in the samples under investigation were secoiridoids and their derivatives, as has already been found in other studies [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. The contribution of phenolic alcohols, such as hydroxytyrosol and tyrosol, of flavonoids with rutin and luteolin 7-glycoside and of acid phenols (particularly vanillic acid) was relevant.…”

“…Bidni is believed to be the oldest cultivar, dating back to Roman times [ 10 ], although studies based on radiocarbon dating have dated it to the mid–late medieval period, before 1450–1669 AD [ 11 ]. The ancient Bidni trees located in the Bidnija area are listed in UNESCO’s Database of National Cultural Heritage Laws, although, since they are living monuments, it is considered more appropriate to speak about “biocultural heritage” [ 12 , 13 ]. Bidni trees produce small fruits which are difficult to harvest, and this has contributed to the progressive abandonment of this cultivar over time.…”

The Harvesting Memories Project: Historical ecology and landscape changes of the Sicani Mountains in Sicily

“…In fact, this ecological pattern is determined by environmental or abiotic factors (e.g., climate, lithology, landforms) that change only over a long period of time which is measurable on the scale of geological eras (Klijn and de Haes 1994). This long continuity in the vegetation pattern is also highlighted by the presence, as dominant species in these forest formations, of oaks, which are secular trees as regards their own physiology, as testified by the widespread presence in the Sicani mountains of numerous enormous individuals with biological cycles of 400-500 years (Schicchi and Raimondo, 2007;Schicchi et al, 2021). The archaeobotanical record has indicated an exclusive use of wood (as building materials or fuel) from the spontaneous plants specific to the natural vegetation of this area, especially evergreen oaks; no wood charcoals undoubtedly connected to cultivated tree plants have been found at the current stage of the investigation.…”