Unpacking Layers of Space –Time Complexity in Land–Use Dynamics. A Case Study from the Olive Agrosystems of Sicily (Italy)

Abstract

The biocultural heritage of historical landscapes is an expression of intertwined ecological and socio-cultural dynamics at different temporal and spatial scales. Such a legacy is what confers high nature value on agricultural systems worldwide. Today there is an urgent need to develop approaches that may allow a more integrated study of biocultural heritage in order to better direct future endeavours for the sustainable management on such agricultural systems. Here, a methodological approach to unpack space-time complexity in the land-use dynamics of historic and current-day agrosystems is presented, based on the use of contextual and spatial-relational segmentation techniques within the research framework of historical ecology.With reference to work done in a case study area in Sicily, the authors first extract geographic contextual configurations and develop a spatial-relational ontology for their semantic interpretation, before using these spatial objects as temporal proxies to disentangle the spatial and temporal dynamics of land use. The result is a cross-disciplinary approach in which perspectives from historical ecology can be used to achieve a deeper understanding of evidence extracted from remotely sensed images. At the same time, advanced spatial analysis techniques may provide a further interpretative tool for scientific inquiry into biocultural heritage.

The Entangled Phenology of the Olive Tree: A Compiled Ecological Calendar ofOlea EuropaeaL. Over the Last Three Millennia With Sicily as a Case Study

“…Muslim authors give precise indications about the most suitable plant associations for the olive: first of all for the wild olive, playing the pollinator role (Ibn al‐‘Awwām Yaḥyá ibn Muḥammad, 1983, p. 541); good associations are with the grape (Ibn al‐‘Awwām Yaḥyá ibn Muḥammad, 1983, p. 519), pomegranate (Ibn al‐‘Awwām Yaḥyá ibn Muḥammad, 1983, p. 525), apple and sea squill ( Drimia maritima L.) (Ibn al‐‘Awwām Yaḥyá ibn Muḥammad, 1983, p. 520), fig tree (Ibn al‐‘Awwām Yaḥyá ibn Muḥammad, 1983, p. 542). These plant associations were quite widely used in Sicily until 50 years ago (Ferrara, 2022 and Focus Groups) and their spatial patterns are remnants that can still be seen today (Ferrara & Wästfelt, 2021). The last 50 years have been a period that has witnessed major changes, characterized by a different concept of spatial intensification in the olive orchards: from spatial arrangements resembling agroforestry and polyculture (“ Around the borders of the farm and along the roads plant elms and some poplars, so that you may have leaves for the sheep and cattle; and the timber will be available if you need it”, Cato the Elder, 6.1–6.3) to a more agrarian system in which the process of intensification leads to an increase in the density of olive trees, a reduction in accessory species and the total disappearance of grazing animals (Ferrara, 2022 and Focus Groups).…”

CONTEXTS.py (CS.py): A supervised contextual post-classification method to access multiple dimensions of complex geospatial objects

“…In recent work [ 17 ], we have shown how unsupervised contextual and spatial-relational analysis can be applied to extract from a single image of the Earth useful classes carrying information that, integrated with other sources of evidence (e.g. local ecological knowledge, ground truth), allows reading the multiple layers of meanings in the historical, cultural and ecological formation processes of a heterogeneous landscape.…”

“…Previous works done with the same method (cf. [ 3 ]), as well as with an unsupervised version of it [ 17 , 20 ] have shown it is preferable to use an unsupervised classification algorithm to prepare the input image for further steps.…”