1. INTRODUCTION
The Galite Archipelago, situated in the northern sector of the Tunisian coastline, is renowned for the richness of its terrestrial and underwater ecosystems (Smith et al., 1997). The strategic geographical location of the Galite Archipelago, positioned between Tunisia and Italy, has long made it a pivotal point on the maritime routes connecting these two regions. Consequently, since ancient times, this archipelago has held substantial strategic and military significance for Tunisia.
The historical and strategic significance of the Galite Archipelago has conferred upon it a genuinely unique role and purpose. It has also raised the pertinent question of its future, with some suggesting that reintroducing a small resident population would be appropriate, thereby restoring its prominence and legitimacy as an integral part of Tunisian territory. This initial concept guided the early planning and management initiatives for the site, bolstered by a government decision dating back to 1999, which aimed to repopulate the archipelago. This management plan, at the time, represented an advocacy for implementing such a scenario within the framework of sustainable development (Smith et al., 2021). As a result, La Galite has emerged as an emblematic site in the Mediterranean, illustrating a unique experiment in repopulation grounded in ecological principles and functioning as an in-situ laboratory for sustainable development (Oueslati, A. 2016). Nevertheless, it is increasingly evident that the implementation of these guidelines is significantly hindered by highly challenging hydrographic and logistical conditions.
La Galite Island stands out due to its rich geological composition, a result of ancient volcanic activity and significant geomorphological dynamism. It exhibits a diverse range of geological facies, including igneous, metamorphic, and sedimentary rocks (Smith et al., 2020).
The island of La Galite features a diversity of soils, with ”isohumic soils” being predominant, associated with more or less metamorphosed volcanic rocks. These soils result from the decomposition of volcanic and metamorphic rocks on the island, providing good drainage and mineral richness (Smith et al., 2020). However, calcomagnesimorphic soils are also present, primarily in areas where calcareous formations, such as the Porto-Farina formation and Quaternary dunes, influence the soil composition. Calcomagnesimorphic soils are characterized by high levels of calcium, magnesium, and calcium carbonate, often exhibiting rendzina-like features, resulting from leaching and mineral redistribution processes (Jones et al., 2018). This diversity of soils is the outcome of the influences of parent rock types and geological processes on La Galite Island, contributing to the variety of the island’s ecosystems.
Land use has a significant impact on vegetation cover, including the presence of Aleppo pines. Bare soils result from various factors such as erosion or fires, which can alter vegetation, including Aleppo pines (Smith et al., 2020).
Degraded areas require restoration efforts to improve vegetation cover, which may involve managing Aleppo pines (Williams, 2022). Thus, land use management plays a central role in the distribution of Aleppo pines on La Galite Island and has a direct impact on its ecosystem.
The fire that broke out in October 2021 on the island of La Galite had significant consequences on its environment. This fire occurred during a vulnerable period, with favorable meteorological conditions for the rapid spread of flames. The fires devastated extensive areas of vegetation, including natural vegetation zones harboring indigenous biodiversity, including Aleppo pines. The intense heat from the fire damaged the soil and made some areas vulnerable to erosion. Furthermore, the dispersal of Aleppo pine seeds by the wind across the entire island contributed to their expansion on the site. In response to this fire, active management measures were taken, including the manual removal of young Aleppo pine shoots to limit their proliferation. This meticulous work aimed to prevent the spread of this invasive species and promote the regeneration of indigenous vegetation. The 2021 fire had a significant impact on the vegetation cover of La Galite, with implications for ecological and ecosystem management.
Early models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE) were initially used for erosion modeling. Integrating these models with spatialization techniques like remote sensing and Geographic Information Systems (GIS) has improved erosion mapping efficiency. The study’s focus is on the Galite archipelago, aiming to use GIS and RUSLE to model soil erosion risk and carbon loss for better land management and sustainable resource assessment.