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.