Author: Javier Maestre Gasteazi Leader of the IUCN CEM Mediterranean Type Ecosystems Specialist Group Chief Operating Officer, Forestales de San Francisco del Sureste, S.L.
Soil loss is one of the main challenges for the conservation and restoration of Mediterranean ecosystems. Irregular rainfall, long dry periods and intense rainfall events, together with disturbances such as wildfires, loss of vegetation cover or certain forestry operations, can considerably accelerate erosion processes.
However, erosion should not be understood as an enemy to be fought at all costs. Erosion, sediment transport and deposition are part of the natural dynamics of the landscape: they connect different parts of a catchment, redistribute materials and contribute to the functioning of downstream ecosystems. The problem arises when their intensity exceeds the system’s recovery capacity, causes excessive soil loss, or creates risks for communities and infrastructure.
From this perspective, we propose a low-impact approach to watershed and forest restoration, based on intervening only where necessary through numerous small, permeable structures distributed across the landscape. Wooden fascines, stone or wooden check dams, small gabions and other simple structures can locally reduce runoff velocity and energy, promote infiltration, and retain part of the soil close to where it begins to be mobilised.
This approach incorporates two complementary concepts: distributed retention and territorial soil equity. Rather than concentrating large amounts of sediment at a few points, distributed retention creates multiple small deposition areas. Territorial soil equity seeks to keep this resource functionally distributed throughout the ecosystem, where it can continue to store water and nutrients, support vegetation and promote ecological recovery.
The aim is neither uniform distribution nor stopping all sediment transport. It is to prevent excessive losses and unnecessary concentrations, conserving soil where it is needed without disrupting natural transfers to downstream ecosystems.
Many of these structures can also be temporary. Following disturbances such as wildfires—an increasingly important issue in Mediterranean landscapes—or logging and thinning operations that temporarily expose the soil, they can provide support during the most vulnerable phase. The objective is to assist the ecosystem until vegetation progressively recovers its capacity to intercept rainfall, reduce runoff and stabilise the soil. |