In the Sahel, exacerbated soils degradation is an ecological indicator
of ecosystem vulnerability. This study examines the effects of
restoration of degraded lands on soils physicochemical properties and
adaptability of planted woody species over a period of 4-6 years. It is
based on: 1) Physicochemical analyses of soils (granulometry,
calcimetry, and organic matter) carried out on 102 samples taken in the
upper 10 centimeters of the soil profile of the rehabilitated and
control sites, 2) measures carried out for the dimensioning of
anti-erosion structures, 3) dendrometric measurements on woody species
planting in 20 plots each with a rectangular shape 60 m × 30 m as well
as characterization of the structure of their root systems.
Physicochemical analyses show an improvement in soil quality and
structure thanks to the erosion control measures. The degradation of
anti-erosion structures, inferred from the rate of siltation of
micro-basins, the subsidence of the bulges, the formation, and extension
of the breaches, is strongly influenced by the topography,
precipitation, and sandy texture of the soils. The restoration
activities have led to the reconstitution of vegetation cover on
degraded soils. Based on dendrometric characteristics, height class
structure, and root systems architecture, significant differences were
observed between woody species planted in anti-erosive structures.
Eucalyptus camaldulensis groups of with a tracer root system and high
density, have the highest structural parameters resulting from the
adaptation of this species on Sahelian degraded lands.
Effects of degraded lands restoration on soils physicochemical properties and adaptability of planted woody species in southwestern Niger