Impact of land management on herbaceous vegetation diversity and forage provision in the Great Green Wall in Burkina Faso

Abstract

Background

In West African semi-arid areas, grazing ecosystems are exposed to severe anthropogenic and climatic pressures. However, little is known about the contribution of local land management practices to increasing herbaceous forage in semi-arid environments. To recommend sustainable practices, this study therefore assessed the effect of three land management types on the diversity, functional structure and forage provision of the herbaceous vegetation in the Great Green Wall in Burkina Faso.

Methods

Floristic diversity, functional structure and the aboveground biomass of the herbaceous vegetation were assessed in 60 plots across three land management types, including fenced land (less disturbed), community forest (moderately disturbed) and fallow land (highly disturbed).

Results

The herbaceous vegetation species richness increased with disturbance, where fenced land (71 species) had lower richness than community forest (95 species) and fallow land (103 species). The dominant life forms in each land management type were therophytes (fenced land: 75.73%, community forest: 78.87% and fallow land: 77.89%). The average cover of grasses (p < 0.001) and forbs (p = 0.049) varied significantly and showed a trend opposite to that of anthropogenic pressure. However, the net pastoral value (p = 0.002) and the total biomass (p < 0.001) decreased significantly according to the disturbance gradient. The net pastoral value ranged from 32.83% in fenced land to 27.69% in fallow land. The total biomass was higher in fenced land (1317 kg ha⁻¹) than in community forest (1205 kg ha⁻¹) and fallow land (1009 kg ha⁻¹).

Conclusions

This study highlights an increase in herbaceous vegetation diversity, which is offset by a decline in the pastoral value of the grazing lands across the disturbance gradient.