Rehabilitation of indigenous browse plant species following exclosure established on communal grazing lands in South Tigray, Ethiopia, and implication for conservation

Abstract

Background: Despite the wide use of indigenous browse plant species, there is almost no information on the rehabilitation of indigenous browse species following area exclosure (AE) established on communal grazing lands (CGL) in Southern Tigray. The objectives of this study were to assess the rehabilitation of browse plant species following AE establishment on CGL. A total of 61 and 59 plots of 10 × 10 m2 size were laid down at 50-m intervals along parallel line transects at AE and GCL, respectively. Data collected on vegetation attributes were subjected to analysis of t test (unequal variances) using R-software. Results: The Shannon diversity index of the browse plant species was 1.25 and 0.81 in AE and CGL, respectively (P < 0.001). The overall population structure of browse plant species in the AE shows a reverse J-shaped population curve and “good” regeneration status, which reveals that the future communities may be sustained. Leaf biomass and basal area of browse plant species were significantly higher in the AE than in CGL (P < 0.001). After exclusion of grazing, AE was found to have positive effects on diversity and aboveground biomass of browse plant species. Conclusions: The study gives an understanding of the diversity, the pattern of population and regeneration of the browse plant species, which may help in the management and conservation of the species. Our results indicate that grazing exclusion is an effective management strategy to restore browse plant species. We concluded that the establishment of AE had a positive effect on the rehabilitation of browse plant species diversity and improved population structure and regeneration potentials of degraded grazing lands. Long-term monitoring and evaluation systems will be required to gain an informed understanding of the roles played by area exclosures in the rehabilitation and conservation of browse palnt species diversity.