Effect of protection on productivity and botanical composition of vegetation in Gireigikh Council, North Kordofan State, Sudan

This study was conducted at Gireigikh Rural Council, Bara Locality in North Kordofan State, Sudan. The objectives of the study were to investigate the effect of protection, through enclosure, on productivity and quality of range. The parameters measured and used as indicators in the evaluation of range were biomass production, botanical composition, density of herbaceous and browse plants, cover, frequency and available browse production. The measurements were done at two sites Eyal Ali which has an enclosure and Mereikha which has no protected site and was open to grazing and other human activities. The results obtained from this study showed that biomass production of rangeland from the herbaceous layer in the enclosure was 635 kg DM/ha compared with 439kg DM/ha for the open access site. Plant cover was 75.6 and 29.4% in the protected and open access sites respectively. The available browse production was 1, 538 and 209 kg/ha in each of the two sites respectively.

The density of herbaceous plants was 642 plant/m² in the protected site and 216 plant/m² in the unprotected site. The densities of trees and shrubs in the two sites were in the range of 129 and 34 trees/ha respectively. The diversity of species composition was limited in the protected site compared with the unprotected site (Four vs. seven species respectively). This may explained by the fact that while no reseeding was practiced in the enclosure, new seeds were always introduced in the open access area through animals and various human activities. It can also be argued that in the absence of grazing pressure some plant species may smother others with low competitive qualities. It was concluded that the enclosure system contributed positively to improving the rangeland resources while the open access resulted in severe deterioration of rangeland resources.