Assessment of Rangeland and the Impact of Grazing on Semi-arid Zone of North Darfur State - Sudan

Abstract

North Darfur State is of considerable importance to Sudan economy. It is ecologically vulnerable and has been exposed to recent desertification and deterioration of rangeland with very serious biological, physical, social and financial losses. For these and other reasons it has been chosen for the study. The research work focused upon assessment of the physical environment to study the vegetation cover and the impact of animal grazing on it. It was conducted over a two years period of 2012 and 2013 at three sites of Alfashir locality (Ummarahik 25km north of Alfashir, Fashar in eastern part of Alfashir about 5km and Berka 30km west of Alfashir) – Western Sudan in semi-arid zone. The objectives were to assess rangelands and the effect of grazing levels on range attributes. Measurements of range components, plant density, vegetation cover, range productivity, species composition,plant frequency, carrying capacity and grazing level were assessed. Results showed that total forage production was low and inadequate to satisfy requirements of livestock for inhabiting the area; average range production all over the area was found to be 50.68 kg/ha and 59.21 kg/ha for the seasons 2012 and 2013 respectively. The average ground cover was about 34.71% and 42.41% for two seasons. The average plant density for the first season was 27.1 plant/m2, while the average plant density for the second season was 29.4 plant/m2. Total plant compositionfor the two seasons was found to be 52.33% / 68.04, litter 10.82% / 6.52%, bare soil 27.74% / 16.18% and fecal dropping was 9.11% / 9.26%. Based on the above percentages the range condition was classified as good. Percentage composition for the four species which dominated the area was Aristida sp (26.75%/ 26.56%), Cenchrus sp (26.25% / 24.55%), Eragrostis sp (20.46% / 22.87%) and Dactyloctenium aegyptium (10.48% / 10.83%). The average frequencies of the four plant species which dominated the area was Aristida sp 83.34%, Eragrostis sp 80.56%, Cenchrus sp 77.78% and Zalya pentandra 64.82%. The carrying capacity was 8.88 ha/AU/month and 7.6 ha/ AU/month for season 2012 and 2013 respectively. The study showed that the average species density of dominants tree and shrub per hectare were Balanites aegyptiaca (16/10), Calotrophis procera (10/10), Acacia tortilis (10/4) and Capparis deciduas (5/5) forthe first and the second seasons respectively. The results showed the higher number of quadrates subjected to grazing were at level (I) with the average percentage of 37.04% for the first season, while the higher number of quadrates subjected to grazing were at level (II) with the average percentage of 42.6% for the second season. The study showed that unwise utilization and exploitation of the rangelands particularly by man causes range deterioration and serious reduction in range production of both quantity and quality. Also continuous removing of trees and overgrazing expose the rangeland to wind erosion. Erosion index and vegetation degradation were very high and vegetation composition was of low quality, so, the study suggested that improvement and rehabilitation such lands rangelands should be done. It is also recommended that a major effort is needed to be exerted in natural resources management in general and range resources inparticular; this is needed for mitigation and recovery of the range at the study area. Further research work is needed to assess rangelands and condition across different ecological zones in North Darfur State.