SOME ASPECTS OF ECOLOGY AND MANAGEMENT OF BOSWELLIA PAPYRIFERA Del. HOCHEST) IN JEBEL MARRA MOUNTAINS; DAR FUR, SUDAN

Abstract

This is an ecologically and managerially oriented research of Boswellia papyrifera in the western and southern sub-hills of Jebel Marra, an isolated volcanic massif in the heart of African content. The research was conducted in the period from April 2001 to Nov. 2002. This research attempted to study Boswellia papyrifera under the following aspects: land forms and soils, the growing stock, natural regeneration, seed and seed germination, phenology and resin collection. Four representative Boswellia sites were chosen for this study. Composite soil samples were taken for physical and chemical analysis. The systematic circular line-plot design was used for the inventory of the growing stock, quadrats as subplots were used for natural regeneration surveys. Germination and viability tests were carried out for the seeds. Resin collections on the basis of diameter at breast height were made, interviews with resin producers were carried out and finally the phenology of the species was observed. The most important results of this research are: 􀂙 Sloping sites were found to be representative for the occurrence of Boswellia papyrifera. Soils of Boswellia papyrifera are sandy loam to sandy clay loam. ٦ 􀂙 Boswellia papyrifera was found to be dominant, frequent, abundant and with an importance value index of 188.5. 􀂙 Boswellia is a prolific seed producer, the seeds are three folds, empty, insect infested and viable seeds, and the latter are the smallest in number. The germination of seeds does not exceed 7% under all treatments and the seedlings survival rates ranges from 27.6 - 31.8%. 􀂙 The most important outcome of this study is the lack of natural regeneration. The main reasons behind are grazing, fires, weed competition and water erosion. The phenophases of the species were found to be determined by rain fall and the flowering habit of Boswellia papyrifera is indeterminate. 􀂙 The average annual resin production per tree is 1.44kg/tree, and the optimum productive diameter at breast height ranges between 16-34 cm., trees with diameters at breast height over 34cm are less productive. 􀂙 Resin production was found to be affected by season. In the early season resin production is low and the intervals of collection is prolonged to four weeks, while in the late season resin production increases and the intervals of collections is shortened to two weeks.