Tsetse fly. Sleeping sickness.A species of the tsetse fly, identified as Glossina morsitans, was discovered in 1903 (April) by Major G. R. Griffith, D.S.O. Beyond its often fatal attacks on animals, it seems otherwise harmless. Sleeping sickness is unknown in the Bahr El Ghazal, though fatal cases have occurred in the Lado enclave, which adjoins it.
7. Forestry.[109]
Fires.The Bahr El Ghazal province is, unfortunately, no exception to the general rule which prevails in the Sudan. Traces of fires are clear everywhere, from the grass lands near the rivers to the innermost portions of the uninhabited forest tracts to the north-east and east of Deim Zubeir. The largest fires are started in the grass lands near the rivers in order to provide tender herbage for the cattle. These, as they sweep inland, are fed by others, which are made to clear the country near the villages, and they are then carried on until they rush on and penetrate into the forest themselves. In the forests, where the paths get overgrown with grass, travellers fire the grass, not only to clear the way, but to provide against coming unexpectedly on wild animals. Further, fires are lighted for hunting purposes. The reed rat, which lives in long grass near water, and which is generally relished for its meat, is hunted by setting fire to the grass, and the hunting of other animals, including the elephant, is accomplished in a similar manner. It is evident that before such fierce fires seedling growth is killed out; that saplings and young trees are killed or mutilated, and that larger trees themselves must suffer, especially on the outskirts of the forests. So heavy is the toll taken that more wood is destroyed each year than is produced by the increase in girth and by the birth of new trees in places respected by the fires once in a way. In other words, the capital is being eaten into, the forests are deteriorating, and, unless protected, will ultimately disappear. Apart from purely economic reasons this is a prospect which is not good to contemplate if the effect of such a denudation is considered.
Forest zones.As before mentioned, the country can be divided into three divisions, according to the amount of drainage. Each of these divisions has its own characteristic vegetation:—
Swamp vegetation.The ambach (Herminiera elaphroxylon), which in places forms dense covers, and on the upper Bahr El Ghazal almost supplants papyrus, is the only plant which may claim to form forest vegetation. It may in future be of use, owing to its lightness, in floating timber down the river.
Lands not always submerged.On the land, which is under water annually at flood time, forest vegetation is scanty, and such trees as there are are usually perched on the top of termite hills. Such are the Sarcocephalus esculentus and Mitragyne Africana (Rubiaceae), the ardeib, dabka, gughan, the small-leaved inderab, and, where the soil is poor, Euphorbia candelabrum. Large expanses of country are treeless, owing to fires and heavy felling.
Highland forests.On the higher ground the chief ones are tamarind and gughan, with sidr bushes, talh (acacia), and talh-beida forests, um shutur, zeitun (edible fruit), abu khamera and heglig, and occasionally habil.
The above trees are also found on the higher land, but generally near water or in clay soil and in smaller quantities. The highland forests, however, differ largely from those on the lower lands, there being little acacia or thorny growth. Among the largest trees are the nwana (tanning bark “mudus”) and abu surug (tanning bark), kuru, riang or bei, shanda and koba (in best parts of forest), digdig (sweet yellow flowers), homra (large tree, allied to mahogany, also called homraya or murraya), and lulu (blackish scaly bark and tufted leaves, gutta-percha tree, above described).
The quality of the forests is at present not high. The best forests are those found in the broad, uninhabited stretch between Deim Zubeir and the Bongo, but even here the frequency of fires has prevented the stock from being at all uniform. In other places, where fires are still more frequent, and where there are traces of former cultivation, the stock is of a much more patchy character, and degenerates into curtains of forest surrounding blanks, or into mere scrub composed of contorted shoots of habil, dorut, kalto, akan, grewia, etc. It is, however, satisfactory to note that, even in such fireworn areas, there are still to be seen scattered here and there enormous trees such as shande, homra, bei, nwana, etc. But at the same time it is also a fact that, except in the case of koba, which reproduces itself fairly freely, the other large trees are not at all largely represented among those of younger generations, notwithstanding the fact that most of them seed abundantly. The most that can be said of these forests is that the larger trees are very fairly represented and that with proper treatment and protection some magnificent reserves could be evolved.
Principal timber trees.Homra: enormous size, would make a fine cabinet wood. Pinkish inside, but soon turns mahogany brown; found on ironstone.