| Measuring drought and drought impacts in Red Sea Province |
|8. Changes in tree density on five sites in Red Sea Province: early 1960s to 1989. Roy Cole|
The purpose of the present study was to assess the impact of increased resource use and drought on vegetation in five areas of Red Sea Province by comparing recent tree density counts with counts obtained from aerial photographs of the same areas taken twenty-five years ago. The tree is important to the dry season survival of all livestock in Red Sea Province. In many mountain, khor and delta areas of the province trees remain green throughout the year; these areas make up the dry season redoubt of pastoralism. Change in the densities of Red Sea Province's tree population has serious and long-term consequences for the pastoral system as a whole.
The issue of the human impact on trees is central to the present study in that, with the exception of a hypothetically severe and prolonged drought, the trees in Red Sea Province should enjoy a safe existence. The growth in human population, particularly Port Sudan, and the consequent increased demand for charcoal, firewood, kiln-fired bricks and pottery, bread, and building material has changed all this and traditional sanctions against destruction of the forest resource have been relaxed in principle and abolished in practice as the rural areas of Red Sea Province have been incorporated into Port Sudan's economic hinterland and structured to supply its needs.
Traditionally, the pastoral economy in Red Sea Province has been dependent upon two natural resources: annual and perennial vegetation. During the rainy, or flooding, season when protein-rich annual vegetation is available livestock make weight gains, reproduce, and provide the greatest quantities of milk. During the dry season when all vegetation except trees and some shrubs dies or dries up, livestock experience weight loss and low production. Any change in the availability of any of the pastoral resources in one season has implications for the survival of livestock in the other season and, if the change is severe enough, for the land use system itself. In some ways, perennial vegetation is more important than annual vegetation in Red Sea Province. When there is a drought and no annual pasture production, it is to the perennial vegetation that the livestock turn for survival. In the dry season, however, there is no alternative. If anything happens to impair dry season fodder production the pastoral system will be weakened.