Egypt

The indigenous desert trees, Acacia spp (A. tortilis, A. raddina, A. ehrenbergiana and Balanites aegyptiaca), are the most common and important fodder plants in Wadi Allaqi. Tamarix nilotica is also an importanat pasture plant that provides permanent fodder; it grows in previously inundated parts of the downstream Wadi Allaqi.

Acacia
Acacia trees (A. raddiana, A. ehrenbergiana and A. tortilis)form a principal element of desert plant communities in Egypt's South Eastern Desert. They are widespread in remote desert areas but sparse near settlements and urban areas as a result of human impact. Acacia trees play an important role in the function of desert ecosystems.

The scarcity of water in the hot desert enhances the young tree to grow a deep root system that is able to make the best use of the available moisture in the soil. The growth of branches above the ground is slow whilst this is happening, and the tree can remain in dwarf form for many years before growing on to reach maturity.

Because of slow growth grazing adversely influences the seedlings more than the mature trees. Very often plants stay in dwarf form waiting the fortune of the rain. As soon as favourable conditions come, they grow quickly. Usually this happens when rain falls in two successive years. This gives considerable grazing for livestock on ephemeral pasture , hence the grazing pressure on Acacia will decrease, and, using the available moisture, trees will quickly establish themselves (Springuel et al., 1995).

Observations in Wadi Allaqi shows that under sufficient water supply and protection from grazing the trees can reach a mature stage and height of seven meters in less than 10 years, while in natural conditions it can take approximately 50 years (Springuel & Mekki, 1994).

Acacia trees are of considerable importance as fodder plants in the desert. They are the drought reserve fodder, which is only fed to stock at times when other food is very scarce. The importance of permanent trees as a drought reserve and as the stable source of food upon which people can always rely is also noted for peoples living north and southeast of Allaqi (Hobbs 1989, Hjort and Dahl 1991).The ripe pods of this species, called ollaaf, are important fodder for domestic animals, particularly during the dry summer months. Acacia trees are nutritious and contain high values of protein, ranging between 5% and 14% in young shoots and 21.20% in fruits (Annex XXX). Also the protein content shows high variability according to the seasons. It is higher in the wet season and low in the dry season. Data in Table 2. (Annex 2) show that in December 94 (after the rain of November 94) the protein content of forage was higher that in dry December 95 when the rains failed for the year.