Browse production and utilization in Tarangire National Park
Authors: VESEY‐FITZGERALD D. 
Published: April 2008

A survey of the vegetation was undertaken in order to ascertain the browse production and its utilization by the existing community of animals in the park. The most prevalent types of woody vegetation are Acacia woodlands in the drainage lines and Commiphora‐Combretum deciduous woodlands on the uplands. As these formations are considered to provide the bulk of the available browse, the animal impact on the woody plants (mainly shrubs and young trees) in relation to replacement growth and regeneration, is the principle theme of the present paper.

The method used for collecting field data is explained. The intention was to collect meaningful information on the composition and dynamic status of the vegetation in relation to the course of plant succession and possible causes of disturbance.

For the present purpose, the data are treated so as to elucidate the effect of browsing on growth and growth on browsing. The main factors considered include, the distribution, status and structure of the vegetation; possible disturbances that may have caused changes from the state of naturalness; the distribution, frequency and density of the commoner species of shrubs and trees; the intensity and effect of browsing on woody plants, and the influence that utilization may have on the course of plant succession or decline.

Conclusions are discussed in the light of conservation. On the one hand it is accepted that browsing animals have to be catered for. On the other, that the productivity and diversity of the vegetation should be maintained.

A balanced situation is one in which utilization is replaced by growth. In these circumstances, both the primary and secondary productivity of the ecosystem is maintained. Both over‐utilization and under‐utilization would indicate an imbalance as a result of which productivity will be lowered.

The survey indicates that only about half the available browse is currently utilized, and of this amount, most is replaceable by growth. On the average, not more than 1 % of any common species is so damaged that recovery is unlikely. Most of the species that are severely damaged are deciduous; those that are least damaged, but at the same time sustain the highest overall impact, are evergreen. Furthermore there is no conclusive evidence that the course of succession is impeded by utilization.

The results of the survey do not, therefore, indicate that there is over‐utilization of the available browse. Other conditions being equal, the browse potential in the park should be sufficient to support the existing community of animals. However, the environment is not stable. The rainfall is low and variable. The vegetation is degraded and because grassy types of vegetation are extensive, the fire hazard is high. Undoubtedly there has been over‐burning for years and a programme of fire management is overdue.

In these circumstances, the following recommendations are made. (1) Further field data should be obtained by using the method explained in this paper. (2) A programme of fire management should be initiated and carried out. (3) Utilization, replacement growth and the progress of plant succession should be monitored in order to ensure that the productivity of the area is being maintained or increased. In this way the goals of management in the park will be assured and it is expected that the browse potential in the park will be able to support a healthy and varied community of animals.