4.1. DEMAND AND SUPPLY OF TREE SEED
4.2. IN SITU CONSERVATION
4.3. EX SITU CONSERVATION
4.4. TREE IMPROVEMENT
Although it is difficult to quantify the demand and supply of tree seed for both agroforestry and afforestation programmes because of poor records, the newly established Botswana National Tree Seed Centre (BNTSC) has some records of tree seed demanded by and supplied to twenty government tree nurseries. The BNTSC supplied these nurseries with 35 kg of both exotic and indigenous tree seed in 1996. In 1999, 75 kg of both exotic and indigenous tree seed were supplied to the same nurseries. It should be borne in mind that private nurseries and other non- governmental organisations do supply tree seed as well and the amount of seed demanded is much higher. The demand of tree seed in Botswana is very low when compared to other countries in the SADC region and this is so because apart from planting ornamental and fruit trees in homesteads, tree planting is not traditionally practised (Otsyina and Walker, 1990). This may be so because the country still has 93 per cent of its land covered with natural forests and woodlands and the people may not have actually felt the need to reforest the land. At 0.1 per cent per annum, Botswana also has the lowest annual deforestation rate in the SADC region (Totolo, 1997). Apart from the above, neither the government nor the private and non-governmental organisations do have massive planting programmes that could demand a lot of tree seed. Currently there are only 7 km2 of plantations in the country, representing 0.0012 per cent of the total land area (Totolo, 1997).
In situ or on site conservation refers to the preservation of whole organisms in their natural areas (Modise, 1992). Certain areas in the country have been set aside on state land for both flora and fauna conservation. These areas are owned by the state and comprise 23 per cent of the total land area of Botswana (NCSA, 1997). Most of it is used as National Parks, Forest and Game Reserves and no settlement is permitted. The National Museum has also set aside some areas and some individual trees as monuments. In all these cases, legislation provides for minimal interference on the state of the resources. With 93 per cent of the country still covered with natural forests, Botswana is in a better position to actively pursue in situ conservation.
Ex situ or off site conservation refers to the storage of whole or parts of organisms outside their natural areas in botanical gardens, zoos, plantations, etc. (Modise, 1992). There are very few ex situ conservation areas in the country. The three herbaria at the Department of National Museum, the University of Botswana and Department of Integrated Agricultural Research do have pressed plant specimens with the one at the Department of National Museum having about 20 000 specimens (Hargreaves, 1992). But apart from these specimens which are mainly for historical value, these herbaria do not have any germplasm stored away for conservation purposes. Some City and Town Councils, e.g. Selibe-Phikwe Town Council, do have some parks that are mainly meant for aesthetical purposes but may as well serve as botanical gardens or arboreta because of the rich plant diversity. Apart from these initiatives, the country is not explored. The National Plant Genetic Resources Committee currently has not made any collections of forest tree germplasm. The newly established BNTSC has also not started any form of ex situ conservation but do have plans of establishing an arboretum before 2003.
There are tree improvement programmes that were initiated by either government or non-governmental organisations such as Forestry Association of Botswana (FAB), Veld Products Research and Thusano Lefatsheng. The government (mainly DFRE) and FAB have always concentrated on exotic tree species elimination and provenance trials of tree species such as Eucalyptus (gum trees), Leuceana leucocephala, Atriplex nummularia (old man’s salt bush), etc. Veld Products Research continues to carry out tree improvement work on indigenous fruit trees such as Sclerocarya birrea subsp. caffra (Morula), Strychnos cocculoides (Monkey orange), Azanza garckeana (Snot apple), Vangueria infausta (wild medlar), etc. Thusano Lefatsheng does some improvement work on non-wood forest products such as Harpagophytum procumbens (grapple plant). Apart from the above programmes, very little tree improvement work is going on in the country even though a National Forestry Research Action Plan was drafted as back as 1992.
