(b) Effects of rainfall on the distribution of vegetation in Nigeria
(1) Heavy rainfall supports tall trees in the South of Nigeria while low rainfall' supports growth of short deciduous trees in the North.
(2) High rainfall areas of over 2000mm rainfall gives rise to forest vegetation.
(3) High and continuous rainfall give rise to evergreen vegetation
(4) Areas which have rainfall between 100mm and 150mm produc3 Guinea Savanna type of vegetation
(5) Areas which have rainfall under 1000mm produce Sudan Savanna typ of vegetation
(6) Areas which have rainfall under 500mi produce Sahel Savanna type of vegetation.
(7) Areas which have rainfall that is less than 300mm produce desert vegetation
Areas with rainfall between — 2000m produce montane vegetation as clearly shown in Jos and Eastern highland.
(9) The commencement of rain marks the beginning of the growth of grasses
(10)As rain decreases northwards, density of vegetation decreases.
Characteristics of Guinea Savanna
(i) It is the largest of all vegetation belts in Nigeria
(ii) It has tall grasses
(iii) The grasses are green during rainy season and turn brown in the dry season.
(iv) The presence of few scattered trees,
(v) Trees are deciduous
(vi) Th trees have thick barks
(vii) Trees have long tap roots
(viii) Some trees have umbrella-shaped canopy
(ix) The tree form gallery forest along the river banks
(x) Tree types are: - oil palm, dum palm, shea butter, isoberlina, etc.