FACTORS THAT INFLUENCE VEGETATION DISTRIBUTION IN TANZANIA

FACTORS THAT INFLUENCES VEGETATION DISTRIBUTION IN TANZANIA 

I’m Kiwale Brasto, Festo. @ 2016

Ruaha Catholic University- Iringa, Tanzania

Published from Kiwale Company Publishers

This handout is here to help all people, therefore all right reserved no one would be allowed to copy, print, or any kind of plagiarism is involved, but read then leave it as it is.

Vegetation defined as the plants of a particular area which may be very diverse or belong to just one or a few species, depending on climatic conditions, the nature of the soil and human activity.

Basically there are two types of vegetation; 

Natural vegetation and artificial vegetation. Natural vegetation is plants that have not been grown by humans. It doesn’t need help from humans and gets whatever it needs from its natural environment. Some types of natural vegetation are forests, tundra, grass lands, woodlands, baobab and ebony and rainforests. Natural vegetation such as forests can regenerate after a long time which is called the secondary forest, example (http://grade7geography.wikispaces.com/).

Artificial vegetation are plants which are planted by man in a particularly area, it differs from natural vegetation in structure, composition, intensity of management, orderliness and uniformity for example pines, conifers and eucalyptus. Artificial vegetation may help alleviate the damaging consequences of the loss of natural vegetation on ecological (biodiversity), also to ellaviate soil erosion around the environment (Capossoli, 2008).

Therefore there are numbers of factors that influence vegetation distribution in Tanzania. Those are;

Climate, this influences vegetation distribution through temperature and rainfall. Rainfall or precipitation it determine the type of vegetation whether forest, grassland or desert, this because water needed for the plants growth and those areas with high rainfall or precipitation have a lot of vegetation, for example pines, mangrove, woodlands, conifers at coastal areas, Njombe, Iringa, and Mbeya because it receives high rainfall per year. While in dry areas contain poor vegetations for example in central part of Tanzania vegetation which found are shrubs, grasses, and baobab trees. Temperature also plays a big role in distribution of vegetation (flora) i.e. whether the forest is tropical or coniferous or the grassland is temperate or tropical (savanna). Where mean monthly temperature remains above 21⁰C for the year and there is a continuous growing and rainy season, broad- leaved evergreen trees tend to dominate (tropical rainforest). Places where there is a resting period in tree growth, either in hot climates with a dry season or cool climates with short growing season, are more likely to have coniferous trees as their dominant vegetation (Waugh, 2005: 256). Also it controls physiological process in plants like rate of growth, fertilization, seed germination and flowering. Some plants need cool conditions or cool in term of temperature therefore in area with high temperature always vegetations also are few and in cool condition many vegetation are growing and existing healthly throughout of the year, because the amount of soil moisture is high than in area with high temperature for example at Isimani, and Kongwa during summer time.

Soil, in some parts there is considerable local variation in vegetation due to differences in soil and underlying parent rock for example grass on chalk, conifers on sand, and deciduous trees on clay. Plant growth is affect by soil texture, structure, acidity, organic content, depth, water and oxygen content and nutrients (Waugh, 2005: 305). Therefore soil determine the vegetation of a given place, this is because different plants require different types of soil, the soil also determine the amount of moisture it can holds, dense vegetation is found in most fertile soil, for example Nyumba nitu forest, Lupembe forest, and Luponde forest at Njombe the soil it allows different vegetation to be present and in poor soil sparse vegetation are found for example at central zone in Tanzania (Tabora, Shinyanga, Singida, Mara and Dodoma) many parts have poor soil that’s why even vegetation are few in number.

Relief and drainage, some plants grow well in slope area while others need flat area. Different plants also require different altitude for them to grow (George, 2003: 704). There is vegetation that is suite to low area and those suited to high area and even the number of vegetation is high in low land area than in high land area like mountains or any hills have few vegetation in high land, a good example at kilimanjano, and Iringa (Kilolo) there are many vegetation in low land.  Drainage also determine the vegetation of a place, there are plants grow best in areas of good drainage and are many while others grow well in swampy condition for example papyrus which only grow in swampy area, mangrove in shallow salty sea areas therefore in area with few or no drainages have few vegetation comparing to area which have many drainage for example Iringa (Mfindi) have many vegetation comparing to area like Dodoma (Kongwa and Chamwino) few drainages hence few vegetation also.

Human activities, man also contributes the distributions of vegetation of an area. Such activities are planting trees in a place which did not have any vegetation, irrigations and burning vegetations, when the vegetation of areas is burnt the growth of other vegetation are encouraged to grow. While if man clear the area for introducing farms, buildings and infrastructure like roads makes an area to have few or no vegetation, for example area around Kilimanjaro mountain.

Government policy, affect the vegetation distribution, government has  gazetted some areas as forest reserves and National Parks in that area tends to have many species of plants for example areas like Ngorongoro at manyara, mikumi at Morogoro, selous at lindi, mkomazi at Arusha and Serengeti at Kilimanjaro. Also through policy like Cut one tree plant 10 trees and re-aforestation has also affected the distribution of vegetation around the environment (Simiyu et al, 2004). But on other areas which is not kept as a National Parks or Game reserves vegetations are reduced by cutting down vegetation for various activities like buildings, farming, introducing infrastructure therefore even the number of vegetation are few comparing to forest reserves and National Parks are many.

Aspect, (the direction in which a slope faces) affects sunlight, temperatures and moisture. South facing slopes in the northern hemisphere are more favorable to plant growth than those facing north because they are brighter, warmer and drier (Waugh, 2005: 305). Therefore aspect it also influences vegetation distribution in Tanzania. The area facing the sun receives more sunlight and hence is warmer than the leeward side. For example the southern part of Mount Kilimanjaro receives more insulation than Northern shapes facing Kenya. This affects the rainfall regime and vegetation growth such that southern shapes are conducive for plants growth while Northern slopes have poor vegetation.

Wind, affects the distribution of vegetation in Tanzania through the processes of pollination and seed distribution. Winds tend to transport pollens and seeds from one place to another, which leads the coverage of vegetation in particular area to be high than other areas (Waugh, 2005: 257). In addition, the place which have a strong wind there are few vegetations exist like at Tabora, Singida and Dodoma during summer period in this areas or regions experience strong wind, sometime vegetation become destructed than area where wind blows normal like Iringa, Njombe, Mbeya, Morogoro, and Mwanza many vegetations are present.

Generally, vegetation can help to get timber, food to man, climate control, pollution abatement, wildlife maintenance (provides shelter and food for wildlife), and preserving adequate water supplies. In Tanzania various parts Deforestation has been taking place highly, something led some areas which was not experiencing semi desert now experiences it for example at Isimani- Iringa, climate has changed comparing to the previous. Therefore we encourage planting trees and other vegetations in various parts of our country to recover the situation as normal especially areas which now do experience semi- desert and the government has to implement all policies toward environmental conservations.