Share this:

Vegetation of Uganda Notes.

Natural vegetation is the total sum of all plants that have grown naturally on the earth’s surface. The natural vegetation that grows in an area mainly depends on the climate of such a region.

Types of natural vegetation in Uganda.

  • Equatorial rain forests/ tropical rain forests.
  • Savannah vegetation
  • Dry region vegetation
  • Montane vegetation/ highland heath and moorland
  • Swampy vegetation.

The distribution of natural vegetation in Uganda

Image From EcoleBooks.com

Tropical rain forests

This is found in Mabira-Mukono, Budongo-Masindi, Kalinju-Bushenyi, etc and has the following characteristics;

  • The forest is thick and luxuriant with much foliage due to heavy and reliable rainfall received in the region throughout the year.
  • The forest contains a variety of tree species like Mvule, Msizi, Mahogany, Ebony, etc. therefore do not grow in pure stand.
  • Trees have got broad leaves and the forest is ever green because they receive reliable well distributed heavy rainfall throughout the year.
  • Trees form canopies and have no under growth due to less lights penetrating through the forest because of the dense canopies.
  • Trees have buttress roots to support the heavy tree stems and many climbers which move from one tree to another.
  • Forests have hard wood trees with a long gestation period and such trees grow up to 50metres high due to competition for light and fertile soils in such regions.

NB. Lumbering, forest exploitation, growing of subsistence crops, wildlife conservation, tourism development, settlement, are the major land use types in tropical rain forests.

 

Problems of land use types in the tropical rain forests of Uganda.

  • Heavy rains cause pest multiplication such as mosquitoes and tsetse flies which transmit human diseases. This affects settlement in areas of Mabira, Ssese, Etc.
  • Impassable roads caused by heavy rains which destroy roads creating potholes. This affects lumbering like in Kibale forest since logs and timber transportation is limited.
  • The humid conditions within the forests and dangerous animals such as snakes limit forest exploitation as it is in Budongo forest.
  • Trees do not grow in pure stand which hinder their selection, felling and transportation of logs.
  • These forests experience fire out breaks during dry seasons and uncontrolled farming has cleared much of the tropical rain forests.
  • Animals from such forests like Ssese forests destroy crops grown near the forests thus hindering crop growing.

 

Savannah vegetation

Savannah covers much of Uganda‘s total land area. It is divided into savannah grassland and woodland. Also dry savannah sometimes known as range lands.

Savannah woodlands

This is found mainly in Kei, Otze, Timu, in northern Uganda, West Nile and some parts of central region.

Savannah grasslands

ecolebooks.com

These are well developed in the fringes of savannah woodlands. It exists in Nakasongola, Luwero, Hoima, Sembabule and in the rift valley areas of western Uganda.

The dry savannah or rangelands are found in Albert flats, Semulik zones, Kotido, Moroto, Kaabong and in Ankole Masaka dry corridor.

 

Savannah vegetation has got the following characteristics.

  • Combination of trees and grasses but the trees are not so close like in forests.
  • Trees are umbrella shaped and shed off their leaves during the dry season.
  • The grasses are very tall up to 1metre like elephant grass due to moderate rains received in the area.
  • It should be noted that different forms of savannah have got different characteristics.

NB. Crop growing, animal rearing, settlement, wildlife conservation in National Parks like Queen Elizabeth, Kabalega, wood collection, hunting are some of the land use types in savannah.

Rangelands / dry savannah

These are dry savannah rangelands which receive 750mm of rainfall and below. In Uganda they include;

  • North eastern Uganda in Karamoja regon of Kaabong, Moroto, Kotido, etc.
  • North Acholi in Maracha district
  • Western rift valley in Albert flats
  • Around L. Edward and L. George in Queen Elizabeth national park
  • Ankole-Masaka dry corridor
  • Bululi-Nakasonglo areas.

 

Distribution of dry savanna vegetation in Uganda

Image From EcoleBooks.com

 

Characteristics of rangelands in Uganda

  • Low and unreliable rainfall of less than 750mm per year which leads to growth of short grass, scrub and thorny thickets.
  • High daily temperature throughout the year of over 300C which has led to growth of thorny trees with thick barks and needle shaped leaves to store enough water for use during drought seasons.
  • Low temperatures at night and high during day which has discouraged settlement in the region and the areas have been left for national parks like Kidepo in north east, Kabalega in Albert flats and Queen Elizabeth in western rift valley.
  • There is low humidity, cloud less skies and rains received is erratic.

Conditions for the growth of dry savannah in Uganda

  • High temperatures of over 260C like in Nakapiripiriti have led to growth of dry savannah vegetation. This facilitates the growth of trees with small twisted leaves so as to avoid loss of moisture through rapid respiration and evaporation.
  • Low humidity content in the atmosphere in the areas like Kotido leads to scarcity of luxurious vegetation except drought resistant vegetation such as thickets.
  • Low and unreliable rainfall between 250-500mm favours growth of dry savannah vegetation in Moroto and Kaabong. This supports growth of acacia, baobab and cactus trees which are drought resistant.
  • The low lying relief in the Albert flats and Kotido district experience high temperatures and low rainfall thus growth of drought resistant vegetation.
  • On the lee-ward side of Mt. Rwenzori there is scarce rains due to descending dry winds thus dry savannah vegetation growth.
  • Poor and sandy soils with limited retention capacity like in Kotido and Kaabong and Albert flats which can only support poor plant life growth thus dry savannah vegetation.
  • Overgrazing like in Karamoja region and in Kiruhura in south western Uganda leads to depletion of vegetation thus encouraging dry savannah vegetation.
  • Wildlife conservation in game parks of Kidepo, Queen Elizabeth and Murchison fall park with animals such as buffaloes, giraffe which eat up vegetation and create dry savannah vegetation.
  • Bush fires by farmers like Basongola and Karamajong has led to growth of stunted grass with short trees which are scattered.
  • Deforestation for farming, lumbering and tsetse fly control like as it was in Albert flats, led to growth of dry savannah vegetation.

 

 

 

Economic activities in rangelands

  • Subsistence farming like nomadic pastoralism in Karamoja and Bululi, production of cereals like maize, millet and cotton like in Kasese.
  • Wildlife conservation through gazettng national parks like Kidepo, L. Mburo, game reserves like Ajai in north western Uganda, etc.
  • Ranglands provide vast land for settlement like in Hoima, Nakasongola, etc
  • Mining like oil from Albertine shores, gold in Karamoja, etc.
  • Rangelands provide a great potential for tourism due to fauna and flora in Kidepo, Queen Elizabeth, etc.
  • Hunting like in Karamoja hunting zone, Bamunanika royal hunting zone in Luwero, etc.
  • Local herbs collection and fruit gathering like in Lwera in Masaka and Nakasongola.

Problems faced in rangeland areas.

  • Water shortage for watering animals and domestic use especially during drought seasons, this leads to death of animals like in Karamoja.
  • Harsh climatic conditions of low rainfall totals and very high temperature during day and very low temperature at night has caused water shortage, famine, poor pasture, fire outbreaks, etc.
  • Tropical pests and diseases which attack animals like nagana, crops and human beings like sleeping sickness hindering settlement and animal rearing.
  • Limited important infrastructure of valley dams, veterinary services, market centres, health centres and roads like in Kaabong which has made the areas remote and inaccessible.
  • Poor land tenure system of communal land ownership which has led to frequent degradation and abuse of rangelands.
  • Unfavourable government policies of utilizing the rangelands like the government of Uganda has neglected such areas of Ankole-Masaka dry corridor and Bululi thus limited infrastructure.
  • Sometimes floods caused by erratic rains in rangeland areas destroy crops and property and also claim human lives like as it was in Teso north eastern Uganda in 2007
  • Some of the rangeland areas have got porous soils which do not favour crop growing. There is also the practice of poor farming methods like overgrazing which cause soil erosion.

Steps taken to over ride these problems

  • Construction of boreholes and valley dam to fight the prolonged drought and water the animals in the region.
  • Cultivation of profitable crops using scientific methods of planting of high breed seeds of cereals with short gestation periods. This has been done in Kitugm and Kotido.
  • Farmers have been encouraged to apply fertilizers and organic manure where soils are poor. The use of irrigation like in Kibimba has increased on food production.
  • Co-operative farming has been encouraged. Also cotton has been grown as a cash crop to increase on food supply like in Bululi and around L. Edward and George.
  • There has been introduction of ranching schemes to provide veterinary services, scientific animal rearing methods, water sources mainly in Ankole-Masaka dry corridor and Bululi-Nakasongola.
  • The government has set up milk collecting centres to enable marketing of cattle products of milk. Also beef markets have been established like in Sanga in Kiruhura district.
  • Activities such as mining have been empowered like the extraction of oil at Albert, gold in Karamoja and tin in Ankole-Masaka corridor.
  • There are aforestation programs to diversify the environment through formation rainfall and protection of land against erosion.
  • Rangelands have been gazatted into national parks and game reserves like Kidepo and Ajai respectively. This has developed the tourist industry and helped to extend social infrastructure like heath services, roads and water to rangelands.
  • The communal land ownership is being checked in favour of individual land ownership as the case in Ankole-Masaka corridor. Also paddocking of grazing land has been encouraged.

Montane vegetation

Vegetation on mountains varies according to the altitude. The higher the altitude, the cooler the temperature. Such temperature favour the growth of different vegetation types as illustrated below.

Vegetation zonation on Mt. Rwenzori

Image From EcoleBooks.com

 

 

 

 

 

 

 

From the above vegetation zonation on Mt. Rwenzori, we realize that vegetation zones reflect changes in climatic conditions i.e.

  • Savannah vegetation reflect tropical climate
  • Tropical rain forest reflect equatorial climate
  • Bamboo and alpine vegetation reflect temperate climate
  • The moorland, heath and bare ice cap reflects polar climate.

NB. Different economic activities are carried out in different zones e.g.

  • In savannah, crop cultivation, mining and quarrying like in Kilembe –Kasese, etc.
  • In equatorial zone, perennial crops growing like tea and coffee in Bujjuku in Kasese, lumbering, etc.
  • In bamboo, the tree poles are exported especially to Germany. There is also fishing from R. Sebwe and Mubuku, etc.
  • The alpine pasture give potential ground for grazing animals especially exotic type.
  • The moorland and ice cap are source of rivers like Mubuku and Nyamwamba. The region also attracts tourists thus foreign exchange.

Factors influencing vegetation cover in Uganda.

  • Climatic factor of rainfall and temperature i.e. areas with abundant, heavy and reliable rainfall over 1500mm per annum have forest cover like Ssese in L. Victoria, well as areas with low and unreliable rainfall below 500mm per annum like Kaabong in Karamoja, there is dry savannah vegetation.
  • Regions with high temperature experiences luxuriant forest growth like Mabira while those with low emperature like on the peak of Rwenzori in western Uganda, vegetation is reduced to alpine, moorland and sometimes bare rocks.
  • The soil nutrients, texture, depth, moisture, content, acidity and alkalinity affect vegetation. Well drained moisture fertile soils leads to growth of dense forests well as poor soils lead to growth of grass vegetation.
  • Altitude, as already illustrated, different altitude levels have different vegetation types. This is because different altitude levels have different temperature and this is clearly seen on Mt. Rwenzori in western Uganda.
  • Latitude, dense vegetation cover like Mabira forest in Mukono grows along the equator due to availability of reliable rainfall, high humidity and hot temperature. With an increase in latitude, there is reduction in growth of vegetation in a dense form.
  • Biotic factor i.e. Animals and birds act as seed carriers (dispersal) and lead to growth of vegetation in many areas. Pests like locusts on the other hand destroy vegetation.
  • Presence of light, this is required for photosynthesis process. Where light is abundant like in Budongo, vegetation growth is luxuriant while limited light cause limited vegetation growth.
  • Winds, these affect the rate of evaporation. Fairy strong winds increase the rate of transpiration resulting into strong growth of vegetation like in Bwindi southwestern Uganda.
  • Human activities such as burning, overgrazing, deforestation, cultivation destroy the existing natural vegetation. However through afforestation and reforestation, reservation, etc, it leads to vegetation growth as it has been in Mbarara, Kabale, Ntungamo in south western Uganda.
  • Government policy, through policies of forest reservation, wetland protection, etc there is vegetation growth. Wars and wildlife conservation leads to destruction of the available vegetation type turning it into another type. This explain why parts of Karamoja in Kidepo valley which were experiencing savannah vegetation has turned in semi-arid vegetation due to wildlife conservation by Ugandan government.


 




Share this:


subscriber

Leave a Reply

Your email address will not be published. Required fields are marked *

Accept Our Privacy Terms.*