The miracle power of bushfire in the Savannah
AS this week was coming to an end, report from Morogoro indicate that bushfire has destroyed a big area with natural vegetation around Mindu dam.
Scientists define fire as the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products.
Fire is hot because conversion of the weak double bond in molecular oxygen, O2, to the stronger bonds in the combustion products carbon dioxide and water.
At a certain point in the combustion reaction, called the ignition point, flames are produced as result of a material reaction.
The flame is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapour, oxygen and nitrogen. If hot enough, the gases may become ionised to produce plasma.
Scientists say, depending on the substances alight, and any impurities outside, the colour of the flame and the fire’s intensity will be different.
Fossils records show for the first time, the first fire sparked on the Earth about 470 million years ago.
Today in Morogoro as leaders, politicians and other stakeholders are trying to find out what is the main cause of this problem, let us learn something about bushfire and its strength.
Moreover, scientists say a wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation starting in rural and urban areas.
Wildfires are often classified by characteristics like cause of ignition, physical properties, combustible material present, and the effect of weather on the fire.
Climatic cycles that include wet periods that create substantial fuels and then are followed by drought and heat often procede severe wildfires. These cycles are made worse by heat waves and droughts caused by climate change.
Wildfire behaviour and severity result from a combination of factors such as available fuels, physical setting, and weather.
Scientists say what is happening around Mindu dam is caused by a wildfire, this is an agent of nature born out of natural forces such the Sun which play a big role to ignite a wildfire both in the grassland of an ecosystem.
Before our eyes this can be a devastating event but scientists say wildfires maintain vegetation standard of an ecosystem by burning down all unwanted, dead, dry and invasive plants.
In a savannah area of Serengeti, Tarangire or Ruaha national parks wildfire maintain the grasslands by destroying 70 per cent of invasive tree plants which try to change the natural vegetation of the animal sanctuary.
By doing this the wildfires do not only clear the savannah but also ashes which are produced from the destroyed plants are used by nature as manure to nourish the soil.
Evolution has equipped plants which are found into the wildfire prone area with special ability of countering its attacks by hiding their root systems deep in the ground.
History shows that wildfires have been around the Earth from more than 125 million years and during that time it contributed into changes of the way plants germinate and survival.
Wildfire or bushfire as it is popularly known play a key role on the savannah by removing tree and other plants which are able to survive the dry season.
This enables the natural grasses of savannah to grow again immediately after rain which quench their thirst and supply them with ashes which are full of important nutrients.
The action and power of the wildfire assure enough supply of fresh, delicious and nutritious grasses to wildebeests, zebras and antelopes which arrive in southern part of Serengeti every year.
On the other hand, bushfire also reduce the number of insects and small reptiles but also enable birds of prey such as secretary bird to get food as they walk behind it while picking preys who may try to escape.
Scientists say without the presence of wildfire the southern part of Serengeti national park would have changed into a huge forest and block or switch the migration out of the ecosystem.
Nature uses the Sun to heat and drain water from dead grasses and other plants by increasing internal temperature from normal standard to more than 100 centigrade.
This situation leads into a plant to dry and create another increase of temperature up to more than 230 centigrade which allows the ignition of fire without the presence of other agents such as kerosene or dynamites.
Scientists say this is a slow process which starts from a spot where temperature is pushed up to 590 centigrade above boiling point which ignite wildfire very easy.
From that point in what scientists call Heat transfer, the first elements of bushfire may start fire and increase temperature of the surrounding area to 800 centigrade which bears powerful flames.
This is delicate situation in any savannah grassland because wildfire is able to gain a deadly speed of up to 10.8 kilometers per hour while destroying almost everything on its way.
The destructive strength of wildfire may be enabled by geographical factors such as wind which supply enough oxygen which facilitates the burning process to attain a deadly speed of 22 kilometers per hour.
From time in history to date this is what has been shocking people whenever a wildfire breakout within their neighbourhoods.
Although human activities may contribute into igniting a wildfire but other natural forces such as lightning and volcanoes are known to have an upper hand on causing this calamity in a savannah.
We need to be careful because different scientific reports show that with this strength in 2010 pockets of wildfires were responsible consuming more than 2 million acres and in 2011 they were also blamed for destroying 5.5 million acres of forest.
These reports were collected from different parts of the world but scientist say more than 3.5 million acres which was destroyed by wildfire human activities played a key role.
Scientists say three elements are required for a wildfire to breakout, these are oxygen, heat and plants that bear fruits or seeds which contain oil substance.
Some ecologists from Europe and America are known to blame shifting cultivation in Africa as main cause of bushfire but few months ago this natural agent destroyed more than 2,400 houses in Canada.
With one of most sophisticated fire extinguishing equipment on Earth, the province of Alberta could not match with the strength of wildfire.
Plants with oil enriched underground roots are known to transfer fire from one bush to another but dry leaves and grasses put additional strength to a wildfire which could stop without their presence.
Despite all accusation and speculation, in East Africa natural forces are responsible for wildfire in national with longer dry season which favours the presence of savannah vegetation.
Due to this fact during dry season nation parks such as Tarangire, Ruaha and Serengeti are prone for attacks from wildfire than Kilimanjaro or Udzungwa which are characterized with tropical forests.
Uluguru Mountains are home to mountain dwarf galago or the Amani dwarf galago, the mammal is endemic to the Eastern Arc mountains of Tanzania and Kenya where it is available at altitudes of between 1,200 and 2,000 meters above sea level.
Meanwhile, scientists say climate is major factor because during rainy season it enables grasses to grow massively in plain of Serengeti but from July things change as the dry season start to bite.
Every year from the month August nature start to turn plains of Serengeti into fire prone area by drying down almost all grasses within the ecosystem.
To deal with this harsh condition nature has enabled wildebeest, zebra, antelopes and other herbivorous special appetite of eating dry grasses but whenever the situation is unbearable the migration is an ultimate solution.
From June to September before the short rains of October, temperature may rise above 27 centigrade during daytime due a clear sky which allows sunrays to heat the ground with all their energies.
During this hot season most of animals involved in the migration spend their time in Grumeti and Ikorongo game reserves which are found on the northern side of Serengeti national park.
In a movement of a clock arm which follows rain patens, every year a resilient contingent of more than 1.8 million animals shifts from one part to another in the greater Serengeti ecosystem.
As they cross crosses hill and plains their hooves beat the ground and break rocks which hit each other and strike the first ignition for a full bushfire in a year.
History show the first wildfire evolved about 420 million years ago after the rise of oxygen concentration in the air and the first charcoal was produced on the Earth.
Scientists say the level of atmospheric oxygen is closely related to the prevalence of charcoal and clearly this show oxygen is the key factor in the occurrence of wildfire.
Historians say fire became more abundant when grasses radiated and became the dominant component of many ecosystems, around the world from HYPERLINK “http://tools.wmflabs.org/timescale/?Ma=6%E2%80%937” 6 to 7 million years ago when the world was still.
Some forest ecosystems in their natural state depend on wildfire, depending on the type of vegetation present, a wildfire can also be classified more specifically as a bushfire, desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire.
Scientists say fire types can be generally characterized by their fuels as follows ground fires are fed by subterranean roots, duff and other buried organic matter, crawling or surface fires are fueled by low-lying vegetation on the HYPERLINK “https://en.wikipedia.org/wiki/Forest_floor” \o “Forest floor” forest floor such as leaf and timber litter, debris, grass, and low-lying shrubbery,
Other types are ladder fires consume material between low-level vegetation and tree canopies, such as small trees, downed logs, and vines, Crown, canopy, or aerial fires burn suspended material at the canopy level, such as tall trees, vines, and mosses.
The ignition of a crown fire, termed crowning, is dependent on the density of the suspended material, canopy height, canopy continuity, sufficient surface and ladder fires, vegetation moisture content, and weather conditions during the blaze.
Meanwhile, lying under the shadow of Uluguru mauntains, Morogoro municipal harbors more than 305,840 people who depend on the supply of water from Mindu dam which was built in 1978 along Ngerengere river.
The beautiful Ngerengere has its catchment on the slopes of Uluguru Mountains which rise for about 2,630 metres above the sea level.
Standing about 200 kilometers away from the Indian Ocean, the range of mountain is surrounded by a beautiful natural forest which is closer to more than 50 villages with about 150,000 farmers.
Climate on the area is dominated by moisture passing inland from the Indian Ocean making the east facing slopes especially wet, with rainfall estimated at over 3,000 millimeters per annum, and some rain falling in every month.
These have enabled the growth of a huge forest around the mountains and provide the water catchment areas for the streams and rivers. This water flows mainly from the forest on the slopes of the Ulugurus into streams joining to form the different rivers including Ngerengere.
Meanwhile different researches show for the past 30 years because of different economic activities on the sides of this river, the level of water flowing on its bed has fallen and something need to be done to stop the situation.
Research findings showed that the maximum air temperature increased at a rate of 0.045% on a span of 30 years, while rainfall has been decreasing with time.
Between 2014 and 2019, because of deforestation has resulted into an increasing trend of wind speed.
Due to all these climate changes, the situation resulted into the decrease of water into Mindu dam as its reservoir capacity dwindled for about 0.57 a year from than 19 years ago.
All these and other unmentioned factors have caused temperature to increase at the rate of 0.045 per cent from the past 30 years, while rainfall has been decreasing with the same time.
Reginald Stanislaus Matillya
Contact mail: HYPERLINK “mailto:rstanslaus@yahoo.com” rstanslaus@yahoo.com
