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Alien plants a threat to natural environment
2008-04-21 10:24:31
By Lusekelo Philemon
Human beings are born with a sense of admiration to good things that impress their eyes. When travelling within Tanzania and sometimes flying abroad, some people tend to pick seeds and stems of the beautiful flowers and fruit trees found out there.
They just pack in their pockets, bags and handbags among others.
They plant along their homesteads and perhaps the farmlands as well as nearby the natural forest reserves without awareness of its environmental impacts.
``We now face a serious problem in fighting against invasive alien plant species, as most of those seeds and stems are not treated,`` says Dr. Mohamed Rose-Anne, Health Services Officer in the Ministry of Agriculture.
She cited examples of some people who she said have a tendency to take fresh fruits like mangoes from China or any other countries in the Middle East to Tanzania.
When they come with those fruits Dr. Mohamed says, some may have bacteria that are harmful to the country\'s environment.
``Most of these fruits and seeds are not treated,`` she says.
She says, the situation threatens the country\'s natural ecological system as some of those species are detrimental to Tanzania\'s environment.
``The problem is more serious because it is a hard task to check in every ones pockets. This is a problem that needs to be addressed. People should know the danger of taking alien plant species in our environment specifically in our natural heritage,`` stresses Dr. Mohamed.
The inlets like region\'s bus terminals like Ubungo in Dar es Salaam, that shelters passenger buses from Kenya, Uganda, Malawi and DRC, airports, ports acts as the main entry points of alien species in the country.
Mohamed says it\'s very difficult to control those species especially those carried by individuals. ``Most of them take those seeds and stems in their bags, which become very difficult. Somehow in the airports, it can be controlled though in a small scale,`` she says.
According to experts, the problem becomes more complicated when it comes to those who use roads, as they can drop anywhere on the way. Few reach the last points of their journeys.
Even if you can establish check-points at the bus terminal, it will be very difficult to control this problem, says Anthony Kuria, Tropical Biology Association (TBA), Project Manager.
TBA works in partnership with tropical countries to build expertise in biodiversity conservation and research. And on this fight against invasive alien plants under the Darwin Initiative Project, TBA is working in collaboration with partners from the UK, Tanzania and New Zealand.
Kuria says, some people take alien plants in the form of food crops like sorghum and other cereals, in which within there are those alien species.
``Sometime ships from abroad have a tendency to off-load polluted water in our ports and by so doing detrimental alien species, end up in the Tanzania\'s water bodies,`` he says.
Pollutants of this nature are the breeding grounds of various invasive weeds including the well-known and menacing water hyacinth and algal blooms.
Experts say, human being has a large share in dispersing these alien species saying animals especially birds and primates too have a share on this.
Prof. Phillip Hulme, of the Tropical Biology Association said the problem is escalating thus in need of urgent measures to slow down its magnitude.
Prof. Hulme says: ``It takes 600 to 900 hours to harvest only one hectare of dense water hyacinth, which is about 50 tons of the aliens from White Nile annually. African countries including Tanzania have to spend a lot of money to deal with the invasive alien species.``
According to him, alien invasive species are a threat to people\'`s livelihoods and the indigenous plants, animal species and the country\'s biodiversity.
The expert says, invasive alien plants-the plants that are not native to a country and whose local abundance and spread is increasing to cover new areas are a major threat to the natural environment.
Prof. Hulme says there is a lot to be done including increasing the level of awareness which was low compared to the developed world.
He stresses that local communities need to be well-informed on the danger of invasive alien plants.
``Awareness campaign from forest management teams and people at the grass roots should be encouraged to rescue the extinction of natural ecological system,`` he says.
Wayne Dawson, a research student at the University of Abardeen-UK, says plant species like lianas, have colonized large part of East Usambara Forest Reserve, hence changing the entire forest structure and dynamics.
``Some of the invasive alien species like Chimonobambusa have dominated all open areas and spread over the forest reserve. Pioneer trees like Cedrela odorata, have a tendency to grow rapidly and they are in high numbers that dominate the forest edges,`` Dawson said.
For Ezekiel Edward, research assistant, Sokoine University, is of the view that comprehensive approaches are highly needed to scale down the magnitude of the problem.
``The Amani Nature Reserve has similar problem that needs a number of stakeholders to come in and address the alarming situation,`` he says, adding that constant removal of seedlings is the best friendly ways to curb the problem in the reserve.
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