Scientists and environmentalists here are raising alarm over the risks from alien invasive weeds that are slowly but surely inching towards Arusha National Park.
The undesirable plants reportedly pose danger to the wildlife and natural growth in the otherwise pristine reserve, located at the base of Mount Meru.
Researchers are already raising alert to conservators in the Arusha National Park regarding the presence of the deadly Parthenium weed, known locally as ‘Gugu Karoti!’
A scientist from the Nelson Mandela African Institute for Science and Technology, Praygod Kweka, stated that the Parthenium Hysterophorus, spreads rapidly along the road leading to both the park and Tanzania’s second highest peak, Mount Meru.
While the weeds have been wreaking havoc in various parts of Arusha, since 2013, it seems they are now on their way to the foot of Mount Meru.
So far they are just a stone-throw away from the entrance of Arusha National Park.
Ramadhan Kilewa, a researcher from the Tropical Pesticide Research Institute (TPRI), said they have already informed the Arusha National Park Management regarding the presence of the Parthenium weed close to the reserve and the importance of taking precautions.
The Assistant Commissioner of Conservation for the Tanzania National Parks, Albert Mziray, who oversees the Arusha National Park, admits that the alien weeds are indeed inching near the main gate, but not yet inside the reserve.
“We have been taking great precautions to protect the park from alien weeds,” said Mziray, explaining that they no longer outsource gravel from outside the park for road rehabilitations, lest they come with such seeds.
The park management is also sensitizing the masses regarding threats of the ‘Magugu Karoti,’ to wildlife, livestock and natural growth.
But the major challenge comes from the fact that the road linking Arusha and Usa-River towns with the villages in the Ngarenanyuki ward on the other side of Arusha National Park, cut through the reserve.
Public means of transport, including passenger vans and buses, cargo trucks and private cars use the road which passes through Arusha National Park.
Such regular human and machinery movements make the reserve to be more susceptible to infiltration of alien plants and other impurities.
According to scientists, Parthenium contains Parthenin, the same compound that is toxic to plants.
The compound when exposed to the skin or breathed into the lungs overtime can have negative effects on both humans and animals.
As species of the Aster Family’s flowering plant, Asteraceae, Parthenium is alien to Tanzania but native to the American tropics. Common names include Santa-Maria, Santa Maria feverfew, whitetop weed, and famine weed. It has been notorious invasive species in India and Australia, but now also in parts of Africa. In India, the weed is called carrot grass, congress grass or Gajar Ghas.
Should the weeds get into the National Park, grazing areas will be affected and likewise the wildlife may suffer, food shortages, infections and other problems.
Cases of dermatitis, asthma, and bronchitis due to the chemicals in the pollen and plant matter had previously been reported among livestock and humans. And if consumed by livestock or wild animals the alien weeds cause lesion in the mouth and excessive salivation. The chemicals also affect lactation in mammals.Researchers