Invasive aquatic plants are the source of the recurring problems in the AEG skill space. For several years, they represent a real threat because they contribute significantly to the decrease in water quality deductions.
Invasive aquatic plants are plants that have the capacity to rapidly colonize an area and spread far from the parent plants while leaving the possibility for other species to coexist and even succeed them.
The causes of the proliferation of invasive aquatic plants are related :
- Either a degraded physical environment (the bed layout, banks)
- either with pollution or chemical disruption of the water or sediment
- Or to a deterioration of the water quality (presence of nutrients in large quantities).
The development of invasive plants is not without consequences, it has impacts on various levels including :
- Impacts on activities
- Human : genes for the practice of fishing, agriculture etc … with the resulting economic impacts,
- Environmental Noise : vis-à-vis biodiversity : competition with native species uncompetitive lead up to their disappearance,
- Degradation of the quality of the environment, and in particular the quality of water : less penetration of light, oxygen deficit especially at night (vegetable breathing phenomenon without photosynthesis) Hydraulic —Incidences : creating hydraulic stoppers causing disruptions localized runoff or one-time increase in water levels.
However, there are several methods of destroying these invasive plants. We can cite :
- The Manual method, which involves the uprooting of plants without the use of motor vehicles ;
- The Mechanical method, which consists of any uprooting of the plant using either mechanical appliances, cleaning of the water body ;
- The Physical method of partial or complete filling of the water by land ;
- The Chemical method which comprises applying a herbicide, generally by direct spraying of plants ;
- The Biological method of letting go in the middle a body that will consume the invasive plant and to reduce, ultimately, people
- The issue of invasive plants, considering its environmental implications, social, and economic, and given the technical and financial constraints eradication must be addressed in a participatory manner, including the authorities, associations, NGOs and administrative structures competent.
Currently in Burkina Faso, there is no formal system of fight against the proliferation of invasive plants. The actions are usually done by the manual method.
This method has the advantage of immediately destroy the plants to enable local people to continue with their activities. It also offers the opportunity to mobilize people for their protection awareness of reservoirs. But the manual method does not have only advantages. It is very costly in labor and sometimes very laborious. It is a method that needs to be repeated several times because the result is not sustainable.
A boudieri, invasive plants dam consist of a single species : the Persicaria senegalensis (thumb of Senegal) called “koublougou” in gourmantché language. Polygonaceae family, they belong to the genus persicaria which includes about 150 species. The thumb of Senegal native of Africa is a land and freshwater plant, which is usually found in wetlands curbs ponds, rivers, gullies and ditches.
It is a perennial herb with erect up to three (03) meters high. It is polymorphic that is to say, it can take many forms. It is also a rapidly developing species which constitutes a real threat to the biodiversity of the environment that colonizes.
The Persicaria senegalensis colonized most of the bowl boudieri dam on at least two (02) ha.
With these observations the Directorate General of Water Agency Gourma (DGAEG) in collaboration with the Provincial Directorate of Environment and Water Resources Tapoa (DPERH-Tapoa), the Departmental Service of Kantchari environment and local residents Dam boudieri undertook destroying the work of these invasive plants by the manual method. The event, which took place from 25 to 29 May 2015, had a strong mobilization of the local population with a significant participation of women.