An invasive species is a species of plant, animal, introduced (not native) fungi in an ecosystem and spreads rapidly causing damage to animals, plants and, in turn, to the entire environment. These species are not native to a given place but are introduced involuntarily or consciously. These species are also known as “alien, introduced or non-native species”. It is known that invasive species cause economic, ecological and environmental damage by shifting the natural balance of bionetwork. It is essential to note that not all non-native species are invasive and it is difficult to classify an organism as invasive.
For a species of flora or fauna to be considered invasive, its reproduction process must overcome some topographical barriers such as mountains and oceans. Invasive species also overcome environmental germination barriers such as the availability of moisture, soil pH, and the availability of nutrients among other things. These alien species have a tendency to form a self-sufficient population and do not need reintroduction in the same area. Their ability to resist minor potions and to spread rapidly is adequate. They can alter the form of growth to adapt to different environmental conditions. Their destructive nature obscures the benefits.
Different species can have different negative effects. These can range from disease, poisoning, migration and even death. This leads to increased spending on medical care, decreased productivity and other negative incidences. An example of an invasive species is the West Nile virus that caused the illness and death of people and horses in the United States. Chinese Sumac lymph causes inflammation of the heart muscle after minimal skin contact. Invasive species have caused the death and migration of wild animals from their natural habitat and decreased the carrying capacity of the areas. These species are known for deforestation and destabilization of the soil. To combat them, the authorities use many resources that would have been used in other productive areas of the economy. The water hyacinth on Lake Victoria in Kenya has led to a decrease in the values of bathing properties and to the decrease in fish resources, thus altering economic gains.
Although destructive, some invasive species have been beneficial to humanity. Historically, several invasive species have been used for medicinal, agricultural and ornamental purposes. Purple salcerella (Lythrum Salicaria) has been preferred by gardeners for generations due to its seed production and beauty. Arictium minus roots are used as a traditional medicinal herb, a remedy for dry skin and sore throat. Invasive species have also been used to prevent soil erosion and combat the spread of deserts. However, most of these are destructive as they often stifle the growth of local species.
Invasive species have raised international concerns. Governments, non-governmental organizations (NGOs), regional bodies and various actors are leading different initiatives to address their spread. Several policies have been developed to help the affected areas and minimize the effects. This reaffirms economic and environmental beliefs in a balanced ecosystem.