CB Bureau
The Kerala State Biodiversity
Board has identified 89 alien invasive species of plants that have become a
major threat for the plant biodiversity of the state. The recent
survey says that 19 of these species are extremely dangerous as they are causing environmental hazard and economic loss by displacing the natural
vegetation, including medicinal plants, and have reduced the availability of
fodder.
The invasive species have entered the country along with the
timber and food grain imports from various countries including Brazil,
Trinidad, Costa Rica, Chile, and Mexico, claimed KV Sankaran, director of
Kerala Forest Research Institute, Thrissur, which conducted the survey and
risk assessment.
The list of the species
includes 39 herbs, 24 shrubs, 15 climbers and 11 trees. While some species were
brought for agriculture and forestry, some others inadvertently reached Kerala.
As part of the survey, around 4,000 points were identified for generation of
data, and each point was selected on the basis of the presence of plants with
visually aggressive growth. The species thus listed were checked against the
catalogue of the native flora. The invasive plants were then subjected to the
Invasive Species Risk Assessment, as per the Invasive Species Assessment
Protocol developed by NatureServe, Virginia, USA.
The listed plants are at various stages of invasion and
colonisation, and different strategies were required for the management of
each. The experts reckon that the quarantine measures at sea and airports
should be made stringent to control the arrival of invasive varieties. Imported
timber should be treated with pesticides as the wood would carry seeds and eggs
of plants and insects. A large number of countries resort to such measures for
protecting their biodiversity.
High-risk species
include Acacia mearnsii (Black wattle), Antigonon leptopus (Mountain rose),
Arundo donax (Giant reed), Chromolaena odorata (Siam weed), Ipomoea cairica
(Kolambipoo), Mikania micrantha (American vally, Kaipu vally, Dhritharashtra
pacha), Mimosa diplotricha var. diplotricha (Anathottavadi), Prosopis juliflora
(Sali) and Sphagneticola trilobata (Singapore daisy).