An intentionally or unintentionally introduced species that has adapted to and reproduces successfully in its new environment.
Naturalised species reproduce naturally in the environments they colonize. Invasive species do this so prolifically that they alter the workings of the natural ecosystems they colonize or invade.
An international team — including scientists from India — have collated information on alien plant species from several sources, ranging from online plant lists to old compilations of India’s national and regional flora. They found that as many as 471 plant species that are alien or exotic — not native to India — are ‘naturalised,’ for they can thrive in the country’s wildernesses by forming stable populations.
Highlights of the findings:
Scientists have developed the first lists of naturalized plants for each State; these lists reveal that 110 alien plants now naturally occur in more than 31 States in India.
At 332, Tamil Nadu has the highest number of naturalized exotics, followed by Kerala (290), while Lakshadweep has the least (17).
The distribution across the Indian States of over 20 of these naturalized species (in the list of 471) is unknown.
A majority of these naturalized plants are herbs such as the invasive Siam weed Chromolaena odorata, native to south and central America.
The new list shows that many exotic species are now part of our natural flora.
India- the ‘hotspots’ of naturalized plant species:
More than 13,000 plant species are now naturalized in ecosystems across the world due to human activity; many of these later turn invasive and impact local flora and fauna.
Last year, a study identified India as one of the ‘hotspots’ of naturalized plant species and of the seven regions in the world that have the highest number of invasive species.
The ENVIS Centre on Floral Diversity hosted by the BSI lists more than 170 invasive plant species in India.