HYDERABAD: India has been ranked 11th in the spread of alien invasive species in urban green areas, according to a first-of-its-kind study conducted in 100 most-populous cities across 40 nations.
Invasive alien species are plants which have been introduced outside their natural ecosystem. Their presence is capable of destorying local species. The infamous Lantana Camara, Eichhornia Crassipes (water hyacinth) and Prosopis Juliflora are examples of plants threatening India’s indigenous flora.
There are a total of 9 Indian cities among the 100 listed by the study. Ahmedabad and Surat are in the top ten, at 7 and 10 respectively, with alien species invading the cities at the rate of 136 metres per year and 118m/yr respectively.
This is followed by Pune at 13, Hyderabad at 26, Bengaluru at 36, Chennai at 37, Delhi at 39, Kolkata at 82 and Mumbai at 100th place. The rate of spread in Hyderabad is 64.67 metres per year. The rate for India on average is 65 metres a year, much higher than the global average of 49.16 m/yr.
The study, published in Biological Invasions journal, was authored by Cang Hui, David M Richardson and Vernon Visser, professors at Stellenbosch University and University of Cape Town, South Africa.
Speaking to Express, Prof Hui, said, “Potential impacts of biological invasions in urban environments, especially in developing nations, are related to the ecosystem disservices (EDS). These disservices could include issues like pollen allergy or toxins from algal blooms, material EDS like roots of trees damaging pavements or natural disasters damaging infrastructure, and safety EDS like breaking of tree branches.”
“Some of the impacts are more likely to be felt in developing nations due to poor governance in domain of environmental and public health and sanitation,” he added.
This is of concern as United Nations Population Fund has predicted that by 2050, 64 pc of the population in developing world and 86 pc in developed world will reside in urban areas. “The spreading rate of alien species in India are negatively correlated with population size and positively correlated with population growth rate. So, in India, medium-size cities located in relatively dry climates with faster population growth should be on the watch,” he added.
Ways to control the spread
Citizens can submit photos to online hubs so that scientists can follow up with the progression of biological invasions and also to detect new invaders
Resolving conflicts between invasion management and basic human rights of private property and privacy, as private lawns are often the source of alien invasive species
Slowing the spread of invasive trees
Controlling large sources of alien invasive populations
Using areas with low or no urban green areas as dispersal barriers