Locals in Manipur’s uplands had always thought the Yellow Himalayan Raspberry (Rubus ellipticus) to be local since it grows wild widely in the mountainsides in Ukhrul, Senapati and more. Yet, this terrestrial plant finds itself amongst the list of worst nuisance plants in the entire world!
By Salam Rajesh
In scientific deliberations it is more often than not quoted that Manipur is lucky enough to find itself thick in the midst of one of the significant biological diversity hotspots in the world – the Indo-Burma Biodiversity Hotspot – with full of the floral and faunal diversity that other parts of the globe could envy.
The State is always proud to talk about the Sangai (Manipur Brow-antlered Deer) and the Shirui Lily (Lilium Macklineae Sealy) that are termed as endemic and rare to site-specific locations, found nowhere else in the world.
Equally interesting now is the information that Manipur too can find itself a spot in world data having floral and faunal species that are listed amongst the world’s worst invasive alien species, that is, plants that do not figure in the old growth species and which had somehow found inroad into the State through different windows, either intentionally or unintentionally.
Lowe and colleagues (2000*) in their assessment of the hundred worst invasive alien species (IAS) in the entire world has listed some species that find common foothold in an obscured location like Manipur, less deliberated by scientists and academicians here, and hardly by State government agencies.
It is definitely interesting to know that Manipur has a species that has been termed as a common nuisance the world over. This is an aquatic plant with beautiful flowers, ironically. Locals know this as Kabo-kang and the world as water hyacinth (Pontederia crassipes, formerly Eichhornia crassipes).
The common example cited of the water hyacinth’s trouble-making is its large presence in Kenya’s famous Lake Victoria where the plant’s influence is so great that it had disrupted everything, right from the ecological system to fishery, livelihoods and economies. A similar incidence is reported from Bangladesh where the water hyacinths had created much havoc in similar fashion, earning the nickname ‘Terror of Bengal’!
Look around Loktak Lake and its environs, Nambul River and the several water bodies within the Manipur River Basin, and the story is as similar as it can be. The State has to spend much money every year to keep clearing the water bodies of this pestering aquatic plant which can reproduce at a fast rate and can easily defy any strategy to erase it.
Amongst the terrestrial plants, the Mile-a-minute weed (Mikania micrantha) can be spotted anywhere in Manipur’s wetland areas and the hillsides, climbing over any support it can find – trees, plants, fences – completely dominating over its host and of course reducing its support host to naught.
And, of course, the wild sage (Lantana camara) has to find itself a spot in this listing. This terrestrial plant has mixed response, however, with some communities frowning upon it as nuisance plant while some like in Rajasthan consider it socially useful and utilize it for green fencing, firewood, and manufacturing furniture out of its wood.
Locals in Manipur’s uplands had always thought the Yellow Himalayan Raspberry (Rubus ellipticus) to be local since it grows wild widely in the mountainsides in Ukhrul, Senapati and more. Yet, this terrestrial plant finds itself amongst the list of worst nuisance plants in the entire world!
Of the hundred worst invasive alien species listed by Lowe and colleagues, it is intriguing to find the Giant Reed (Arundo donax), locally called as Luwang-Tou in the vernacular and which is abundantly found within the Loktak wetland complex including the Keibul Lamjao National Park. People here always thought it was local but as it turns out, the plant finds itself in the ‘nuisance’ listing, as one that can reproduce fast enough to over-run local or native species overnight.
The Giant African Snail (Achatina fulica) was once sighted everywhere in urban Imphal localities, perched on banana stem, on trees, on bamboo fences, literally anywhere, but it is less seen now. How it is gradually disappearing is not understood but this terrestrial invertebrate finds itself in the list of the world’s worst IAS.
And of the fish species it is naturally the Puklaobi (common carp, Cyprinus carpio) which notches the world’s headlines. The common carp was also listed by India’s National Biodiversity Authority amongst the nuisance fish species in the country. It is credited with diversity decline of native fish species wherever it had made its presence felt. Yet, in Manipur people consider it as a delicacy and harvest the fish in cultured ponds and fish farms.
Three more fish species find themselves in the list, and all three are there very much in Manipur, apparently introduced without the least concern on how or when they will turn invasive. These are the Tunghanbi (Mozambique tilapia), Ngakra (Clarias batracus), and the Western mosquito fish (Gambusia affinis). The Gambusia was widely introduced in the natural drainage and drains to contain mosquito larvae.
It is intriguing to understand why the Khoining (Red vented Bulbul, Pycnonotus cafer) finds a place amongst the hundred worst IAS. This bird has always been seen as part of the local natural environment, and yet it is listed amongst the nuisance bird species. Perhaps its ability to adapt itself in any given environment and ultimately becoming invasive could be why it is in the list.
The most interesting and intriguing mammal species to figure in this listing is the domestic cat (Felis catus), perhaps obviously as it can reproduce in litters at a time and occupy any available space, whether it be homes, garages, sewerage systems, and becoming feral finally.
The common goat (Capra hircus) and the wild pig (Sus scrofa) understandably find their places in this listing, with their capability to reproduce fast and can become feral. Manipur’s Mahabali-yong with their cousins Macaca fascicularis find obvious place in the listing. The macaca species are often seen in viral videos of harassing tourists and residents everywhere across the globe.
The rabbit (Oryctolagus cuniculus) was intentionally introduced in Australia by the immigrant settlers from Europe and it ultimately became highly invasive in that country, eating up the vegetable crops and frustrating farmers, ultimately prompting the Government to take up wide scale eradication measures to control the spread of the carrot-eating mammal.
The listing of the hundred world’s worst invasive alien species is designed to enhance awareness of the fascinating complexity, and also the terrible consequences, of invasive alien species, according to the authors. Species were selected under two broad criteria: their serious impact on the biological diversity and human activities, and their illustration of important issues surrounding biological invasion.
{*For more information, look over Lowe S., Browne M., Boudjelas S., De Poorter M. (2000). 100 of the World’s Worst Invasive Alien Species: A selection from the Global Invasive Species Database, published by The Invasive Species Specialist Group (ISSG), a specialist group of the Species Survival Commission (SSC) of the World Conservation Union (IUCN)}.