As you drive up the Kufri- Chail road from Shimla near Munda Ghat at a height of 1700 metres, the untrained eye will only see the slopes dominated by blue pine. But taxonomist Dr Vaneet Jishtu is quick to spot the odd white oak tree among them. “Blue pine is an invasive exotic species which is edging out the local oak,” he points out. It is not only indigenous species like the oak that are being edged out but also the rich treasure of medicinal plants, notably the eight plants or “Ashtavarga” that constitute the Ayurvedic elixir “Chavanprash.”
Dr Jishtu says in Himachal Pradesh all the eight constituents of ‘Ashtavarga’ were fairly common till the turn of the 19th century.
Henry Collect records in his Flora Simlensis, published in 1902, that kshirakakoli or Lilium polyphyllum, one of the Ashtavarga constituents was a common undergrowth of the deodar forests. Similarly, the seven other species were commonly found in open grasslands, shrubberies and in the forest undergrowth. It is surprising that in a matter of just about 110 years, wild populations of Lilium polyphyllum have almost vanished from the state, he said.
Ashtavarga comprises eight plants called Jeevaka, Rishbhaka, Meda, Mahameda, Kakoli, Kshirakakoli, Riddhi and Vriddhi. “It was after investing in large scale surveys that I have been able to locate a few areas of its occurrence. I am also trying to grow them in ex situ conservation plots near Shimla. Since, the populations of these ashtavarga plant species have dwindled and very few people recognize them, the companies manufacturing Chavanprash or other formulations must be using their substitutes,” he pointed out.
Dr Jishtu has an “Ashtavarga” project which aims at reviving these eight herbs. A scientist in the Himalayan Forest Research Institute, Dr Jishtu’s arboretum at Potter’s Hill, is a living museum of sorts where he grows local species like the Indian maple and medicinal plants. The arboretum is slowly becoming something of a tourist attraction. His aim is to have at least 150 species which reflect the rich biodiversity of the Himalaya, a place where he has been trekking for the last 20 years.
In Himachal Pradesh 47 medicinal plant species are on the Red list and 11 species are Critically Endangered.
While Blue Pine or Pinus wallichiana is an invasive species, it is very much native to the region, Dr Jishtu said, adding that it is a strong light demander, tending to be invasive under favourable conditions, like openings in the forests, where it replaces the original forest species. These invasive plant species highly reduce the available habitats or niches for the growth of native plants. As a result large areas get covered with a single species, he explained.
The pretty yellow and white flowers which have covered much of the hillsides and roadsides in Shimla are also an invasive plant from South America (Solanum chacoense, a species of wild potato). It has naturalized in the Shimla and the Himachal hill forest after its escape from the wild potato germplasm collection at the Central Potato Research Institute, Shimla, Dr Jishtu said.
There are several other non-native species which include herbs, shrubs and trees species like Acacia. Overall, the invasion of these non-native species highly reduces the species diversity and composition and as a result the plant communities become less productive and are in danger of being wiped out, he said. The state has planted exotic species which can’t take the weight of snowfall and often if there is a heavy storm, collapse. The forest department tends to plant exotic species apart from the state tree deodar or native broadleaved species. As a result they largely rely on trees like Black locust from America, Australian Silver Oak, Tree of Heaven from China, Crimson Bootlebrush from Australia, Queensland Blue Gum from Australia, Occidental Plane from North America and Blue Jacaranda from South America.
Even the common grazing areas are losing their grass with the invasion of weeds like lantana and parthenium. North West Himalayas, considered as one of the globally recognized biological hotspots, is home to many endemic, rare and endangered tree species. The plant biodiversity richness of this region is very important from the point of view of species richness of India, he added.
