With experts issuing sustained warnings over the health hazards created by Russian Poplars or Rusi Frass in summers, there seems to be no end to this pestering problem. Based on their research in the field, Anzar A Khuroo and Akhtar H Malik from Kashmir University offer a scientific solution to curb the menace.
Over the past few years, “Russian poplar” trees locally called as Rusi Frass have become a source of public health hazard in the Kashmir valley. During the late spring season, the pollination process of these trees creates a nuisance for the populace.
Even though the issue has been widely reported, however, most of the media reports are based on conflicting and confusing information about the biology of organisms. A clear scientific understanding about these trees is a prerequisite for framing any policy on the plantation of these in the valley.
The poplar plants, scientifically known as Populus, belong to the botanical family of Salicaceae. Unlike the majority of plants where both the male (stamens) and female (pistils) organs are borne on the same flower, the poplars are distinct in showing dioecy condition. In other words, just like we human beings, poplars have male (staminate) and female (pistillate) organs (flowers) on separate individuals, and that is why we distinguish them as male and female poplars, respectively. Each of these male and female flowers are very small in size and densely packed together in the form of hanging inflorescences called catkins on separate individuals. Again, the poplars are unique in producing flowers first and then the leaves; in Kashmir, we have seen that the poplars usually flower in late winter to early spring.
In poplar plants, the wind is the natural agency that brings about pollination. Pollination simply means the mating of male and female individuals, whereby the pollens (a product of stamens) mate with an egg (a product of pistils). The pollination ultimately leads to the production of a fruit (called capsule in poplars). It is this capsule that on maturity becomes dry and splits apart to release the inside seeds. The seeds in these poplars – the source of future propagation are surrounded by a tuft of cottony white hair, which basically acts as a parachute for its wind dispersal over long distances. However, the quantity of cottony hairs in seeds varies from species to species. While as, its quantity is quite large in “Russian poplar”, it is relatively miniscule in other species that grow in Kashmir.
Indeed, the poplars are multipurpose trees. The products from these trees make a significant contribution to our economy. The foliage is used as forage for livestock, branches chopped to be used as fuelwood, timber used for manufacturing packing boxes for apple, plywood industry, construction of houses, etc. By providing an alternative source of timber, they have substantially eased out pressure on our natural forests, thus contributing to the conservation of our forests.
Based on our study of plant specimens of poplars collected from all over the State, the number of poplar tree species that we have been able to scientifically identify is five, as given in the Table. Out of these, only two species are indigenous: Qilam Frass and Ladakhi Frass. The remaining 3 species: Doodh Frass, Kashur Frass and Rusi Frass are all non-indigenous; and have been introduced into the Valley from time to time. Although, we expect the occurrence of many hybrids (i.e., products of two unrelated species), but it is difficult to identify them as a scientific species.
Scientific name English name Kashmiri name
Populus alba White poplar Doodah Frass
Populus ciliata Himalayan poplar Qilam Frass
Populus pamirica Ladakh poplar Ladakhi Frass
Populus deltoids Eastern cottonwood Rusi Frass
Populus nigra Black poplar Kashur Frass
Available scientific literature indicates that the English name “Russian poplar” is a misnomer. In fact, the Rusi Frass has no connection with Russia at all. It is a poplar species whose native range falls in the continent of North America, and there from it has been introduced elsewhere in the world, including Kashmir valley, where it has become ‘successfully’ naturalized. Its correct scientific name is Populus deltoides and the names such as Populus ciliata, Populus euphratica by which it is known in the Forest Department are incorrect. It is known by the common name of Eastern cottonwood, thus reflecting the huge cottony mass of its seeds. The Eastern cottonwood has been introduced into Valley by the Department of Forests under the Social/Agro-Forestry schemes, perhaps four decades back. Undoubtedly, being one of the fastest growing species of poplars, the cultivation of Eastern cottonwood became popular throughout the Kashmir, gradually replacing the other species. These species of poplars are now restricted to few pockets in the Valley. For instance: Kashur Frass can be seen along the Srinagar-Baramulla highway; Doodah Frass inside natural forests along lower foothills.
At the time of introduction, the Forest Department most likely brought the Populus deltoides (maybe other species also) here in the form of cuttings or seedlings. At this stage of life-cycle, it would have been difficult to ascertain whether these will grow into male or female. Once, these cuttings/seedlings matured into trees across the Valley, it became evident that the Department had introduced female individuals of Populus deltoides. The standard scientific practice for exotic introductions throughout the world is the mandatory initial trial period so that the impacts are assessed before its mass cultivation. At this point of time, we have every reason to believe that such a practice was thrown to winds.
In the Valley, as female individuals of Populus deltoides are grown, the possibility of so-called “pollen allergy” from this plant as stated by various ‘experts’ sounds unscientific. In the absence of male individuals, the ‘seeds’ from the female plants should be unviable, as there are no pollens available of the same species. It is for this reason, billions of these ‘seeds’ falling on the ground do not germinate to form new seedlings. It is the cuttings which are used for its propagation. Nevertheless, based on our surveys throughout the Valley, we have observed only one population of this species growing as a pure stand of seedlings along the river banks. The population requires further research, investigation and continuous monitoring, until it reaches the flowering stage.
We suspect that these cottony seeds act as vector for the dissemination of everything that is present in the atmosphere during this season, such as spores of bacteria, fungi, dust particles, pollen of other flowering plants growing in the area, that are actually causing human health hazards. The cottony seeds also block the light in our houses by attaching to mesh windows and doors. Besides, it forms a dense mat over the green turf in our gardens and along the roads. It engulfs the flowers of other plants of agri and horticultural importance possibly hampering their pollination and thus fraught with huge commercial implications. The plantation of these poplar trees most likely is one of the factors in bringing our lakes, wetlands to the present state of crisis.
The problem of cottony seeds requires a management strategy that is scientific and systematic, and in a lighter vein, scam-less. In the short term, the annual lopping of these trees may alleviate the problem to some extent. Aerial spraying may be an option in the developed world, but not here in the Valley as it requires huge sum. Banning the fresh plantation of female trees of this species will work on the ground only when we can provide an alternative option. The male trees of this species should be introduced only after a detailed impact assessment. The government can formulate an incentive scheme for cutting of the female trees from private lands. Above all, the lesson from poplar menace is that the un-scientific schemes may provide short-term economic gains but are fraught with long-term ecological problems.
However, the introduction of male trees of this species without complete eradication of the female trees throughout the Valley will be an invitation to another ecological disaster of much bigger proportion, what is scientifically known as biological invasions. In that horrible situation, billions of viable seeds may start germinating uncontrollably all along the banks of our lakes, marshes, streams, rivers, and even spread to forests.
(Dr. Anzar A Khuru is senior Assistant Professor & Akhtar Hussian is Curator, at Centre for Biodiversity & Taxonomy, University of Kashmir)
Poplars Are Rs 600 Crore Business
To prevent frequent summer allergy, J&K government has finally banned plantation Russian thistle, a poplar species. Allergy creates mass morbidity and it has remnained in focus of public discourse.. While fresh plantations are a punishable offence now, the standing trees will be gradually axed to reduce the risk, at least in Srinagar.
Introduced in not so distant past, the ‘Russian’ breed grows fast and has made the endemic poplar species nearly extinct. Kashmir massively depends on poplar (Populus deltoids) wood for veneer industry and boxes for apple, the mainstay of the periphery. The tree was actually imported from US as part of the World Bank funded social forestry project in 1982. Its plantation is banned in most of the West and Europe.
As the jungles of poplars emerged on the wastelands, the quantum of pollen that the tree contributes to atmosphere at the start of summer becomes an unmanageable issue. The microscopic pollen is released by the cotton like substance that the tree sheds. The pollen are inhaled by people and it triggers pollen allergy. Chest diseases specialist Dr Naveed Nazir said his hospital gets nearly 70 patients to the OPD in summer because of the pollen allergy and around twenty percent of them required in-door case. In certain cases, it can cause life threatening problems, especially in the newborn and those suffering from respiratory problems. The crisis impacts tourism as well.
Experts have more interesting details. Botanist Prof Zaffar A Reshi said the seeds are infertile and cause nothing other than a health crisis. The invisible granules have hairy appendages custom-made for air-transport and eventually get into the human body. “These are only shed by female poplars and if only male poplars saplings are planted as a matter of policy, the crisis can be managed,” he said.
As the ban is in force, now the government will have to offer an alternative to the people. Poplar is at the core of managing the raw material for nearly 100 veneer and ply-board units, and manages nearly 100 percent of the requirements of the apple sector. Off late, it is the poplar that makes part of the roofing in surging housing sector.
Last summer when lawmakers started investigating the crisis, they were told by the forest officials that the society manages around 30 million cubic feet of timber from poplars a year and its turnover is more than Rs 600 crore. They put the poplar tree number at 14090070 in rural and 804850 in the urban areas. They had suggested against a ban insisting it would add to the pressures on forests, currently protected by the apex court. They also asserted that the poplar is one of the few trees that fixes carbon at a faster rate than many other species. However, they had no answer to the larger issue that many expert point out that poplars are one of the key factors in lowering the water table.