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November 2018 Edition of Power Politics is updated.         November 2018 Edition of Power Politics is updated.
Issue:November' 2018

ECOLOGICAL CONCERN

Serious threat to herbs & medicinal plants

Rakesh Lohumi

Lantana Camara a poisonous weed The uncontrolled spread of giant tree climbers, obnoxious weeds and disease-causing organisms is emerging as a serious threat to the forest cover which has already suffered irretrievable damage in the Himalayan mountain ranges due to reckless and excessive human activity. The growing weed menace from the Himalayan foothills in the north to the Tamil Nadu in the south is a matter of ecological concern as they pose a serious threat to the biodiversity, particularly the valuable herbs and other medicinal plants. These species have invaded large tracts of pastures and agriculture land and they also hampering proper regeneration of forests. Several lakh hectares of productive land and forest area have been usurped by weeds across the country and their march is continuing unabated.
The ongoing climatic changes, a consequence of global warming and indiscriminate anthropogenic activity, have created conditions conducive to the growth of alien invasive plant species which are invading forest areas at an alarming pace. As per some recent studies over 40 per cent of the species in the Indian flora are alien, of which 25 per cent are invasive. They pose a serious threat to the biodiversity, particularly the valuable herbs and other medicinal plants. With winters getting shorter and snow becoming increasingly scarce, the dormancy period has been reduced. As a result the shrubs and herbaceous plants, particularly the invasive species, on the forest floor are growing much faster and almost round the yearAll the climbers and other invasive plants species, which have become a cause of ecological concern, are alien species not native to the country. Towering deodars and other tall trees could be seen in strangulating embrace of the twining vines in forests, particularly in the western Himalayan region. The unrestrained spread of these species poses a serious threat not only to forests and agricultural land but to biodiversity in totality. Interestingly, most of the troublesome invasive species were brought to India from America, Europe and other parts of the world as ornamental plants. Their uncontrolled spread is a serious hurdle in sustainable use of biodiversity. In the long run it may lead to extinction of some species and alter the functions of the ecosystem like hydrology and adversely impact the goods and services provided by ecosystems. Weeds are estimated to cause around 30 per cent loss in in progressively warmer conditions in the middle hills and even higher ranges.

Lantana in lower hiills All the climbers and other invasive plants species, which have become a cause of ecological concern, are alien species not native to the country. Towering deodars and other tall trees could be seen in strangulating embrace of the twining vines in forests, particularly in the western Himalayan region. The unrestrained spread of these species poses a serious threat not only to forests and agricultural land but to biodiversity in totality. Interestingly, most of the troublesome invasive species were brought to India from America, Europe and other parts of the world as ornamental plants. Their uncontrolled spread is a serious hurdle in sustainable use of biodiversity. In the long run it may lead to extinction of some species and alter the functions of the ecosystem like hydrology and adversely impact the goods and services provided by ecosystems.

Dry trees Weeds are estimated to cause around 30 per cent loss in potential crop production. The alien species account for 42 per cent of the weeds and their impact on farm production of the country in monetary works out to over $ 38 billion annually. One of the most obnoxious weeds Lantana Camara has spread across the length and breadth of the country rapidly as being poisonous it is not consumed by animals and all the more difficult to control. Another species that has been spreading as aggressively is Eupatorium adenophorum, which has already occupied large tracts of land in the plains and has now entered the Himalayan foothills recently.
The ongoing climate changes are only helping the weeds to spread and they are intruding into the flora-rich sub-temperate zone in the ecologically fragile Himalayan region.
The implications for the biodiversity will be enormous and far-reaching as large scale invasion of forests by poisonous weeds is taking a heavy toll on useful grasses and bushes which provided fodder for the cattle. Also, the dominance of single species on the forest floor also increases the danger of wild fires which spread quickly due to thick undergrowth.
There are over 40 species of climbers and creepers in the middle and higher hill areas but those posing a threat to the trees in states like Himachal and Uttarakhand are the fast-growing Hedera helix, Vitis himalayan and Ficus sarmentosa. While climbers are choking trees, other invasive weeds are covering more and more area on the forest floor.
In absence of concerted efforts to arrest the spread of weeds, some aggressive alien species have invaded forest and agriculture land across the country. Large gregarious patches species like Lantana, Ageratum, Parthenium (Congress grass) and Eupatorium have come conspicuously right from Himalayan foothills in the north to the Tamil Nadu in the south, posing a major threat to the indigenous flora.
Surinder Kumar, a former director of HFRI, says climbers over-running trees and obnoxious weeds dominating the under storey of forests is not good for biodiversity.
The government must take immediate steps, including appropriate silvicultural practices, to deal with the fallout of ongoing environmental degradation on forests as it will have serious implications in the long run and livelihoods of people will be at stake.

Surinder Kumar, a former director of HFRI, says climbers over-running trees and obnoxious weeds dominating the under storey of forests is not good for biodiversity. The government must take immediate steps, including appropriate silvicultural practices, to deal with the fallout of ongoing environmental degradation on forests as it will have serious implications in the long run and livelihoods of people will be at stake.

A tree overwhelmed by a climber Effective policy and technological intervention is required to protecting the already threatened trees, medicinal plants and other useful species and conserving the biodiversity.
A pilot study conducted by Himalayan Forestry Research Institute (HFRI) brought certain peculiar characteristics that help the weed to spread quickly and make it potentially a destructive species. According to Dr K S Kapoor, Group Coordinator Research, HFRI, under favourable conditions the single seed of Eupatorium can quickly rise to infestation and become difficult to manage if goes unnoticed. With large number of seeds and rootstocks that facilitate vigorous regeneration eradicating it is very tough job as it quickly established at inaccessible places like precipitous cliff faces.
It has been spreading fast along the Shiwaliks in the Himalayan region. In Himachal over 60 per cent of the 2600 sq km of area under forest cover in the lower elevations up to an altitude of 1000 m has been infested with Lantana Camara. All the invasive weeds and climbers species together are marching up at an alarming pace and the changing on micro-weather is helping the weeds to move into the flora-rich and ecologically fragile subtemperate zone of Himalayan region.
As per forest department survey carried out March 2011, the four prominent weeds have already usurped 3,65,000 hectare of land and they have appeared at altitudes up to 1500 m. It involves 185,201 hectare of forest area and Lantana alone occupies over 1,77,000 hectare.
The other three species were flourishing along road sides and on barren, fallow and colourable waste lands and agricultural land. Eupatorium, parthenium and Ageratum have been growing with Lantana at places.
Some medicinal plants like viola (banafsha) have already been weeded out from the pine forests and the steady uphill march of invasive species will wipe out more such important herbal resources.
Rhododendron is fast disappearing from hills around Shimla, while Pinus gerardiana, , an important forest species of tribal areas popularly known as Neoza pine, is on the list of endangered trees. Oak forests which play a vital role in maintaining the hydrological cycle in hills are also on the decline . The weed menace is not confined to forests or agriculture land; it has invaded orchards, village common land, parks, road sides and other public places. In many areas farmers have stopped growing crops as large portion of their cultural land has come under weeds.
Effective technological intervention along with well-coordinated efforts, with the involvement various concerned departments and agencies, on the ground are required for controlling the spread of weeds. Any further delay will have long term implications as it will severely affect the biodiversity and ecosystem. The weeding out of indigenous flora will virtually put livelihoods of local communities at stake. The cost of controlling its spread comes to over Rs 5000 per hectare which is prohibitive. The participation of the local people is essential for any such initiative to e successful.
Environmentalists see global warming as a possible reason behind the prolific growth and some studies on behavioural ecology of climbing plants have been conducted in the USA and parts of Europe. One of the studies showed that removal of woody vines from infested trees in forests of Panama by cutting them off nearly trebled their growth rate and their forest-carbon storage increased by a fifth.
Eologists from the National Capital Region Network in the US have revealed manifold increase in climbers. As per one of the studies the trees in the periphery of forests are particularly vulnerable to vine infestation. The rate of trees with vines rose from 21.5 to 25.7 percent between 2010 and 2014 and the percentage of vines on trees that were non-native invasive species increased from 33 to 44 percent over the period.
Adverse fallout of climate change is the frequent outbreak of forest diseases, which were virtually unknown in the Himalayan region until recently. The viral infection and insect attacks covered a host of species in higher hills of Himachal hitherto known for disease-free cool environment. The species tha have become vulnerable include, commercially important deodar (cedrus deodara) and kail (blue pine) in higher hills, shisham, kikar and sal in lower hills and salix in the tribal Lahaul Spiti.
A modest beginning has been made with the launch of the Rs 316 crore German Development Bank funded climate proofing project Besides enhancing fodder production capacity of forests and pastures by rehabilitation of areas infested with weed lantana in about 15,000 hectares efforts will be made to revive traditional water springs and catchment areas of around 150 season rivulets.