INVASION: A Threat to Himalayas

Himalaya’s pristine green environment is fading and facing an unexpected danger from the common invasive species. Scientists argue that as the temperatures soar in the Himalayas, invading plants and insects may pose a major conservation threat. Invasive alien species have become a severe crisis and the international community has promised to focus on this growing problem under global commitment to mitigate their harmful and unfavorable impacts, as Invasive alien are the second largest threat to biodiversity.
More and more of these invaders, in the form of larvae or seeds, are surviving in Himalayas, where temperatures have risen by more than 3 0C over the last few decades. Glaciers have retreated, exposing more land which has been colonized by mosses that is found to be growing more quickly and thickly than ever before – providing potential homes for invaders. The process is particularly noticeable in the northern states of Jammu and Kashmir, which is most vulnerable to global warming.
Due to the rich and fauna, a large percentage of plants are used as medicine in different forms. The cultural use of some of these herbs in medicine through customs dates back to 3000-1000 BC and was the only means of curative and/or protecting the human population from various ailments. The therapeutic properties of these herbs is reflected from the view that most of these possess the bioactive principles, anti-cancer as well as anti-ageing (anti-oxidant) properties apart from antipyretic, asthmatic, diuretic and other properties. Currently, most of the industries in India thrive on the resources that they get from Himalayas. A large proportion of population is associated with these industries. A good number of people in the region scrape out a living through smallholder farming, almost fully reliant on the environment and its resources for their source of revenues. As that environment changes, because of land degradation, shifts in the monsoon, and groundwater depletion, their lives and livelihoods become more precarious.
Indigenous to the Indian sub-continent, the ship rat (Rattus rattus) have caused disappearance and decline of native birds and have spread throughout the world. New disease such as avian influenza A (H5N1) organisms are proving fatal, attack humans and animals, in both temperate and tropical countries. A. dealbata interferes with the establishment of pioneer herbaceous species in the ecological succession process and can also affect trees if they are hit by a colonizing front. A. farnesiana is mostly a weed of pastures and able to form dense thorny thickets, which may cause injury to livestock and may shade out native fodder species. Alien species cause loss of biodiversity including species extinctions, changes in hydrology and ecosystem function. L. leucocephala is a risk to native biodiversity as L. leucocephala establish itself it replaces native vegetation and that can encourage suitable conditions for the establishment of even more aggressive invaders. The mimosine in the leaves of L. leucocephala can cause hair loss, infertility and stomach problems in livestock, especially those that are not ruminants. Alternanthera sessilis is also a weed in fields with sorghum, millet, Eleusine spp., maize, cotton, cassava, cereal crops, pastures, and vegetable farms. The exotic plant species vary from native one, based on their requirements, modes of resource acquisition and more consumption which may cause changes in soil structure, its profile, decomposition, nutrient content, moisture, etc. It results considerable unwanted impacts on the biodiversity and ecosystems. Thus, Invasive species are a grave impediment for conservation and sustainable use of biodiversity. Biological invasions now operate on global level and it will undergo fast increase due to increasing globalization of markets, rise in global trade, travel and tourism.
On the other hand, it is global warming that is the main driver to the fading greenery of Himalaya. Temperatures have been rising steadily in the Himalayas, since meteorological data began to be collected. This shows that over the past 60 years the region has warmed up by around half a degree Celsius every decade.
For scientific organization of invasive species, knowledge about the impact of invasive species, their ecology, morphology, phenology, reproductive biology, physiology and phytochemistry is necessary. Monitoring of attack can be done through qualitative approach like species inventory and quantitative approach using phyto-sociological methods and mapping using ground-based methods, remotely-sensed images. A better planning is needed for early detection and reporting of infestations of spread of new and naturalized weeds says Chandra Sekar, at G. B. Pant Institute of Himalayan Environment & Development, Almora, India a study published in American Journal of Plant Sciences. A study by Wani et al, 2006 published in International Journal of Botanyhighlighted the threat to Himalayas by invasion as well. “We have got to act now if we want to save this last, pristine environment.”
(The author is Assistant Professor in Department of Environmental Science, ITM University Gwalior)