Mosses make way to higher altitudes
KATHMANDU: Climate change has not only been forcing the animal to migrate to high altitude but also compelling the plants to follow their footsteps. Three species of moss, earlier available in low land area are now being spotted at the periphery of the Kathmandu Valley and even in higher altitude.
“In my recent study, I recorded three species of low land mosses found in high lands,” said moss researcher Nirmala Pradhan, who is doing her PhD on low land mosses. “Adverse climate change has caused dryness and decline in photosynthesis process and its productivity,” she added.
These species are Funaria, Physcomitrium and Bryum psyeudotriquestrum. “Funaria is sub-tropical species available at 1,000 m, which is now found in temperate Kathmandu,” said Pradhan. “While Physcomitrium (bowl moss) available at 300 m can also be seen in the vicinity of Kathmandu.”
Pradhan said, lowland species of Bryum is available now at an altitude ranging from 2,900 to 6,000 meters. “Birds, insects and wind help disperse the sperm from one place to another,” she said.
Statistics presented by Pradhan suggest there are 21,000 species of non-flowering moist plant Moss in the world. Among them, 1,150, including 31 endemic species, are available in Nepal. Four of them are considered to be endangered species.
Moss, a non-flowering plant, is very useful in the production of antibiotics, decorating houses, prevention of soil erosion, and as pollution indicator. ‘’It works effectively to heal wounds and cracks and is seen as a source of fuel, food for birds and animals,among others,” she added.
Kumudini Shakya, yet another researcher in bio-monitoring, argued that the results of the metal pollution in the valley are dreadful. “We have concluded the first experiment in Nepal. It showed that the moss is more effective than lichen, which was experimented earlier, to oversee the accumulation of air-borne heavy metals in the Kathmandu valley,” she said.
The field research was conducted in three areas — ring road, inside ring road and outside the ring road. The experimentation and observation was done on two categories of clean and polluted zones. Species of Thuirdium, Tasyphyllum and Giraldii mosses were tested in clean areas while Brachythecium, erythrodontium julaceum and Faerronia matsumurae were examined in polluted areas.
“The heavy metals were highly accumulated in all of the species except in Giraldii moss,” said Shakya. “The metals were examined in heavy traffic areas such as Ratnapark, Chabahil, Putalisadak, Lagankhel and Kalanki.” She said. “The content of lead, cadmium, chromium, silver, mercury, uranium, copper, zinc, cobalt, manganese and nickel were high in the valley air.”
Researchers say these are very toxic and harmful to both human beings and plants. The scientific gravity of these metals should not exceed 4.5gm/c³ in the air. “However, the measurements of lead, cadmium and chromium were recorded very high,” she added. “The measurement in lead is 3.45-83mg/kg moss, cadmium .01-2.25mg/kg and chromium 2.5-70.5mg/kg.”