- Regular forest fires in the western Himalayas are harming the region’s flora and fauna.
- A recent study says if forest fires continue, the area occupied by pines, cedars and rhododendrons in the western Himalayas will shrink considerably.
- The range of these trees is likely to shift towards the northern and north-eastern parts of the Himalayas owing to higher moisture availability there.
- The study also notes that oak, another typical Himalayan tree, will remain comparatively unaffected by the fires and the area occupied by oaks will remain unchanged.
The western Indian Himalayas, spread across Jammu and Kashmir, Himachal Pradesh and Uttarakhand, have always been known for their pines, cedars and oaks. These trees are so typical to the region that it is hard to imagine a Himalayan narrative that does not evoke their images. However, frequent forest fires occurring in the region are fast becoming a threat to these trees. A new study conducted by scientists from the International Centre for Integrated Mountain Development (ICIMOD), Nepal and the Indian Institute of Technology, Kharagpur, says that if forest fires continue in this manner it would greatly reduce the area occupied by pines, cedars and rhododendrons in the western Himalayas.
“Highest range reduction was predicted in cedars followed by pines, by 2030 and 2080, respectively. In the case of rhododendrons, large range reduction was predicted by 2050, mostly at higher altitudes in the Himalayan region,” said Vishwas S. Chitale, one of the authors of the study and a Remote Sensing Specialist – Ecosystems, Geospatial Solutions, at ICIMOD, Nepal.
The researchers, however, found that the area occupied by oaks, another tree typical to the western Himalayas, would remain unchanged. The researchers haven’t yet been able to pinpoint why exactly oaks would apparently remain resistant to forest fires, but they are trying to find an answer.
Forest fires are not unusual
Forest fires are no strangers to the western Himalayas. There are earlier records of major forest fires having occurred in these parts of the Himalayas in 1911 and 1921. Subsequently, each decade has seen at least one major fire. The years 2002 to 2016 saw devastating fires in Uttarakhand. In 2017 the intensity of fire abated a little, but again in 2018, both Uttarakhand and Himachal Pradesh were ravaged by forest fires. In fact, reports show that the number of forest fires in India went up from 13,898 in 2011 to 35,888 in 2017. Clearly, fire is a recurrent concern in the Himalayan region.
Not only do such fires ravage the flora and fauna on an immediate basis, but also recurrent fires can cause long-term alterations to the ecology of a place. As predicted by Chitale and colleagues in the present study, forest fires will cause a range reduction of 5-8 percent for pines, 11-13 percent for cedars and 12-16 percent for rhododendron.
Other (unrelated) studies have also shown that fires can modify soil properties too. In pine forests particularly, “fire depletes the soil of the bacteria that promote the growth of native plants,” said Adesh Saini of the Center for Research on Himalayan Sustainability and Development, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan.
How do these destructive fires occur?
Most fires are manmade and spread mostly aided by the resin-filled pine leaves. Locals set fire to the forests in the hope that once the trees fall, they would be replaced by grasses that would serve as fodder for their animals, explained Saini.
Unfortunately, though, native grasses like Pennisetum that used to grow after a fire dies down are now being replaced by invasive species like Bidens pilosa (kumber), Lantana camara and Erigeron annuns, Saini and his colleagues have observed. Kumber is particularly unpopular among the locals as its mature flowers bear spines, making it totally unsuitable as a fodder plant.
To an extent, these observations corroborate the predictions made by the study. Chitale says: “Tracts of land emptied by the fire are likely to be replaced by sub-tropical plants or even invasive species. However, it is hard to predict exactly which species.”
Another observation that the researchers have made is that the range of these trees would “shift towards the northern and north-eastern parts of the Himalayas owing to the higher moisture availability there. The amount of rainfall in western Himalayas is approximately a quarter of that in eastern Himalayas, causing more dryness in vegetation in western Himalayas, leading to more forest fires occurring here, than in eastern Himalayas”.
The present study says that if these forest fires can be put in check, the outcome would be different. And, the best way to combat forest fires is to be better prepared to deal with it. Chitale and his colleagues are now focusing on identifying areas prone to forest fires. They hope this information will help forest officials to figure out the areas “which need special attention and improved fire preparedness”.
Chitale V., and Behera M.D. (2019). How will forest fires impact the distribution of endemic plants in the Himalayan biodiversity hotspot? Biodiversity and Conservation. https://doi.org/10.1007/s10531-019-01733-8
Banner image: Pine tree line towards Triund peak, above McLeod Ganj, Himachal Pradesh. Photo by Sanyam Sharma/Wikimedia Commons.