The research was carried out in Norway (Representational)
London:
Reindeers, famous for pulling Santa's sleigh on Christmas Eve, may have a significant impact on slowing the process of climate change, a new study claims.
Researchers in Sweden found that when reindeers reduce the height and abundance of shrubs in the Tundra region through grazing the level of surface albedo - the amount of solar energy reflected by the Earth into space - is increased.
The research was carried out in the north of Norway, in the Troms region which comprises of four topographically-defined vegetation types that vary in shrub height and shrub abundance.
"Our theory was that heavy grazing by reindeer increases summer albedo, through a reduction in shrub height, abundance and leaf area index (LAI)," said lead researcher Mariska te Beest, from Umea University in Sweden.
"The effect reindeer grazing can have on albedo and energy balances is potentially large enough to be regionally important," said te Beest.
"It also points towards herbivore management being a possible tool to combat future warming. Most of the arctic tundra is grazed by either domesticated or wild reindeer, so this is an important finding," she stated.
"Of course, the impact the reindeer have will vary according to their densities and the subsequent effects on the vegetation levels across the whole tundra," she added.
Te Beest and her team surveyed and studied sites around 100 metres above the tree line that were prone to being grazed by reindeers in Reisadalen, Norway. They used a unique experimental set-up, where a fence built in the 1960's separated areas experiencing either light or heavy grazing by reindeer.
The study combined land surface computer modelling with measurements of albedo and vegetation characteristics taken in the field.
To test their thesis, the team worked through the summer season and estimated reindeer activity by using vegetation trampling indicators, and through the collection of dung.
They also measured the abundance of vegetation, its leaf area index, and the soil moisture and temperature levels, as well as the albedo levels.
Scientists already noted that reindeers have the capacity to reduce the intensity of shrubs in the Arctic Tundra.
"We found that high densities of reindeer changed arctic tundra vegetation by decreasing shrub abundance. This resulted in corresponding shifts in LAI, canopy height and NDVI - the amount of live green vegetation," said te Beest.
"These pronounced changes in vegetation led in a substantial increase in albedo across the growing season. Our modelling results showed this increase in albedo would result in a corresponding decrease in net radiation and latent and sensible heat fluxes - indicating that heavily grazed sites absorbed less radiation," she said.
"Our results show that reindeer have a potential cooling effect on climate, by changing the summer albedo. Although the estimated differences might appear small, they are large enough to have consequences for the regional energy balance," te Beest said.
The study was published in the journal Environmental Research Letters.
(with inputs from PTI)
Researchers in Sweden found that when reindeers reduce the height and abundance of shrubs in the Tundra region through grazing the level of surface albedo - the amount of solar energy reflected by the Earth into space - is increased.
The research was carried out in the north of Norway, in the Troms region which comprises of four topographically-defined vegetation types that vary in shrub height and shrub abundance.
"Our theory was that heavy grazing by reindeer increases summer albedo, through a reduction in shrub height, abundance and leaf area index (LAI)," said lead researcher Mariska te Beest, from Umea University in Sweden.
"The effect reindeer grazing can have on albedo and energy balances is potentially large enough to be regionally important," said te Beest.
"It also points towards herbivore management being a possible tool to combat future warming. Most of the arctic tundra is grazed by either domesticated or wild reindeer, so this is an important finding," she stated.
"Of course, the impact the reindeer have will vary according to their densities and the subsequent effects on the vegetation levels across the whole tundra," she added.
Te Beest and her team surveyed and studied sites around 100 metres above the tree line that were prone to being grazed by reindeers in Reisadalen, Norway. They used a unique experimental set-up, where a fence built in the 1960's separated areas experiencing either light or heavy grazing by reindeer.
The study combined land surface computer modelling with measurements of albedo and vegetation characteristics taken in the field.
To test their thesis, the team worked through the summer season and estimated reindeer activity by using vegetation trampling indicators, and through the collection of dung.
They also measured the abundance of vegetation, its leaf area index, and the soil moisture and temperature levels, as well as the albedo levels.
Scientists already noted that reindeers have the capacity to reduce the intensity of shrubs in the Arctic Tundra.
"We found that high densities of reindeer changed arctic tundra vegetation by decreasing shrub abundance. This resulted in corresponding shifts in LAI, canopy height and NDVI - the amount of live green vegetation," said te Beest.
"These pronounced changes in vegetation led in a substantial increase in albedo across the growing season. Our modelling results showed this increase in albedo would result in a corresponding decrease in net radiation and latent and sensible heat fluxes - indicating that heavily grazed sites absorbed less radiation," she said.
"Our results show that reindeer have a potential cooling effect on climate, by changing the summer albedo. Although the estimated differences might appear small, they are large enough to have consequences for the regional energy balance," te Beest said.
The study was published in the journal Environmental Research Letters.
(with inputs from PTI)
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