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Nowhere is the argument about the state of the Himalayan forests more
fierce than in Nepal’s Sagarmatha National Park, which includes Mount Everest.
The park was established in 1976 because of growing concern about the destruction
of forests and erosion of soils around the world’s highest mountain.

A paper in the Swedish journal Ambio in 1983 said that the park, in
the Khumbu region of Nepal, was being despoiled and identified tourism as
the root of local deforestation. Inside the park the 2500 native Sherpas
are outnumbered each year by an invasion of around 5000 tourists. The Sherpas
chop down trees and shrubs to burn to keep the tourists warm at night on
their mountain treks. ‘Sagarmatha has suffered more deforestation during
the past two decades than in the preceding 200 years,’ said the paper.

In a region overrun by Westerners one might assume that the evidence
for deforestation is rock-solid. But, according to Alton Byers, of the Woodlands
Mountain Institute, Franklin, West Virginia, this is not so. After taking
new photographs to compare with vistas taken in the late 1950s, he concluded
that since then, ‘far less forest removal and geomorphic damage has occurred
than has been hitherto assumed’. The findings, said Byers, ‘directly counter
the previous statements of scientists, developers, tourists and management
authorities’. But he warned that nobody should attempt to extrapolate his
own findings to other areas of the Himalayas. Otherwise there was a danger
of ‘the transformation of new ‘facts’ (Khumbu landscape stability) into
new ‘myths’ (there are no problems in the Himalayas)’.

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Myth 2 – Deforestation causes soil erosion

Deforestation, says Lawrence Hamilton of the East-West Environment and
Policy Institute in Hawaii, is an almost meaningless term, covering everything
from peasants harvesting fuelwood and fodder, to forest burning and commercial
logging. ‘The cutting of trees alone does not directly cause erosion,’ he
says, though heavy logging equipment and the cutting of logging roads can,
and over-grazing of cleared land will do so.

It is often claimed that tree cover protects soil from the impact of
raindrops. Not so, says Hamilton. Experiments show that ‘raindrop impact
on bare soil under tree canopies greater than 10 metres in height is greater
than on bare soil in the open’. This is because drops falling from a high
canopy are larger than normal, and so do more damage. What protects soil
is low vegetation.

* * *

Myth 3 – Himalayan sediment causes floods

Even if there were more sediment in the Ganges, Brahmaputra and their
tributaries as they emerge from the Himalayas, it is unlikely that this
could increase deposition far downstream. Eroded material will rarely travel
all the way downstream in one or even a few trips. It will be deposited
on the river bed or mud banks many times, says Lawrence Hamilton. ‘Even
if land conservation activities could virtually shut off all human-caused,
accelerated erosion in the hills, there would be little change in sediment
in the lower reaches of a river for decades . . . In very large basins such
as the Ganges it may take centuries.’

This finding is confirmed by recent Pakistani efforts to reduce siltation
in reservoirs in the Indus Valley with upstream soil conservation projects.