大象传媒

On their southern face, the mountains are thickly forested. Why is this so different to the dry lands beyond the snows? At 3,000 metres, in the great Himalayan forests of northern India, some of the peaks are enveloped by clouds and rise to above 7,000 metres. This great Himalayan barrier intercepts the moisture-laden winds of the monsoon, forcing them upwards to release their burden of rain and snow, creating a carpet of lush vegetation. Grey langurs feast on the young shoots of Indian horse chestnut. These are the same langurs that we find over much of India, but more thickly furred, to withstand the cold of the mountains. In winter these forests are deep in snow, but in spring they burst into a new growth a banquet of opportunity for leaf eaters like langurs. As you climb up the mountains the forest changes. Oak and chestnut give way to spruce and fir, and on the edge of the alpine meadows, to birch. One group of plants extends over that whole range of altitudes: rhododendrons.