Tropical Dry Deciduous Forests: These forests occur mostly near Yamuna Riverand on the foothills and extend up to the altitudes of 1,200 metres. The predominant species are kuri, kemela, jhingan, and mandar. The chief undergrowths are dhaula, binda, basingha and the gandela. Sal Forests: These forests exist up to the altitude of 1,066 metres, their best growths being found in the valley of the Bandal in tehsil Tehri. Small tracts of the Sal forests may also be seen in the neighbourhood of Muni ki Reti and Shivpuri in tehsil Dev Prayag. Sal is highly gregarious. The upper limit of Sal is regulated to a great extent by frost. In excessively dry localities, it gives way to more xerophytic species. It does not extend beyond the outer ranges of the Himalayas even though the main river valleys in the northern part of the district are much below the maximum elevation at which this species may grow. It is commonly found up to the altitude of 762 metres on the southern aspects and 1,066 metres on the northern. The other chief trees found in these forests are sain, bakli, jhingan, haldu, kanju, sandhan, rohini and amaltas. The wood of the sandhan is used for making agricultural implements. Grass abounds in Sal forests, wherever sufficient light reaches the ground. In most Sal forests, Sal comprises 80 to 90 percent of the dominant tree species and tends to form a dense tree canopy. The Sal forests had originally contained a much higher percentage of miscellaneous species. Chir Forests: These forests ordinarily extend on the southern aspects from 1,000 metres to 2,150 metres and on the northern aspects from 900 metres to 2,000 metres throughout the district, growing best in the valleys of the Bhilangana and its tributaries, Alaknanda River and Mandakini. Chir is found on almost all geological formations though, on certain southern slopes with limestone subsoil, it is not found because of the dryness of the soil coupled with relatively high temperatures. Nevertheless, chir forests can establish themselves on dry southern aspects where owing to xerophytic conditions and the prevalence of fires, few other trees or shrub species survive. In all chir forests, pine is the dominant tree species present though, on the northern aspects where, there is more moisture in the soil and fires are less destructive, scattered trees of there species also occur. Chir forests are seldom very dense. The ground is covered with grass, sometimes dense, whatever the aspect of density or overhead canopy, and there is also a discontinuous undergrowth of shrubs, often so widely scattered that even from a short distance their presence is scarcely noticeable. The open nature of these forests, the absence of other tree species and the scarcity of the undergrowth are attributable to fires which have in the past swept annually throughout their length and breadth, to the xerophytic conditions under which they grow and to the fact that the chir is often located near tracts under cultivation which leads to its heavy lopping and felling. Towards its lower limit, chir gets mixed up with trees of miscellaneous species and, less frequently, with sal forests. The chir is tapped for resin and its wood is used for building purposes. The seed also yields oil and, when baked, it becomes edible. Deodar Forests: These forests occur in the northern part of Tehri Garhwal District in tehsil Pratapnagar in a small area, associated with blue pine and cypress between the altitudes of 1,520 metres and 2,150 metres above sea level. The forests are open and the trees do not attain great height. Fir and Spruce forests also occur in the northern part of Tehri Garhwal District between the altitudes of 2,150 metres and 3,050 metres. Wherever silver fir occurs, it is the dominant species excepting when it occurs mixed with spruce even where, it is equally important. Oak Forests: The three principal oaks are banj, moru and kharsu, each occupying more or less a distinct altitudinal zone in the district. Banj forests are ordinarily found between the heights of 1,800 metres and 2,150 metres above sea level. They also occupy moist ravines running down into the chir zone where they reach levels as low as 1,050 metres. A notable feature of banj forests is its capacity to establish itself on the most unfavourable southern aspects. Those on the northern aspects are comparatively denser. On southern aspects, the ground is almost invariably clothed with dense grass, while on northern aspects the incidence of grass is much less. The banj has a large number of shrubs associated with it. Moru forests are found at between 1,980 metres and 2,750 metres above sea level and occupy an intermediate zone between banj and kharsu, which form extensive forests on the southern aspects, where the moru occurs sporadically. It attains its maximum development at elevations between 2,125 metres and 2,450 metres on moist soils and especially where the subsoil is limestone. The kharsu forests occupy very extensive tracts at heights between 2,350 metres and 3,500 metres in the northern part of tehsil Pratap Nagar (except in the north-east) and in the north-eastern part of tehsil Devprayag. It is found equally on the northern and southern aspects and has few successful competitors, excepting silver fir and moru. The fir, however, occurs only on a small fraction of the area occupied by kharsu. At its upper limit, moru passes into forests of birch and silver though, on southern slopes, it more frequently passes directly into pastureland without any gradual transition. Typical khasru forests are dense, the most common associate being burans, which is almost as abundant in the kharsu forests as it is in the banj forests. Shrubs also occur in diverse varieties. Alpine Pastures: These are found in the north eastern part of Tehri Garhwal District in tehsils Pratap Nagar and Devprayag between heights of 3,500 metres and 5,000 metres above sea level. The land in these parts is covered with snow from October to May but, from June to September, varieties of grasses, herbs, shrubs and flowers grow in the area in abundance. The area provides beautiful and extensive pasture lands for the cattle. On the northern aspects, birch is also found. Large variety of herbal plants bushes, scrubs and grass are also found in the district. |