Included here are the upper plains of the Ganges extending from the Aravalli Hills and the Yumana River eastwards to the Kosi River where the river bends close to the Rajmahal Hills.

Most of the original moist deciduous forest of the Upper Gangetic Plain was probably dominated by Shorea robusta (sal). It forms an upper canopy tree reaching heights of up the 35 m. Other commonly associated trees would have included Adina cordifolia, Dillenia pentagyna, Lagerstroemia parviflora, Stereospermum suaveolens, Terminalia belerica and T. tomentosa. However, today only one large continuous stand remains. It extends along the Himalayan foothills of Utter Pradesh and includes the Corbett, Dudwa and Rajaji national parks. In the Siwali Hills, where the Corbett National Park has been established, canopy trees other than the ones mentioned above include Anogeissus latifolia, Diospyros tomentosa, Garuga pinnata, Lannea coromandelica and Pinus roxburghii. Common second story species are Buchanania lanzan, Dendrocalamus strictus, Ehretia laevis, Ougeinia oojeinensis and Semecarpus anacardium, while typical third story species include Berberis asiatica, Clerodendron viscosus, Colebrookea oppositifolia, Indigofera cassioides, Murraya koenigii, Pogostemon plectranthoides and Woodfordia fruticosa. Common shrub layer species are Chrysopogon fulvus, Heteropogon contortus and Thysanolaena maximus, while typical herbs include Bauhinia vahlii and Milletia auriculata. However, the physiognomy of these forests depends on various factors particularly relating to variations in local climate, topography, geology and soil. In the hilly areas, sal is often stunted while in dry areas it is usually confined to the cooler more moist depressions. In the outer Himalayas it can ascend to altitudes of about 1500 m, but the best sal forests occur at low altitudes on deep loamy soil.

References

Duthie, J. F. 1973a. Flora of the Upper Gangetic Plain. Volume. 1. Ranunculaceae to Cornaceae. Bishen Singh Mahendra Pal Singh.

Duthie, J. F. 1973b. Flora of the Upper Gangetic Plain. Volume. 1. Plumbaginaceae to Juncaceae. Bishen Singh Mahendra Pal Singh.

Khanna, K. K., Mudgal, V., Ubiyal, B. P. & Sharma, J. R. 1999. Dicotyledonous Plants of Uttar Pradesh. Bishen Singh Mahendra Pal Singh, Dehra Dun, India.

Misra, R. 1959. The status of the plant communities in the Upper Gangetic Plain. The Journal of Indian Botanical Society. XXXVIII: 1-7.

Puri, G. S., Gupta, R. K., Meher-Homji, V. M. & Puri, S. 1989. Forest Ecology. Plant form, diversity, communities and succession. 2nd Edition. Volume 2. Oxford & IBH Publishing Co. PVT. Ltd.