The Gir ecosystem falls in the semi-arid zone with bio-geography province of Gujarat Rajwara. The dry-deciduous teak forest, misc. forest, dry-thorn forest, Savannah, shrub land and wetland made the zone as a last remaining abode of the Asiatic Lion (Panthera leo persica). The Government of Gujarat has declared an area of 1412.1 sq. km. as Protected Area (PA), comprises 258.7 sq. km. as National Park and 1153.4 sq. km. as Sanctuary. Besides this 470.5 sq. km. of forest area forms a buffer Zone as reserved, protected and unclassified forests. Thus, a total area of 1882.6 sq. km. makes up the Gir forest. Of this, 1502.7 sq. km. lies in Junagadh and Gir Somnath districts while 379.9 sq. km. in Amreli district. Owing to its rich and diverse flora and fauna, Gir significantly has become a very stable ecosystem with tremendous regenerating, self-supporting and sustaining power.
Gir lies between 20° 40’ and 21° 50’ N latitude and 70° 50’ and 71° 15’ E longitude. The terrain is mainly undulating with moderate hills, valleys and plateaus without definite direction of hill ranges. The northern parts are relatively hillier than the southern part, with the general drainage direction being south and southwest.
The volcanic origin hills are Deccan trap formation with major Dolomite and Basalt rocks. Besides it sandstone, limestone and metamorphic schist are also present. Volcanic rocks have given rise to black cotton soil, while sandstone and limestone have given rise to reddish brown sandy loam soil. Soil texture varies from gravelly along the riverbanks, clay in deep valleys, to stony and murrum of hills.
Gir has tropical monsoon climate, with three distinct seasons – summer, monsoon and winter. Late November to early March is cool and dry, with temperatures dropping to around 10° C in midwinter. This is followed by a hot dry summer with peak temperatures rising to well above 40° C. Mid-June to September is the monsoon period. The bulk of precipitation is during July and August. Rainfall data of the past 28 years received at Kamleshwar Dam in the western part of Gir and Raval Dam in the eastern part show that the average rainfall at these areas is 1000 mm and 600 mm respectively. Owing to irregular monsoon and uneven distribution of rainfall drought years are not uncommon.
Gir forms the catchment of seven perennial rivers viz the Hiran, the Saraswati, the Datardi, the Shingoda, the Machhundri, the Ghodavadi and the Raval.
The northern aspect of the northern ridges forms the catchment of Shetrunji river, which flows outside the sanctuary area. All these major rivers of Gir have perennial water supply except during severe drought. At the peak of summer, surface water for wild animals is available at only about 300 water points. In order to tap water resources, four dams have been constructed along the Hiran, the Machhundri, the Raval and the Shingoda respectively. The total catchment area of these is 820 sq km, while water from rest of the areas remains untapped.
During droughts, surface water is not available at majority of these points. Water scarcity is a serious problem in Eastern part of the Gir during droughts. Ensuring the availability of water during peak summer is one of the major tasks of the Forest Department staff.
Santapau and Raizada (1955) have, recorded more than 400 plant species in Gir, whereas the Botany Department of M S University of Baroda has recorded 507. According to Champion and Seth’s classification of forest types (1964), the Gir forest falls under 5A/C1 – a very dry teak forest. Teak occurs mixed with dry deciduous species. The degradation stage of this sub type areas also met within this tract are as under:
1. Sub-type 5/DS1– Dry deciduous scrub forest
2. Sub-type 5/DS2– Dry savannah forests (locally known as vidis)
Sr. No. No. of Species Life forms Percentage
1 Tree 132 26.03
2 Shrub 48 9.47
3 Herb 232 45.76
4 Climber 64 13.61
5 Grass 26 5.13
Total 507 100.00
Teak bearing areas are mainly confined to the Western portion of the Gir forests, which constitute nearby half of the area. The remaining area (Gir East) has a greater variety of species.
The unique ecosystem of Gir harbours about 38 species of mammals, around 300 species of birds, 37 species of reptiles and more than 2000 species of insects.
The main carnivores of Gir are the Asiatic lion, the Leopard, the Jungle cat, the Hyena, the Jackal, the Mongoose, the Civet cat, and the Ratel. The Desert cat and the Rusty Spotted cat are very rare. The main herbivores of Gir are the Chital, the Nilgai, the Sambar, the Four-horned antelope, the Chinkara and the Wild boar. Adjunct to Gir forest, there is a small population of Blackbuck.
Among the smaller mammals, the Porcupine and the Black-naped Hare are common. The Pangolin is rare. The reptilian fauna is represented by the Marsh Crocodile, the Star Tortoise, the Monitor Lizard and a number of snake species. The Python is also found sometimes along the stream banks. It is worth mentioning that the Gir forest has a higher population of the Marsh Crocodiles than any other PA in India.
Most of the 300 species of avifauna here are resident. The main scavenger is the vulture, of which six species have been recorded. Some of the typical birds of Gir are the Crested Serpent Eagle, the Bonelli’s Eagle, the Crested Hawk Eagle, the King Vulture, the Brown Fish Owl, the Great Horned Owl, the Bush Quail, the Pygmy Woodpecker, the Black-headed Oriole, the Crested Swift and the Indian Pitta. The Grey Hornbill is now extinct from the area.
In terms of conservation values, Gir
• is the largest compact tract of dry deciduous forest in the semi-arid western part of the country;
• is the last home of the Asiatic lion (Panthera leo persica) – its last surviving gene pool in nature the world;
• is a rich biodiversity area supporting large number of species including several endangered species;
• has the highest concentration of top carnivores. The Lion and the Leopard (over 500), and possibly the single largest population of the Marsh Crocodiles in the country;
• is the catchment area of seven rivers which sustain the economic prosperity of this drought prone region;
• ensures the ecological security and environmental amelioration for the region; climate, water, salinity prevention and pollution absorption;
• is an important biological research area with considerable scientific, educational, aesthetic and recreational values; and
• is the cradle of cultural and religious evolution in Saurashtra.