Location and General Description
The Rann of Kutch Seasonal Salt Marsh [IM0901] lies at the end of the Luni River, which drains the Aravalli Hills and flows southward only to dissipate into the dry, arid salt flats represented by this ecoregion. Geographically, the ecoregion extends across the northwestern Indian State of Gujarat and southern Pakistan's Sind Desert region, sitting along the Tropic of Cancer.
Since the Mesozoic, the Little and Great Ranns were extensions of the shallow Arabian Sea until geological uplift closed off the connection with the sea, creating a vast lake that was still navigable during the time of Alexander the Great (WII 1993). But over the centuries, silting has created a vast, saline mudflat. During the brief wet season, the mudflat becomes flooded. Then it becomes parched under the relentless, searing heat of the long dry season; the ecoregion has one of the highest annual evaporation rates in the region (WII 1993). Average summer temperatures hover around 44(C but can reach highs of 50(C, and the minimum winter temperatures approach or even drop below freezing (WII 1993).
The July to September monsoon rains flood the vast, flat area to a depth of about 0.5 m. Several rivers-the Bhambhan, Kankavati, Godhra, and Umai from the south, the Rupen and Saraswati from the east, and Banas from the northeast-drain into the Ranns during the monsoon. Several sandy, salt-free areas of higher ground that rise to 2-3 m lie above the flood level and provide wet-season refuges for the ecoregion's wildlife. These refuges are known as bets, and three (Pung-bet, Vacha-bet, and the Jhilandan-bet) in particular are important refuges for wild asses.
The vegetation consists of grasses and dry thorny scrub such as Apluda aristata, Cenchrus spp., Pennisetum spp., Cymbopogon spp., Eragrostis spp., and Elionurus spp. (Puri et al. 1989). There are hardly any large trees except in the bets, where the exotic Prosopis juliflora has begun to invade. Seedpods from the Prosopis provide year-round food for the wild asses. In the Little Rann the vegetation is classified into Salvadora scrub and tropical Euphorbia scrub (Champion and Seth 1968).
Despite the inhospitable conditions, this ecoregion harbors several charismatic mammal species of conservation importance, including the Asiatic wild ass, chinkara (Gazella bennettii), nilgai (Boselaphus tragocamelus), wolf (Canis lupus), blackbuck (Antilope cervicapra), striped hyena (Hyaena hyaena), desert cat (Felis silverstris), and caracal (Felis caracal).
The overall mammal fauna is estimated at about fifty species, including a single strict endemic species (table 1). The Asiatic wild ass and blackbuck also represent threatened species (IUCN 2000).
Table 1. Endemic Mammal Species.
Equidae Equus hemionus
An asterisk signifies that the species' range is limited to this ecoregion.
The ecoregion also harbors more than 200 bird species. Although none are endemic, the ecoregion does harbor the globally threatened lesser florican (Eupodotis indica) and houbara bustard (Chlamydotis undulata) (IUCN 2000). Other birds of conservation importance include the demoiselle crane (Anthropoides virgo) and lesser flamingo (Phoeniconaias minor) (WII 1993).
Three protected areas cover more than three-fourths of this ecoregion (table 2). The large Wild Ass Sanctuary in India was designated especially to protect the last population of this endangered species.
Table 2. WCMC (1997) Protected Areas That Overlap with the Ecoregion.
Protected Area Area (km2) IUCN Category
Keti Bunder South 980 IV
Kachchh Desert 13,540 IV
Wild Ass Sanctuary 7,170 IV
Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.
Types and Severity of Threats
The primary threats to this ecoregion's habitat are from cattle grazing even within the protected areas, vehicular traffic that damages the fragile ecosystem, and cutting trees to make charcoal. The proposed expansion of the commercial salt extraction operations will result in disturbances to wildlife, especially to the wild ass population and the floricans, bustards, flamingoes, and pelicans (WII 1993). Feral pigs around the fringes of the sanctuary carry disease, degrade habitat, and disrupt reproduction of ground-nesting birds.
Justification of Ecoregion Delineation
We used MacKinnon's (1997) digital map of original habitat that depicts the extent of the Rann of Kutch salt marshes to define the boundaries of this ecoregion. Both the Rann of Kutch Seasonal Salt Marsh [IM0901] and the Indus Valley Desert [IM1302] lie within the Thar Desert biogeographic province.
References for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.
Indo-Pacific Reference List
Prepared by: Gopal S. Rawat and Eric D. Wikramanayake