ASSESSMENT OF PRODUCTIVE POTENTIAL OF BROWSE SPECIES AND THEIR MANAGEMENT STRATEGY IN THE DEGRADING RANGELANDS OF CHOLISTAN DESERT

Abstract

The Cholistan rangelands have been on decline due to various stresses and their effects can be visualized on its flora particularly on browse species. Therefore, a baseline study was carried to determine the productivity potential of browses with specific objectives of investigating their floristic composition, vegetation structure, forage productivity, and nutritive evaluation. Total 25 browse species belonging to 12 families and 17 genera were identified whereas Chenopodiaceae, Mimosaceae, and Rhamnaceae were found as dominant families that were mainly contributing to browse cover. In the investigated area two phenological seasons were recorded, first from February to April and second from September to November, whereas December to January and May to August were almost dormant phases. Further, based on economic importance of browses, maximum species were observed to be used as forage/fodder that clearly indicated that this area could serve as potential rangeland. According to phytosociological study, twenty browse communities were documented on the basis of importance value index. Multivariate analysis of twenty stands has delineated three vegetation associations inhabiting the sandunal, interdunal sandy and clayey saline habitats. Soil physio-chemical analysis revealed that texture of sandunal habitat was sandy; interdunal was sandy loam while clayey saline was clayey. Results have exposed that organic matter, and soil nutrients were better at interdunal sandy habitat whereas pH, EC, Na, and soil moisture were high at clayey saline habitat. It was estimated that browse productivity was high (8029.1 kg/ha) in wet season as compare to dry season (5422.9 kg/ha), correspondingly carrying capacity was high during wet season (16 ha/AU/Y) than dry season (24 ha/AU/Y). Moreover, during dry season, mostly stands were observed to be overgrazed while in wet season maximum stands were moderately grazed. High carrying capacity and good grazing status of stands in wet season was due to better forage production. Based on palatability classification, 22 species were found to have palatability to varying degree and 03 species were non-palatable. In palatable species, leaves of 14 species; shoot/stem of 13 species, flower of 04 species, and fruit of 03 species were grazed by livestock, whereas cattle were observed to graze on 07 species; goat and sheep like 10 species each while camel prefer 20 species. Subsequently, nutritive evaluation revealed that browse species were good source of dry matter and protein whereas; concentration of almost all the minerals (micro and macro) was less than required level for ruminants grazing therein. The findings of this study indicate that the browse productivity of Cholistan rangelands was low and fluctuate according to seasons. Therefore, they need proper protection, management, and rehabilitation through ecological approaches. This would be possible with the participation of government and local peoples to make these range resources sustainable. Key words: Cholistan rangelands, Browse species, Floristic composition, Phenology, vegetation structure, Multivariate analysis, Biomass production, Carrying capacity, Palatability, Nutritive evaluation