STUDIES ON THE PRODUCTIVE POTENTIAL AND CONSERVATION STRATEGY OF MAJOR RANGE GRASSES IN THE DEGRADING RANGE LANDS OF CHOLISTAN DESERT

Abstract

This base line as well as comprehensive study about the productive potential of grasses in Cholistan desert was conducted for two consecutive years from 2009 to 2010. The aim of this study was to study the floristic composition, vegetation structure, biomass production, carrying capacity, palatability and nutritional evaluation of grass species. Based on our findings, total 27 grass species consisting of 16 genera, belonging to family Poaceae were identified. The documented grasses comprised of 13 annuals species and 14 perennials species whereas therophyte was dominant life form including 16 grass species followed by hemicrytophytes with 09 species and phanerophytes with 02 species. Abundance of grasses showed that 06 grass species were found very common, 14 were common and 07 species were rare. In current study, two phenological seasons were recognized from the Cholistan desert. First season started from February and ended in May while second phenological season was from August to December. Maximum grass species were found to be flowering during the second spell as compare to first one. Further, based on economic use classification it was observed that all 27 grasses were being used as fodder/forage while 05 species were used as medicine in the investigated area. Based on phytosociological study, twenty grass communities were identified from selected range sites. However, multivariate analysis has produce three major vegetation groups i.e. interdunal, sandunal and clayey saline group. The soil texture of sandunal group was sandy, interdunal group was sandy loam whereas clayey saline group was clayey. Moreover, it was observed that fluctuations in rainfall pattern influenced the biomass productivity of range grasses in the study area. There was high biomass production in wet season (8068 Kg/ha) as compared to dry season (5595 Kg/ha). Following the biomass productivity of grasses, overall carrying capacity of rangelands of Cholistan desert was 24.20 ha/AU/year during dry season and 17.25 ha/AU/year in wet season. However, stocking rate varied from 0.041 AU/ha/year in dry season to 0.057AU/ha/year in wet season. In this study, degree of palatability showed that all the identified grass species were palatable. Out of which 18 grass species were highly palatable while 07 were moderately palatable and 02 were less palatable species. Among 27 palatable grass species 25 species (92.6%) were used by goats, 26 species (96.3%) were used by sheep and cattle, and camel were using only 07 grass species (25.9 %). It was noted that flower and fruit parts of grasses were grazed in 14 species (51.8 %) and 08 species (29.8 %) respectively, whereas in 26 species (96.3%) leaves were used and in 23 species (85.1%) stem parts were grazed. Similarly, nutritional evaluation consisting of chemical, structural, and mineral analysis of major range grasses was conducted. Results showed that grasses were good source of dry matter and crude protein but deficient in other nutrients and remained fail to meet the animal requirements for optimum livestock production in Cholistan rangelands. Overall, this study showed that the investigated rangeland is less productive and needs proper management and rehabilitation through ecological approaches. There is a need that Government should give complete protection to this rangeland and provide alternate resource of energy to lessen the burden on this area. It is recommended that low stocking rate during growing seasons and moderate stocking rate during dry spell by proper livestock management technique improve range biomass, species diversity, and rangeland carrying capacity. This all would be possible with the participation of local people/pastoralist and Government to make the resources sustainable.