The Thar Desert,Sindh,Pakistan is characterized by low productivity.Besides,economy is based on agriculture,livestock and mining,nevertheless,livestock graze freely on public and private land.The aim of this research ...The Thar Desert,Sindh,Pakistan is characterized by low productivity.Besides,economy is based on agriculture,livestock and mining,nevertheless,livestock graze freely on public and private land.The aim of this research was to determine biomass production and to evaluate the effects of continuous and seasonal grazing on protected and unprotected plots.A 45 ha protected rangeland area of Hurrabad in the Umerkot Thar desert was selected and divided into three blocks of 15 ha each.Blocks of the same size were also established in unprotected area.The data for vegetation biomass,canopy cover,forage nutrients and weight gain of animals in two seasons(spring and summer)was collected from both protected and unprotected sites.The results showed that biomass significantly increased in summer in both sites.However,the biomass values in protected sites were significantly higher.Similarly,the vegetation cover also seemed to increase in summer in both protected(90.7%±0.29%)and unprotected sites(39.2%±0.09%).The foliar concentrations of all nutrients varied significantly with season.The average final live-weight gain for does on the protected grazing sites during the 42-day period in spring and the 96 days after the monsoon was almost double that of does grazing on the unprotected site during 2016 and 2017(P<0.05).The study concludes that the protection of grazing lands during certain periods can lead to better production of vegetation and livestock and improve range conditions.展开更多
[Objective] The aim of this study was to evaluate the effect of livestock exclusion on the health of grassland ecosystem accurately and quantitatively. [Method] One open grazing site and five seasonal exclusion sites,...[Objective] The aim of this study was to evaluate the effect of livestock exclusion on the health of grassland ecosystem accurately and quantitatively. [Method] One open grazing site and five seasonal exclusion sites, which had the same vegetation composition （taking Leymus chinensis and Stipa krylovii as main species） and soil type, were chosen as research objects for the VOR and CVOR evaluation of the effect of open grazing and livestock exclusion on the health of typical steppes, and for building the calculation model for VOR and CVOR indices to evaluate the health of typical steppes with different exclusion periods. [ Result] The VOR and CVOR composite indices both could accurately evaluate the health of typical steppes, and the evaluation results from the both indices were quite consistent. Although the condition （C）, vigor（V）, organization （O） and resilience（ R ） indices changed differently in different exclusion periods, the VOR and CVOR composite indices increased gradually with the peri- od of exclusion prolonged, and the health condition of typical steppe changed from ＂alert＂ level （in the open grazing and earlier exclusion period） to ＂healthy＂ level （after 13 to 20 years＇exclusion）. [ Conclusion] The application of exclusion was beneficial to the recovery of degraded grassland ecosystem.展开更多
基金financial support of the rangeland monitoring trials in the Thar Desertsupport of The International Center for Agricultural Research in the Dry Areas (ICARDA), CRP Livestock and the Livestock and Climate Initiative of the OneCGIAR
文摘The Thar Desert,Sindh,Pakistan is characterized by low productivity.Besides,economy is based on agriculture,livestock and mining,nevertheless,livestock graze freely on public and private land.The aim of this research was to determine biomass production and to evaluate the effects of continuous and seasonal grazing on protected and unprotected plots.A 45 ha protected rangeland area of Hurrabad in the Umerkot Thar desert was selected and divided into three blocks of 15 ha each.Blocks of the same size were also established in unprotected area.The data for vegetation biomass,canopy cover,forage nutrients and weight gain of animals in two seasons(spring and summer)was collected from both protected and unprotected sites.The results showed that biomass significantly increased in summer in both sites.However,the biomass values in protected sites were significantly higher.Similarly,the vegetation cover also seemed to increase in summer in both protected(90.7%±0.29%)and unprotected sites(39.2%±0.09%).The foliar concentrations of all nutrients varied significantly with season.The average final live-weight gain for does on the protected grazing sites during the 42-day period in spring and the 96 days after the monsoon was almost double that of does grazing on the unprotected site during 2016 and 2017(P<0.05).The study concludes that the protection of grazing lands during certain periods can lead to better production of vegetation and livestock and improve range conditions.
基金supported by the National Natural Science Foundation of China(32071564)the Department of Science and Technology of Inner Mongolia Autonomous Region of China(2019ZD007 and 2022LHQN03001)the Open Project of Collaborative Innovation Center for Grassland Ecological Security,Ministry of Education of China.Conflict of interest statement.
基金supported by National Key Fundamental Research and Development Fund of China (No.2007CB106800)
文摘[Objective] The aim of this study was to evaluate the effect of livestock exclusion on the health of grassland ecosystem accurately and quantitatively. [Method] One open grazing site and five seasonal exclusion sites, which had the same vegetation composition （taking Leymus chinensis and Stipa krylovii as main species） and soil type, were chosen as research objects for the VOR and CVOR evaluation of the effect of open grazing and livestock exclusion on the health of typical steppes, and for building the calculation model for VOR and CVOR indices to evaluate the health of typical steppes with different exclusion periods. [ Result] The VOR and CVOR composite indices both could accurately evaluate the health of typical steppes, and the evaluation results from the both indices were quite consistent. Although the condition （C）, vigor（V）, organization （O） and resilience（ R ） indices changed differently in different exclusion periods, the VOR and CVOR composite indices increased gradually with the peri- od of exclusion prolonged, and the health condition of typical steppe changed from ＂alert＂ level （in the open grazing and earlier exclusion period） to ＂healthy＂ level （after 13 to 20 years＇exclusion）. [ Conclusion] The application of exclusion was beneficial to the recovery of degraded grassland ecosystem.
