Influence of rangeland protection and seasonal grazing on aboveground vegetation,forage quality and weight gain of small ruminants–a study in Thar Desert,Pakistan

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.

Dryland agriculture and rangeland restoration priorities in Afghanistan

Afghanistan is threatened by rangeland degradation.A quantitative visual analysis of Google Earth Imagery was used to systematically locate,characterize and quantify the current extent of rangelands in Afghanistan degraded as a consequence of dryland agriculture.Climate data were used in conjunction with dryland agriculture locations to establish a climate envelope comprised by temperature and mean annual precipitation to create a geographical mask known to contain dryland agriculture.Within this mask we created a grid of 100 km2 cells that we analyzed individually to access dryland agriculture extent.Climatic limits to sustainable dryland agriculture and areas of high restoration priority were also assessed as was the distribution of rain-fed agriculture with respect to the location of traditional migration routes for extensive livestock producers.The extents of agriculture in Afghanistan,at both upper and lower elevations,correlated most closely with mean annual temperature（MAT） at the upper elevation limits,and with mean annual precipitation（MAP） at the lower elevation limits.In total,dryland agriculture comprised 38,980 km2 of former native rangeland.Conversion was highest in the northwestern,northern and northeastern provinces of Herat,Badghis,Faryab,Jawzjan,Sar-e-Pul,Samangan,Balkh,Baghlan,Kunduz,Takhar and Badakhshan,with the highest percentage of conversion occurring in Takhar.An MAP value of 〈400 mm is perceived by farmers as the current climatic limit to sustainable dryland agriculture across the northern regions of the country.Uder this MAP value,approximately 27,677 km2 of converted rangeland met the need for restoration priority.Climate projections indicate that Afghanistan will become warmer and drier in the coming decades.One consequence of this trend is that the MAP threshold of 〈400 mm to sustainable dryland agriculture will become obsolete in the coming decades.Restoration of currently converted rangelands is needed to restore critical grazing areas as is the adoption of prudent range management policies to prevent further land degradation and support a vital livestock industry.Food security is at stake as the conversion of rangelands to unsustainable rain-fed agriculture may leave large tracks of land unusable for either agriculture or livestock production.

Modelling the impact of climate change on rangeland forage production using a generalized regression neural network:a case study in Isfahan Province,Central Iran

Monitoring of rangeland forage production at specified spatial and temporal scales is necessary for grazing management and also for implementation of rehabilitation projects in rangelands. This study focused on the capability of a generalized regression neural network（GRNN） model combined with GIS techniques to explore the impact of climate change on rangeland forage production. Specifically, a dataset of 115 monitored records of forage production were collected from 16 rangeland sites during the period 1998–2007 in Isfahan Province, Central Iran. Neural network models were designed using the monitored forage production values and available environmental data（including climate and topography data）, and the performance of each network model was assessed using the mean estimation error（MEE）, model efficiency factor（MEF）, and correlation coefficient（r）. The best neural network model was then selected and further applied to predict the forage production of rangelands in the future（in 2030 and 2080） under A1 B climate change scenario using Hadley Centre coupled model. The present and future forage production maps were also produced. Rangeland forage production exhibited strong correlations with environmental factors, such as slope, elevation, aspect and annual temperature. The present forage production in the study area varied from 25.6 to 574.1 kg/hm^2. Under climate change scenario, the annual temperature was predicted to increase and the annual precipitation was predicted to decrease. The prediction maps of forage production in the future indicated that the area with low level of forage production（0–100 kg/hm^2） will increase while the areas with moderate, moderately high and high levels of forage production（≥100 kg/hm^2） will decrease both in 2030 and in 2080, which may be attributable to the increasing annual temperature and decreasing annual precipitation. It was predicted that forage production of rangelands will decrease in the next couple of decades, especially in the western and southern parts of Isfahan Province. These changes are more pronounced in elevations between 2200 and 2900 m. Therefore, rangeland managers have to cope with these changes by holistic management approaches through mitigation and human adaptations.

Effect of Different Stocking Rates on Deyeuxia angustifolia Bog Meadow in Sanjiang Plain of China

This paper investigated the effects of cattle grazing on herbage production and its nutrient and soil characteristics over the grazing season. The grazing experiment was conducted on Deyeuxia angustifolia Bog meadow grassland established in 2010 in Sanjiang Plain. Four grazing treatments were light grazing （LG）, moderate grazing （MG）, heavy grazing （HG）, and a non-grazed exclosure （CK） with corresponding stocking rates of 0.6, 1.0, 1.4, and 0 AU·hm2. month-1, selected as three replications. And then found out the optimum carrying capacity after analyzed the nutrition balance between livestock and grassland. Heavy grazing led to a decline in grassland productivity and soil nutrients. The SOM and the TN content in the soil layer of 0-10 cm were much higher than that in the soil layer of 20-30 cm. More attention should be paid to the nutrient changes in the soil layer of 20-30 cm. Currently, studies showed that the reliable carrying capacity in this type of grassland was 1.0 AU·hm-2. month-l. Inclusion of rangeland health monitoring and optimum stocking rate into grassland management model could facilitate the sustainable development of the grassland.

Towards Regional Synergy: Reconciling Rangeland Ecological Functioning with Forage Production of Cultivated Pasture

Animal husbandry and crop farming are specialized for development in separate areas on the Tibetan Plateau. Such a pattern of isolation has led to current concerns of rangeland and farming system degradation due to intensive land use. The crop-livestock integration, however, has been proven to increase food and feed productivity thorough niche complementarity, and is thereby especially effective for promoting ecosystem resilience. Regional synergy has emerged as an integrated approach to reconcile rangeland livestock with forage crop production. It moves beyond the specialized sectors of animal husbandry and intensive agriculture to coordinate them through regional coupling. Therefore, crop-livestock integration(CLI) has been suggested as one of the effective solutions to forage deficit and livestock production in grazing systems. But it is imperative that CLI moves forward from the farm level to the regional scale, in order to secure regional synergism during agro-pastoral development. The national key R & D program, Technology and Demonstration of Recovery and Restoration of Degraded Alpine Ecosystems on the Tibetan Plateau, aims to solve the problems of alpine grassland degradation by building up a grass-based animal husbandry technology system that includes synergizing forage production and ecological functioning, reconciling the relationship between ecology, forage production and animal husbandry, and achieving the win-win goals of curbing grassland degradation and changing the development mode of animal husbandry. It is imperative to call for regional synergy through integrating ecological functioning with ecosystem services, given the alarming threat of rangeland degradation on the Tibetan Plateau. The series of papers in this issue, together with those published previously, provide a collection of rangeland ecology and management studies in an effort to ensure the sustainable use and management of the alpine ecosystems.