Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors...Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors.This study aims to identify the various rangeland use forms and determine the types of livestock feeding system in the El Ouara rangelands of Ben guarden District in southern Tunisia by analysing the importance of supplemental feeding and main determinants of this practice.Data were collected by a survey that targeted a sample of 50 breeders in the El Ouara rangelands.Descriptive statistics and binary logistic regression were used to analyse the data.The results showed that there are two types of association practiced by breeders:“Cherka”association practiced by 10.00% of breeders and cash payment association practiced by 53.00% of breeders.Then,transhumance,sedentary,and semi-urban forms are the main ways in which breeders use the rangelands.There are four livestock feeding systems in the El Ouara rangelands being used to feed livestock:natural rangeland,rangeland-based,mixed,and concentrate-based feeding systems.Supplemental feeding has become fundamental for the livestock feeding system in the El Ouara rangelands.The breeders with the largest camel size still use the natural rangeland feeding system,while the breeders who have the largest herd size practice the mixed feeding system.The logistic regression results reveal that breeder age,cereal area,herd size,migrant remittance,second activity,and agricultural development group membership can significantly impact the supplemental feeding.In summary,this study can help policy-makers plan innovative practices based on climatic change,ensure the sustainability of livestock feeding system,and make effective decisions for local development.展开更多
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
Water plays a critical role in beef cattle production. Current methods used to estimate the blue water footprint of beef cattle are largely based on generic values that do not make provision for different production s...Water plays a critical role in beef cattle production. Current methods used to estimate the blue water footprint of beef cattle are largely based on generic values that do not make provision for different production systems within different regions. Total production cycle measurements should therefore be considered to accurately assess the blue water footprint of beef cattle grazing natural rangeland. The aim of the study was to measure water intake of extensive Bonsmara cattle grazing Marikana Thornveld over a full production cycle at the ARC-Roodeplaat Research Station. Measurements commenced at weaning (June 2017) and continued until the heifers weaned their first calves at approximately 210 days of age (July 2019). Water consumption differed between 21.4 litre per animal per day when the heifers were still growing to 54.3 litres during lactation, relating to between 6.7% and 12.0% of live weight. The blue water footprint over the total production cycle was calculated to be 27,147 litres.展开更多
Net primary production(NPP) is an indicator of rangeland ecosystem function. This research assessed the potential of the Carnegie Ames Stanford Approach(CASA) model for estimating NPP and its spatial and temporal chan...Net primary production(NPP) is an indicator of rangeland ecosystem function. This research assessed the potential of the Carnegie Ames Stanford Approach(CASA) model for estimating NPP and its spatial and temporal changes in semi-arid rangelands of Semirom County, Iran. Using CASA model, we estimated the NPP values based on monthly climate data and the normalized difference vegetation index(NDVI) obtained from the MODIS sensor. Regression analysis was then applied to compare the estimated production data with observed production data. The spatial and temporal changes in NPP and light utilization efficiency(LUE) were investigated in different rangeland vegetation types. The standardized precipitation index(SPI) was also calculated at different time scales and the correlation of SPI with NPP changes was determined. The results indicated that the estimated NPP values varied from 0.00 to 74.48 g C/(m^2·a). The observed and estimated NPP values had different correlations, depending on rangeland conditions and vegetation types. The highest and lowest correlations were respectively observed in Astragalus spp.-Agropyron spp. rangeland(R^2=0.75) with good condition and Gundelia spp.-Cousinia spp. rangeland(R^2=0.36) with poor and very poor conditions. The maximum and minimum LUE values were found in Astragalus spp.-Agropyron spp. rangeland(0.117 g C/MJ) with good condition and annual grassesannual forbs rangeland(0.010 g C/MJ), respectively. According to the correlations between SPI and NPP changes, the effects of drought periods on NPP depended on vegetation types and rangeland conditions. Annual plants had the highest drought sensitivity while shrubs exhibited the lowest drought sensitivity. The positive effects of wet periods on NPP were less evident in degraded areas where the destructive effects of drought were more prominent. Therefore, determining vegetation types and rangeland conditions is essential in NPP estimation. The findings of this study confirmed the potential of the CASA for estimating rangeland production. Therefore, the model output maps can be used to evaluate, monitor and optimize rangeland management in semi-arid rangelands of Iran where MODIS NPP products are not available.展开更多
Rangelands of Central Asia (referring to Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan in this study), the largest contiguous area of grazed land in the world, serve as an important source of livelih...Rangelands of Central Asia (referring to Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan in this study), the largest contiguous area of grazed land in the world, serve as an important source of livelihood for pastoral and agro-pastoral communities in this region. They also play an important role in absorbing CO<sub>2</sub> as a global carbon sink. However, unsustainable management of rangelands has led to their degradation hugely by downgrading their potential agro-ecological, environmental and socio-economical roles. This paper reviewed the rangeland degradation in Central Asia, a topic which so far has received only scant coverage in the international scientific literature. It also provided examples of successful experiences and outlined possible options that land managers can adopt to enhance the sustainable management of these vast degraded rangelands. The experiences and lessons described in this paper may also be relevant for other degraded rangeland areas, especially in the developing countries. The causes of rangeland degradation within the Central Asian region are numerous, complex and inter-related. Therefore, while addressing the factors associated with improper rangeland management may shed some light on the causes of rangeland degradation, the scope of this paper would not be all-encompassing for the major causes of degradation. There is a need to develop and widely apply the viable and locally accepted and adapted packages of technical, institutional and policy options for sustainable rangeland management. Incentivizing the collective action of small-scale pastoralists who group together to facilitate access to remote pastures can reduce the degree of overgrazing within community pastures, such as those near the settlements. We also found that migratory grazing through pooling of resources among small-scale pastoralists can increase household income. After their independence, most Central Asian countries adopted various rangeland tenure arrangements. However, the building of enhanced capacities of pasture management and effective local rangeland governance structures can increase the likelihood, which will be sustainable and equitable. Finally, this paper presented several promising technical options, aiming at reversing the trend of rangeland degradation in Central Asia.展开更多
Based on analysis of the development potential of rangeland resources in China＇s mountain areas, the paper makes analysis and forecast in human carrying capacity of rangeland resources. It provides some reference for...Based on analysis of the development potential of rangeland resources in China＇s mountain areas, the paper makes analysis and forecast in human carrying capacity of rangeland resources. It provides some reference for drawing up the development strategy in mountain areas.展开更多
Although the effects of non-grazing and heavy grazing on vegetation structure have been extensively studied in a wide range of ecosystems, the effects of moderate grazing on desert land are still largely unknown. Many...Although the effects of non-grazing and heavy grazing on vegetation structure have been extensively studied in a wide range of ecosystems, the effects of moderate grazing on desert land are still largely unknown. Many management opportunities exist for increasing forage intake. In order to determine an optimal management method of desert rangelands with high heritage value, we examined the respective effects of heavy grazing, moderate grazing and non-grazing on total vegetation cover, species richness, the Shannon-Wiener diversity index and rangeland productivity. Sampling was done from 2010 to 2012 （from the second year after treatments were imposed） using permanent transects under different grazing intensities. While total vegetation cover, species richness, Shan- non-Wiener diversity index, species composition and primary production were significantly greater on the ungrazed site and significantly weaker on the heavily grazed site, in contrast, moderate grazing had no significant effect on total vegetation cover, species richness, Shannon diversity index, species composition and primary production. These studies suggest that desert rangelands plant communities in general lack response to moderate grazing disturbance, and if managed properly they can provide a valuable source of feed for livestock.展开更多
The high Zoige Basin （Ruoergai Plateau） on the eastern Tibetan Plateau is a fault depression formed during intensive uplifting of the Tibetan Plateau. The wetland is globally important in biodiversity and is compose...The high Zoige Basin （Ruoergai Plateau） on the eastern Tibetan Plateau is a fault depression formed during intensive uplifting of the Tibetan Plateau. The wetland is globally important in biodiversity and is composed of marshes, bogs, fens, wet meadows and shallow water interspersed with low hills and sub-alpine meadows. Most of the Zoige wetlands have long been one of the most important grazing lands in China. Recent rangeland policy has allowed grazing, and usable wetland areas have been being legally allocated to individuals or groups of households on a long-term lease basis. Privatizafion of the wetland has impacted the Zoige wetlands in aspects of hydrologic condition, landscape and biodiversity. The uneven spatial distribution of water resources onprivatelands has led to the practice of extracting ground water, which has decreased the perched water table in Zoige. Fencing off the rangelands and grazing on expanding sand dunes have affected landscapes. Variation in the water table has led to the changes in vegetation diversity, resulting in the changes in wildlife and aquatic diversities and ecosystem processes. Making use all year round of the pasture that was previously grazed only in summer has shrunk the daily activity space of wildlife, and the newly erected fences blocked the movement of wild animals looking for food in the snow to lower and open areas. To maintain the favorable conditions of the Zoige wetland ecosystem, the author suggests that, in addition to biophysical research and implementation of conservation practices, there is an immediate need to initiate an integrated management program, increase public awareness of wetland functions and provide better training for the local conservation staff.展开更多
Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual fa...Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.展开更多
Estimation of above-ground biomass is vital for understanding ecological processes. Since direct measurement of above-ground biomass is destructive, time consuming and labor intensive, canopy cover can be considered a...Estimation of above-ground biomass is vital for understanding ecological processes. Since direct measurement of above-ground biomass is destructive, time consuming and labor intensive, canopy cover can be considered as a predictor if a significant correlation between the two variables exists. In this study, relationship between canopy cover and above-ground biomass was investigated by a general linear regression model. To do so, canopy cover and above-ground biomass were measured at 5 sub-life forms（defined as life forms grouped in the same height classes） using 380 quadrats, which is systematic-randomly laid out along a 10-km transect, during four sampling periods（May, June, August, and September） in an arid rangeland of Marjan, Iran. To reveal whether obtained canopy cover and above-ground biomass of different sampling periods can be lumped together or not, we applied a general linear model（GLM）. In this model, above-ground biomass was considered as a dependent or response variable, canopy cover as an independent covariate or predictor factor and sub-life forms as well as sampling periods as fixed factors. Moreover, we compared the estimated above-ground biomass derived from remotely sensed images of Landsat-8 using NDVI（normalized difference vegetation index）, after finding the best regression line between predictor（measured canopy cover in the field） and response variable（above-ground biomass） to test the robustness of the induced model. Results show that above-ground biomass（response variable） of all vegetative forms and periods can be accurately predicted by canopy cover（predictor）, although sub-life forms and sampling periods significantly affect the results. The best regression fit was found for short forbs in September and shrubs in May, June and August with R^2 values of 0.96, 0.93 and 0.91, respectively, whilst the least significant was found for short grasses in June, tall grasses in August and tall forbs in June with R^2 values of 0.71, 0.73 and 0.75, respectively. Even though the estimated above-ground biomass by NDVI is also convincing（R^2=0.57）, the canopy cover is a more reliable predictor of above-ground biomass due to the higher R^2 values（from 0.75 to 0.96）. We conclude that canopy cover can be regarded as a reliable predictor of above-ground biomass if sub-life forms and sampling periods（during growing season） are taken into account. Since,（1） plant canopy cover is not distinguishable by remotely sensed images at the sub-life form level, especially in sparse vegetation of arid and semi-arid regions, and（2） remotely sensed-based prediction of above-ground biomass shows a less significant relationship（R^2=0.57） than that of canopy cover（R^2 ranging from 0.75 to 0.96）, which suggests estimating of plant biomass by canopy cover instead of cut and weighting method is highly recommended. Furthermore, this fast, nondestructive and robust method that does not endanger rare species, gives a trustworthy prediction of above-ground biomass in arid rangelands.展开更多
The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined ma...The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10 g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.展开更多
[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecolo...[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecological protection and management in the lower reaches of Shiyang River. [Methods] One-way ANOVA analysis and correlation analysis were carried out with the aid of SPSS19.0 software for different types of desert rangeland soils. [Results](i) Among the communities surveyed, there are 31 species belonging to 9 families and 28 genera, including 12 shrub plants, 8 perennial herbs and 11 annual herbs. There are more single genus, occupying 50% of total genus. L. ruthenicum occupies an important position in the community with relatively higher importance value. It plays a dominated role in the community.(ii) In the soils with depths of 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm in different types of desert rangeland, the organic carbon contents in the saline alkali soil were the highest, with the values of 1.08%, 0.98%, 0.89% and 0.972%, respectively. Compared with that in sandy land, soil organic carbon in saline alkali land(0-10 cm) had the significant difference(P<0.05), available soil potassium in saline alkali land(except the depth of 20-40 cm) and the total phosphorus content in saline alkali land(0-10 cm) had the significant difference(P<0.05), the total soil nitrogen, alkali-hydrolyzable nitrogen, available phosphorus and the total potassium content had no significant difference(P>0.05). Soil organic carbon, available soil phosphorus in saline alkali land, total soil potassium on sand dune and total soil phosphorus in saline alkali land and gravel in different soil layers of the same type of desert rangeland had distinct aggregation effect.(iii) The soil microbial biomass in different types of desert rangeland displayed from high to low as saline alkali land > sandy land > fixed and semi fixed sandy land > gravel. The discrepancy of soil microbial biomass varied in different types of desert rangeland. The four soil enzyme activities in salinization was the highest. Soil invertase activity in saline alkali land in different soil layers were the highest. For different soil layers in the same type of desert rangeland, soil microbial biomass and invertase decreased gradually with the deepening of soil layer.(iv) There was a significant positive correlation between soil organic matter and microbial biomass carbon, microbial biomass nitrogen, phosphatase and sucrase(P<0.01), and a significant positive correlation with urease and catalase(P<0.05). Phosphorus content was significant positively correlated with urease, phosphatase and invertase(P<0.01), and positively correlated with microbial biomass carbon(P<0.05). Soil available potassium content was significant positively correlated with microbial and phosphatase(P<0.01). [Conclusions] The species of L. ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River clearly shows that most species belong to a few families, and a few species belong to most families, and many species are single genus or single family. Soil organic carbon, soil available phosphorus, total phosphorus, soil microbial biomass and enzyme activity in salinization land had distinct surface aggregation effects, so salinization land provides excellent growth environment for the growth of L. ruthenicum, which is of great significance for the protection of L. ruthenicum population.展开更多
Land-surface greening has been reported globally over the past decades.While often seen to represent ecosystem recovery,the impacts on biodiversity and society can also be negative.Greening has been widely reported fr...Land-surface greening has been reported globally over the past decades.While often seen to represent ecosystem recovery,the impacts on biodiversity and society can also be negative.Greening has been widely reported from rangelands,where drivers and processes are complex due to its high environmental heterogeneity and societal dynamics.Here,we assess the complexity behind greening and assess its links to various drivers in an iconic,heterogeneous rangeland area,the IberáWetlands and surroundings,in Argentina.Time-series satellite imagery over the past 19 years showed overall net greening,but also substantial local browning both in protected and unprotected areas,linking to land use,temporal changes in surface water,fire,and weather.We found substantial woody expansion mainly in the unprotected land,with 37%contributed by tree plantations and the remaining 63%by spontaneous woody expansion,along with widespread transitions from terrestrial land to seasonal surface water.Fire occurrences tended to reduce greening with unprotected areas experiencing widespread and frequent fire.However,protected areas had more browning in unburnt areas than burned areas.Temporal variation in annual precipitation and temperature tended to nonlinearly influence fire occurrences with an interplay of human fire management,further shaping the vegetation greening,pointing to high complexity behind the observed rangeland greening involving interactions among local drivers.Our findings highlight that the observed overall greening is an outcome of multiple trends with clear negative impacts on biodiversity and the local livestock-oriented culture(notably expanding tree plantations)and spontaneous vegetation dynamics,partly involving spontaneous woody expansion.The latter has positive potential for biodiversity and ecosystem services in terms of woodland recovery,but can become negative in such a natural savanna region if expansions develop on a too broad scale,highlighting the importance of ensuring recovery of natural fire and herbivory regimes in protected areas along with sustainable rangeland management elsewhere.展开更多
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 deg...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.展开更多
This paper describes the capability of remote sensing in the monitoring of rangeland vegetation productivities and dynamics in the foothill areas of Uzbekistan, in order to enhance the sustainable utilization of natur...This paper describes the capability of remote sensing in the monitoring of rangeland vegetation productivities and dynamics in the foothill areas of Uzbekistan, in order to enhance the sustainable utilization of natural resources. Seasonal productivity, including above-ground biomass, density, coverage, foliar chlorophyll, and carotene content, was measured for the Artemisia diffusa, the dominant species of the study area. The Normalized Difference Vegetation Index (NDVI), extracted from time-series Landsat TM5 satellite images, was used to obtain pertinent data regarding vegetation coverage and potential productivities. Seasonal precipitation was found to be a key factor in governing soil moisture in the semi-arid foothill rangelands, which directly influence the dynamics of plants and productivities. Precipitation and soil moisture determine the length of the plant growing season and further influence NDVI values. We found that time-series NDVI was significantly correlated with the seasonal green and total above-ground biomass of vegetation and coverage of Artemisia diffusa, soil moisture, and changeable nitrogen. We also found that the foliar chlorophylls of Artemisia diffusa was significantly correlated with the green above-ground biomass (r = 0.44, P < 0.05). The results can contribute to further monitoring of ecosystem health and habitat conditions using remote sensing (RS) as an accurate tool in large rangeland areas.展开更多
The proliferation of woody species alters the vegetation structure, leading to loss of rangeland productivity. It aimed to assess the influence of tree density on vegetation and soil chemical properties at three level...The proliferation of woody species alters the vegetation structure, leading to loss of rangeland productivity. It aimed to assess the influence of tree density on vegetation and soil chemical properties at three levels of encroachment;open, moderate and dense. Each level of encroachment was replicated 3 times, a 5000 m<sup>2</sup> plot was marked per replicate. Four belt transects 200 m<sup>2</sup> were placed per plot. Woody species within each belt transect per replicate were identified and recorded to evaluate woody species composition. Grass species composition was assessed using a step point method. Soil was sampled per replicate and analysed for chemical properties. Results showed that 71% of grasses were increasers and 29% decreasers. <em>Digitaria eriantha</em> and <em>Eragrostis obtusa </em>were the most dominant species. <em>Vachellia karoo</em> and <em>Aloe ferox</em> were the most dominant woody species. The dense had high nitrogen (1.48%) compared to the moderate (0.23%) and the open (0.17%). Increaser species, soil carbon, soil pH increased with the increase of tree density. It was concluded that the replacement of highly palatable grasses with inferior ones was due to improper rangeland management practices. It was recommended that land users form rangeland management associations and set up conservation agreements for proper management of resources.展开更多
The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectivel...The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailai Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soils of shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than in overgrazed rangeland soils, the Pavail concentration, however, was significantly greater in the soils of shrubland site, and increased by 59.1% and even 289.6% in the soils of shrubland site comparing to those in the soils of range-land and millet field sites. Among the three sites, CV exceeding 40% were found for SO4, Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.展开更多
1. Pastoral husbandry is the basis of animal husbandry in Xingjing Animal husbandry in Xingjing Uygur Autonomous Region is supported by the some57 million ha natural rangeland (Commission for Integrated Servey of Natu...1. Pastoral husbandry is the basis of animal husbandry in Xingjing Animal husbandry in Xingjing Uygur Autonomous Region is supported by the some57 million ha natural rangeland (Commission for Integrated Servey of Natural Resources(CISNAR), 1989). The rangeland provides feeds for the 33 million heads of grazing animals(48.698 million sheep units) in the region. Natural rangeland takes about 35% of the展开更多
Assessing rangeland productivity is critical to reduce ecological degradation and promote sustainable livestock management.Here,we estimated biomass productivity and carrying capacity dynamics in the Borana rangeland ...Assessing rangeland productivity is critical to reduce ecological degradation and promote sustainable livestock management.Here,we estimated biomass productivity and carrying capacity dynamics in the Borana rangeland of southern Ethiopia by using field-based data and remote sensing data(i.e.,normalized difference vegetation index(NDVI)).Data was collected from both rainy and dry seasons when biomass production was high and low respectively.Results of linear regression showed that both biomass production(R^(2)_(adj)=0.672)and NDVI value(R^(2)_(adj)=0.471)were significantly decreased from 1990 to 2019.Field data and NDVI values for mean annual biomass showed a significant linear relationship.The model accuracy in the annual relationship between the observed and predicted biomass values was strong(R^(2)_(adj)=0.986)but with high standard error,indicating that the observed biomass production in the rangeland area was not in good condition as compared with the predicted one.This study suggests that,using NDVI data and field-based data in combined way has high potential to estimate rangeland biomass and carrying capacity dynamics at extensively grazed arid and semi-arid rangelands.And to use for estimating stoking rates and predicting future management techniques for decision making.展开更多
Himalayan rangelands, the crucial but by and large the neglected ecosystems, are an integral part of mountain farming systems. The present investigation is based on the extensive survey and collection of mid-altitude ...Himalayan rangelands, the crucial but by and large the neglected ecosystems, are an integral part of mountain farming systems. The present investigation is based on the extensive survey and collection of mid-altitude range plants from Almora and Champawat districts of Kumaun division in the Uttarakhand Himalaya in India, from September 2003 to June 2007. The rangelands studied were oak types, chirpine types, grass types and mixed ones. Some 300 species of grasses, other herbaceous plants, trees and shrubs were found in the mid-altitude rangelands. A sizeable number of species belonged to the family of Poaceae. The grass-dominated rangelands especially harboured a variety of grass species of good fodder value. The diversity of fodder plants is a proportion of the enormous biodiversity occurring in the parts of the Himalaya. A panorama of the biodiversity emerged in this study, which is of both intangible value and direct value for the livestock- and rangeland- dependent mountain communities, suggests a very high scope of the utilization of this natural and uncultivated biodiversity for supporting livestock- based livelihoods of the region. This biodiversity also has enormous bearing on the cultivated area of the region.展开更多
文摘Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors.This study aims to identify the various rangeland use forms and determine the types of livestock feeding system in the El Ouara rangelands of Ben guarden District in southern Tunisia by analysing the importance of supplemental feeding and main determinants of this practice.Data were collected by a survey that targeted a sample of 50 breeders in the El Ouara rangelands.Descriptive statistics and binary logistic regression were used to analyse the data.The results showed that there are two types of association practiced by breeders:“Cherka”association practiced by 10.00% of breeders and cash payment association practiced by 53.00% of breeders.Then,transhumance,sedentary,and semi-urban forms are the main ways in which breeders use the rangelands.There are four livestock feeding systems in the El Ouara rangelands being used to feed livestock:natural rangeland,rangeland-based,mixed,and concentrate-based feeding systems.Supplemental feeding has become fundamental for the livestock feeding system in the El Ouara rangelands.The breeders with the largest camel size still use the natural rangeland feeding system,while the breeders who have the largest herd size practice the mixed feeding system.The logistic regression results reveal that breeder age,cereal area,herd size,migrant remittance,second activity,and agricultural development group membership can significantly impact the supplemental feeding.In summary,this study can help policy-makers plan innovative practices based on climatic change,ensure the sustainability of livestock feeding system,and make effective decisions for local development.
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.
文摘Water plays a critical role in beef cattle production. Current methods used to estimate the blue water footprint of beef cattle are largely based on generic values that do not make provision for different production systems within different regions. Total production cycle measurements should therefore be considered to accurately assess the blue water footprint of beef cattle grazing natural rangeland. The aim of the study was to measure water intake of extensive Bonsmara cattle grazing Marikana Thornveld over a full production cycle at the ARC-Roodeplaat Research Station. Measurements commenced at weaning (June 2017) and continued until the heifers weaned their first calves at approximately 210 days of age (July 2019). Water consumption differed between 21.4 litre per animal per day when the heifers were still growing to 54.3 litres during lactation, relating to between 6.7% and 12.0% of live weight. The blue water footprint over the total production cycle was calculated to be 27,147 litres.
文摘Net primary production(NPP) is an indicator of rangeland ecosystem function. This research assessed the potential of the Carnegie Ames Stanford Approach(CASA) model for estimating NPP and its spatial and temporal changes in semi-arid rangelands of Semirom County, Iran. Using CASA model, we estimated the NPP values based on monthly climate data and the normalized difference vegetation index(NDVI) obtained from the MODIS sensor. Regression analysis was then applied to compare the estimated production data with observed production data. The spatial and temporal changes in NPP and light utilization efficiency(LUE) were investigated in different rangeland vegetation types. The standardized precipitation index(SPI) was also calculated at different time scales and the correlation of SPI with NPP changes was determined. The results indicated that the estimated NPP values varied from 0.00 to 74.48 g C/(m^2·a). The observed and estimated NPP values had different correlations, depending on rangeland conditions and vegetation types. The highest and lowest correlations were respectively observed in Astragalus spp.-Agropyron spp. rangeland(R^2=0.75) with good condition and Gundelia spp.-Cousinia spp. rangeland(R^2=0.36) with poor and very poor conditions. The maximum and minimum LUE values were found in Astragalus spp.-Agropyron spp. rangeland(0.117 g C/MJ) with good condition and annual grassesannual forbs rangeland(0.010 g C/MJ), respectively. According to the correlations between SPI and NPP changes, the effects of drought periods on NPP depended on vegetation types and rangeland conditions. Annual plants had the highest drought sensitivity while shrubs exhibited the lowest drought sensitivity. The positive effects of wet periods on NPP were less evident in degraded areas where the destructive effects of drought were more prominent. Therefore, determining vegetation types and rangeland conditions is essential in NPP estimation. The findings of this study confirmed the potential of the CASA for estimating rangeland production. Therefore, the model output maps can be used to evaluate, monitor and optimize rangeland management in semi-arid rangelands of Iran where MODIS NPP products are not available.
基金the Asian Development Bank,the International Center for Agricultural Research in the Dry Areas,Russian Scientific Fund(14-38-00023)the CGIAR Research Program on Dryland Systems for their support and funding
文摘Rangelands of Central Asia (referring to Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan in this study), the largest contiguous area of grazed land in the world, serve as an important source of livelihood for pastoral and agro-pastoral communities in this region. They also play an important role in absorbing CO<sub>2</sub> as a global carbon sink. However, unsustainable management of rangelands has led to their degradation hugely by downgrading their potential agro-ecological, environmental and socio-economical roles. This paper reviewed the rangeland degradation in Central Asia, a topic which so far has received only scant coverage in the international scientific literature. It also provided examples of successful experiences and outlined possible options that land managers can adopt to enhance the sustainable management of these vast degraded rangelands. The experiences and lessons described in this paper may also be relevant for other degraded rangeland areas, especially in the developing countries. The causes of rangeland degradation within the Central Asian region are numerous, complex and inter-related. Therefore, while addressing the factors associated with improper rangeland management may shed some light on the causes of rangeland degradation, the scope of this paper would not be all-encompassing for the major causes of degradation. There is a need to develop and widely apply the viable and locally accepted and adapted packages of technical, institutional and policy options for sustainable rangeland management. Incentivizing the collective action of small-scale pastoralists who group together to facilitate access to remote pastures can reduce the degree of overgrazing within community pastures, such as those near the settlements. We also found that migratory grazing through pooling of resources among small-scale pastoralists can increase household income. After their independence, most Central Asian countries adopted various rangeland tenure arrangements. However, the building of enhanced capacities of pasture management and effective local rangeland governance structures can increase the likelihood, which will be sustainable and equitable. Finally, this paper presented several promising technical options, aiming at reversing the trend of rangeland degradation in Central Asia.
文摘Based on analysis of the development potential of rangeland resources in China＇s mountain areas, the paper makes analysis and forecast in human carrying capacity of rangeland resources. It provides some reference for drawing up the development strategy in mountain areas.
文摘Although the effects of non-grazing and heavy grazing on vegetation structure have been extensively studied in a wide range of ecosystems, the effects of moderate grazing on desert land are still largely unknown. Many management opportunities exist for increasing forage intake. In order to determine an optimal management method of desert rangelands with high heritage value, we examined the respective effects of heavy grazing, moderate grazing and non-grazing on total vegetation cover, species richness, the Shannon-Wiener diversity index and rangeland productivity. Sampling was done from 2010 to 2012 （from the second year after treatments were imposed） using permanent transects under different grazing intensities. While total vegetation cover, species richness, Shan- non-Wiener diversity index, species composition and primary production were significantly greater on the ungrazed site and significantly weaker on the heavily grazed site, in contrast, moderate grazing had no significant effect on total vegetation cover, species richness, Shannon diversity index, species composition and primary production. These studies suggest that desert rangelands plant communities in general lack response to moderate grazing disturbance, and if managed properly they can provide a valuable source of feed for livestock.
文摘The high Zoige Basin （Ruoergai Plateau） on the eastern Tibetan Plateau is a fault depression formed during intensive uplifting of the Tibetan Plateau. The wetland is globally important in biodiversity and is composed of marshes, bogs, fens, wet meadows and shallow water interspersed with low hills and sub-alpine meadows. Most of the Zoige wetlands have long been one of the most important grazing lands in China. Recent rangeland policy has allowed grazing, and usable wetland areas have been being legally allocated to individuals or groups of households on a long-term lease basis. Privatizafion of the wetland has impacted the Zoige wetlands in aspects of hydrologic condition, landscape and biodiversity. The uneven spatial distribution of water resources onprivatelands has led to the practice of extracting ground water, which has decreased the perched water table in Zoige. Fencing off the rangelands and grazing on expanding sand dunes have affected landscapes. Variation in the water table has led to the changes in vegetation diversity, resulting in the changes in wildlife and aquatic diversities and ecosystem processes. Making use all year round of the pasture that was previously grazed only in summer has shrunk the daily activity space of wildlife, and the newly erected fences blocked the movement of wild animals looking for food in the snow to lower and open areas. To maintain the favorable conditions of the Zoige wetland ecosystem, the author suggests that, in addition to biophysical research and implementation of conservation practices, there is an immediate need to initiate an integrated management program, increase public awareness of wetland functions and provide better training for the local conservation staff.
基金the financial support provided by the Flemish Interuniversity Council (VLIR) of Belgium in favour of the first author
文摘Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.
文摘Estimation of above-ground biomass is vital for understanding ecological processes. Since direct measurement of above-ground biomass is destructive, time consuming and labor intensive, canopy cover can be considered as a predictor if a significant correlation between the two variables exists. In this study, relationship between canopy cover and above-ground biomass was investigated by a general linear regression model. To do so, canopy cover and above-ground biomass were measured at 5 sub-life forms（defined as life forms grouped in the same height classes） using 380 quadrats, which is systematic-randomly laid out along a 10-km transect, during four sampling periods（May, June, August, and September） in an arid rangeland of Marjan, Iran. To reveal whether obtained canopy cover and above-ground biomass of different sampling periods can be lumped together or not, we applied a general linear model（GLM）. In this model, above-ground biomass was considered as a dependent or response variable, canopy cover as an independent covariate or predictor factor and sub-life forms as well as sampling periods as fixed factors. Moreover, we compared the estimated above-ground biomass derived from remotely sensed images of Landsat-8 using NDVI（normalized difference vegetation index）, after finding the best regression line between predictor（measured canopy cover in the field） and response variable（above-ground biomass） to test the robustness of the induced model. Results show that above-ground biomass（response variable） of all vegetative forms and periods can be accurately predicted by canopy cover（predictor）, although sub-life forms and sampling periods significantly affect the results. The best regression fit was found for short forbs in September and shrubs in May, June and August with R^2 values of 0.96, 0.93 and 0.91, respectively, whilst the least significant was found for short grasses in June, tall grasses in August and tall forbs in June with R^2 values of 0.71, 0.73 and 0.75, respectively. Even though the estimated above-ground biomass by NDVI is also convincing（R^2=0.57）, the canopy cover is a more reliable predictor of above-ground biomass due to the higher R^2 values（from 0.75 to 0.96）. We conclude that canopy cover can be regarded as a reliable predictor of above-ground biomass if sub-life forms and sampling periods（during growing season） are taken into account. Since,（1） plant canopy cover is not distinguishable by remotely sensed images at the sub-life form level, especially in sparse vegetation of arid and semi-arid regions, and（2） remotely sensed-based prediction of above-ground biomass shows a less significant relationship（R^2=0.57） than that of canopy cover（R^2 ranging from 0.75 to 0.96）, which suggests estimating of plant biomass by canopy cover instead of cut and weighting method is highly recommended. Furthermore, this fast, nondestructive and robust method that does not endanger rare species, gives a trustworthy prediction of above-ground biomass in arid rangelands.
基金Project supported by the National Natural Science Foundation of China (No. 40371081).
文摘The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10 g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.
基金Supported by Regional Fund Project of Gansu Province,China(31560128,31760709,31860175,31460134,31460223)Open Fund Project of Key Laboratory of Gansu Province(GSDC201506)Youth Science and Technology Project of Gansu Province(18JR3RA019)
文摘[Objectives] To study structural characteristics of Lycium ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River, and provide theoretical basis for ecological protection and management in the lower reaches of Shiyang River. [Methods] One-way ANOVA analysis and correlation analysis were carried out with the aid of SPSS19.0 software for different types of desert rangeland soils. [Results](i) Among the communities surveyed, there are 31 species belonging to 9 families and 28 genera, including 12 shrub plants, 8 perennial herbs and 11 annual herbs. There are more single genus, occupying 50% of total genus. L. ruthenicum occupies an important position in the community with relatively higher importance value. It plays a dominated role in the community.(ii) In the soils with depths of 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm in different types of desert rangeland, the organic carbon contents in the saline alkali soil were the highest, with the values of 1.08%, 0.98%, 0.89% and 0.972%, respectively. Compared with that in sandy land, soil organic carbon in saline alkali land(0-10 cm) had the significant difference(P<0.05), available soil potassium in saline alkali land(except the depth of 20-40 cm) and the total phosphorus content in saline alkali land(0-10 cm) had the significant difference(P<0.05), the total soil nitrogen, alkali-hydrolyzable nitrogen, available phosphorus and the total potassium content had no significant difference(P>0.05). Soil organic carbon, available soil phosphorus in saline alkali land, total soil potassium on sand dune and total soil phosphorus in saline alkali land and gravel in different soil layers of the same type of desert rangeland had distinct aggregation effect.(iii) The soil microbial biomass in different types of desert rangeland displayed from high to low as saline alkali land > sandy land > fixed and semi fixed sandy land > gravel. The discrepancy of soil microbial biomass varied in different types of desert rangeland. The four soil enzyme activities in salinization was the highest. Soil invertase activity in saline alkali land in different soil layers were the highest. For different soil layers in the same type of desert rangeland, soil microbial biomass and invertase decreased gradually with the deepening of soil layer.(iv) There was a significant positive correlation between soil organic matter and microbial biomass carbon, microbial biomass nitrogen, phosphatase and sucrase(P<0.01), and a significant positive correlation with urease and catalase(P<0.05). Phosphorus content was significant positively correlated with urease, phosphatase and invertase(P<0.01), and positively correlated with microbial biomass carbon(P<0.05). Soil available potassium content was significant positively correlated with microbial and phosphatase(P<0.01). [Conclusions] The species of L. ruthenicum community and soil properties on different types of desert rangeland in the lower reaches of Shiyang River clearly shows that most species belong to a few families, and a few species belong to most families, and many species are single genus or single family. Soil organic carbon, soil available phosphorus, total phosphorus, soil microbial biomass and enzyme activity in salinization land had distinct surface aggregation effects, so salinization land provides excellent growth environment for the growth of L. ruthenicum, which is of great significance for the protection of L. ruthenicum population.
基金This work was supported by Troels Myndel Petersens Botanisk Tax-onomiske Forskningsfond,the Carlsberg Foundation(Semper Ardens project MegaPast2Future,Grant CF16-000)VILLUM FONDEN(VILLUM Investigator project,Grant 16549)+4 种基金the Youth Innovation Promotion As-sociation CAS(Grant 2018084)H2020 Marie Skłodowska-Curie Ac-tions(Grant 840865)National Natural Science Foundation of China(Grant 41701392,Grant 41871347)Major State Basic Research Devel-opment Program of China(Grant 2013CB733405)the Strategic Pri-ority Research Program of the Chinese Academy of Sciences(Grant XDA19030404).
文摘Land-surface greening has been reported globally over the past decades.While often seen to represent ecosystem recovery,the impacts on biodiversity and society can also be negative.Greening has been widely reported from rangelands,where drivers and processes are complex due to its high environmental heterogeneity and societal dynamics.Here,we assess the complexity behind greening and assess its links to various drivers in an iconic,heterogeneous rangeland area,the IberáWetlands and surroundings,in Argentina.Time-series satellite imagery over the past 19 years showed overall net greening,but also substantial local browning both in protected and unprotected areas,linking to land use,temporal changes in surface water,fire,and weather.We found substantial woody expansion mainly in the unprotected land,with 37%contributed by tree plantations and the remaining 63%by spontaneous woody expansion,along with widespread transitions from terrestrial land to seasonal surface water.Fire occurrences tended to reduce greening with unprotected areas experiencing widespread and frequent fire.However,protected areas had more browning in unburnt areas than burned areas.Temporal variation in annual precipitation and temperature tended to nonlinearly influence fire occurrences with an interplay of human fire management,further shaping the vegetation greening,pointing to high complexity behind the observed rangeland greening involving interactions among local drivers.Our findings highlight that the observed overall greening is an outcome of multiple trends with clear negative impacts on biodiversity and the local livestock-oriented culture(notably expanding tree plantations)and spontaneous vegetation dynamics,partly involving spontaneous woody expansion.The latter has positive potential for biodiversity and ecosystem services in terms of woodland recovery,but can become negative in such a natural savanna region if expansions develop on a too broad scale,highlighting the importance of ensuring recovery of natural fire and herbivory regimes in protected areas along with sustainable rangeland management elsewhere.
基金funded by the U.S.Agency for International Development (306-A-00-06-00521-00)
文摘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.
文摘This paper describes the capability of remote sensing in the monitoring of rangeland vegetation productivities and dynamics in the foothill areas of Uzbekistan, in order to enhance the sustainable utilization of natural resources. Seasonal productivity, including above-ground biomass, density, coverage, foliar chlorophyll, and carotene content, was measured for the Artemisia diffusa, the dominant species of the study area. The Normalized Difference Vegetation Index (NDVI), extracted from time-series Landsat TM5 satellite images, was used to obtain pertinent data regarding vegetation coverage and potential productivities. Seasonal precipitation was found to be a key factor in governing soil moisture in the semi-arid foothill rangelands, which directly influence the dynamics of plants and productivities. Precipitation and soil moisture determine the length of the plant growing season and further influence NDVI values. We found that time-series NDVI was significantly correlated with the seasonal green and total above-ground biomass of vegetation and coverage of Artemisia diffusa, soil moisture, and changeable nitrogen. We also found that the foliar chlorophylls of Artemisia diffusa was significantly correlated with the green above-ground biomass (r = 0.44, P < 0.05). The results can contribute to further monitoring of ecosystem health and habitat conditions using remote sensing (RS) as an accurate tool in large rangeland areas.
文摘The proliferation of woody species alters the vegetation structure, leading to loss of rangeland productivity. It aimed to assess the influence of tree density on vegetation and soil chemical properties at three levels of encroachment;open, moderate and dense. Each level of encroachment was replicated 3 times, a 5000 m<sup>2</sup> plot was marked per replicate. Four belt transects 200 m<sup>2</sup> were placed per plot. Woody species within each belt transect per replicate were identified and recorded to evaluate woody species composition. Grass species composition was assessed using a step point method. Soil was sampled per replicate and analysed for chemical properties. Results showed that 71% of grasses were increasers and 29% decreasers. <em>Digitaria eriantha</em> and <em>Eragrostis obtusa </em>were the most dominant species. <em>Vachellia karoo</em> and <em>Aloe ferox</em> were the most dominant woody species. The dense had high nitrogen (1.48%) compared to the moderate (0.23%) and the open (0.17%). Increaser species, soil carbon, soil pH increased with the increase of tree density. It was concluded that the replacement of highly palatable grasses with inferior ones was due to improper rangeland management practices. It was recommended that land users form rangeland management associations and set up conservation agreements for proper management of resources.
文摘The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailai Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soils of shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than in overgrazed rangeland soils, the Pavail concentration, however, was significantly greater in the soils of shrubland site, and increased by 59.1% and even 289.6% in the soils of shrubland site comparing to those in the soils of range-land and millet field sites. Among the three sites, CV exceeding 40% were found for SO4, Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.
文摘1. Pastoral husbandry is the basis of animal husbandry in Xingjing Animal husbandry in Xingjing Uygur Autonomous Region is supported by the some57 million ha natural rangeland (Commission for Integrated Servey of Natural Resources(CISNAR), 1989). The rangeland provides feeds for the 33 million heads of grazing animals(48.698 million sheep units) in the region. Natural rangeland takes about 35% of the
基金the University of Chinese Academy of Science (UCAS) and CAS-TWAS fellowship program that provide funding and the PhD Scholarship for the first authorthe African Great Green Wall Adaptation Technical Cooperation Research and Demonstration (2018YFE0106000)+5 种基金Science and Technology Partnership Program,Ministry of Science and Technology of China (Grant No.KY201702010)Integration and application of appropriate technologies for desertification control in Africa (Grant No.SAJC202108)International cooperation and Exchanges NSFC (Grant No.41861144020) financial support to do this paperthe CAS Key Technology Talent Program supportthe support of the "Tianchi doctor program" of Xinjiang Uygur Autonomous Region in 2020the ESA CCI Land Cover project
文摘Assessing rangeland productivity is critical to reduce ecological degradation and promote sustainable livestock management.Here,we estimated biomass productivity and carrying capacity dynamics in the Borana rangeland of southern Ethiopia by using field-based data and remote sensing data(i.e.,normalized difference vegetation index(NDVI)).Data was collected from both rainy and dry seasons when biomass production was high and low respectively.Results of linear regression showed that both biomass production(R^(2)_(adj)=0.672)and NDVI value(R^(2)_(adj)=0.471)were significantly decreased from 1990 to 2019.Field data and NDVI values for mean annual biomass showed a significant linear relationship.The model accuracy in the annual relationship between the observed and predicted biomass values was strong(R^(2)_(adj)=0.986)but with high standard error,indicating that the observed biomass production in the rangeland area was not in good condition as compared with the predicted one.This study suggests that,using NDVI data and field-based data in combined way has high potential to estimate rangeland biomass and carrying capacity dynamics at extensively grazed arid and semi-arid rangelands.And to use for estimating stoking rates and predicting future management techniques for decision making.
文摘Himalayan rangelands, the crucial but by and large the neglected ecosystems, are an integral part of mountain farming systems. The present investigation is based on the extensive survey and collection of mid-altitude range plants from Almora and Champawat districts of Kumaun division in the Uttarakhand Himalaya in India, from September 2003 to June 2007. The rangelands studied were oak types, chirpine types, grass types and mixed ones. Some 300 species of grasses, other herbaceous plants, trees and shrubs were found in the mid-altitude rangelands. A sizeable number of species belonged to the family of Poaceae. The grass-dominated rangelands especially harboured a variety of grass species of good fodder value. The diversity of fodder plants is a proportion of the enormous biodiversity occurring in the parts of the Himalaya. A panorama of the biodiversity emerged in this study, which is of both intangible value and direct value for the livestock- and rangeland- dependent mountain communities, suggests a very high scope of the utilization of this natural and uncultivated biodiversity for supporting livestock- based livelihoods of the region. This biodiversity also has enormous bearing on the cultivated area of the region.
