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Supplemental feeding on rangelands:new dynamics of the livestock in the El Ouara rangelands in southern Tunisia
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作者 Houda RJILI Mohamed JAOUAD Chaker SELMI 《Regional Sustainability》 2023年第4期359-368,共10页
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
关键词 Livestock feeding system Supplemental feeding Rangeland use forms “Cherka”association Cash payment association El Ouara rangelands
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Estimation of spatial and temporal changes in net primary production based on Carnegie Ames Stanford Approach(CASA) model in semi-arid rangelands of Semirom County, Iran 被引量:9
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作者 Fatemeh HADIAN Reza JAFARI +2 位作者 Hossein BASHARI Mostafa TARTESH Kenneth DCLARKE 《Journal of Arid Land》 SCIE CSCD 2019年第4期477-494,共18页
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
关键词 CASA NPP ESTIMATION light utilization efficiency vegetation type drought RANGELAND condition SEMIARID rangelands
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Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia 被引量:12
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作者 Mouldi GAMOUN 《Journal of Arid Land》 SCIE CSCD 2014年第3期324-333,共10页
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
关键词 rangelands management grazing pressure richness DIVERSITY PRODUCTIVITY
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Bayesian Estimation of Shrubs Diversity in Rangelands under Two Management Systems in Northern Syria
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作者 Abdoul Aziz Niane Murari Singh Paul C. Struik 《Open Journal of Ecology》 2014年第4期168-173,共6页
The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the r... The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the Shannon index and the Simpson index, were studied for the four combinations of two sites, Hammam and Obeisan, and two grazing methods, Closed and Open, using frequentist and Bayesian approaches. We simulated the a priori and a-posteriori distributions of the Shannon and Simpson diversity indices, where from a range of values for a constant in the a priori distribution the best value normalizing the distribution of the diversity indices was chosen. The Bayesian diversity estimates were higher than their frequentist counterparts and had lower standard errors. The grazing methods at each site and sites under each grazing method delivered significant diversity of shrub species. The Bayesian estimates resulted in lower p-values than the frequentist approach for two cases reflecting in Bayesian method’s higher power. Bayesian approach is recommended as it has a wider framework for inference on diversity studies. 展开更多
关键词 Arid rangelands Species Abundance DIVERSITY Shannon INDEX SIMPSON DIVERSITY INDEX Bayesian Method
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Rangelands of Central Asia:challenges and opportunities 被引量:8
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作者 Alisher MIRZABAEV Mohamed AHMED +2 位作者 Jutta WERNER John PENDER Mounir LOUHAICHI 《Journal of Arid Land》 SCIE CSCD 2016年第1期93-108,共16页
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
关键词 rangeland degradation flock mobility OVERGRAZING sustainable rangeland management DRYLANDS land tenure
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Impact of rangeland enclosure and seasonal grazing on protected and unprotected rangelands in Chakwal region, Pakistan
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作者 ISLAM Muhammad RAZZAQ Abdul +5 位作者 ZUBAIR Muhammad HASSAN Sawsan AHMAD Sarfraz GUL Shamim RISCHKOWSKY Barbara LOUHAICHI Mounir 《Journal of Mountain Science》 SCIE CSCD 2022年第1期46-57,共12页
Scrub rangelands support livestock grazing and provide ecosystem services to their inhabitants. The present study was conducted in Chakwal, an important tract of the Pothwar Plateau,which sustains herds of small domes... Scrub rangelands support livestock grazing and provide ecosystem services to their inhabitants. The present study was conducted in Chakwal, an important tract of the Pothwar Plateau,which sustains herds of small domestic and nomadic ruminants. Urbanization and uncontrolled grazing practices have reduced rangeland productivity and increased soil erosion and resulted in poor land conditions. This study assessed the influence of two years of rangeland protection on aboveground vegetation biomass and the chemical composition of plants and aimed to determine the influence of seasonal grazing on the live-weight gain of small ewes.Using the line intercept method, vegetation data from protected and unprotected plots in 2015 and 2016 were collected at two sites, Dhulli and Begal.Vegetation cover was assessed from images using VegMeasure. Results showed that protected study sites displayed higher vegetation biomass(834 and 690 kg ha^(-1)) compared to the unprotected study site(477 and 326 kg ha^(-1)) during April and August of both years. In the seasonal grazing trial, the experimental ewes that grazed on protected rangelands showed higher live-weight gain(33–63 g day^(-1)) compared to live weight of ewes(17–21 g day^(-1)) that grazed on unprotected rangelands during the experimental period of 127 days at both sites. The results suggest that the Chakwal rangeland has tremendous potential to improve vegetation productivity but modern livestock management and seasonal grazing practices are needed to improve carrying capacity and livestock productivity. 展开更多
关键词 Seasonal grazing Climate change PRODUCTIVITY RANGELAND Protected area
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Land Use and Land Cover Dynamics in the North-Eastern Somali Rangelands of Eastern Ethiopia
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作者 Fikre Zerfu Abdurehman Mektel Biniyam Bogale 《International Journal of Geosciences》 2019年第9期811-832,共22页
Drastic changes have occurred in Siti zone rangeland over nearly the last three decades, due to rapid land conversion dynamics in the area. In the zone, the land-use change over time and space and temporal trends rang... Drastic changes have occurred in Siti zone rangeland over nearly the last three decades, due to rapid land conversion dynamics in the area. In the zone, the land-use change over time and space and temporal trends rangeland condition have never been studied. This study analyzed land use and land cover (LULC) change dynamics since the 1980s. Three dates, 1985, 2001 and 2017, Landsat images were used for classification and analysis of the various LULC. The three images were geo-referenced, re-sampled and processed for classification, using the maximum likelihood classifier algorithm. Moreover, field observations and information from local people were used for triangulation to patterns LULC dynamics. From 1985 to 2017, the general trend observed in the land use/cover change in the rangeland resources in the study districts implies a loss of grassland cover was compensated by an increase in cultivated areas, settlement and shrub/bush land cover. Moreover, the encroachments of invasive plant, Prosopis, settlement and the promotion of cultivation to pastoral way of livelihood have exacerbated the decline of rangeland cover. The study findings have shown important changes in the LULC patterns in the north-eastern Somali rangelands of eastern Ethiopia. These trends are certainly the characteristics of a pastoral way of life turn to settlement. This suggests that major changes in the socio-ecological driving forces affecting landscape dynamics have occurred in the last three decades or so. 展开更多
关键词 Pastoralist Remote Sensing PROSOPIS AGRICULTURE RANGELAND Land Use/Cover
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Ecosystem Services of Grazed Grasslands in the Flooding Pampa
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作者 Elizabeth J.Jacobo Adriana M.Rodríguez 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第6期1179-1202,共24页
The Flooding Pampa grasslands are the last remnant of the Rio de la Plata grasslands in Argentina.Anthropo-genic interventions have led to severe degradation and,as a result,the ecosystem services provided by the gras... The Flooding Pampa grasslands are the last remnant of the Rio de la Plata grasslands in Argentina.Anthropo-genic interventions have led to severe degradation and,as a result,the ecosystem services provided by the grass-lands are declining,in terms of provisioning,regulating,and supporting services.We synthesized the existing literature on the ecosystem goods and services provided by these grasslands under grazing in different conditions and conservation status.We found that plant and animal diversity and primary production are the most studied ecosystem services,while climate regulation,water supply,nutrient cycling,meat production and erosion control,in that order,are less studied.Cultural services are under-researched.Continuous grazing and glyphosate spraying are the main drivers of grassland degradation.Controlled grazing and conservative stocking rates have been shown to reverse degradation and demonstrate that livestock production is compatible with ecosystem conserva-tion by maintaining regulating and provisioning services.As these management strategies are poorly integrated,improving their implementation will require important changes in farmers’decisions and the development of policies that create the economic conditions for this to happen.Research is needed to understand the conditions that prevent the knowledge generated from being transferred to producers and translated into practices that would improve the provision of ecosystem services. 展开更多
关键词 Salado basin SUSTAINABILITY BIODIVERSITY rangelands meat production adaptative multi paddock grazing process technologies AGROECOLOGY
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Experimental Exclusion of Guanaco Grazing Increases Cover, Diversity, Land Function and Plant Recruitment in Patagonia
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作者 Carla Cepeda Gabriel Oliva Daniela Ferrante 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第7期1383-1401,共19页
Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco popula... Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century. 展开更多
关键词 rangelands HERBIVORY biodiversity OVERGRAZING carrying capacity FAUNA
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Grazing Impacts on the Diversity and Composition of Alpine Rangelands in Northwest Yunnan 被引量:6
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作者 Michelle A.Haynes Zhendong Fang Donald M.Waller 《Journal of Plant Ecology》 SCIE 2013年第2期122-130,共9页
Aims The eastern Himalayan region of southwest China represents the world’s most biodiverse temperate region as well as a cultural hot-spot undergoing rapid cultural and ecological change.This area represents the cen... Aims The eastern Himalayan region of southwest China represents the world’s most biodiverse temperate region as well as a cultural hot-spot undergoing rapid cultural and ecological change.This area represents the center of origin for many plant groups including horticulturally valuable species of Pedicularis,Rhododendron and Primula.alpine meadows here also provide summer pastures for Tibetan yak herders and the source for important medicinal plants.stocking levels for livestock here have quadrupled over the last five decades and shrubs are encroaching into many historical rangelands.Yak herders voice concerns over both shrub encroachment and shrinking grasslands.in this study,we sought to determine:(i)are alpine rangelands in Deqin County overgrazed and degraded?(ii)What are the local impacts of grazing on plant diversity and community composition?and(iii)which environmental variables covary with these differences in species composition across the grazing gradient?Methods To examine the ecological impacts of grazing in Deqin County,northwest Yunnan and assess its long-term sustainability,we used county records to determine historical population and livestock numbers,confirmed the results of interviews by Haynes(2011)and surveyed plant species richness and cover along a grazing gradient extending away from herder huts.along these transects,we sampled 1 m2 quadrats at 5 m intervals,noting species present and per-cent cover for vascular plants,grasses,sedges,rushes,moss,lichen,exposed rock,bare ground and feces.We also measured the average and maximum plant height within each quadrat.We then computed species richness for each of the 38 transects,calculating alpha and beta diversities.We used one-way aNoVas to compare mean species richness values and average and maximum plant height across grazing intensities.To chart changes in composition along the 100m gradient,we also plotted the percent cover of graminoid,forb,shrub and bare ground versus distance from the hut.We applied Nm ordi-nation to relate community patterns to environmental variables and grazing intensity using distances to determine species groupings.Important Findingslivestock impacts are clearly evident with proportions of grass and bare ground decreasing,shrubs increasing and forbs maintaining even cover with increasing distance from the huts.in comparison with earlier surveys of sites farther from huts,we found reduced plant cover and diversity.Plant species richness almost doubles with increasing distance from herder huts from 9.9 to 19.3 species per 1 m2 quadrat.an ordination of species and environmental variables demonstrates that grazing strongly affects plant community com position across these plots with strong impacts on palatable plants.if herd sizes remain large and suitable areas for grazing continue to decline,the cumulative impacts of grazing appear likely to degrade the rich diversity of the region and reduce rangeland quality,threatening its ability to sustain current grazing levels. 展开更多
关键词 alpine rangelands biodiversity conservationgrazing Southwest China
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Plant species composition and diversity depending on piospheres and seasonality in the southern rangelands of Kenya 被引量:1
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作者 S.O.Jawuoro O.K.Koech +1 位作者 G.N.Karuku J.S.Mbau 《Ecological Processes》 SCIE EI 2017年第1期159-167,共9页
Introduction:Scarcity of water in the rangelands of Kenya has led to the introduction of piospheres.Previous research has however produced contrasting results on the effects of piospheres and seasonality on ShannonWi... Introduction:Scarcity of water in the rangelands of Kenya has led to the introduction of piospheres.Previous research has however produced contrasting results on the effects of piospheres and seasonality on ShannonWiener’s diversity index,and therefore,this information is still deficient.In this study,the impact of these piospheres on plant species composition,diversity,and richness was assessed.Methods:Vegetation sampling was done during both the long rains(April)and the dry season(August).Three piosphere types(dam,trough,and a seasonal river)were studied using 0.25 m2 quadrats to sample vegetation at intervals of 20 m along 100-m transects.Four 100-m transects were used per piosphere(north,east,south,and west directions).Shannon-Wiener’s diversity index was used to determine species richness and composition.Twoway ANOVA was used to determine if piospheric distance had an effect on species diversity,richness,and evenness using GenStat 15th edition.Results:A total of 22 grasses and 29 forbs were recorded in the study area.The most abundant grasses near the piospheres were Eragrostis tenuifolia(12.9%)and Cynodon dactylon(10.6%).E.tenuifolia is an increaser species and was therefore most abundant in areas of severe grazing while C.dactylon has been known to be tolerant to grazing.The most abundant forbs were Crotalaria brevidens(37.5%).The Shannon-Wiener diversity index significantly increased(F=25.07,P=0.001)with distance from the three piospheres owing to the high grazing intensity near the piospheres and was significantly different between piospheres,being higher(F=10.05,P=0.001)at 20 m from the river(1.2±0.1)compared to a similar distance from the dam(0.9±0.1)and the trough(0.8±0.2).This was probably because the trough was smaller in size compared to the other piospheres,thereby concentrating more grazing animals per unit area and causing a greater impact on plant species.Conclusions:The study demonstrated that species diversity,richness,and evenness were low near the piospheres due to heavy grazing.Similarly,the lowest species diversity,richness,and evenness were recorded near the trough compared to the dam and the river.This study therefore recommends that range reseeding and rest period be done to rehabilitate degraded areas and facilitate plant regeneration.Larger piospheres should also be used to minimize animal impact per unit area. 展开更多
关键词 PIOSPHERE Species composition Shannon-Wiener diversity Species richness rangelands
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Effect of piospheres on physio-chemical soil properties in the Southern Rangelands of Kenya
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作者 S.O.Jawuoro O.K.Koech +1 位作者 G.N.Karuku J.S.Mbau 《Ecological Processes》 SCIE EI 2017年第1期142-148,共7页
Introduction:Water-based interventions haphazardly introduced in the drylands of Kenya have led to the introduction of piospheres used as concentration mounts.Not much is known about the effect of these piospheres on ... Introduction:Water-based interventions haphazardly introduced in the drylands of Kenya have led to the introduction of piospheres used as concentration mounts.Not much is known about the effect of these piospheres on soil physio-chemical properties,especially in the Kenyan rangelands where the government and other development agencies have created piospheres aimed at curbing water shortages and sustaining livestock production.The study assessed the effect of piospheres on soil physio-chemical characteristics in the southern rangelands of Kajiado,Kenya,in order to provide evidence-based insights that will be useful in guiding future water interventions.Methods:Soil samples were collected within 0.25-m2 plots at 20-m intervals along 100-m transects from three piospheres(a dam,a trough,and a seasonal river).Two-way ANOVA was used to determine if there were significant differences in soil parameters between piospheric distances.Results:Soil bulk density significantly different between piospheric distances(F=22.25,P=0.001)and piospheres(F=13.10,P=0.002),being highest at 20 m from the trough(1.1–1.21 gcm−3)relative to a similar distance from the dam(1.01–1.20 gcm−3)and the river(1.1–1.17 gcm−3).On the other hand,mean soil aggregate stability significantly increased(F=66.89,P=0.001)with piospheric distance,being lowest at 20 m from the trough(43.9–46.2%),the dam(43.1–48.9%),and the river(46.6–47.5%).Conclusions:High soil bulk density and consequent low soil porosity,hydraulic conductivity,and moisture content demonstrated that grazing was high near the piospheres.It is recommended that livestock should be herded away from the piospheres after drinking water to ensure that grazing livestock spend less time near the piospheres if reduced soil compaction is to be realized.Piospheres should also be better planned and placed at landscape level to exploit landscape heterogeneity. 展开更多
关键词 Piospheres Grazing pressure Bulk density Hydraulic conductivity rangelands
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Climate change effects on rangelands and rangeland management:affirming the need for monitoring
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作者 Daniel W.McCollum John A.Tanaka +6 位作者 Jack A.Morgan John E.Mitchell William E.Fox Kristie A.Maczko Lori Hidinger Clifford S.Duke Urs P.Kreuter 《Ecosystem Health and Sustainability》 SCIE 2017年第3期1-14,共14页
Uncertainty as to the extent and magnitude of changes in conditions that might occur due to climate change poses a problem for land and resource managers as they seek to adapt to changes and mitigate effects of climat... Uncertainty as to the extent and magnitude of changes in conditions that might occur due to climate change poses a problem for land and resource managers as they seek to adapt to changes and mitigate effects of climate variability.We illustrate using scenarios of projected future conditions on rangelands in the Northern Great Plains and Desert Southwest of the United States.These two regions are different in the ways climate change is projected to affect the regions.Projection of a longer and warmer growing season in the Northern Great Plains could lead to increased forage production and land productivity.Highly uncertain effects on summer monsoons that primarily control rangeland productivity in the Desert Southwest,combined with the possibility of more intense and/or frequent drought events,could present land managers with challenges stemming from decreased forage production and land productivity.Climate projections,though uncertain,provide land managers with basic insight into future conditions they might encounter.They need more.A focus on vulnerability and resilience,with explicit recognition of interactions between ecological and socio-economic factors,coupled with systematic monitoring and assessment of observable conditions on the land to supplement information based on climate projections,will more effectively provide critical and specific information managers need to adaptively manage rangelands under uncertain climate futures. 展开更多
关键词 adaptive management climate change INDICATORS MONITORING rangelands RESILIENCE uncertainty VULNERABILITY
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A review of concentrated flow erosion processes on rangelands:Fundamental understanding and knowledge gaps 被引量:2
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作者 Sayjro K.Nouwakpo Christopher J.Williams +3 位作者 Osama Z.Al-Hamdan Mark A.Weltz Fred Pierson Mark Nearing 《International Soil and Water Conservation Research》 SCIE CSCD 2016年第2期75-86,共12页
Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil,water and dissolved elements.On rangelands,soil,nutri... Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil,water and dissolved elements.On rangelands,soil,nutrients and water are scarce and only narrow margins of resource losses are tolerable before crossing the sustainability threshold.In these ecosystems,concentrated flow processes are perceived as indicators of degradation and often warrant the implementation of mitigation strategies.Nevertheless,this negative perception of concentrated flow processes may conflict with the need to improve understanding of the role of these transport vessels in redistributing water,soil and nutrients along the rangeland hillslope.Vegetation influences the development and erosion of concentrated flowpaths and has been the primary factor used to control and mitigate erosion on rangelands.At the ecohydrologic level,vegetation and concentrated flow pathways are engaged in a feedback relationship,the understanding of which might help improve rangeland management and restoration strategies.In this paper,we review published literature on experimental and conceptual research pertaining to concentrated flow processes on rangelands to:(1)present the fundamental science underpinning concentrated flow erosion modeling in these landscapes,(2)discuss the influence of vegetation on these erosion processes,(3)evaluate the contribution of concentrated flow erosion to overall sediment budget and(4)identify knowledge gaps. 展开更多
关键词 EROSION RANGELAND Concentrated flow RILL GULLY
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Improved drought tolerance in Festuca ovina L.using plant growth promoting bacteria
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作者 Fateme RIGI Morteza SABERI Mahdieh EBRAHIMI 《Journal of Arid Land》 SCIE CSCD 2023年第6期740-755,共16页
Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid areas.In response to a specific environmental stress,plants ... Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid areas.In response to a specific environmental stress,plants can use the most effective bacteria to support and facilitate their growth and development.Today,plant growth promoting rhizobacteria(PGPR)is widely used to reduce drought stress on plant growth.In this study,the effects of drought on Festuca ovina L.germination,growth,and nutrient absorption were investigated using PGPR in a factorial test with a completely random design under four water regimes.Soil water content was kept at 100%FC(field capacity),70%FC(FC),50%FC,and 30%FC.The treatments were inoculated with Azotobacter vinelandii,Pantoea agglomerans+Pseudomonas putida,and a mixture of bio-fertilizers.Results showed that the effects of drought stress were significantly reduced(P<0.05)when A.vinelandii and P.agglomerans+P.putida were used separately,however,the combined treatment of bio-fertilizers had a greater influence on seed germination than the single application.P.agglomerans+P.putida under 30%FC condition resulted in higher increases in stem,root length,and plant dry biomass.The highest uptake of nutrients was observed for the combined treatment of bio-fertilizers under 30%FC condition.Therefore,the use of A.vinelandii and P.agglomerans+P.putida,applied separately or combined,increased tolerance to drought stress in F.ovina by increased germination indices,dry weight,stem length,and root length.Because of the beneficial effects of PGPR on the growth characteristics of plants under drought conditions and the reduction of negative effects of drought stress,inoculating F.ovina seeds with Azotobacter and Pseudomonas is recommended to improve their growth and development characteristics under drought conditions.PGPR,as an affordable and environmentally friendly method,can improve the production of forage in water-stress rangelands. 展开更多
关键词 bio-fertilizers element uptake drought stress RANGELAND water scarcity
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Influence of rangeland protection and seasonal grazing on aboveground vegetation,forage quality and weight gain of small ruminants–a study in Thar Desert,Pakistan
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作者 ISLAM Muhammad RAZZAQ Abdul +7 位作者 HASSAN Sawsan ZUBAIR Muhammad KALROO Muhammad Waseem KHAN Attaullah GUL Shamim AHMAD Sarfraz RISCHKOWSKY Barbara Ann LOUHAICHI Mounir 《Journal of Mountain Science》 SCIE CSCD 2023年第2期403-414,共12页
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
关键词 Rangeland productivity Seasonal grazing Stocking rate Thar Desert Vegetation quality
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Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?
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作者 M'hammed BOUALLALA Souad NEFFAR +1 位作者 Lyès BRADAI Haroun CHENCHOUNI 《Journal of Arid Land》 SCIE CSCD 2023年第6期667-694,共28页
The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodivers... The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion. 展开更多
关键词 desert pavements hot and arid rangeland plant diversity land degradation sand encroachment plant functional trait Sahara Desert
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The Blue Water Footprint of Extensive Beef Production on Semi-Arid Rangeland over a Full Production Cycle in South Africa
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作者 Susanna M. Grobler Michiel M. Scholtz Hosia T. Pule 《Agricultural Sciences》 CAS 2023年第3期335-345,共11页
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
关键词 Beef Cattle Marikana Thronveld Natural Rangeland Water Intake
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UAV and Satellite-Based Sensing to Map Ecological States at the Landscape Scale
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作者 Guillermo E. Ponce-Campos Mitchel McClaran +1 位作者 Philip Heilman Jeffrey K. Gillan 《Open Journal of Ecology》 2023年第8期560-596,共37页
Mapping ecological states in semi-arid rangelands is crucial for effective land management and conservation efforts because it identifies difference in the ecological conditions across a landscape. This study presents... Mapping ecological states in semi-arid rangelands is crucial for effective land management and conservation efforts because it identifies difference in the ecological conditions across a landscape. This study presents an innovative approach for mapping two ecological states, Large Shrub Grass (LSG) and Large Shrub Eroded (LSE), within the Sandy Loam Upland and Deep (SLUD) ecological sites using a combination of drone and satellite data. The methodology leverages the Largest Patch Index (LPI) as a proxy metric to estimate eroded areas and classify ecological states. The integration of unmanned aerial vehicle (UAV) data with satellite-based remote sensing provides a scalable approach that can benefit various stakeholders involved in rangeland management. The study demonstrates the potential of this methodology by generating spatial layers at the landscape scale to inform on the state of rangeland ecosystems. The workflow showcases the power of remote sensing technology to map ecological states and addresses limitations in spatial coverage by integrating UAV and satellite data. By utilizing the bare ground LPI metric, which indicates the connectedness of bare ground, the methodology enables the classification of ecological states at a regional scale. This cost-effective approach potentially offers a standardized and reproducible method applicable across different sites and regions. The accuracy of the classification process is evaluated by comparing the results to ground-based polygons, dirt roads, and water locations. While the model performs well in identifying eroded areas, misclassifications occur in regions with mixed vegetation cover or low biomass. Future research should focus on incorporating temporal information from historical remote sensing archives to improve understanding of ecological state dynamics. Additionally, validation efforts can be enhanced by incorporating more ground-truth data and testing the methodology in diverse rangeland areas. The workflow serves as a blueprint for scaling up ecological states mapping in similar semi-arid rangelands. Further work should involve refining the approach through additional validation and exploring new remote sensing datasets. The methodology can be replicated in other regions to inform land management decisions, promote sustainable resource use, and advance the field of ecological states mapping. 展开更多
关键词 Ecological Sites Ecological States RANGELAND Largest Patch Index UAV Remote Sensing
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Land desertification and restoration in Middle East and North Africa(MENA) region 被引量:3
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作者 Hassan M.El Shaer 《Research in Cold and Arid Regions》 CSCD 2015年第1期7-15,共9页
The Middle East and North Africa (MENA) region is characterized by high population growth, degraded and fragile nat- ural ecosystems, and a limited amount of arable lands. It is one of the most water-scarce regions ... The Middle East and North Africa (MENA) region is characterized by high population growth, degraded and fragile nat- ural ecosystems, and a limited amount of arable lands. It is one of the most water-scarce regions in the world. The region is heterogeneous in terms of the countries' economies, but because it includes some of the richest and some of the poorest countries in the world, regional average economic performance statistics are misleading. The region is mostly semi-arid and arid, with significant areas of extreme aridity. These areas are further challenged by extreme temperatures, frequent drought, land degradation, and desertification. Recent changes in climate patterns, such as prolonged droughts, record temperatures, and increased rainfall irregularity, intensity and distribution, have all further negatively impacted the natural and agro-ecosystems in the region. Such changes have led to increased vulnerability of the people dependent on such re- sources for their livelihood. This article focuses on the impact of land desertification due to climate changes on the prevailing natural resources, and discusses several approaches for mitigating or alleviating desertification. It is clear that water shortage is a problem in many countries of this predominantly arid region, and is unlikely to be reduced and may be exacerbated by climate change. Proposed adaptation strategies might include more efficient organization of water supplies, treatment, and delivery systems, and increased use of groundwater. It is necessary to develop alternative production and management systems appropriate to the socioeconomic and environmental conditions in order to prevent further degradation of the prevailing agro-ecosystems and sustain the livelihoods of farmers living in marginal conditions. Grasslands, livestock, and water resources are likely to be most vulnerable to climate change in the region because they are located mostly in marginal areas. Changes in cropping practices and improved irrigation practices, and introducing proper livestock-fodder crop production integrated systems, could significantly enhance water use efficiency, eliminate the impact of desertification, and improve local livelihoods. 展开更多
关键词 degradation SALINITY climate changes water resources LIVESTOCK rangelands
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