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Semi-automated detection of rangeland runoff and erosion control berms using high-resolution topography data

International Soil and Water Conservation Research 2024年第1期12卷 217-226页

作者： Li Li Changjiang River Scientific Research Institute of Changjiang Water Resources Commission Wuhan430010China Research Center on Mountain Torrent&Geologic Disaster Prevention Ministry of Water ResourcesWuhan430010China University of Arizona School of Natural Resources and the EnvironmentTucsonAZ85719USA

An inventory of topographic modifications is essential to addressing their impacts on hydrological and morphological processes in human-altered watersheds.However,such inventories are generally lacking.This study presents two workflows for semi-automatic detection of linear earthen runoff and erosion control berms in rangelands using high-resolution topographic data.The workflows consist of initial object identification by applying either morphological grayscale reconstruction(MGR)or the Geomorphon(GEO)method,followed by identification refinements through filters based on objects’horizontal and vertical information.Three sites were selected within the Altar Valley,Arizona,in the southwestern United States.One site was used for developing workflows and optimizing filter thresholds,and the other two sites were used to validate workflows.The results showed that:1)The MGR-based workflow methodology could produce final precision and detection rates of up to 92%and 75%,respectively,and take less than 5 s for a 10.1 km^(2) site;2)The workflow based on the MGR method yielded greater identification accuracy than did the GEO workflow;3)Object length,orientation,and eccentricity were important characteristics for identifying earthen berms,and are sensitive to general channel flow direction and berm shape;4)Manual interrogation of topographic data and imagery can significantly improve identification precision rates.The proposed workflows will be useful for developing inventories of runoff and erosion control structures in support of sustainable rangeland management.

关键词： Earthen berm rangeland Grayscale morphological reconstruction Geomorphon LiDAR

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Impact of rangeland enclosure and seasonal grazing on protected and unprotected rangelands in Chakwal region, Pakistan

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Journal of Mountain Science 2022年第1期19卷 46-57页

作者： ISLAM Muhammad RAZZAQ Abdul ZUBAIR Muhammad HASSAN Sawsan AHMAD Sarfraz GUL Shamim RISCHKOWSKY Barbara LOUHAICHI Mounir International Center for Agricultural Research in Dry Areas(ICARDA) South AsiaIslamabad 44050Pakistan Animal Science Division Pakistan Agricultural Research CouncilIslamabad 44050Pakistan Department of Forestry and Range Management Bahauddin Zakariya UniversityMultan 66000Pakistan International Center for Agricultural Research in Dry Areas(ICARDA) Amman 11185Jordan Natural Resource Division Pakistan Agricultural Research CouncilIslamabad 44050Pakistan Botany Department University of Balochistan Quetta 87300Pakistan Department of Natural Resource Sciences McGill UniversityQuebec H9X3V9Canada International Center for Agricultural Research in Dry Areas(ICARDA) SSAILRI campusAddis Ababa 5689Ethiopia International Center for Agricultural Research in Dry Areas(ICARDA) Tunis 1004Tunisia

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.

关键词： Seasonal grazing Climate change Productivity rangeland Protected area

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Borana rangeland of southern Ethiopia:Estimating biomass production and carrying capacity using field and remote sensing data

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Plant Diversity 2022年第6期44卷 598-606页

作者： Yeneayehu Fenetahun You Yuan Xin-Wen Xu Yong-Dong Wang National Engineering Technology Research Center for Desert-Oasis Ecological Construction Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences818 South Beijing RoadUrumqi 830011XinjiangChina University of Chinese Academy of Sciences Beijing100049China

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.

关键词： NDVI Biomass Carrying capacity rangeland Borana Season

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Canopy cover or remotely sensed vegetation index,explanatory variables of above-ground biomass in an arid rangeland,Iran

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Journal of Arid Land 2018年第5期10卷 767-780页

作者： Fatemeh PORDEL Ataollah EBRAHIMI Zahra AZIZI Department of Range and Watershed Management Shahrekord University Department of RS-GIS Science and Research Branch Islamic Azad University

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-gro

关键词： rangeland biomass non-destructive method arid ecosystems NDVI

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Complex causes and consequences of rangeland greening in South America -multiple interacting natural and anthropogenic drivers and simultaneous ecosystem degradation and recovery trends

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Geography and Sustainability 2020年第4期1卷 304-316页

作者： Wang Li Robert Buitenwerf Renata Nicora Chequín Javier Elias Florentín Roberto Manuel Salas Julia Carolina Mata Li Wang Zheng Niu Jens-Christian Svenning Center for Biodiversity Dynamics in a Changing World(BIOCHANGE) Aarhus UniversityNy Munkegade 114Aarhus C 8000Denmark Section for Ecoinformatics and Biodiversity Department of BiologyAarhus UniversityNy Munkegade 114Aarhus C 8000Denmark State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China Instituto de Botánica del Nordeste(CONICET-UNNE) Sargento Cabral 2131c.c.209C.P.3400Argentina University of Chinese Academy of Sciences Beijing 100049China

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 regi

关键词： South America rangeland Vegetation greening Climate change Sustainability Remote sensing

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Legacy earthen berms influence vegetation and hydrologic complexity in the Altar Valley,Arizona

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International Soil and Water Conservation Research 2023年第4期11卷 755-763页

作者： Mary H.Nichols Sara E.Duke Chandra Holifield Collins Lauren Thompson Southwest Watershed Research Center USDA-ARS2000 E.Allen Rd.TucsonAZ85719USA Southern Plains Area Research Center USDA-ARSSPARCCollege StationTX77845USA University of Arizona College of Science GraduateTucsonAZ85719USA

Across the American Southwest water development has played a critical role in managing rangelands.Earthen berms have been constructed throughout US rangelands to manage runoff and reduce erosion.The berms altered runoff patterns to increase soil moisture with positive local vegetative response.However,altered runoff patterns can be considered a disturbance that affects broader scale vegetation patterns.We hypothesized that the hydrologic impacts of earthen berms in semiarid rangelands will be reflected in contrasting upslope and downslope vegetation patterns.A supervised classification of grass,shrubs,and bare soil was performed using orthographic imagery taken in June 2016 to quantify the effects of 181 earthen berms in the uplands and floodplain of the Altar Valley in Southern Arizona,US.Intact berms blocked runoff,creating downslope runoff"shadows"within which the precipitation is the dominant water input.We documented more bare soil downslope of intact berms in comparison with upslope.Grass and shrub cover affected by berms were related to soil texture.Grass and shrub cover were not different above and below intact berms on fine textured soils,but on sites with coarser textured soil,grass cover was lower downslope of berms.Where breaches occurred on coarser textured soils,the up and downslope differences in grass cover diminished.This study points to the role of conservation structures in adding additional complexity to already heterogeneous landscapes by creating patchwork assemblages of vegetation and bare soil proximal to earthen runoff and erosion control berms.

关键词： Legacy conservation structure Earthen bank Earthen berm Land degradation rangeland

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PASTORAL HUSBANDRY AND CONSERVATION AND UTILIZATION OF rangeland RESOURCES IN XINJIANG,GHINA

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干旱区资源与环境 1993年第Z1期7卷 293-296页

作者： Shen Changjiang Commission for Integrated Survey of Natural Resources (CISNAR), the Chinese Academy of Sciences, Beijing 100101, P. R. of China

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

关键词： Pastoral Husbandry rangeland Resources Resource Conservation and Utilization

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Improved drought tolerance in Festuca ovina L.using plant growth promoting bacteria

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Journal of Arid Land 2023年第6期15卷 740-755页

作者： Fateme RIGI Morteza SABERI Mahdieh EBRAHIMI Department of Range and Watershed Management Faculty of Water and SoilUniversity of ZabolZabol ***Iran

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(Prangelands.

关键词： bio-fertilizers element uptake drought stress rangeland water scarcity

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rangeland Condition and Herbage Utilization by Herbivores of the Kafue Flats North Bank: A Historical Perspective before the Construction of the Itezhi-Tezhi Dam, Zambia

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Open Journal of Ecology 2018年第2期8卷 126-145页

作者： Harry Chabwela Chansa Chomba Daudi Chimbali Maxwell Malama School of Natural Sciences Department of Biological Sciences University of Zambia Lusaka Zambia School of Agriculture and Natural Resources Disaster Management Training Centre Mulungushi University Kabwe Zambia Department of National Parks and Wildlife Services Chipata Zambia Department of National Parks and Wildlife Services Chilanga Zambia

This study was carried out in Blue Lagoon National Park and the North Bank portion of the Kafue Flats Game Management Area along the Kafue River in Zambia. The aim of the study was to determine rangeland condition and utilization by wildlife as well as livestock grazing in Kafue Flats, to establish the baseline data for monitoring after the construction of the Itezhi-Tezhi dam.? Line intercept method and enclosure plots were used to sample in all recognized vegetation types and basal cover and frequency measurements were taken using line intercept method while enclosure plots were used to determine rangeland utilization. Data obtained from records showed that the area had annual mean rainfall of 535 mm at Itezhi-Tezhi, but the lowest rainfall recorded was 214 mm in the 1978-1979 rainy season and the highest was 1, 184 mm in the 1975-1976 season. With regard to range condition, bare ground was highest in the Termitaria vegetation at Nakenda-Critchley (62%), Bowa (57.6%) and Muwezwa (48.45%) while basal cover was relatively high in the flood plain at Namunyona (47.8%). Litter had an almost even distribution in all vegetation types and percent standing crop biomass was relatively high in all sample plots. rangeland utilization was relatively high around Nakenda-Chitanda (43.54%) in the flood plain and Bowa (31.42%) in the Termitaria vegetation. It was concluded that Termitaria vegetation was largely at high risk of degradation due to overgrazing. While the impact of dams, environmental flows and flood pulse are discussed, detailed research and monitoring should be introduced in addition to the promotion of management of pastures in this rangeland.

关键词： rangeland Assessment Grazing rangeland Utilization Wildlife Livestock Flood Pulse

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Influence of Tree Density on Vegetation Composition and Soil Chemical Properties in Savanna rangeland of Eastern Cape, South Africa

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Agricultural Sciences 2021年第10期12卷 991-1002页

作者： Sive Tokozwayo Keletso Mopipi Eric Cofie Timpong-Jones Department of Rural Development & Agrarian Reform D&#246 hne Agricultural Development Institute Stutterheim Eastern Cape South Africa Department of Livestock & Pasture University of Fort Hare Alice Eastern Cape South Africa Livestock and Poultry Research Center School of Agriculture College of Basic and Applied Sciences University of Ghana Legon Ghana

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 m2 plot was marked per replicate. Four belt transects 200 m2 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. Digitaria eriantha and Eragrostis obtusa were the most dominant species. Vachellia karoo and Aloe ferox 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.

关键词： Encroachment Composition Density rangeland

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