Asgari, H. M.

Beniaz, M.

Khedrigharibvand, H.

Shahriary, E.

Tavili, A.

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Relationships between Veresk Rangeland Vegetation and Environmental Characteristic Using Multivariate Analysis Methods E. Shahriary University of Tehran, Iran M. Beniaz University of Tehran, Iran A. Tavili University of Tehran, Iran H. M. Asgari University of Tehran, Iran H. Khedrigharibvand University of Tehran, Iran Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/1-4/13 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 ]162　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　Grasslands/Rangelands Resources and Ecology ——— Ecology of Grasslands/RangelandsRelationships between veresk rangeland vegetation and environmental characteristic usingmultivariate analysis methodsE . Shahriary ,M . Beniaz , A . Tav ili , H . M . A sgari ,H . K hedri gharibv and１ The University o f Tehran , Natural Resources Faculty , P .O .Box :３１５８５‐４３１４ ,K araj , I ran . E‐mail : eshahriary＠ gmail .com (Corresponding author ) ２ ,３ . The University o f Tehran , Natural Resources Faculty , P .O .Box :３１５８５‐４３１４ , K araj ,I ranIntroduction Interest in how various landscape components affect biotic and abiotic resources has grown over the past ２‐３decades (Brosofske et al , ２００１) . The distribution and abundance of range species has been correlated with a variety of complexenvironmental gradients . Environmental factors affect range plant grow th and need to be understood and considered byrangeland managers . Plant grow th and development are controlled by internal regulators , which are modified according toenvironmental conditions ( Manske １９９７ ) . Of the most ecologically important environmental factors affecting rangeland plantgrow th and distribution are topography ( slope , aspect , and elevation) and soil properties ( Jafari et al , ２００４ ) . Environmentalfactor effects on vegetation could be considered as a main ecological subject during last recent decades .Materials and methods The study was conducted at Zereshkin rangelands , approximately ６０ km south west of Savadkouh , innorth of Iran (５２° ５２′５８″ — ５２°５８′５″ E , ３５°５５′５１″ — ３５° ５８′４０″ N) .Based on field surveys , five vegetation types were identifiedat the study area . Fif teen １ m２ quadrats with ５０ m distance from each other were established along each of four ２００ mtransects . Vegetative sampling method was randomized systematic . Soil samples were taken at the starti and end points of eachtransect . Data matrix of environmental factors and vegetation types was made . The windows version of PC‐ORD (McCune andMefford , １９９７ ) was used for ordination of vegetation types on a gradient of site factors . Data were analyzed by principalcomponent analysis ( PCA) .Results Figure １ shows the distribution of vegetative types of Zereshkin rangeland defined by the first two axes of the PCA . Asshown in Figure １ , the location of types in four quarters is different . The distance between the indicator points of the vegetationtypes along each axis shows the degree of similarity and dissimilarity of types in the environmental factors . In axis １ , thecoefficients of some factors are negative such gravel , thus those types located in quarter １ , have inverse relationship with thisfactors . In axis ２ , coefficients some of factors are positive such as silt ３０‐６０ cm , Therefore , those types that are lying in thethird quarter have inverse relationships with this factors . For example , as shown in Figure １ , Da .gl‐Br .to . type is relativelyequally affected by PC１ and PC２ . Since this type has been located in negative side of axes １ , therefore , it has a positivetendency to soils with high gravel percentage on top . The distribution of this type is negatively related to nitrogen percentageand OC of soil samples , that is , an increase in N and OC of soil leads to decrease of mentioned type occurrence in the study area .　 　 Figure 1 Distribution o f Zereshkin rangeland ty pes de f ined by the f irst twoaxes o f PCA .Discussion Results showed thatdifferent vegetation types showdifferent relationships with underlyingsoil characteristics . It seems that themost important factors affecting theoccurrence and separation ofvegetation in Zereshkin are texture ,OC and nitrogen . Soil texture controlsdistribution of plants by affectingmoisture availability , aeration anddistribution of plant roots ( Jafari etal . , ２００４ ) . Soil organic carbon is animportant determinant of soil fertilitybecause of its impact on ion exchangecapacities and its near‐stoichiometricrelationship to nitrogen . Future studies on the vegetation‐site factor relationships of rangelands should attempt to studyintegrated site factors effects on vegetation occurrence and separation .ReferencesBrosofske , K .D . , J . Chen and T .R . Crow . ( ２００１ ) . Understory vegetation and site factors : Implications for a managedWisconsin landscape . Forest Ecology and Management １４６ : ７５‐８７ .Jafari , M . , M .A . Zare Chahouki , A . Tavili , H . Azarnivand and Gh . Zahedi Amiri . (２００４) . effective environmental factorsin the distribution of vegetation types in Poshtkouh rangelands of Yazd province ( Iran) . Journal o f A rid Env ironment ５６ :６２７‐６４１ .McCune , B . , and M .J . Mefford . (１９９７) . PC ＿ ORD . Multivariate Analysis of Ecological Data Version ３ .０ . M jM so f tw aredesign . Glenden Beach , OR .Ax is2 Fe.ov-Da.gl .... Da.gl-Br.to .... Da.g!,_-Bra.pi fe .ov-br.to Br.to-Po.bu .... Axis 1 

Relationships between Veresk Rangeland Vegetation and Environmental Characteristic Using Multivariate Analysis Methods

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Relationships between Veresk Rangeland Vegetation and Environmental Characteristic Using Multivariate Analysis Methods

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