چکیده:
The purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelands of Nodushan, Yazd. The plant species cover and the environmental variables were measured at 9 sites. Soil samples were taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. Vegetation was classified using twoway indicator species analysis (TWINSPAN). Data was analyzed using the ordination method of canonical correspondence analysis (CCA). Results showed that soil texture, organic matter, gypsum, salinity, C/N ratio, and elevation greatly affected the distribution of vegetation. Anabasis aphylla reflected the high salinity and saturation
moisture content of soils. Ephedra strobilacea reflected a high level of soil gypsum and a high C/N ratio. Artemisia aucheri was characterized by a gradient of increasing elevation, high organic matter, and available water. Determining the vegetation-environment relationships at these sites facilitates the improvement and reclamation of arid and semi-arid shrubland ecosystems.
خلاصه ماشینی:
ir DESERT 18 (2013) 19-26 Influence of Environmental Factors on Distribution of Plant Species in Nodushan Rangelands of Yazd Province (Iran) M.
Results showed that soil texture, organic matter, gypsum, salinity, C/N ratio, and elevation greatly affected the distribution of vegetation.
One important characteristic of an arid environment is the high intensity of plant and soil variability (Tongway & Ludwig, 1994).
com distribution and growth of plants, plays an important role in the ecology of vegetation (Muller-Dombois & Ellenberg, 1974).
(2004) suggested that the distribution pattern of vegetation in the Poshtkouh rangelands of Yazd was mainly related to soil characteristics such as salinity, texture, and soluble potassium, gypsum, and lime contents.
(2009) applied CCA for evaluating vegetation-environment relationships in the arid rangelands of southern Khorasan and concluded that environmental factors affecting water availability were the most effective in the distribution of vegetation groups.
CCA (Gauch & Wentworth, 1976) is a procedure that combines within one algorithm a reciprocal averaging solution for a correspondence analysis on species site data and a weighted multiple regression analysis on environmental factor-site data (Ter Braak, 1986).
Among the soil attributes, texture, available water, saturation moisture, organic matter, gypsum, ECe and C/N ratio greatly affected the distribution of plants.
In arid and semi- arid zones, soil salinity is an important factor in the distribution of plant species (Caballero et al.
Basically, soil texture affects the distribution of vegetation under identical climatic conditions (Liao & Chang, 2004).