Assessment of Spatial Variability of Soil Characteristics and Plant Diversity in Semi-Arid Grasslands

Abstract

Semi-arid areas comprise a considerable acreage in Turkey and the vegetation cover is very sensitive in those areas. This study was conducted in a typical semi-arid area at the Çankırı Karatekin University Campus for the purpose of analyzing spatial relationships between soil properties and the number of plant species (NPS) per square meter, which is an important indicator for desertification studies. Two transects (one normal and other parallel to the slope) were placed on north-east and another two transects on south-west aspect of a hill in the study area. Soil samples were taken from 0-5 and 5-20 cm soil depth from 5-m apart on each transect and the NPS per square meter was determined at each sampling point. The soil samples were analyzed for physical (sand, silt, clay, bulk density, field capacity, wilting point, plant available water content, aggregate stability) and chemical (pH, electrical conductivity, organic matter and CaCO3 contents) properties. Descriptive statistics were calculated for all soil variables and the NPS. The results showed that the NPS was similar in mean and coefficient of variation on all the four transects. The correlation coefficients among the measured soil variables and the NPS changed between 0 and 0.82. The correlogram analysis of soil variables and cross-correlogram analysis between soil variables and the NPS were performed. The results of geostatistical analysis showed that sand content, bulk density, plant available water content, silt content, and EC spatially related to the NPS. The results have a potential for use in studies of grassland development.

Keywords

• Correlogram analysis
• desertification
• geostatistics
• plant diversity
• semi-arid graaslands

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