Asafoetida volatile oil components (AVOCs) are directly affected by microenvironmental changes. Here, this research aimed to investigate the AVOCs through gradients of micro-topography and edaphic factors in an arid area in central Iran (northern hemisphere) during two consecutive years. Soil and topography data were sampled simultaneously with oleo-gum-resin sampling using 20 plots placed in the area. Data were submitted to a PCA analysis. The AVOCs were significantly affected by both micro-topography and soil properties (P < 0.01). The components of carbonothioic dihydrazide and 1,3,6-0ctatriene, 3,7-dimethyl showed the most negative and positive relationship with the micro-elevation from 0 to 60 cm (R2 = 0.39, 0.44, respectively). Some components showed severe changes depending on the geographical direction, where the highest (42.2%) and lowest (25.1%) values of carbonothioic dihydrazide were obtained under the geographical direction of south and north, respectively. Also, nitrogen, phosphorus, organic matter and silt with R2 = 0.72, 0.52, 0.84 and 0.63, respectively, were positively correlated with some AVOCs, i.e., thiopropionamide and naphthalene, 1,2,3,5,6,8a-hexahy….
