The relationship between the morphological traits of the medicinal plant Stachys inflata Benth and environmental factors

Stachys inflata Benth is a medicinal species widely used among people and industries, and its growth conditions and factors affecting its growth are important for principled management and multi-purpose exploitation of rangelands. This study aimed to investigate the effect of soil and topographical factors on the morphological traits of Stachys inflata Benth in the northern rangelands of West Azerbaijan province, Iran.

Eight rangeland sites in Chaipareh and Khoy counties were selected using a systematic-random method, and 80 plots were established along linear transects. The percentage of canopy cover, length of the flowering stem, length, width, and area of the leaf, length and width of the canopy, height of the plant, depth of rooting, number of main branches, root dry weight, and leaf and stem dry weight were measured. The topographical factors of elevation, slope percentage, and aspect were recorded, and the percentage of bare soil, litter, rock, and gravel was estimated. Soil samples were taken from each site to measure soil parameters. The effects of soil and topographical factors on the morphological traits of Stachys inflata Benth were analyzed using Redundancy Analysis (RDA) and clustering analysis (CA).

The results showed that the functional traits of Stachys inflata Benth are under the combined influence of soil and topographical factors. The amount of sand, electrical conductivity, and cations of the rangelands and less amount of elevation values, exposure of the range to the sun, organic carbon, silt, clay, lime, and acidity were found to be positively correlated with biomass production. The dendrogram related to the classification of traits showed the division of traits into 12 separate clusters based on the similarity of the traits.

The results suggest that Stachys inflata Benth prefers harsher environmental conditions for biomass production, and it can be recommended as a suitable species to increase its abundance in degraded sites. The findings of this study provide valuable information for the management and exploitation of rangelands in the northern region of West Azerbaijan province, Iran.