Distribution and importance of some endemic Astragalus L. species in semi-arid environmentally sensitive areas: a case study from northern Turkey

ABSTRACT Background: The objective of this study was to determine the distribution of some endemic species of the genus Astragalus L. (Astragalus anthylloides Lam., Astragalus lycius Boiss. and Astragalus xylobasis var. angustus (Freyn & Sint.) Freyn & Bornm.) species, and the interaction between soil, climatic characteristics and desertification risk which affect the distribution of these species in the semi-arid environment of Cankiri, northwest Turkey. During the vegetation period in 2017, soil and plant samples were collected from 180 points. Desertification risk (DR) and environmentally sensitive area index (ESAI) were calculated for each sampling point using the desertification indicator system for Mediterranean Europe (DIS4ME). Results: According to the DIS4ME system in the forest areas, DR values for A. anthylloides and A. lycius were lowest with 0.49 (no desertification risk) and highest with 3.73 (moderate desertification risk), and with an average of 2.20 in the field (low desertification risk). For A. xylobasis var. angustus in grassland, the DR values ranged from a low of 5.01 to a high of 5.42. The ESAI values ranged from 1.34 to 1.50 in the forest areas where the species A. anthylloides and A. lycius were distributed, and they ranged between 1.33 and 1.47 for A. xylobasis var. angustus in the grassland areas. The results of the analysis between the DR values and Astragalus L. species changes according to the land use types and plant distribution. Conclusion: When the relationships between all three of these endemic species’ DR values are evaluated together, they emerged as the best plant species indicator for determining desertification status.