Habitat characteristics of Capparis spinosa in Sistan region

Background and objectives: A large part of Iran is occupied by arid and semi-arid climatic condition which is highly vulnerable. Native plant species that are well adapted to the environmental conditions of these areas have particular importance. They are helping sustainability of the ecosystem as, provides livestock nutrition and are used as medicinal plants. Having knowledge about the ecological characteristics of the plants can prevent destruction and regressive trend of the plant community and making it possible to take proper managerial decisions. Plant growth in natural habitats is the result of the function of various biological factors such as climate, soil, and topography, so identifying these factors as habitat needs of plants is the first step in their protection and restoration. This study aimed to investigate some habitat characteristics‎ of Capparis spinosa as a medicinal and soil protecting species in Sistan. Methodology: The distribution areas of Capparis spinosa were determined firstly with the help of the experiences of experts from Agricultural Research Centers and the Department of Natural Resources, and field visits in Sistan region. In order to study the vital annual changes of the plant, three sites, namely Zahak, Hirmand, and Hamoon, were selected and phenological stages were monitored during the plant growth period by regular visits on specific points in 2019. Vegetations were measured in a random-systematic method at each site. Four transects were setup with the length of 200m long and 100m side distance. On each transect 10 plots with the size of 4m2 were placed to estimate the canopy cover, density, frequency, percentage of litter, gravel, and bare soil. Soil samples were taken to investigate physical and chemical properties in four composite samples (from the first and last plots). Morphological traits as fruit numbers, wet and dry weight of fruits, number of stems, plant height, leaf length, leaf width, and root depth in each habitat were measured from four plant stands randomly. Data analysis was performed using analysis of variance (ANOVA) by IBM SPSS Statistics 26.0 and principal component analysis (PCA) using Past4.0. Results: The results of the vegetative period of Capparis spinosa ‎ showed that the first leaf emerges in early March and the end of the vegetative period happened in December and the plant has two flowering (June and October) and seeding periods (July and November) in a year. There were significant differences between habitats in the aspect of quantitative characteristics of vegetation and morphological traits. Hirmand habitat has more cover percentage, frequency, density, litter percentage, fruit number per plant, number and length of stem, and rooting depth than the other two sites. It also grows with species such as white saxaul (Haloxylon persicum), tamarix (Tamarix ‎aphylla), bindii (Tribulus terrestris), Alhaji camelerom, halsola (Salsola rigida), shrubby Seablite (Suaeda fruticosa), bermuda grass (Cynodon ‎dactylon), harmal (Peganum harmala), tumbleweed (Salsola Kali), desert grass (Stipagrostis plumose), Citrullus colocynthis and colocynth (Seidletzia ‎rosmarinus). The soil of Hirmand was more acidic (8/7) and had higher levels of lime (8/7), sand (86/7), Cilt (8/9), organic carbon (0/6) and organic matter (0/8) than other habitats. PCA revealed that the soil texture and height were the most important factors affecting the distribution of this species. Soil texture, and height were not different in the three habitats. Conclusion: Investigation of different phenological stages in the plant activity period showed the simultaneous growth of this plant with 120-day winds of Sistan region (120-day winds in Sistan start in early June and continue until the end of September), therefore it is possible preventing of destructive environmental effects by planting this species in Eolian harvesting zones. Moreover, this species have medicinal importance and a long vegetative period which has increased the importance of species cultivation in the region. Since the three habitats studied are in poor condition, it is recommended to rehabilitate areas with the cultivation of this species, especially in Helmand habitat, which has more favorable conditions in terms of soil and micro-climate characteristics.