Document Type : Research Paper
Authors
Abstract
Autecology of plant species is an important portion of ecological studies in natural resources science. This study was conducted to investigate on autecology of Hedysarum kopetdaghi. This range plant species is a perennial plant from Papilionaceae family that grows mostly in range ecosystems of Golestan National Park. Ecological characteristics such as climate, topography, soil, phenology, regeneration, chemical compounds, and preference value of the plant were studied. Precipitation and temperature data were collected from Khan Cheshmeh Climatology Station which is located near the study area. The results showed that this species grows at scattered spots in rangeland ecosystems of the area. Based on data collected in several years, annual rainfall of the study area is 249.5 mm and means annual temperature is 11.9 degree Centigrade. Soil studies showed that Hedysarum kopetdaghi appears on soils with silt–loam texture and pH of 7.5–7.9. No sign of salinity was found in the soil. The plant has a vertical tap root system. The major root penetrates soil more than 2 meters. In its major ecosystem, canopy cover of this species is about 0.2-1/16%. The density and frequency of this species are 70-1500 plant/ha and 3-15%, respectively. Vegetative growth stage of Hedysarum kopetdaghi species usually starts in late march. Flowering is completed in late May and early June. Seed ripening occurs in late June and early July. Above ground materials of Hedysarum kopetdaghi contains 27.13% crude protein at the vegetative growth stage. Preference value of this plant is 75% for sheep and goats. Grazing the related rangeland ecosystems in inappropriate season, as well as overgrazing, are the major causes of biological degradation creating endangering conditions for this range plant. This species has a high level of resistance to grazing and relatively harsh natural conditions. This plant is a suitable range species to be used in range seeding programs for degraded ranglands of the study area or similar rangeland ecosystems.
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