Document Type : Research Paper
Author
Assistant Professor, Range Research Division, Research Institute of Forests and Rangelands, Tehran, Iran
Abstract
The objective of study on phenology of range plant species is to assess the changes of different phenology stages (germination, flowering, seed maturity stages, autumn growth and winter dormancy) in order to adjust range utilization programs, prevention of early or late grazing, recognition of nutritional value of the plant species, determining livestock entry and exit time and seed collection. Artemisia sieberi is a shrubby species with an appropriate forage value distributed as a dominant species in arid and semi arid steppe regions of Iran. It is resistant to drought and relative salinity which widely grows in loamy, sandy and loamy clay soils. In this study, phenological stages of Artemisia sieberi were investigated in six different sites of steppe regions of Iran. Accordingly, data of the phenological stages were recorded for vegetative and reproductive stages respectively in 15-day and 7-day intervals. With regard to the direct relationship between phenological stages and climatic factors especially temperature and precipitation, these data were taken from the nearest synoptic station for each site. According to the results, vegetative growth stage of Artemisia sieberi starts from early March early April and continues to July if moisture is available. The flowering stage starts from early July and continues to late October. Seed ripening stage gradually starts from early September to late January. The start of the winter dormancy is late January which continues to early February. Our results show a long-term phenology for Artemisia sieberi indicating its resistance to environmental conditions. Consequently, comprehensive recognition of phenological stages of Artemisia sieberi as a key species enables us to manage the grazing, adjust the entry and exit time for livestock, grazing intensity and appropriate grazing systems to be applied by range managers and utilizers.
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