The study of Flora, biological form and the chorology of plant covering in Sistan region– IRAN

ABSTRACT:Floristic study of each region is really significant and as a birth –certificate for the region, it indicates the existence of plants and their condition. Therefore, studying geographical origin and floristic Study of each region are considered to be the most effective methods for management and protecting existing reservations.Deserts,primarily includes regions where in no trees are seen and have weak plant covering.Desertʹs plant covering is a simple growing that its structure has been developed very little and its coveringbecomes clearer and not more continuous with the increase of dryness. What is strange in these deserts is the presence of scattered covering in conditions that rainingWon’t be even more than 100 mm and this point is very interesting from the view point of desert Plants ecology. Sistan region is one of the driest regions in the world. The purpose of studying and IntroducingFlora of the region, is to collect all existing plants, in Sistan region with the help of Refining and desert observation during 3 years which have been done from 2004 to 2007 .The Obtained results of desert studies and collecting plant species indicate that even though this region Has had a dry climate and has tolerated severe drought years, it has significant anddivertibleFlora.The existing plant elements in this region have been studied and they are considered to be 28Families and 20 varieties and genders. The kind of Astraea with 21.7%, the kind of Brassicacease with 10.8% and chenopodiaceous with9.7% are the most numbers of these species , that totally , they consists of 42.8% out of all sorts of species. The obtained results of classifying growth forms with the method of Ranker in the region have been studied and it shows that trophies with 55% Hemicryptophyte with 24% are the most important life Forms in the region. To study plant chorology of the region shows that species with growth cerotype of Iran-Tourane with 52% are considered to be the most important chorology groups that exist in the region. Therefore in Sistan region in spite of severe dry, some plants can be seen and it is not Lack of plants completely and plant life is seen everywhere, so that plants are observable in the region, in proper conditions and raining.