IRANIAN JOURNAL OF RANGE AND DESERT RESEARCH
Year:2000 | Volume:- | Issue:2|Papers Count:3

The recognizing of basic concepts and technical terms in domain of desert and desertification is the first step to make researches easy, so that, a common apprehension from these technical key terms would be obtained. This paper with the considering aforesaid fact, has tried to discuss about the most important issues in desert literature.For instance, what is "desertification"? How does it exist and relate to "desert"? Is desert a kind of "natural reserve" or "natural resource"? Is it renewable or unrenewable'? Is decertified or creeping desert the same desertification'? Is desertification the same "soil degradation" or "land degradation"? Are both or none of them'? Fundamentally, what is the "Land"? What difference does it make with "areas"? What relation does it have with "geographical space"? How will be a land, desertified? At last, which ones are better: anti-kavirification, anti-desertification, desertry or controlling desertification?This paper is an answer to such questions, until some of inexpressive or wrong approaches will be probably cleaned of this keywords.

Annual medica go species are used in Ley Farming system in mediterranean climates. They increase soil fertility and produce forage for livestock.Seven species of annual medic’s M scutellata, M. rngosa Cv. Paragosa, M tnmcatula cv. (Jemalong, Bornng, Hannaford), M. orbicularis, M. rigidula were compared for seed production in Sanandaj in Randomised Block Design, Resultes Showed that Pod production of Annual Medicago species were different. M. scutellata produced more pod than the other species. Pod production for each species was factulated in different years and it was depended on rainfall.In conclusion M. scutellata would be a good species for seed production in high altitude (2200m).

The phenological stage of some important rangeland plants were assessed from 1994 to 1996. The sutdy was conducted in Hanna Research Station of Semirom, Esfahan, Iran. Starting date and duration of the grazing period however were the main objective of the study. Bromus tomentellus and Stipa barbata, Astragalus cyclophyllon, Onobrychis melanotricha and Polygonum domosum and Erutia ceratoeides from the forbs as representative of the shrubs were studied. Ten relatively uniform stands of each species were measured. Annual life cycle of the plants were divided into two periods, more active phase which was from initial growth to anthesis and less active phase from anthesis to maturity. Within the first phase every 15 days, and in second phase every 30 days, data were recorded. Analysis of data shows that physiological and morphological behavior of the species is synchoronized with climatic condition. Also the phenological type that show the start and end of each phenological stage and it's correlation with climatic factors were drawn on amberothermique curve of the station. Livestock entrance and exit, and Suitable grazing period of the range were determined according to the phenological data. It was also concluded that growth period of drought tolerant species such as shrubs are longer than forbs and grasses.