comparing plant functional types in an old-field and a natural rangeland vegetation

this research was conducted to compare plant functional types (pft) and traits in an old field (abandoned for 28 years) and a control site in the baharkish rangelands quchan iran. in the both sites 40 randomized quadrates were established. floristic list frequency canopy cover and 20 vegetative phenological and morphological plant traits were measured for all plant species within each quadrate. according to the pearson correlation analysis and by using r software 9 plant traits including life form plant canopy reproduction mode reserve organ root type leaf phenology growth form life cycle and regeneration mode were known as the major plant functional traits. data classification and ordination were applied on a matrix of 9 traits ×112 species by using canoco and twinspan softwares. it led to identification of 5 plant functional types. total canopy cover of two pft was significantly (70%) reduced and that of three pft’s were relatively (10 20%) increased in the abandoned field. in conclusions plants being annual therophyte geophytes and rhizomatus are tolerant whereas those being perennial (phaneropyte chemaphyte hemicryptophyte) having tap root system and wide canopy cover are known as sensitive to ploughing disturbance.