Study of competition between two rangeland species Bromus tomentellus, Poa pratensis In order to protect them in rangeland ecosystems

Mutual relations between two plants, establishment and survival their affects,  therefore, knowledge of how this relationship can be use for the maintenance repair and management of pastures and rangeland species. of the cognition which effective ingredient can be facilitated and competition to predict the vegetation dynamics and ecosystem management in one area can be used. This research was to study the potential competition between the two species pasture B. tomentellus and P. pratensis  also survey the effect of competition ground and shoot organs in the form of laboratory work and sampling from the pasture was carried. This experiment in a completely randomized design with four treatments (two control and two competition treatment) in gonbade kavus university in 2015 took place in the greenhouse. For cultivation plants and competitive environment of the plastic pots whth diameter and height of 22 cm was used.  Pots filled with rich soil and the seed was planted by characteristic pattern. The pots were watered every day.  Prune cultivated species were used to achieve the intended density. In order to evaluate the coverage of these two species in the pasture was go to saraliabad area of Gorgan and measurements were carried of vegetation. The results show factors shoot dry weight and height of B. tomentellus species significant difference statistically there was no between competition and control treatment but in the shoot dry weight and height of p. pratensis species significant difference statistically between  the competition and control treatment was observed. The results this research  showed that ground organ dry weight and root length between control and competition treatment meaningful in both species.  Analysis of the data shows that shoot organ in any B. tomentellus species in competition with p. pratensis species not recessive and has been able to give compensatory response but the performance of p. pratensis species decreased in competition with B. tomentellus species and compensatory response has been no observed. According to the results of vegetation measurements in the saralianad area in percent attendance in the study plots B. tomentellus species 21/6% and p. pratensis species 12/2% was measured that expressing conquest and superiority of B. tomentellus species in the shoot organ part than p. pratensis species in the area of study.