comparison of techniques for density measurement in three plants communities f.ovina, b. tomentellus and p.ferulacea (research station: rangelands of saral in kurdistan province)

for assessment and comparison of measuring density methods of festuca ovina, bromus tomentellus and prangos ferulacea, three plants communities are selected. in all of plant community, reference area was defined and samples 7000 (70*100) square meter was selected. whole the area, sampling was accumplished as systematic-random. in each area, 5 transect 100 meter are established. then in areas 7000 square meter, all of the basic species are counted by strip transect and real plant density is measured. this plant density is remarked as a control and plant density that is measured by others methods are compared with it. density measuring methods in this research were: species counting counted in quadrate of 1 square meter, point-centered quarter, angle order, nearest-neighbor, random pairs and closest individual methods. the results showed that among these methods for festuca ovina, neighbor nearest method is most accurate and angle order method has low accurate. moreover angle order method is the slowest and quadrate method is rapid. in bromus tomentellus, among these methods for this species, point-centered quarter method is the most accurate. angle order method has low accurate in these methods. also angle order method is slowest and counted quadrate method is rapid. in prangus ferulacea, in these methods for this species, point-centered quarter method is the most accurate and angle order is the least accurate. moreover angle order method is the slowest and count plant quadrate method is rapid.