Assessing of plant functional traits to Environmental Factors using RLQ and Q-corner Methods (Case study: Zeyar rangeland, Mazandaran province)

The functional properties of a plant can link the plant physiology with community and ecosystem processes. Thus it provides an appropriate tool for investigation of environmental changes and biodiversity. For this purpose, Zeiar rangeland of Damavand Mountain were selected as the 6000ha study area​​. A stratified-random sampling method was used for the sampling of vegetation and soil. Topographic variables including slope, height, and slope direction were used to classify the study area and making a land mapping unit map. In each unit, 10 plots of 1 m 2 were randomly established and list of the plant within the plot were. In addition plants numbers, and functional characteristics including leaf specific area, leaf dry matter, plant height and seed weight were measured and put it in the list. Three soil samples were taken from 0-30 cm depth in each sampling unit. Soil variables including nitrogen, phosphorus, potassium and organic carbon content were measured in the laboratory. The climatic variables taken into account were annual relative humidity, mean annual temperature and mean annual rainfall. Effect of environmental factors on functional properties were evaluated using RLQ and Q-corner methods in ade4 package of R software. The results showed that the first RLQ axis showed 84% environmental variability and 87% variance of features. The correlation coefficient along the RLQ axes were 0.62 and 71% which is the best correlation. Also, the results of Fourth-corner test showed that leaf specific area was positively and significantly correlated with soil organic carbon, phosphorus and nitrogen. Leaf dry matter and seed weight were negatively correlated with soil organic carbon. Combining the two methods could clearly improve the relationships between RLQ axes and environment-trait variables. Thus usage of the methods is suggested fot the same studies.