Analysis of Artemisia ordosica Plant Morphology and Structure Characteristics in Mu Us Sandland

The dominant wind was northwest in Mu Us sand land area except summer. There were differences in morphological and structural characteristics of the muture Artemisia ordosica plants in different orientation because of the dominant wind aspect. The crown radius in the northwest direction was significantly shorter than that of in the rest three directions, while there were no significant differences in the crown radius among the other three directions. The LAI value in the southeastern direction was significantly greater than that of in the northwestern within the same distances from the plant roots, while the DIFN value in the southeastern direction was significantly lower than the northwestern direction. There were no significant differences in either LAI or DIFN values between the southwest and northeast directions, whose values were between the southeastern and northwestern directions. The study showed that the dominant wind influenced upon not only the crown radius but also the foliage densiy in different directions, causing sparser branches and less leaves in the windward northwestern direction. The most important three factors affecting the morphological and structural characteristics of Artemisia ordosica plants were the wind frequency × wind speed in the winter season, the frequency of wind directions in the winter and the wind frequency× wind velocity in the spring season.