Abstract: A peculiar ecotone forms in the arid and semiarid Ordos Plateau of China, and it provides an important habitat for diverse shrub communities that play an important role in maintaining the desert ecosystem and sustaining the local stock raising. Caragana tibetica community is a zonal vegetation type in this grasslanddesert ecotone. It occupies a largest area constituting an important rangeland and contributing to ecological stability in this region. We investigated the morphological characteristics of aboveground part of C. tibetica individuals. Underground part was studied only for the selected medium and small sized individuals. Soil moisture content inside and outside of C. tibetica nebkhas was measured, sand landforms were distributed around shrubs, and fissuration of roots and stems of C. tibetica was examined. We found that the individuals of C. tibetica were 57 cm long, 44 cm wide and 22 cm tall in average. Nebkhas were 77 cm long, 52 cm wide and 16 cm high in average, and their average volume was 0.071 m3. It was found that 18 thick stems of C. tibetica emerged from each nebkha surface in average. The length of stems buried in nebkhas varied in a range of 8-10 cm for each class with about 2/3 of them being dead. Number of stems in the lower class was 2-3 times higher than that in the higher class. Roots were stratified into two layers. In addition, stems buried in nebkhas grew adventitious roots. The rootshoot ratio varied in a range of 0.35-0.53. Generally, the soil layer of 20-60 cm in depth is characterized by small and fine roots and higher soil moisture content. Nebkhas play an important role in supporting and protecting aboveground part of C. tibetica. Stems and roots of the shrub are also characterized by the interesting phenomenon of fissuration. Our findings indicate that morphological characteristics of  C. tibetica are developed as a result of adaptability of C. tibetica to drought environment.

Key words: Caragana tibetica, nebkha, cushion shrub, stem, root, fissuration, Ordos Plateau