Abstract: In this paper, the photosynthetic organs stained with dust on the whole plants of 10 shrub species planted in Tazhong Botanical Garden in the hinterland of the Taklimakan Desert were sampled, and their dustholding capabilities were analyzed using the multiple indices in mass subtraction method. The results were as follows: (1) Dustholding capabilities of plant photosynthetic organs are closely related to the environment. The plants growing in the desert hinterland can hold more dust by their photosynthetic organs than those growing in the peripheral regions of the desert; (2) Though photosynthetic organs of Haloxylon ammodendron and Calligonum caput-medusae degenerated into the assimilative branches with extremely degenerated leaves similar to needles of coniferous species, their dust holding capabilities are higher than those of coniferous species mentioned in other paper. The dustholding capabilities of photosynthetic organs of H. ammodendron are higher than those of C. caput-medusae because of its assimilative branches with shorter knot spacing and more leaves; (3) Though leaves of Tamarix plants also degenerated extremely, they have the excellent dustholding capabilities by their photosynthetic organs, higher than H. ammodendron and C. caput-medusae, and even higher than broadleaved shrubs and broadleaved trees, because of their photosynthetic organ surface characteristics (such as the relatively bigger leaf size, abundant tomenta and salt secretion), a mass of leaves, and greater photosynthetic organ density of crown. Therefore, the dustholding capabilities of these Tamarix plants mentioned in this paper are distinctly different; (4) Photosynthetic organs of the whole plants, unit weight and unit surface area can only represent the dustholding capabilities in some aspects, but dustholding amount of unit volume crown can represent the dustholding capabilities of photosynthetic organs of plants more holistically. The dustholding capabilities of photosynthetic organs of 10 shrub species are in an order of Tamarix austromongolica > T. elongata > T. juniperina > T. androssowii > T. hispida > T. hohenackeri > T. ramosissma > T. taklamakanensis > H. ammodendron > C. caput-medusae. These results may provide a scientific basis for tree species selection and distribution in landscaping and shelterbelt construction and dustholding effect evaluation, and also a reference in studying the correlation between plants and soils in arid regions.

Key words: shrub, crown, photosynthetic organ, dustholding capability, density, Taklimakan Desert