Biomass Distribution and Root Architecture Characteristics Differed Between Alhagi sparsifolia and Tamarix ramosissima

Alhagi sparsifolia and Tamarix ramosissima are dominant phreatophytic deep-rooted species at the southern edge of the Taklamakan Desert. They have adapted to the hyperarid environmental conditions through rapid development of root systems that access groundwater to satisfy demands for both water and nutrients. The plant community consisting of the two species is the most important landscape vegetation, and it plays an essential role in maintaining the fragile ecological environment in the desert-oasis transition zone.

Because the roots of the two species are very deep (the root of A. sparsifolia could reach to 16 m; and the root of T. ramosissima could reach to 20m), there are great difficulties to study the root ecology in the natural conditions.

Therefore, one-year-old seedlings of A. sparsifolia and T. ramosissima were chosen in this study to investigate the strategies to adapt to the harsh habitat based on the analysis of biomass distribution and root architecture by using the excavation method and measuring the related growth parameters.

The results showed that the biomass distribution of two species differed. T. ramosissima had more biomass in the shoots, whereas A. sparsifolia had more biomass in the roots. The root architecture of two species differed. The root distribution of T. ramosissima resembled a "herringbone" formation in vertical profile, whereas the roots of A. sparsifolia were distributed in the form of a web, with dichotomous architecture.

The study provided the basis for the restoration of the degenerate vegetation in the severe environment in the southern edge of the Taklamakan Desert. The result was published in Arid Land Research and Management in July 2013.