Abstract: We explored the relationship between C, N and P stoichiometry of coarse roots in 45 species of desert plants and environmental factors from 44 sites in Xinjiang. The results showed that coarseroot C, N and P concentrations of these species were 440±73, 9.86±3.84, and 0.82±0.48 mg·g^-1, respectively, and C∶N, C∶P and N∶P averaged 51±21, 707±388, and 15±10, respectively. Significant differences in nutrient concentration existed among three plant lifeforms. Specifically, coarseroot C concentrations decreased in the order of trees, shrubs and herbs, while root P showed an opposite trend. The coarse-root N concentration was the highest in shrubs. Only C vs P and N vs P in roots showed allometric growth relationships, with power exponents being -0.460 and 0.699, respectively. There were nonlinear relationships of coarse-root C, N and P with longitude, latitude, mean annual temperature (MAT), and mean annual precipitation (MAP). In comparison with life-form and soil nutrient content, climatic factors (MAP, MAT) had greater effects on the stoichiometric characteristics of C, N and P in the coarse roots of desert plants, which reflects water limitation for plant growth in deserts.

Key words: heavy metal, bioavailability, mangrove sediment, Dongzhai Harbor.