The Stoichiometric Characteristics Of Nine Kinds Of Endangered Plands In Eastern Alxa And Western Ordos

Stoichiometric has become one of the important means to study element balances in ecological system. In order to clarify the stress adaptation and feedback ability of desert plants under the extreme environmental conditions, nine dominant species along the desert ecosystems in Eastern Alashan and Western Ordos were selected to study the stoichiometric characteristics of carbon(C), nitrogen(N), phosphorous(P), C:N, C:P, N:P and C:N:P. The results show that (1)the averages of three growing seasons of root, stem and leaf of C, N, P, C:N: P are respectively:408.91 mg·g-1、13.68 mg·g-1、1.18 mg·g-1、60.46; 490.53 mg·g-1、11.45 mg·g-1、0.98mg·g-1、50.69; 410.25 mg·g-1、 21.80 mg·g-1、1.36 mg·g-1、17.70; 490.47mg·g-1、6.39 mg·g-1、1.75mg·g-1、 19.26; 382.41mg·g-1、5.94mg·g-1、1.28mg·g-1、1064.34; 316.14 mg·g-1、 14.84 mg·g-1、1.63mg·g-1、307.82; 423.97 mg·g-1、7.95 mg·g-1、 2.61 mg·g-1、452.10; 428.27 mg·g-1、7.38 mg·g-1、2.55 mg·g-1、526.80; 364.88 mg·g-1、15.75 mg·g-1、2.91 mg·g-1、346.93. (2)The averages of the Tetraena mongolica of three seasons of root, stem and leaf of C, N, P, C:N,C:P,N:P,C:N:P are:431.99 mg·g-1、15.23 mg·g-1、1.99 mg·g-1、 57.78、558.78、8.54、215.04; 373.09 mg·g-1、8.80 mg·g-1、1.87 mg·g-1、 80.83、622.07、5.47、423.08; 351.77 mg·g-1、12.32 mg·g-1、1.87 mg·g-1、 49.07、441.03、7.43、197.21. (3) The differences in every scale, different organs and different seasons of the nine species are various. (4) The N content of the roots, stems and leaves of those plants significantly higher, the P content of the stems and leaves of those plants significantly lower, the P content of the roots of those plants had less differences. The C, N and P contents of the seven populations of the Tetraena mongolica were positively correlated with the C, N and P contents in rhizospheric soil. Compared with the existing research results of desert plants, the N content in each organ of nine kinds of plants is significantly higher, the P content of stems and leaves is significantly lower and the P content of root is no significantly different. The research provides a case reference to the material circulation and biodiversity protection of Chinese desert ecosystem.