Dynamic analysis of stoichiometric ratios of C, N, and P during different growth periods in four herbaceous plants from Gurbantünggüt Desert

To study the dynamic changes in C, N, and P content and stoichiometric ratios in desert plants during different growing periods, four desert herbaceous plants, (i.e., Agriophyllum squarrosum (L.) Moq., Bassia dasyphylla (Fisch.et Mey.) O. Kuntze, Ceratocarpus arenarius L., and Suaeda glauca (Bge.) Bge.), widely distributed in Gurbantünggüt Desert, were selected. Results indicated that:Seasonal dynamics of leaf C, N, and P content and C:N, C:P, and N:P mass ratios in the four herbaceous plants showed different trends throughout the whole growth period. The variation coefficients of each index during the different growth periods also demonstrated significant differences among species. Seasonal variation analysis of leaf C, N, and P content and their stoichiometric ratios showed that seasonal variations in N and P content and C:N and N:P ratios were larger, whereas variations in C and C:P were smaller. The seasonal variation coefficients of C and C:P in the four herbaceous species ranged from 2.43% to 15.80% and from 6.77% to 18.67%, respectively. Moreover, N and P content as well as the C:N and N:P ratios ranged from 21.26%-34.38%, 11.18%-30.26%, 18.52%-27.11%, and 14.90%-25.91%, respectively. The variation coefficients of C, N, and P content and stoichiometric ratios in the four herbaceous plants during the entire growth period were sorted as:N (30.00%) > C:N (22.87%) > N:P (20.12%) > P (17.76%) > C:P (11.72%) > C (9.02%). Overall, results showed that changes in C, N, and P content and stoichiometric ratios were significantly correlated with their growth periods and plant species.