古尔班通古特沙漠四种草本植物不同生长期C、N、P化学计量比的动态变化分析

以古尔班通古特沙漠地区广泛分布的4种荒漠草本植物沙蓬（Agriophyllum squarrosum（L.） Moq.）、雾冰藜（Bassia dasyphylla（Fisch.et Mey.） O.Kuntze）、角果藜（Ceratocarpus arenarius L.）和碱蓬（Suaeda glauca（Bge.） Bge.）为对象，对他们在不同生长期的C、N、P含量及计量比的动态变化进行研究。结果显示：4种植物的C、N、P含量以及C：N、C：P、N：P在整个生长期的变化趋势不同，不同生长期各个指标的变异系数在物种间存在明显差异；4种植物的C、N、P含量及计量比的季节性变异分析结果表明，N、P含量及C：N、N：P的季节性变异幅度较大，相反，C含量和C：P的变异幅度较小；4种植物C含量和C：P由季节变化所引起的变异系数范围分别为2.43%~15.80%和6.77%~18.67%，而N、P含量和C：N、N：P的变异系数范围分别为21.26%~34.38%、11.18%~30.26%、18.52%~27.11%、14.90%~25.91%；整个生长季内，4种植物C、N、P含量及计量比的变异系数依次为：N（30.00%） > C：N（22.87%） > N：P （20.12%） > P（17.76%） > C：P（11.72%） > C（9.02%）。研究结果表明4种植物在不同生长周期的C、N、P含量及计量比的变化规律与他们的生长周期和植物种类存在显著相关性。

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.