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A Simplified Model with Soil Water Limitation on Spring Wheat Growth


The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO2 conductance of assimilation (gc) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θR,80), ambient temperature (Ta), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψc,1.5). Some applications in research program of field experiment of atmosphere-land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).

考虑土壤水分限制的春小麦生长简化模型
郑海雷1* 米谷俊颜2 黄子琛3

(1. 厦门大学生物系,厦门361005;2.  日本冈山大学生物资源研究所,冈山710;3.  中国科学院兰州沙漠研究所,兰州730000)

摘要:建立了以日长 (L)和日总辐射 (TDR)为自变量的春小麦 (Triticumaestivum L .)碳同化和干物质累积 (DMA)的简化模型 ;考虑了水分限制下光能利用效率 (α)、碳传输导度 (gc)均被降低的设定 ,将反映春小麦水分状况的叶水势 (Ψ)作为参数纳入本模型 ;Ψ则通过多元回归由 80cm土层相对含水量 (θR ,80 )、气温 (Ta)、水汽压差 (VPD)、低于- 1.5MPa叶水势之和 (Ψc ,1.5)给出。讨论了模型在“黑河地区地气相互作用研究”中的应用实例。模型分析和模拟结果表明 ,该简化生长模型能较好地描述春小麦在水分限制和无水分限制条件下的干物质累积过程。

关键词: 春小麦;生长;简化模型;水分限制


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