该文应用气象数据、土壤物理属性实测数据、土壤水分分布式动态模型和植被表面净辐射模型的模拟结果,利用多元线性回归分析方法,建立了植被净第一性生产力模型,实现了鄂尔多斯高原东部砂质荒漠化地区考考赖沟流域尺度上30 m×30 m空间分辨率的植被生产力精确模拟,并且用植被生产力的野外实测数据对模拟结果进行了验证表明: 实测值与模拟值在固定沙丘、半固定沙丘和样线2上都达到0.05显著性相关水平;不同位置的实测植被生产力数据多分布在1∶1直线附近,模拟值与实测值吻合较好;植被生产力实测值与模拟值的相对误差范围为3.22%~6.27%,偏斜度范围在-12.84%~4.43%。该文的研究方法可以为流域尺度上植被生产力的精确模拟提供借鉴和参考。

Aims Net primary production (NPP) is plant community production and is the basis of matter and energy cycles of ecosystems. The aim of this study is to accurately simulate NPP on the watershed scale in an area of desertification using simulated results of accumulated soil water replenishment and net radiation.

Methods Using a digital elevation model (DEM) at 30 m×30 m spatial resolution, accumulated soil water replenishment was simulated by using the distributed dynamic model of soil water, and net radiation was simulated by using the Penman-Monteith formula. TheNPP model was developed based on NPP data, accumulated soil water replenishment and net radiation. NPP was accurately simulated for the Kaokaolaigou watershed of the sandy desertification area in eastern Erdos Plateau by inputting the simulated results of the accumulated soil water replenishment and net radiation into the NPP model. We tested the simulated NPP results.

Important findings The test of the simulated NPP results shows that the correlation level between measured and simulated values is 0.05 for the fixed dunes, semi-fixed dunes and sample line 2 and simulated and measured values are in close agreement. The range of relative error between simulated and measured values is 3.22%-6.27%, and the range of skewness between simulated and measured values is from -12.84% to 4.43%. Results show that NPP is different on different slopes and aspects. The NPP decreased from 233.39 to 112.91 g DW·m^-2·a^-1 when the slope increased from 0° to 20°, the maximumNPP of 283.21 g DW·m^-2·a^-1 occurred on flatland and the minimum NPP of 101.68 g DW·m^-2·a^-1 occurred on the south aspect. In conclusion, the NPP model can be used to simulate the distribution of NPP. This research method may allow precise simulation of NPP on a watershed scale.