Key variables for simulating leaf area and N status: Biomass based relations versus phenology driven approaches
Key variables for simulating leaf area and N status: Biomass based relations versus phenology driven approaches
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DOI：
10.1016/j.eja.2018.04.008
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发表时间：
2018-10-01
影响因子：
5.2
通讯作者：
Justes, E.
中科院分区：
文献类型：
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作者：
Ratjen, A. M.;Lemaire, G.;Justes, E.
物候发育可以被视为作物的生物钟，作物模型开发人员使用这个时间线来描述与叶面积动态相关的各种过程。临界芽氮浓度（cN（crit），量化作物氮状态的参考）、叶茎分配和比叶面积（SLA）通常被模拟为发育阶段或热时间驱动函数的函数。然而，通过考虑与生物量相关的过程配方，可以更好地纳入环境变化的影响。本文利用已发表的新数据，比较了与冬小麦和玉米叶面积动态相关的过程的模拟，使用（a）BBCH（类似于Zadoks尺度的十进制代码）、xsatge或热时间尺度和（b）基于芽干质量（DM）或叶面积指数（LAI）的替代配方。对于 cNcrit 和叶茎划分，基于 DM 的模型优于发育方法，这反映在较低的 RMSE 上。由于 LAI 和 DM 之间的异速生长联系，叶茎划分和 SLA 不是独立的。因此，LAI 比发育性状更好地解释了冠层 SLA。发育阶段对于确定某些事件（例如从营养发育到生殖发育的转变）是必要的，但我们的结果表明物候学无法捕获 LAI 和 DM 之间的异速生长关系。
Phenological development can be seen as the biological clock of crops and crop model developers used this timeline for describing various processes associated with leaf area dynamics. The critical shoot nitrogen concentration (cN(crit), a reference to quantify crop nitrogen status), leaf-stem partitioning and specific leaf area (SLA) are often simulated as a function of developmental stages or thermal time driven functions. However, the impact of environmental variability might be better incorporated by considering process formulations related to bio-mass.Using published and novel data, this paper compares the simulation of processes associated with leaf area dynamics of winter wheat and maize using (a) BBCH (decimal code similar to the scale of Zadoks), xsatge or thermal time scale and (b) alternative formulations based on shoot dry mass (DM) or leaf area index (LAI). For both cNcrit and leaf-stem partitioning, the model based on DM was superior to the developmental approaches, as reflected in lower RMSE.Owing to the allometric link between LAI and DM, leaf-stem partitioning and SLA are not independent. Consequently, LAI explained canopy SLA better than developmental traits.Developmental stages are necessary to determine certain events like the switch from vegetative to reproductive development, but our results indicate that phenology cannot capture the allometric relationship between LAI and DM.