Application of the process-based model BIOMASS to Eucalyptus globulus subsp. globulus plantations on ex-farmland in south western Australia: I. Water use by trees and assessing risk of losses due to drought
Application of the process-based model BIOMASS to Eucalyptus globulus subsp. globulus plantations on ex-farmland in south western Australia: I. Water use by trees and assessing risk of losses due to drought
复制标题
基于过程的模型 BIOMASS 在蓝桉亚种中的应用。
DOI：
10.1016/s0378-1127(97)00305-8
复制
发表时间：
1998
影响因子：
3.7
通讯作者：
G. Dimmock
中科院分区：
文献类型：
--
作者：
F. Hingston;J. Galbraith;G. Dimmock
基于过程的模型 BIOMASS (McMurtrie, R.E., Rook, D.A., Kelliher, F.M., 1990a. 在水和氮限制的地点对辐射松的产量进行建模。For. Ecol. Manage. 30, 381–413) 用于模拟生长在地中海气候区西南部的五个蓝桉种植园的水平衡。澳大利亚。使用中子水分计测量的土壤含水量变化的季节模式与其中两个地点的模拟结果非常吻合。在这些地点，土壤储存可用水的能力是明确的。在一种情况下，土壤储水能力受到土壤到基岩的深度的限制，而在另一种情况下，则受到到不可渗透的硅质硬土的深度的限制。在另外两个土壤较深的地点，对土壤含水量季节性变化的测量表明，根部从至少 6 m 深处吸取水分。模拟的地表3 m深度土壤含水量与冬春季节的测量值吻合较好，但低于夏末/秋季节的测量值。这表明该模型在模拟不同深度土壤水提取的分配方面并不完全成功。使用 BIOMASS 模型的早期版本（McMurtrie 等人，1990a）和修改版本（McMurtrie, R.E.、Leuning, R.、Thompson, W.A.、Wheeler, A.M., 1992）模拟土壤含水量变化之间存在微小差异。冠层光合作用和水分利用模型结合了叶片 CO2 交换的机械公式。For.Ecol.管理 52, 261–278）。差异是由于估计冠层平均最大气孔传导率 (Gc) 的不同假设造成的。在该模型的早期版本中，假设所有种植园的 Gc 均为常数值。然而，在修改后的版本中，Gc 对每个种植园进行了集成的 C 同化，这又取决于树冠中遮荫叶子的比例。使用修改后的版本进行的模拟与测量的土壤含水量更加一致。在第五个地点，根部可以进入 3 m 深的地下水位，模拟的土壤含水量季节模式与测量估计值之间的一致性很差。实测土壤含水量远高于模拟值。这一现象可以通过地下水位上方毛细管边缘的水向上运动来解释。 BIOMASS 模型成功模拟了种植园的土壤含水量，可以定义土壤深度和土壤储水量，这表明该模型有潜力评估这些地点因干旱造成的树木死亡风险。讨论了与降雨及其季节分布、土壤储水量和叶面积指数的影响相关的风险。
The process-based model BIOMASS (McMurtrie, R.E., Rook, D.A., Kelliher, F.M., 1990a. Modelling the yield of Pinus radiata on a site limited by water and nitrogen. For. Ecol. Manage. 30, 381–413) was applied to simulate the water balance at five plantations of Eucalyptus globulus growing in the Mediterranean climatic region in the southwest of Australia. Seasonal patterns of variation of soil water content, measured using a neutron moisture meter, were in good agreement with simulations for two of the sites. At these sites the capacity of the soils to store available water was well defined. In one case the soil water storage capacity was limited by the depth of soil to basement rock, while in the other it was limited by the depth to impenetrable siliceous hardpan. At another two sites, where the soils were deep, measurements of seasonal changes in soil water content showed that roots extracted water from at least 6 m depth. The soil water contents simulated for the surface 3 m depth agreed well with measurements for the winter/spring period but were lower than measured values for the late summer/autumn period. This suggests that the model was not completely successful in simulating partitioning of soil water extraction from different depths. There were small differences between the simulations of variation in soil water content using the earlier version of the BIOMASS model (McMurtrie et al., 1990a) and the modified version (McMurtrie, R.E., Leuning, R., Thompson, W.A., Wheeler, A.M., 1992. A model of canopy photosynthesis and water use incorporating a mechanistic formulation of leaf CO2exchange. For. Ecol. Manage. 52, 261–278). The differences are due to different assumptions for estimating the average maximum stomatal conductivity (Gc) of the canopy. In the earlier version of the model, a constant value of Gcwas assumed for all plantations. However, in the modified version Gcvaried with integrated C assimilation for each plantation, which in turn depended on the proportion of shaded leaves in the canopy. Simulations using the modified version agreed more consistently with measured soil water contents. At a fifth site, where roots would have access to a watertable at 3 m depth, the agreement between the simulated seasonal pattern of soil water content and values estimated from measurements was poor. Measured soil water contents were much higher than those simulated. This observation is explained by upward movement of water in the capillary fringe above the watertable. The success of the BIOMASS model in simulating soil water contents at plantations where the soil depth, and therefore soil water storage, can be defined, suggests the model has potential for assessing the risk of tree mortality due to drought on these sites. The risk is discussed in relation to effects of rainfall and its seasonal distribution, soil water storage and leaf area index.