| 摘要: |
| 【目的】正确认识粗皮桉林分的蒸腾耗水特征，明确环境和林分结构变化对其蒸腾的影响，建立蒸腾多因素集成模型，为桉树产业的可持续经营管理和水资源高效利用提供理论依据。【方法】以雷州半岛地区12年生的粗皮桉为研究对象，采用热扩散探针技术连续监测其液流速率，并通过尺度转换，探讨粗皮桉林分日蒸腾耗水的季节变化特征，同时采用回归分析，明确潜在蒸散（ETP）、土壤含水量（CSW）和叶面积指数（ILA）与林分日蒸腾耗水量（Qd）的独立关系，并利用连乘方程形式构建了Qd的多因素集成模型。【结果】① 粗皮桉林分的年蒸腾耗水量为743.4 mm，Qd呈先增大后减小的季节变化趋势，雨季（5－10月）蒸腾耗水量为456.5 mm，占年蒸腾耗水量的61.41%，但仅占同期降雨量的34.95%，旱季该比例增加到105.01%。② Qd随ETP呈凸抛物线函数增长，而随ILA和CSW均呈饱和指数函数增长，且均存在阈值效应。③ Qd与ETP、CSW和ILA耦合得到的多因素集成模型可解释粗皮桉高度分散Qd的87%以上，拟合精度较单因素显著提高。【结论】雨季虽是粗皮桉蒸腾耗水的主要时期，但旱季的林水矛盾更为突出，因此应加强粗皮桉旱季的水分管理；此外，粗皮桉的多因素集成模型不但拟合精度更高，还可用于预测因粗皮桉生长和林分管理措施引起的冠层结构变化后的蒸腾量，评估未来全球气候变化对粗皮桉林分蒸腾的影响，应用前景更为广泛。 |
| 关键词: 粗皮桉 蒸腾耗水 潜在蒸散 土壤含水量 叶面积指数 |
| DOI：10.13207/j.cnki.jnwafu.2025.07.007 |
| 分类号: |
| 基金项目:“十四五”国家重点研发计划项目（2023YFD2201005）；广西重点研发计划项目（桂科AB23026010）；广东省林业科技创新项目（2022KJCX020）；广东湛江桉树林生态系统国家定位观测研究站运行项目（KS2024160017）；林业生态监测网络平台运行项目（2024CG232） |
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| Characterizing and modeling the transpiration water use of Eucalyptus pellita on Leizhou Peninsula,South China |
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LIU Yusheng, DU Apeng, CAO Haoyang, XU Yuxing, ZHU Wankuan, HUANG Runxia, WANG Zhichao
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Research Institute of Fastgrowing Trees,Chinese Academy of Forestry,National Positioning Observation and Research Station of Eucalyptus Forest Ecosystem in Zhanjiang,Zhanjiang,Guangdong 524022,China
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| Abstract: |
| 【Objective】This research aimed to correctly understand the characteristics of transpiration and water consumption in Eucalyptus pellita forest stands,to clarify the effects of environmental and stand structure changes on transpiration,and to establish a multifactorial integrated model of transpiration,so as to provide a theoretical basis for the sustainable management of the eucalyptus industry and the efficient use of water resources.【Method】The 12-year-old rough-skinned E. pellita in the Leizhou Peninsula area were used as study object,and the heat diffusion probe technique was used to continuously monitor their sap flow rate.The scale conversion was used to explore seasonal variation characteristics of daily transpiration and water consumption of E.pellita forest stands,while regression analyses were used to clarify the independent relationships between the potential evapotranspiration (ETP),the soil moisture content (CSW),the index of leaf area (ILA) and the daily transpiration water consumption (Qd).A multi-factor integrated model of Qd was also constructed by using the equation of the chain of multipliers.【Result】① The annual evapotranspiration water consumption of E. pellita forest stands was 743.4 mm,and Qd increased firstly and then decreased seasonally.The transpiration water consumption in the rainy season (from May to October) was 456.5 mm,which accounted for 61.41% of the annual evapotranspiration water consumption.It only accounted for 34.95% of the rainfall of the rainy season,which was increased to 105.01% in the dry season.② Qd increased as a convex parabolic function with ETP,and increased as a saturated exponential function with both ILA and CSW.A threshold effect can be observed in all of them.③ The multifactorial integrated model obtained by coupling Qd with ETP,CSW and ILA could explain more than 87% of the highly dispersed Qd of E. pellita,and the fitting accuracy was significantly improved compared with that of a single factor.【Conclusion】Although the rainy season is the main period of transpiration and water consumption of E. pellita,the forest water conflict is more prominent in the dry season.The water management of E. pellita should be strengthened in the dry season.In addition,the multifactorial integrated model of E. pellita not only has a higher fitting accuracy,but also can be used to predict the transpiration of E. pellita after changes in the canopy structure caused by the growth of E. pellita and the stand management measures,as well as to assess the impacts of the global climate change on E. pellita transpiration.Its application prospect is much more promising. |
| Key words: Eucalyptus pellita transpiration water consumption potential evapotranspiration soil moisture content leaf area index |
