植物生态学报 ›› 2022, Vol. 46 ›› Issue (12): 1508-1522.DOI: 10.17521/cjpe.2022.0099

• 中国典型生态脆弱区碳水通量过程研究专题论文 • 上一篇    下一篇

辽西半干旱地区两种典型人工林生态系统能量通量及蒸散特征

王俐爽1, 同小娟1,*(), 孟平2, 张劲松2, 刘沛荣1, 李俊3, 张静茹1, 周宇2   

  1. 1北京林业大学生态与自然保护学院, 北京 100083
    2中国林业科学研究院林业研究所, 北京 100091
    3中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室, 北京 100101
  • 收稿日期:2022-03-18 接受日期:2022-06-15 出版日期:2022-12-20 发布日期:2023-01-13
  • 通讯作者: *同小娟(tongxj@bjfu.edu.cn)
  • 基金资助:
    国家重点研发计划(2020YFA0608101);国家自然科学基金(31872703);国家自然科学基金(31570617)

Energy flux and evapotranspiration of two typical plantations in semi-arid area of western Liaoning, China

WANG Li-Shuang1, TONG Xiao-Juan1,*(), MENG Ping2, ZHANG Jin-Song2, LIU Pei-Rong1, LI Jun3, ZHANG Jing-Ru1, ZHOU Yu2   

  1. 1School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
    2Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
    3Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2022-03-18 Accepted:2022-06-15 Online:2022-12-20 Published:2023-01-13
  • Contact: *TONG Xiao-Juan(tongxj@bjfu.edu.cn)
  • Supported by:
    National Key R&D Program of China(2020YFA0608101);National Natural Science Foundation of China(31872703);National Natural Science Foundation of China(31570617)

摘要:

在气候变暖背景下, 半干旱地区林水矛盾日益突出。了解该区人工林的能量通量和蒸散(ET)变化, 可为今后造林树种的选择提供参考。该研究采用涡度相关法分别对辽西半干旱地区油松(Pinus tabuliformis)、樟子松(Pinus sylvestris var. mongolica)人工林的水热通量进行了一年(2019年10月至2020年10月)的连续观测, 利用界限温度结合归一化植被指数(NDVI)的变化特征确定了生长季长度(4月11日至10月10日), 分析了潜热通量(LE)、感热通量(H)、净辐射(Rn)、土壤热通量(G)及ET的季节动态, 利用回归分析和通径分析探讨了气温(Ta)、Rn、空气水汽压亏缺(VPD)、土壤含水量(SWC)、NDVI对ET的影响。结果表明: 油松、樟子松人工林的Rn、G、H都呈单峰形季节变化趋势, LE的波动更剧烈。全年来看, 能量消耗以H为主, 其次是LE, G消耗的能量较少。波文比生长季均值分别为1.82和2.23, 小于年平均值(3.43和4.44)。生长季ET分别为302.79和247.54 mm, 占全年ET的82.89%和84.20%; 年ET分别为365.29和293.99 mm, 为同期降水量的87.81%和72.23%。Priestley-Taylor系数(α)和退耦因子(Ω)可以用来说明SWC和冠层导度(gc)对ET的影响。油松、樟子松人工林的α年平均值分别为0.30和0.24, Ω分别为0.12和0.07。全年来看, SWC是影响该区两种人工林ET的主导因子, 其次为Rn。在不受水分胁迫下, Rn对ET影响更大; Ta和VPD对ET的综合影响较小, 多为间接作用。NDVI和gc是影响两种人工林的ET的重要生物因子, 对ET的控制作用在生长季更为明显。该研究说明辽西半干旱地区的油松和樟子松人工林都采取保守的耗水策略, 维持了生态系统的水量平衡, 是该地区适宜的造林树种。

关键词: 半干旱地区, 人工林, 能量通量, 蒸散, 生物环境因子

Abstract:

Aims Under the background of climate warming, the contradiction between forest and water in semi-arid areas is becoming increasingly prominent. Understanding the changes in energy flux and evapotranspiration (ET) of the plantation ecosystems in this area can provide a reference for future selection of afforestation tree species.

Methods In this paper, the water and heat fluxes of Pinus tabuliformis and Pinus sylvestris var. mongolica plantations in semi-arid area of western Liaoning were observed continuously for one year (October 2019 to October 2020) using the eddy covariance method. The length of growing season (April 11 to October 10) was determined using the critical temperature combined with the variation characteristics of normalized differential vegetation index (NDVI). The seasonal dynamics of latent heat flux (LE), sensible heat flux (H), net radiation (Rn), soil heat flux (G) and ET were analyzed. The effects of air temperature (Ta), Rn, vapor pressure deficit (VPD), soil water content (SWC), and NDVI on ET were discussed by applying regression analysis and path analysis.

Important findings The Rn, G and H of P. tabuliformis and P. sylvestrisvar. mongolica plantations showed single-peak seasonal variation trends, and the seasonal dynamics of LE fluctuated more sharply. During the whole year, energy consumption was dominated by H, followed by LE, and G consumed less energy. The average values of Bowen ratio during the growing season were 1.82 and 2.23, respectively, smaller than annual average values (3.43 and 4.44). The ET during the growing season was 302.79 and 247.54 mm, accounting for 82.89% and 84.20% of the annual ET, respectively. The annual ET was 365.29 and 293.99 mm accounting for 87.81% and 72.23% of precipitation in the same period. Priestley-Taylor coefficient (α) and decoupling factor (Ω) were used to analyze the effects of SWC and canopy conductance (gc) on ET. The annual mean values ​​of α was 0.30 and 0.24, respectively, and the Ω values was 0.12 and 0.07, respectively. During the whole year, SWC was the dominant factor affecting the ET of two plantations, followed by Rn. Under non-water-stressed conditions, Rn had a greater impact on ET.The combined effects of Ta and VPD on ET were small, which were mostly indirect effects. NDVI and gc were important biological factors affecting the ET of the two plantations, especially during the growing season. This study shows that P. tabuliformis and P. sylvestrisvar. mongolica plantations in the semi-arid area of western Liaoning Province adopt a conservative water consumption strategy to maintain water balance of the ecosystem, and these species are suitable afforestation tree species in this area.

Key words: semi-arid region, plantation, energy flux, evapotranspiration, bioenvironmental factor