| 引用本文: | 牛永强,吴喆滢,徐文娴,等.马占相思幼树雨季液流速率对环境因子的响应[J].灌溉排水学报,2021,(5):62-68. |
| NIU Yongqiang,WU Zheying,XU Wenxian,et al.马占相思幼树雨季液流速率对环境因子的响应[J].灌溉排水学报,2021,(5):62-68. |
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| 摘要: |
| 【目的】揭示幼龄马占相思液流速率变化特征及其与环境因子关系，为马占相思人工林可持续经营提供理论依据。【方法】2014年6—10月利用Dynagage包裹式液流传感器和DL2e环境因子测量系统，对海南西部人工林幼龄马占相思液流速率及主要环境因子进行连续监测，研究了幼龄马占相思液流速率变化特征其与环境因子的关系。【结果】晴天和阴天马占相思树干液流速率日变化总趋势基本相同，呈现出较快上升-峰值-波动下降的趋势，晴天、阴天日平均液流速率分别为3.07 mL/(cm2?h)和1.59 mL/(cm2?h)；而雨天液流速率变化较为平缓，变化规律不明显，日平均液流速率为0.78 mL/(cm2?h)。晴天马占相思液流速率最大值出现在09:00左右，“蒸腾午休”现象显著；而阴天、雨天液流速率最大值出现的时间延后，“蒸腾午休”不明显或不存在。晴天马占相思液流速率变化主要受饱和水汽压差、空气相对湿度、气温影响，阴天主要受气温、饱和水汽压差、光合有效辐射影响，而雨天主要受光合有效辐射和气温的影响。【结论】马占相思液流存在明显昼夜节律，液流速率峰值早于光合有效辐射峰值，且光合有效辐射越强，液流速率峰值出现时间越早；晴天、阴天、雨天3种天气条件下，对液流速率影响最大的环境因子分别为饱和水汽压差、气温和光合有效辐射。 |
| 关键词: 包裹式液流传感器；马占相思；液流速率；环境因子 |
| DOI：10.13522/j.cnki.ggps.2019472 |
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| The Response of Sap Flow in Young Acacia Mangium to Environmental Changes During Rainy Season in Hainan |
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NIU Yongqiang, WU Zheying, XU Wenxian, HAN Qi, ZHAO Congju
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1. Danzhou Forest Farm, Danzhou 571749, China; 2. School of Life Sciences, Hainan Normal University, Haikou 571158, China; 3. School of Geography and Environment Science, Hainan Normal University, Haikou 571158, China
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| Abstract: |
| 【Objective】Sap flow in plant is modulated by many biotic and abiotic factors, and the objective of this paper is to study how sap flow in young Acacia mangium responds to environmental changes during rainy season in Hainan province of south China. 【Method】The experiment was conducted at Danzhou forest farm in western Hainan; sap flow in young Acacia mangium and changes in its immediate surrounding environment were measured continuously using the Dynagage sap flow sensor and DL2e environmental data acquisition systems, respectively, from June to October in 2014. The relationship between the sap flow and the environmental factors was analyzed using different methods. 【Result】In sunny or cloudy days, the sap flow showed diurnal variation, increasing to a peak followed by a oscillating decline, with a daily average of 3.07 mL/(cm2·h) and 1.59 mL/(cm2·h) respectively. In contrast, the sap flow in rainy days varied gently with a daily average of 0.78 mL/(cm2·h). The sap flow peaked at 09:00 in the morning on sunny days characterized by a noticeable transpiration plateau, while cloudy or rainy days delayed the arrival of the sap-flow peak and blurred the transpiration plateau. Path analysis showed that in sunny days the change in sap flow was affected mainly by water vapor pressure deficit (VPD), air relative humidity (RH) and air temperature (Ta), while in cloudy days it was affected by Ta, VPD and photosynthetically active radiation (PAR) more. On rainy days, PAR and Ta impacted on the sap flow most.【Conclusion】The sap flow in young Acacia mangium shows diurnal variation, and it peaks ahead of PAR. The stronger the PAR is, the earlier the sap flow peaks. On sunny, cloudy or rainy days, the dominant factor affecting the sap flow is VPD, Ta, and PAR, respectively. |
| Key words: dynagage sap flow sensors; Acacia mangium; sap flow velocity; environmental factors |
