黄河三角洲白蜡人工林小气候特征的时空动态变化

Spatial Temporal Variation Process of Microclimate Characteristics of Fraxinus chinensis Plantation in the Yellow River Delta

在山东省盐碱地造林试验站的12年生白蜡人工林内(山东黄河三角洲森林生态系统定位研究站的定位观测样地),设有25 m综合梯度观测塔(包含森林小气候观测系统),在高度1.5、3.5、11.0、13.0 m处分别设置4层气象传感器(空气温度、相对湿度、风速传感器),在高度3.5、11.0 m处设有两层四分量辐射传感器。于2015年3月—2016年2月,每个月份选择3个晴天代表日,按照数据采集频率为10 min的间隔24 h不间断采集数据,分析黄河三角洲地区白蜡人工林小气候特征的时空动态变化。结果表明:一年中,冠层内太阳辐射始终低于冠层上,冠层内年均太阳辐射可降低84.91%;林冠层在4月份表现出一定的保温作用,7月份表现出一定的负作用;一年中,观测塔高度3.5 m处的湿度基本高于观测塔高度11.0、13.0 m处的湿度,且4个月(4、7、10月份和次年1月份)的日变化特征显示林冠层夜间增湿作用明显;不同高度的风速,从大到小依次为13.0 m高处、11.0 m高处、1.5 m高处、3.5 m高处,林冠层年均可降低风速73.54%。

We set an integrated gradient observation tower of 25-m high including forest microclimate observation system in a 12-year Fraxinus chinensis plantation（the sample plots of Forest Ecosystem Research Station of the Yellow River delta in Shandong）stand at Saline-Alkaline Land Afforestation Experimental Station of Shandong Province,and there were four-layer meteorological sensors（sensors of air temperature,relative air humidity and wind speed）at the high of 1.5,3.5,11.0,13.0 m,and two layer four-component radiation sensor at 3.5,and 11.0 m.In March 2015-February 2016,we chose three sunny typical days from every month,and collected data for 24 h continuously with 10 min acquisition frequency,and analyzed the spatial temporal variation process of microclimate characteristics of Fraxinus chinensis plantation in the Yellow River delta.The solar radiation within canopy were lower than that of the above canopy all the year,and the average annual solar radiation could be reduced by 84.91%.The canopy showed a certain heat-preservation function in April,but negative effect in July.All the year round,the relative air humidity of 3.5 m were almost higher than 11 and 13 m,and the canopy showed the humidifying obviously at night from the diurnal variation of the chosen 4 months.The sequence of wind velocity of different height in a descending order of the height of 13,11,1.5 and 3.5 m,and the canopy could reduce the wind velocity by 73.54%.