大兴安岭南段天然白桦次生林蒸散特征研究

发布时间：2018-06-21 03:28

本文选题：天然白桦次生林 + 蒸散特征　；参考：《内蒙古农业大学》2017年硕士论文

【摘要】：森林蒸散是森林生态系统水分循环中至关重要的一部分。为研究半干旱区天然白桦次生林蒸散特征变化,本论文以赛罕乌拉生态站的天然白桦次生林为研究对象,从乔木蒸腾、灌木与草本蒸腾、土壤与枯落物蒸发过程出发,研究大兴安岭南段天然白桦次生林蒸散特征。同时,利用内蒙古赛罕乌拉森林生态系统国家级定位观测研究站(简称:赛罕乌拉森林生态站)的气象数据、白桦树干液流数据与植被、土壤实测数据,建立潜在蒸散(ET0)与实际蒸散(ET)的分析模型。主要研究结果如下:(1)2016年生长季内5～9月单株白桦树干液流速率变化总体趋势为单峰曲线或多峰曲线,5月份的树干液流速率日变化特征是夜间大于白天。5～9月树干液流最高分别为 1.84 g·cm-2·h-1、17.76 g·cm-2·h-1、18.95g·cm-2·h-1、11.43g·cm-2·h-1、4.54g·c·cm-2·h-1。晴天的液流速率阴天的液流速率雨天的液流速率,在晴天时,白桦单木树干液流速率总体趋势是6月8月7月5月9月,阴天、雨天的液流速率月份差异不明显。天然白桦次生林单木树干液流变化范围为0.48～52.76L/d。(2)2016年生长季内5～9月天然白桦次生林蒸散总量为209.29mm,不同月份的蒸散量变化总体趋势为7月6月8月9月5月,7月份的蒸散量最大,并且具体数值为60.12mm,9月份蒸散量为27.09mm,6月与8月相差不大分别为55.22mm、44.39mm,5月的蒸散量为22.47mm。天然白桦次生林每月乔木层蒸腾量所占总蒸散的73.70%,灌木层蒸腾量占总蒸散量的1.00%,草本层蒸腾量占总蒸散量比率为15.83%,土壤层与枯落物层占总蒸散量的9.48%。(3)通过对天然白桦次生林蒸腾与气象因子的相关性分析,得出结论为,天然白桦次生林蒸腾速率与冠层净辐射、空气温度、风速有显著的正相关性,天然白桦次生林蒸腾速率与空气湿度有显著的负相关性。(4)通过对天然白桦次生林潜在蒸散(ET0)计算,并与实际观测蒸散量(ET)的建立回归模型。同时,使用部分数据对其进行模拟检验,最大的相对误差为9.430%,最小的相对误差为0.33%,平均相对误差为4.22%,显示模拟效果较好。
[Abstract]:Forest evapotranspiration is an important part of forest ecosystem water cycle. In order to study the change of evapotranspiration characteristics of natural Bai Hua secondary forest in semiarid region, this paper took the natural Bai Hua secondary forest of Saihanula ecological station as the research object, based on the evaporation process of tree transpiration, shrub and herbaceous transpiration, soil and litter. The evapotranspiration characteristics of natural Bai Hua secondary forest in the southern part of Daxing'an Mountains were studied. At the same time, the meteorological data, dry liquid flow data of birch tree, vegetation and soil measured data were used from the National Positioning observation Research Station of Saihanula Forest ecosystem in Inner Mongolia (abbreviated as Saihanula Forest Ecological Station). The analysis models of potential evapotranspiration et 0) and actual evapotranspiration et 0) were established. The main results are as follows: (1) during the growing season of 2016, the general trend of the variation of dry liquid flow rate of single birch tree during May ~ September is that the diurnal variation of sap flow rate in May is larger than that in May. The highest sap flow was 1.84 g cm-2 h-1 (17.76 g cm-2 h-1) 18.95 g cm-2 h-1 (11.43g cm-2 h-1) 4.54g c cm-2 h-1. Liquid flow rate on cloudy days. On sunny days, the general trend of sap flow rate in single tree trunk of Bai Hua is June, August, July, May, September, June, August, May, September. There is no significant difference in liquid flow rate between cloudy and rainy days. The total evapotranspiration of natural Bai Hua secondary forest was 209.29mm in May ~ September in 2016. The general trend of evapotranspiration in different months was July, August, May, July, May, July. The largest amount of evapotranspiration, The evapotranspiration was 27.09 mm in September, 55.22 mm in June and 44.39 mm in August. The evapotranspiration in May was 22.47 mm. Natural Bai Hua secondary forest accounts for 73.70% of total evapotranspiration in tree layer, 1.00% of total evapotranspiration in shrub layer, 15.83% in herbaceous layer, 9.48% of total evapotranspiration in soil layer and litter layer. Correlation analysis of transpiration and meteorological factors in Bai Hua secondary forest, It was concluded that the transpiration rate of natural Bai Hua secondary forest was positively correlated with net canopy radiation, air temperature and wind speed. There was a significant negative correlation between transpiration rate and air humidity in natural Bai Hua secondary forest. 4) the potential evapotranspiration (ET0) of natural Bai Hua secondary forest was calculated and the regression model was established with the observed evapotranspiration. The maximum relative error is 9.430, the minimum relative error is 0.33, and the average relative error is 4.22.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S715

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