施加氮肥与去除灌草措施对杉木人工林水分利用效率的影响

发布时间：2018-04-15 23:07

本文选题：经营措施 + 杉木人工林　；参考：《南昌工程学院》2017年硕士论文

【摘要】：近几十年来,人工林在我国森林面积所占的比重越来越来大。人工林面积扩张对区域水资源的影响是当前关注的焦点问题,尤其是在当前全球气候变化背景下,如何科学地经营人工林,更加高效的利用水资源,已经成为人工林经营管理一个非常重要的研究方向。为此,本研究选择亚热带地区具有代表性的杉木人工林为研究对象,从叶片、单木、林分尺度上,以不进行处理的杉木林为对照,探讨施加氮肥、去除灌草和两者复合(施肥+除草)措施对水分利用效率的影响,以期为科学评估人工林耗水提供基础数据。通过1年的监测(2015年6月—2016年7月),取得了以下研究结果:(1)去除灌草措施没有对叶片的气孔导度产生显著的影响,而施加氮肥措施和施加氮肥与去除灌草复合措施使叶片的气孔导度提升了56.74%和55.29%,达到了显著水平(P0.05)。(2)去除灌草对叶片叶绿素的含量没有明显的影响,施加氮肥与施加氮肥结合去除林下植被的措施则显著的提高了叶片叶绿素含量,叶绿素含量分别增加了14.8%和16.3%。(3)去除灌草后土壤水分的蒸发量增加了58.51%,施加氮肥并去除灌草后蒸发量增加了68.50%,相比于对照,去除灌草措施和施加氮肥并去除灌草措施增加量达到了显著;施加氮肥后土壤蒸发量相较于对照有所下降,但没有达到显著水平。(4)比较不同季节树干液流平均速率我们发现:夏季春季秋季冬季,春季和冬季的各种经营措施都不会对全天的液流速率产生显著的影响。在秋季晴天去除灌草措施会使液流速率显著减小,在秋季雨天两者的复合(施肥+除草)措施会使液流速率显著减小。夏季施加氮肥的措施会使全天的液流速率显著的大于其他处理措施,特别是在晴天各种处理间的相互差异显著。不同处理下的杉木的年蒸腾量为:未施肥未除草措施368.53mm,去除灌草措施342.25mm,施加氮肥措施397.21mm,施肥并除草措施368.44mm。(5)实验样地不同经营措施杉木人工林水分利用效率为:未施肥未除草措施4.83×10~(-3)m~3/m~3(木材/水),去除灌草措施4.82×10~(-3)m~3/m~3(木材/水),施加氮肥措施4.91×10~(-3)m~3/m~3(木材/水),施肥并除草措施4.86×10~(-3)m~3/m~3(木材/水)。通过分析,添加氮肥的措施可以提高杉木人工林的水分利用效率,去除灌草和施加氮肥与去除灌草相结合的措施都会对杉木人工林的水分利用效率起负面作用。因此,在实际的林业生产活动中可以考虑保留其林下植被,并选择春、秋和冬季进行施肥,从而提高杉木生产的水分利用效率。
[Abstract]:In recent decades, the proportion of plantations in the forest area in China is more and more large.The impact of plantation area expansion on regional water resources is the focus of attention, especially in the context of global climate change, how to manage plantations scientifically and make more efficient use of water resources.It has become a very important research direction of plantation management.Therefore, the representative Chinese fir plantation in the subtropical region was selected as the research object, and the application of nitrogen fertilizer was studied on the scale of leaf, single wood, stand and non-treated Chinese fir forest.The effect of the removal of shrub and the combination of fertilization and herbicide on water use efficiency in order to provide basic data for scientific evaluation of water consumption of artificial forest.After one year of monitoring (June 2015 to July 2016, the following results were obtained: 1) the removal of shrub had no significant effect on the stomatal conductance of leaves.The stomatal conductance of leaves was increased by 56.74% and 55.29% by applying nitrogen fertilizer and the compound measures of nitrogen fertilizer and shrub removal.The application of nitrogen fertilizer combined with nitrogen fertilizer to remove the undergrowth vegetation significantly increased the chlorophyll content of leaves.Chlorophyll content increased by 14.8% and 16.3wt%, respectively.) the evaporation of soil water increased by 58.51% and that of nitrogen fertilizer and irrigation grass increased by 68.50%, compared with the control.The increase of soil evaporation was significantly increased by removing irrigation and applying nitrogen fertilizer, and the soil evaporation was decreased compared with the control after applying nitrogen fertilizer, and the soil evaporation was significantly increased after the application of nitrogen fertilizer, and the increase of soil evaporation was lower than that of the control.Compared with the average rate of sap flow in different seasons, we found that summer, spring, autumn and winter, all kinds of management measures in spring and winter have no significant effect on the rate of sap flow throughout the day.The removal of irrigation grass on sunny days in autumn will significantly decrease the liquid flow rate, and the combination of the two measures (fertilization and weeding) in rainy days in autumn will significantly reduce the liquid flow rate.The application of nitrogen fertilizer in summer made the liquid flow rate of the whole day significantly higher than that of other treatments, especially in sunny days.The annual transpiration of Cunninghamia lanceolata under different treatments was 368.53mm, 342.25mm, 397.21mm and 368.44mm, respectively.Fertilizing without weeding measures 4.83 脳 10 ~ (-3) ~ (3) / m ~ (3) (lumber / water, removal measures 4.82 脳 10 ~ (-1) -3 ~ (-3) / m ~ (3)) (wood / water), applying nitrogen fertilizer measures (4.91 脳 10 ~ (-3)) ~ (3) / m ~ (3) (timber / water), fertilization and weeding measures (4.86 脳 10 ~ (10)) -3 ~ (-3) / m ~ (3) (wood / water).Through the analysis, the measures of adding nitrogen fertilizer can improve the water use efficiency of Chinese fir plantation. The removal of irrigation grass and the combination of nitrogen fertilizer and shrub can all play a negative role in the water use efficiency of Chinese fir plantation.Therefore, in the actual forest production activities, we can consider to retain its undergrowth vegetation, and choose spring, autumn and winter to fertilize, so as to improve the water use efficiency of Chinese fir production.
【学位授予单位】：南昌工程学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S791.27

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