Effects of lower pruning on water interception of trees
ZHU Zhijun, NIU Jianzhi, XU Jun
1. Beijing Forestry University, School of Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, 100083, Beijing, China;
2. Beijing Collaborative Innovation Center for Eco-environmental Improvement with Forestry and Fruit Trees, 102206, Beijing, China
Abstract:[Background] Lower pruning is one mainly method of forest tending. Canopy interception is an important process of forest hydrological cycle. Lower pruning can effectively change the characteristics of canopy interception. Few researches focus on this aspect. In this study, 6 kinds of typical Beijing mountain afforestation tree species Platycladus orientalis, Pinus tabuliformis Carr., Quercus variabilis Blume, Acer elegantulum Bunge, Pinus bungeana Zucc. and Cotinus coggygria Scop. are used to be the research objects, exploring the way of lower pruning treatments for characteristics changes in the canopy interception.[Method] The method of indoor simulated rainfall was adopted in the experiment. An equipment of canopy interception measurement was made to measure the amount of water interception. There are three parts of the equipment, a bench scale to measure the weight, a metal rain cover to block rain drops and barbed wire to put litters. We put the pot with experimental trees on the bench scale and then start raining. We read the weight on bench scale every 30 seconds. After one hour's raining, continue reading the weight until the weight reading was unchanged. In this research we used weight to express the canopy interception. The final weight reading is the minimum interception(Cmin) of the tree. The maximum of bench scale during the raining is called the maximum interception(Cmax). We can get the data of canopy interception with higher precision in this way. After lower pruning, put trees on the equipment under the rainfall device to repeat experiment. After that, tree litters were put on the barbed wire. The thickness was 2 cm. We repeated the rainfall experiment.[Results] 1) Lower pruning treatment influenced the conifer's canopy interception more than that of broad-leaved tree. The maximum interception of coniferous species decreased by more than 50%. However broad-leaved tree species decreased by less than 20%. 2) The interception ability of the lower layer leaves of broad-leaved trees was much stronger than that of the lower branches. While the interception ability of the lower and lower leaves of the coniferous trees was equal. The interception percentage of lower leaves of coniferous species was significantly less than that of broad-leaved species (P<0.05). Therefore, the interception percentage of lower branches was opposite. 3) After laying tree litters of 2cm, the difference of the maximum interception and the minimum interception between before and after lower pruning was below 10%.[Conclusions] The results show that the interception characteristics of coniferous and broad-leaved canopy vary with the intensity of the lower pruning, which is mainly reflected in that the coniferous tree species has stronger response strength than the broad-leaved tree species. Laying litters under the forest may effectively reduce the influence of lower pruning on the flow of trees.
王佑民. 我国林冠降水再分配研究综述(Ⅰ)[J]. 西北林学院学报, 2000, 15(3):1. WANG Youmin. Review of research on China's precipitation redistribution(Ⅰ)[J]. Journal of Northwest Forestry College, 2000, 15(3):1.
YOSHINOBU S, TOMO'OMI K, ATSUSHI K, et al. Experimental analysis of moisture dynamics of litter layers:The effects of rainfall conditions and leaf shapes[J]. Hydrological Processes, 2004, 18(16):3007.
[4]
LI X, NIU J, XIE B. Study on Hydrological Functions of Litter Layers in North China[J]. Plos One, 2013, 8(7):e70328.
[5]
KEIM R F, SKAUGSET A E, WEILER M. Storage of water on vegetation under simulated rainfall of varying intensity[J]. Advances in Water Resources, 2006, 29(7):974.
[6]
LEVIA D F, MICHALZIK B, NÄTHE K, et al. Differential stemflow yield from European beech saplings:the role of individual canopy structure metrics[J]. Hydrological Processes, 2015, 29(1):43.
[7]
DUNKERLEY D. Percolation through leaf litter:What happens during rainfall events of varying intensity[J]. Journal of Hydrology, 2015, 525:737.
[8]
HERWITZ S R. Interception storage capacities of tropical rainforest canopy trees[J]. Journal of Hydrology, 1985, 77(1/2/3/4):237.
[9]
WANG A, DIAO Y, PEI T, et al. A semi-theoretical model of canopy rainfall interception for a broad-leaved tree[J]. Hydrological Processes, 2010, 21(18):2458.
[10]
GEIΒLER C, LANG A C, VON O G, et al. Impact of tree saplings on the kinetic energy of rainfall:The importance of stand density, species identity and tree architecture in subtropical forests in China[J]. Agricultural & Forest Meteorology, 2012, 156(2/3):31.
[11]
LEHR J H, KEELEY J, LEHR J, et al. Water encyclopedia:surface and agricultural water[M]. John Wiley & Sons Inc, 2005:1.
[12]
张振宽. 人工中幼林抚育管理技术[J]. 现代农业科技, 2013(19):200. ZHANG Zhenkuan. Management technology of artificial middle and young forest tending[J]. Modern Agricultural Sciences and Technology, 2013(19):200.
[13]
王勇, 乔永, 孙向阳. 鹫峰国家森林公园土壤系统分类研究[J]. 北京林业大学学报, 2010, 32(3):217. WANG Yong, QIAO Yong, SUN Xiangyang. Classification of Jiufeng Forest Park soil system[J]. Journal of Beijing Forestry University 2010, 32(3):217.
[14]
徐军, 牛健植. 北京鹫峰山区常见树种的枝叶及枯落物截留特征[J]. 水土保持学报, 2016, 30(1):103. XU Jun, NIU Jianzhi. The foliage and litter interception characteristics of common tree species in Jiufengshan Mountain Area of Beijing[J]. Journal of soil and water conservation, 2016, 30(1):103.
[15]
霍云梅, 毕华兴, 朱永杰,等. QYJY-503C人工模拟降雨装置降雨特性试验[J]. 中国水土保持科学, 2015, 13(2):31. HOU Yunmei, BI Huaxing, ZHUN Yongjie, et al. Characteristics of artificial rainfall produced by QYJY-503C simulation system[J]. Science of Soil and Water Conservation, 2015, 13(2):31.
[16]
李嵩, 王冀. 北京市短历时强降水变化特征及未来预估[C]. 中国气象学会年会, 2011:12. LI Song, WANG Ji. Characteristics and future prediction of short diachronic precipitation in Beijing[C]. Annual Meeting of the China Meteorological Society, 2011:12.
[17]
徐军. 林冠和枯落物结构对水分截留和溅蚀的影响[D]. 北京:北京林业大学, 2016:47. XU Jun. Effects of the structure of canopy and litter on water retention and splash erosion[D]. Beijing:Beijing Forestry University, 2016:47.
[18]
范世香, 高雁, 程银才,等. 林冠对降雨截留能力的研究[J]. 地理科学, 2007, 27(2):200. FAN Shixiang, GAO Yan CHENG Yincai, et al. Study on rainfall interception ability of forest canopy[J]. Scientia Geographica Sinica, 2007, 27(2):200.
[19]
王金叶. 森林生态水文过程研究[M]. 北京:科学出版社, 2008:28. WANG Jinye. Study on ecological hydrological process of forest[M]. Beijing:Science Press, 2008:28.