【作者】 文小莲；

【导师】 文仕知；

【作者基本信息】 中南林业科技大学 ， 水土保持与荒漠化防治， 2010， 硕士

【摘要】 森林植被对于降雨分配和养分循环具有重要意义。本文从森林结构和水文过程出发,通过对大气降水的观测,分析了枫香人工林降水再分配及对养分循环的作用,为深入了解枫香人工林生态系统的生态水文功能提供科学依据。主要结果如下：(1)枫香人工林林冠截留、穿透水和树干茎流,分别占降水总量的29.11%、69.28%、1.62%；月降水条件下,林冠截留量、穿透水量和树干茎流量与大气降水量显著正相关(p<0.01),相关系数分别为0.993、0.925、0.906；随着降水量级的逐渐增大,截留率、穿透率和茎流率相应降低,夏季截留率最大,春季次之,冬季截留率最小；穿透率和茎流率均表现为春季最高、夏季次之,秋季最低。(2)大气降水pH值在5.31-7.24范围内变化,大气降水pH值平均值为6.45,基本成呈中性,观测时段出现3次pH值<5.6的酸雨；大气降水经过枫香人工林冠层后,pH值发生变化,穿透水pH值为6.81,树干茎流pH值为5.85,总体表现为穿透水>大气降水>茎流。(3)观测期间大气降水NH4+-N、NO3--N、PO3-、K、Ca、Mg元素含量(加权平均值)分别为：0.96 mg.L-1、2.29 mg.L-1、0.23 mg.L-1、4.38 mg.L-1、5.02 mg.L-1、0.41 mg.L-1,大小顺序依次为：Ca>K>NO3--N>NH4+-N>Mg>PO3-；大气降水微量元素含量Zn>Fe>Mn>Pb>Cu,含量分别为：0.134 mg.L-1、0.086 mg.L-1、0.038 mg. L-1、0.023 mg. L-1、0.021 mg.L-1,并表现明显的月际和季节变化；大量元素月平均含量与月降水量显著相关(p<0.05),微量元素含量则主要与降水频率有关;大气降水经过枫香人工林冠层后,穿透水、树干茎流大量元素含量增减不一,但总的趋势是大气降水经过枫香人工林林冠层后化学元素含量呈增加趋势,即：树干茎流>穿透水>大气降水。(4)大气降水经过枫香人工林林冠后,穿透水、树干茎流表现明显的养分富集现象,养分淋溶作用明显,并具有不同程度季节变化。穿透水中NH4+-N、N03--N、PO3-年均淋溶系数小于1,呈现负淋溶；K、Ca、Mg年均淋溶系数分别为1.08、3.35、3.29,表现为明显的养分富集作用。树干茎流大量元素中除P03-元素表现为负淋溶外,其它五项元素淋溶系数均大于1,养分富集作用显著。枫香人工林林冠、树干对微量元素具有显著的净化作用,除Mn元素外,枫香人工林穿透水、树干茎流Zn、Cu、Fe、Pb淋溶系数均小于1,表现为负淋溶。更多还原

【Abstract】 Rainfall distribution of forest vegetation and nutrient cycling is important. Enter the forest after rainfall, canopy interception, throughfall and stem-flow water form a new distribution pattern, reflecting the forest canopy on rainfall storing function. Meanwhile, rainfall redistribution, due to trees on chemical precipitation with physical, chemical and biological adsorption, absorption and leaching effects, changed the chemical properties of precipitation, reflecting the trees on the water quality regulation. In this study, forest structure and hydrological process, through an observation of atmospheric precipitation, the nutrient analysis of the precipitation distribution and nutrient cycling, To better understand the nutrient ecosystems to provide the scientific basis for ecological and hydrological functions. The main results are as follows:(1) Liquidambar formosana Plantation canopy interception, throughfall and stem-flow, accounting for the total precipitation 29.11%、69.28%、1.62%; monthly precipitation, canopy interception, throughfall and stem-flow of water and atmospheric precipitation was significantly positive correlated (p<0.01), correlation coefficients were0.993、0.925 and 0.906; With the precipitation level increases, the rate of canopy interception、penetration and stem-flow reduced accordingly; for canopy interception, autumn crown retention largest, followed in spring, winter rate of the minimum; Penetration rate of water flow rate and stem the performance of the highest in spring, summer, second, and lowest in autumn.(2) Precipitation pH value changed in the range of 5.31～7.24, the average precipitation pH value is 6.45, basically as neutral; during observed periods, there was three times acid rain, which pH values is below 5.6; the pH values was changed after through the canopy of Liquidambar formosana Plantation; the throughfall pH value was 6.81 and stem-flow was 5.85, which tendency is:stem-flow> precipitation> throughfall.(3) During observed periods, the mean concentrations (weighted average)of elements of NH4+-N、NO3--N、PO3-、K、Ca、Mg were:0.96 mg. L-1、2.29 mg.L-1、0.23 mg. L-1、4.38 mg. L-1、5.02 mg. L-1、0.41 mg. L-1, The sequence of Ca>K > NO3--N> NH4+-N> Mg> PO3-; sequence of microelements in precipitation was Zn>Fe>Mn>Pb>Cu, concentrations were::0.134 mg. L-1、0.086 mg. L-1、0.038 mg. L-1、0.023 mg. L-1、0.021 mg. L-1, showed obviously seasonal variation; there was significantly correlation between macro-elements concentrations and monthly precipitation (p<0.05), microelements are mainly related with the precipitation frequency; the concentrations of Canopy interception、throughfall and stem flow are changed largely after through the canopy of Liquidambar formosana, but the overall trend is through the canopy of Liquidambar artificial the concentrations of precipitation was increased, which is stem flow> throughfall> precipitation.(4) After through the canopy of Liquidambar formosana Plantation the concentrations chemical element were increased. Throughfall and stem-flow performed significant nutrient enrichment, nutrient leaching significantly, with seasonal variation.the Average coefficient of macro-elements of throughfallless than 1,showed negative eluviate, which were NH4+-N、NO3--N、PO3-; K、Ca、Mg Elements of annual eluviate coefficients were1.08、3.35、3.29, showed significant nutrient enrichment; the macro-elements of stem-flow showed negative eluviate in addition to the PO3- element,which were eluviate coefficient large than 1, stem-flow nutrient enrichment significantly. For microelements,Liquidambar artificial canopy showed significant purification,except Mn element, the elements of Zn, Cu, Fe, Pb of stem-flow which eluviate coefficients were less than 1, showing a negative cream dissolve.更多还原