【作者】 虞木奎；

【导师】 姜志林；

【作者基本信息】 南京林业大学 ， 生态学， 2003， 博士

【摘要】 本文针对火炬松人工林，尤其是工业用材林基地建设中存在的主要问题，以安徽中部丘岗地区栽植的各类试验林为研究对象，研究火炬松及其林分的生理生态学特性，主要研究火炬松林分的光合、蒸腾、树干液流、林木营养及林分养分循环和新造幼林水土流失特性等，在此基础上，研究了火炬松人工林林分结构调控技术，主要包括初植密度、植穴配置、抚育间伐和伴生树种的选择与配置的综合结构调控技术，进而按照生态系统管理的要求，提出了火炬松人工林可持续经营的综合配套技术。为火炬松人工林实行生态系统管理，达到可持续经营提供理论依据。主要结果如下： 1、火炬松光合生理生态特性 采用美国产的Licor-6400便携式光合作用测定系统，测定了11年生不同间伐林分（初植密度1830株／ha，弱度、中度、强度间伐后保留密度分别为1600、1200和1020株／ha），和不同初植密度林分（林分密度分别为3333、1667、1111株／ha）；不同层次（中部枝叶和上部枝叶）、不同叶龄（当年生枝针叶和2年生枝针叶）的光合生理、生态指标，并进行了CO₂倍增对光合作用的影响，同步测定的净光合速率(Pn，μ mol CO₂·m^-2·s^-1、蒸腾速率(Tr，m mol·m^-2·s^-1)、气孔导度(COND，mol·m^-2·s^-1)、胞间CO₂浓度(Ci，μ mol CO₂·mol^-1)、饱和蒸气压差（VPD，Kpa）、气温（Ta，℃）叶温（T1，℃）、光合有效辐射(PAR，μ mol photons·m^-2·s^-1)、空气相对湿度（RHr，％）、叶室相对湿度（RHs，％）、进气CO₂浓度(Ca，μ mol CO₂·mol^-1)、叶室CO₂浓度(Cs，μ mol CO₂·mol^-1)的相互关系，以及与湿地松对比的研究，结果表明： ● 火炬松净光合速率的日进程为一宽单峰曲线，上午10时之前快速上升，14时后迅速下降，在12-14时出现峰值。 ● CO₂浓度倍增火炬松净光合速率差异极显著，CO₂浓度为800μ mol CO₂·mol^-1与400μ mol CO₂·mol^-1的净光合速率分别为4.10和2.25μ mol CO₂·m^-2·s^-1，CO₂倍增能显著地提高光合速率。 ● 不同间伐处理火炬松净光合速率差异显著，强度间伐平均为3.57μ mol CO₂·m^-2·s^-1，中度间伐3.01μ mol CO₂·m^-2·s^-1，弱度间伐3.10μ mol CO₂·m^-2·s^-1。 ● 不同密度处理火炬松净光合速率差异显著，1667株／ha林分平均为4.26μ molCO₂·m^-2·s^-1、1111株／ha为3.98μ mol CO₂·m^-2·s^-1、3333株／ha为3.95μ mol CO₂·m^-2·s^-1。 ● 不同针叶类型处理乎均净光合速率差异显著，上部和中部枝针叶分别为3.15和3.21μmol CO₂·m^-2·s^-1；1年生枝和2年生枝针叶分别为3.39和2.89μ mol CO₂·m^-2·s^-1。 ● 不同间伐处理火炬松蒸腾速率差异显著，强度间伐处理平均为0.708 m mol·m^-2·s^-1，弱度间伐处理为0.581 m mol·m^-2·s^-1，中度间伐为0.518 m mol·m^-2·s^-1。强度间伐处理的蒸腾速率明显大于其它两种间伐强度。 ● 1111株／ha的湿地松林分净光合速率为4.91μ mol CO₂·m^-2·s^-1，显著大于相同密度火炬松林分。.净光合速率与同步测定的生理生态因子向的回归分析结果达到极显著水平，相关系数R=0.9977，决定系数RR二0.9954;通径分析显示，各因子的直接作用（括号内的数字为直接作用系数）)J匝序为:Ca（10.730）>Cs（一10.287）>RHs（一0464）>RHr（0.405）>COND（0.320）>TI（一0.259）>Tr（0.235）>VPD（0.098）>ei（一0.055）>几（0.051）>队R（0.038）;因为ea是人为设定的，分别设为400和800，mol Co:·m一2·S一’，如不考虑ea，则CS为影响Pn的主导因子，且为负效应;COND主要通过RHs和Tr影响Pn，Ci、VPD、Ta、TI主要通过Cs影响Pn，Tr主要通过RHr、CONo、TI等影响Pn，RHr主要通过TI、Tr、COND等影响Pn，础S主要通过COND和Cs影响Pn，PAR主要通过CS、TI、RHr、Tr和COND影响Pn。2、火炬松树干液流特点 采用澳大利亚ICT公司的ICT一2000TE树干液流测定系统，使用TDP热耗散探头、自动气象站和ZENO数据采集器，同步观测11年生不同径阶火炬松及对比湿地松和木荷树干液流和环境因子，结果表明:.秋季正常天气情况下，火炬松树干液流表现为双峰曲线或单峰曲线，有一定幅度的“午休”现象，日出后，树干液流迅速上升，峰值出现在中午前后，日落后至日出前液流微弱或J一L近无上升液流。.白天10时至17时平均为26c耐h左右，最大达到54clll巾左右，胸径与树干液流流速的关系不密切;不同径阶火炬松树干液流流量呈现极显著差异，观测的4株样木胸径分别为1 3.5、10.2、15.7、16.6cm，秋季每天的耗水量分别为13.28、13.27、36.33、49.sokg/d。.环境因子对树干液流的影响次序为:气温>相对湿度>光合有效辐射>土壤温度>土壤水分，气温是影响树干液流主导因子，温度越高，树干液流就大，林木蒸腾耗水就多;其次是相对湿度，因其直接作用为负值，表明相对湿度与树干液流成反比;光合有效辐射主要是通过影响气温和相对湿度进而影响树干液流的。.火炬松与对比的湿地松和木荷树干液流有一定的差异，晴天树干液流流速火炬松最大巨为双峰曲线，?更多还原

【Abstract】 Pinus taeda is the most important industry tree species in southern America. It has been introduced to China since 1948, and becomes one of the major tree species of plantations in middle and north subtropic in China. Based on the investigation of experimental plantations of Pinus taeda located in the middle region of Anhui province, the ecophysiological characteristics of Pinus taeda and its plantations were studied in this paper, which include photosynthesis, stem sap flow, nutrient contents, nutrient cycling and the character of water and soil erosion in the young plantations. Furthermore, the optimum stand structure of Pinus taeda including planting density, distribution of the planting spot, thinning, choice and distribution of mixed tree species, were also studied. On the bases of the result obtained from this research, a comprehensive and ecological management techniques of Pinus taeda plantation was suggested in order to achieve sustainable management of the plantation. The key results are as follows:1. Photosynthesis ecophysiology of Pinus taedaPhotosynthesis (Pn, i mol CO2 m-2 s-1), transpiration (Tr, m mol m-2 s-1) and some ecophysiological factors such as stomata conduction (COND, mol m-2 s-1),dense of CO2 between cells(Ci, u mol CO2 mol-1), dispatch of saturation air press( VPD, Kpa), air temperature( Ta, ), leaf temperature( Tl, 癈 ), available radiation of photosynthesis( PAR, i mol photons s m-2s-1), relative humidity of air (RHr,%),relative humidity of leaf chamber(RHs,%),enter dense of CO2 (Ca, V mol CO2 mol-1), dense of CO2 in leaf chamber( Cs, i mol CO2 -mol-1) of different management Pinus taeda stands were investigated using the portable photosynthesis system Licor-6400. The results as follows:The daily course of net photosynthesis velocity of Pinus taeda is a single width curve. Before 10 A.M., it is ascend rapidly, and the peak appears between 12 and 14 hours of the day. After 2 p.m., it is descend quickly.When doubled the dense of CO2, the difference of net photosynthesis velocity of Pinus taeda is significant. As the dense of CO2 is 800 i mol CO2 mol-1 and 400 i mol CO2 Mol-1, net photosynthesis velocity is 4.10 and 2.25 i mol CO2 m-2 s-1 respectively. Doubled the dense of CO2 could increase photosynthesis velocity greatly.To the stands of Pinus taeda with different thinning intensities, the net photosynthesis velocity shows remarkable difference, of which the average of strong thinning 3.57 i mol CO2 m-2 s-1, the middling thin is 3.01 u mol CO2 m-2 s-1 the weak thin is 3.10 u mol CO2 m-2 s-1To the stands of Pinus taeda with different densities, velocities of net photosynthesis show remarkable difference, of which the average of 1667 stems / ha stands is 4.26 u mol CO2 m-2 s-1, 1111 stems/ ha is 3.98 u mol CO2 m-2 s-1, 3333 stems/ ha is 3.95 u mol CO2 m-2 s-1The average velocities of net photosynthesis show significant difference in different types of needles. They are 3.15 and 3.21 i mol CO2 m-2 s-1 in upper and central needles respectively and 3.39 and 2.89 i mol CO2 m-2 s-1 in one year and two years needles respectively.In different thinned Pinus taeda stands, the velocities of transpiration show notable difference. To the strong thinned stand, the average is 0.708 m mol m-2 s-1 while to the weak thinned, the average is0.581m mol m-2 s-1 and to the middle, which is 0.518 m m-2 s-1The velocity of net photosynthesis of Pinus elliottii stands with 1111 stems/ ha is 4.91 u mol CO2 m-2 s-1, which is much greater than Pinus taeda stands.Regression analysis shows that there exists good relationship between the velocity of the net photosynthesis and the physiology ecosystem factors, and the relation coefficient (R) reached 0.9977, and decision coefficient (RR) is 0.9954. The all path analysis shows that the direct function (arithmetic figure in the brackets is direct function coefficient) of each factor is in proper order for: Ca(10.730)> Cs(-10.287)> RHs(-0.464)> RHr(0.405)> COND(0.320)> Tl(-0.259)> Tr(0.235)> VPD(0.098)> Ci(-0.085)> Ta(0.051)> PAR (0.038). Except Ca更多还原