小兴安岭白桦次生林内红松光合对林隙大小与林隙内位置的适应性研究  

Study on the photosynthetic adaptability of Pinus koraiensis to the forest gaps in different sizes and at various positions of the Betula platyphylla secondary forest in the Xiaoxing’an mountains

作　　者：田博宇 牟长城 李佳欣 叶林 TIAN Boyu;MU Changcheng;LI Jiaxin;YE Lin(Center for Ecological Research,School of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China;Academy of Forestry,Yichun 153000,Heilongjiang,China)

机构地区：[1]东北林业大学林学院生态研究中心,黑龙江哈尔滨150040 [2]黑龙江省伊春市林业科学院,黑龙江伊春153000

出　　处：《中南林业科技大学学报》2022年第9期159-170,共12页Journal of Central South University of Forestry & Technology

基　　金：“十三五”国家重点研发计划项目(2017YFC0504102)。

摘　　要：【目的】揭示顶极种红松幼年期光合对林隙大小与林隙内位置的适应规律,对我国东北次生林恢复地带性顶极植被阔叶红松林尤为重要。【方法】采用CIRAS-2光合仪,测定小兴安岭白桦次生林大(201~211 m^(2))、中(169~174 m^(2))、小(100~102 m^(2))林隙内中心区、过渡区与边缘区及林内红松幼树(35 a)生长季的光合参数(最大净光合速率、光饱和点、光补偿点、蒸腾速率和气孔导度等)及其微环境因子(光照强度、叶片温度等),揭示次生林内红松幼树光合对林隙大小和林隙内位置的适应规律及机制。【结果】1)白桦次生林中红松幼树生长季平均最大净光合速率(2.4~8.4μmol·m^(-2)·s^(-1))在各大小林隙内各位置(小林隙边缘区除外)显著高于林内54.2%~250.0%,且在林隙内各位置均呈现出大林隙(20.0%~96.4%)>中林隙(35.4%~57.1%)>小林隙的递增规律性;2)其生长季平均最大净光合速率在大、中林隙内呈中心区(18.2%~52.7%)>过渡区(20.0%~25.0%)>边缘区的递增规律性,而在小林隙内呈中心区(29.7%~71.4%)>过渡区=边缘区的递增趋势;3)红松针叶的光饱和点和蒸腾速率、气孔导度及水分利用效率在林隙内高于林内(28.7%~250.0%),在大林隙内均高于小林隙(8.7%~75.9%),但其光补偿点、比叶面积(大林隙中心区)及叶绿素含量却林隙内低于林内(15.6%~81.9%),大林隙低于小林隙(14.4%~47.5%),表现出明显的生理和形态适应性;4)在大、中林隙内各位置之间同样表现出明显的生理与形态适应性,其光饱和点呈中心区>过渡区>边缘区(8.8%~40.1%)的递增规律性,光补偿点却呈中心区<过渡区<边缘区(28.2%~62.0%)的递减规律性,其蒸腾速率和气孔导度为中心区>过渡区=边缘区(20.0%~96.9%),但其比叶面积、叶绿素含量却为中心区显著低于边缘区(12.7%~31.6%)。【结论】温带小兴安岭白桦次生林内红松幼树光合能力随着林隙增大而增大及自林隙内边缘区�【Objectives】The study aimed to reveal the photosynthetic adaptation law of Pinus koraiensis to forest gaps in the secondary forest,which is of great significance to the restoration of zonal climax vegetation of broad-leaved P.koraiensis forest in Northeast China.【Methods】The CIRAS-2 photosynthetic apparatus was used to measure the photosynthetic parameters(the maximum net photosynthetic rate,light saturation point,light compensation point,transpiration rate,stomatal conductance,etc.)and the micro-environmental factors(light intensity,leaf temperature,etc.)of the P.koraiensis saplings(35a)at the central,transitional and marginal areas of forest gaps in three different sizes(large gap-201-211 m^(2),medium gap-169-174 m^(2),small gap-100-102 m^(2))in the Betula platyphylla secondary forest in the Xiaoxing’an mountains of China,to reveal the photosynthetic adaptation rules and mechanisms of P.koraiensis saplings to the forest gaps in different sizes and at different positions.【Result】(1)The average maximum net photosynthetic rate(Pmax)(2.4-8.4μmol·m^(-2)·s^(-1))of P.koraiensis saplings in the forest gap of three different sizes and at all positions of the B.platyphylla secondary forest during the growing season(except the marginal area of small forest gap)was 54.2%-250.0%significantly higher than that in the forest understory.In addition,the increasing regularity of the large forest gap(20.0%to 96.4%)>the medium forest gap(35.4%to 57.1%)>the small forest gap was observed in all positions of the forest gaps.(2)The Pmax also showed an increasing regularity as the central area(18.2%to 52.7%)>the transitional area(20.0%to 25.0%)>the marginal area in the large and medium forest gaps.However,in the small forest gaps,there was an increasing trend as the central area(29.7%to 71.4%)>the transition zone=the marginal area.(3)The light saturation point,transpiration rate,stomatal conductance and water use efficiency of P.koraiensis needles in forest gaps were 28.7%-250.0%higher than those in forest understory,wh

关 键 词：温带小兴安岭 红松幼树 光合适应性 林隙大小 林隙内位置 

分 类 号：S718.45[农业科学—林学]