摘要
【目的】评价光学仪器法测定马尾松林叶面积指数(LAI)的精度,为准确监测马尾松林LAI季节动态提供技术支持。【方法】以凋落物法测定值代表马尾松林真实的LAI,对展叶调查、异速生长方程法和光学仪器法(半球摄影法和LAI-2200植物冠层分析仪)获取的马尾松林LAI季节动态进行评估,并量化不同因素包括集聚指数(ΩE)、木质比例(α)和针簇比(γE)对光学仪器测定值的影响。【结果】马尾松林内主要树种的平均叶寿命为1.53~1.94,比叶面积(SLA)差异较大(99.15~278.33 cm^(2)/g)。不同方法测定马尾松林LAI的季节动态均呈单峰形变化模式,且在7月达到峰值。在各调查时期,凋落物法的测定值与异速生长方程法的测定值差异不显著。半球摄影法测定的有效叶面积指数(Le)比凋落物法、异速生长方程法的测定值分别低估了49%~64%和47%~61%;LAI-2200植物冠层分析仪法测定的Le低估了25%~44%和20%~42%。半球摄影法测定的Le经自动曝光、α、ΩE及γE校正后,精度明显提高,比凋落物法、异速生长方程法平均低估了8%和5%;LAI-2200植物冠层分析仪法测定的Le经α、ΩE及γE校正后,其精度大幅度提高,比凋落物法、异速生长方程法平均低估了6%和2%。【结论】考虑影响光学仪器法测定LAI的因素后,半球摄影法和LAI-2200植物冠层分析仪法测定的LAI精度得到明显提高,表明两种光学仪器法均能相对准确地测定马尾松林LAI的季节动态,可为不同区域马尾松林LAI季节动态的研究提供方法参考。
【Objective】Evaluate the accuracy of the leaf area index(LAI)of Pinus massoniana by optical instrumentation to provide technical support for accurately monitoring the LAI seasonal dynamics of P.massoniana forest.【Method】We evaluated the seasonal dynamics of LAI estimated by leaf-spreading surveys,the anisotropic growth equation method,the apomictic method,and optical instrumental methods(hemispherical photography and the LAI-2200 plant canopy analyser)in the P.massoniana forest by using the apomictic method measured values as representative of the true LAI values of P.massoniana forest,and we considered the sources of error of the LAI determined by the optical instrumental methods(clumping index(ΩE),woody-to-total area ratio(α),and needle-cluster ratio(γE)).【Result】The mean leaf lifespan of the major species within the P.massoniana forest ranged from 1.53 to 1.94,and SLA varied widely(99.15 cm^(2)/g-278.33 cm^(2)/g).The seasonal dynamics of LAI in P.massoniana forests determined by different methods showed a single-peak change pattern,and reached a peak in July.In each period,there was no significant difference between the value determined by litterfall method and allometry method.During the entire investigation period,the effective leaf area index(Le)measured by DHP was underestimated by 49%-64%and 47%-61%,respectively,compared with the values measured by litterfall method and allometry method.Le measured by LAI-2200 underestimates 25%-44%and 20%-42%,respectively.The accuracy of Le measured by DHP was obviously improved after corrected by automatic exposure,α,ΩE andγE.Compared with litterfall method and allometry method,the accuracy was average underestimated by 8%and 5%.Generally speaking,after corrected byα,ΩE andγE,the accuracy of LAI-2200 was greatly improved,compared with litterfall method and allometry method,it was underestimated by an average of 6%and 2%,respectively.【Conclusion】After considering the factors that affect the determination of LAI by optical instrument method,the acc
作者
冉佳璇
罗光浪
何世强
丁贵杰
谭伟
戚玉娇
RAN Jiaxuan;LUO Guanglang;HE Shiqiang;DING Guijie;TAN Wei;QI Yujiao(College of Forestry,Guizhou University,Guiyang 550025,Guizhou,China;Guizhou Provincial Forest Resources and Environment Research Center,Guizhou University,Guiyang 550025,Guizhou,China;Guizhou Singularity Forest Survey and Design Co.,Anshun 561000,Guizhou,China;Guizhou Academy Forestry,Guiyang 550005,Guizhou,China)
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2024年第5期56-66,共11页
Journal of Central South University of Forestry & Technology
基金
国家重点研发计划项目(2017YFD0600302)
贵州省科技计划项目(黔科合支撑[2019]2874)
贵州省一流学科建设项目(GNYL[2017]007)。
关键词
马尾松人工林
叶面积指数
季节动态
凋落物法
半球摄影法
LAI-2200植物冠层分析仪
Pinus massoniana plantation
leaf area index
seasonal dynamics
litter collection
digital hemispherical photography
LAI-2200 plant canopy analyzer method
