海南儋州地区橡胶林叶面积指数月动态研究

海南儋州地区橡胶林叶面积指数月动态研究

摘要叶面积指数（Leaf Area Index，LAI）是描述植被冠层结构的重要参数，它对分析橡胶光合潜力、预测产量和评估灾害都具有重要意义。本研究利用LAI-2000获得了海南儋州两院地区30个橡胶林连续2年半的LAI月动态。结果表明：（1）橡胶林LAI最小值出现在1～2月的落叶季，最小值为（0.54±0.14）m2/m2；随后的第一篷叶抽叶期（3～4月），LAI快速增长，4月底平均值增至3以上[最大观测值为（4.48±0.82）m2/m2]，平均占全年最大LAI的77.75%；之后增长趋于缓慢，至9月底达到年度最大值，最大观测值为（5.27±0.79）m2/m2。（2）LAI年际差异较大，平均LAI相差可达1以上，影响因素主要有年际物候差和台风灾害等；（3）不同年龄的橡胶林之间LAI存在差异，在第一篷叶期间，平均LAI为老龄橡胶林（>20龄）>幼龄及初开割林（≤10龄）>中龄橡胶林（11～20龄），而在之后至落叶前期，平均LAI

次序为幼龄及初开割林>老龄橡胶林>中龄橡胶林。

关键词叶面积指数；月动态；橡胶林；海南

分类号S794.1

Monthly Dynamics of Leaf Area Index of Rubber Plantation in Danzhou，Hainan Island，China

CHEN Bangqian1，2）WU Zhixiang1）YANG Chuan1）QI Dongling1）

LI Xiangping2）LAN Guoyu11）XIE Guishui1）TAO Zhongliang1）

SUN Rui1）XIAO Xiangming2）

（1 Rubber Research Institute / Tropical Cops Investigation & Experiment Danzhou Station

of Ministry of Agriculture，CATAS，Danzhou，Hainan 571737，P. R. China

2 Institute of Biodiversity Science，Fudan University，Shanghai 200438，P. R. China）

Abstract Leaf area index （LAI）is an important parameter in description of the vegetation canopy structure，and is of vital importance for photosynthetic potential analyzing，yield prediction and disaster assessment in rubber plantations. In this study，LAI-2000 was used to measure the monthly LAI of 30 rubber plantations in Danzhou City，Hainan Island，China for more than two years. The results show that the minimum LAI （0.54±0.14）was found in late January and February，when most rubber trees had shed their leaves due to the cold temperature and dry weather. Subsequently，the LAI of rubber plantations increased significantly in March and April，then

slowly increasing until reached the maximum value in late September，which had a value of （5.27±0.79）in 2013. By the end of April，the average LAI increased to three or more，and accounts for about 80% of the total annual maximum LAI. However，the average LAI is differing largely among different years，mainly due to the inter-annual phenological difference and natural disasters such typhoons. In addition，the mean LAI differs at different age groups. The order of mean LAI in March and April is aged rubber plantations （>20 years）>young rubber plantations （≤10 years）>mid-aged （11～20 years）rubber plantations. However，the LAI of young rubber plantations would exceed the aged rubber plantations after April because they are seldom bearing latex tapping and almost of their nutrient are used for biomass accumulation. Keywords leaf area index ；monthly dynamic ；rubber plantation ；Hainan

植被叶面积指数（Leaf Area Index，LAI）通常指单位土地面积上所有叶片表面积的总和，或单位面积上植物叶片的垂直投影面积的总和[1]。LAI是植被冠层结构的一个重要参数，叶面积的大小及其分布直接影响着植被的许多生物物理过程，如光合呼吸、蒸腾和降水的截获、碳能量等[1-4]，同时它也是确定陆地生态系统物质和能量交换大小的一个重