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应用生态学报 ›› 2017, Vol. 28 ›› Issue (3): 757-762.doi: 10.13287/j.1001-9332.201703.011

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大兴安岭地区主要植被类型的叶片聚集度系数

黄婷, 范文义*, 毛学刚, 于颖   

  1. 东北林业大学林学院, 哈尔滨 150040
  • 收稿日期:2016-07-28 发布日期:2017-03-18
  • 通讯作者: *E-mail: fanwy@163.com
  • 作者简介:黄婷,女,1992年生,硕士研究生.主要从事叶片聚集度系数研究.E-mail:931372264@qq.com
  • 基金资助:
    本文由国家自然科学基金项目(31300533)资助

Foliage clumping index of main vegetation types in Daxing’an Mountains, Northeast China

HUANG Ting, FAN Wen-yi*, MAO Xue-gang, YU Ying   

  1. College of Forestry, Northeast Forestry University, Harbin 150040, China
  • Received:2016-07-28 Published:2017-03-18
  • Contact: *E-mail: fanwy@163.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (31300533)

摘要: 叶片聚集度系数量化了在树冠随机的情况下叶片空间分布的聚集程度,对生态模型建模有重要作用.本研究利用MODIS BRDF模型参数产品(MCD43A1)以及土地覆盖类型数据(MCD12Q1),基于Ross-Li半经验模型模拟了热点和暗点的反射率,计算归一化的热点与暗点差值指数(NDHD),结合最小二乘法模拟的NDHD与聚集度系数的关系,反演了2014年8月500 m分辨率的大兴安岭地区植被叶片聚集度系数.并在大兴安岭地区采用冠层分析仪TRAC采样测量,对聚集度系数进行实地验证并对结果进行分析.结果表明: Ross-Li模型模拟的数据与样地实测数据具有显著的相关性(R2=0.8879),说明利用MCD43A1数据反演聚集度系数算法的可行性;MODIS近红外波段对叶片聚集度系数变化的灵敏度比红色波段更高;随着太阳天顶角的增加,Ross-Li模型推导出的聚集度系数呈线性增长趋势(R2=0.9699),说明叶片聚集度系数与天顶角变化有关.

Abstract: The foliage clumping index quantifies the cluster degree of the leaf spatial distribution under random canopy. It is of comparable importance for establishment of ecological models. MODIS BRDF model parameter products (MCD43A1 data) and land cover types (MCD12Q1 data) were used in this study to simulate the reflectivity of the hot spots and dark spots, and calculate the normalized difference between hotspot and darkspot (NDHD) based on the Ross-Li semi-empirical model. Least square method was then used to simulate the relationship between NDHD and the foliage clumping index and foliage clumping index products of 500-m resolution in August 2014 were retrieved. Measurements of the foliage clumping index in Daxing’an Mountains were conducted by using the TRAC (Tracing Radiation and Architecture of Canopies) sampling instrument for mo-del validation and analysis. Results showed that it was a feasible algorithm to retrieve clumping index from MCD43A1 product with the correlation of simulated data and the measured data of significance (R2=0.8879). The MODIS near infrared wave band was more sensitive than that on red band to foliage clumping index change. With the increase of the solar zenith angle, the clumping index retrieved by Ross-Li model had a linear increase (R2=0.9699), which indicated that the foliage clumping index related to the solar zenith angle.