大气CO_(2)浓度升高背景下冬小麦冠层光谱特征和地上生物量估算  

Spectral characteristics of winter wheat canopy and estimation of aboveground biomass under elevated atmospheric CO_(2)concentration

作　　者：黄宏胜 张馨月 居辉[1] 韩雪[1] HUANG Hong-Sheng;ZHANG Xin-Yue;JU Hui;HAN Xue(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]中国农业科学院农业环境与可持续发展研究所,北京100081

出　　处：《作物学报》2024年第4期991-1003,共13页Acta Agronomica Sinica

基　　金：国家重点研发计划项目(2019YFA0607403);中国农业科学院科技创新工程农业绿色低碳科学中心专项项目;中央级公益性科研院所基本科研业务费(CAAS-CSGLCA-202301,BSRF202202)资助~~

摘　　要：本研究旨在探究大气CO_(2)浓度升高对冬小麦全生育时期冠层光谱特征的影响,并基于筛选的敏感波段建立地上生物量(AGB)与光谱参数的定量关系。为此,在2021—2022年的冬小麦生长季,利用开放式CO_(2)富集系统(Mini-FACE),设定大气CO_(2)浓度(ACO_(2),(420±20)μL L^(–1))和高CO_(2)浓度(ECO_(2),(550±20)μL L^(–1))两个处理水平,分析了高CO_(2)浓度下光谱特征变化,基于连续投影算法(SPA)、逐步多元线性回归(SMLR)和偏最小二乘法回归(PLSR)筛选AGB敏感波段并构建估算模型。结果表明:CO_(2)浓度升高使冬小麦拔节期和开花期AGB显著增加。红边和近红边反射率及红边面积在拔节期增加,在开花期和灌浆期降低,蓝边、黄边和红边位置在不同生育时期均发生移动;AGB的敏感光谱波段主要分布在红边和近红边区域,CO_(2)浓度升高缩小了AGB敏感波段范围,但不影响AGB的估算;AGB的SMLR和PLSR模型均取得了较高的估算精度(R^(2)>0.8),其中SMLR模型中的R_(799′)、D_(y)、SD_(y)和PRI等特征参数与AGB显著相关,R^(2)为0.866。PLSR模型(R^(2)>0.9)在估算精度和稳定性上优于SMLR模型。本研究可为未来高CO_(2)浓度下冬小麦生长发育的遥感监测提供理论基础和技术方法。The objective of this study is to investigate the effect of elevated atmospheric CO_(2)concentration on the canopy spectral characteristics of winter wheat during the whole growth period and to establish quantitative relationships between above-ground biomass(AGB)and spectral parameters based on the screened sensitive bands.For this purpose,during the winter wheat growing season of 2021–2022,two treatment levels of atmospheric CO_(2)concentration(ACO_(2),(420±20)μL L^(–1))and elevated CO_(2)concentration(ECO_(2),(550±20)μL L^(–1))were set based on the Free Atmospheric CO_(2)Enrichment System(Mini-FACE),and the changes of spectral features were analyzed under elevated CO_(2)concentration.AGB sensitive bands were screened and the estimation models of AGB were constructed based on the successive projections algorithm(SPA),stepwise multiple linear regression(SMLR),and partial least squares regression(PLSR).The results showed that elevated CO_(2)concentration significantly increased AGB in winter wheat at jointing and anthesis stages.The red-edge reflectance,near red edge reflectance,and red-edge area increased at jointing stage and decreased at anthesis and maturity stages.The positions of the blue-edge,yellow-edge,and red-edge were shifted at different growth stages.The sensitive spectral bands of AGB are mainly distributed in the red-edge and near red-edge bands,and the elevated CO_(2)concentration narrows the range of the sensitive bands of AGB,but does not affect the estimation of AGB.The SMLR and PLSR models of AGB both achieved high estimation accuracy(R^(2)>0.8),where the characteristic parameters such as R799',D_(y),SD_(y),and PRI in the SMLR model were significantly correlated with AGB,with an R^(2)of 0.866.The PLSR model(R^(2)>0.9)outperformed the SMLR model in terms of estimation accuracy and stability.This study can provide the theoretical basis and technical methods for the remote sensing monitoring of winter wheat growth and development under elevated CO_(2)concentration in the future.

关 键 词：CO_(2)浓度升高 冬小麦 地上生物量 冠层光谱特征 回归分析 

分 类 号：S512.11[农业科学—作物学]