CAJ | 학술논문

利用反射光谱探测植物的生理生态活动是定量遥感新的发展方向。通过盆栽川滇高山栎幼树,控制其植物水分胁迫程度,分别测定不同水分胁迫条件下川滇高山栎的光谱响应曲线和叶片水分指标的各自变化,并从光谱曲线中提取对水分敏感的光谱指数,分析高山栎水分胁迫下的高光谱特征的响应特点以及与光谱指数之间的关系。结果表明：在水分胁迫下川滇高山栎的光谱曲线可见光区（VIS）和近红外区（NIR）均呈现明显的趋势性变化;不同水分处理下归一化植被指数NDVI分别与相对含水量（RWC）、等效水厚度（EWT）均呈显著正相关关系,水分反射指数（WI）与含水量指标RWC、EWT分别均呈显著正相关关系,表明NDVI与WI光谱指数能够很好地预测川滇高山栎叶片水分的变化,而光化学反射指数PRI在预测水分含量方面的有效性受胁迫强度的影响,与水分指标的关系并不稳定。通过水分胁迫后以及随后进行的复水试验,川滇高山栎光谱指数的时间序列清晰显示了先下降后上升的变化特征,并且当叶片水分胁迫达到第42天时,叶片相对含水量达到最低值0.31,此时NDVI、WI、PRI分别达到最低临界值0.71、0.98、-0.15,需要立即复水,否则川滇高山栎幼树光合等生理特征无法恢复。通过比较研究在不同水分胁迫下,与川滇高山栎水分变化状况敏感的光谱指数,可为基于高光谱遥感技术监测植被水分状况提供参考。
이용반사광보탐측식물적생리생태활동시정량요감신적발전방향。통과분재천전고산력유수,공제기식물수분협박정도,분별측정불동수분협박조건하천전고산력적광보향응곡선화협편수분지표적각자변화,병종광보곡선중제취대수분민감적광보지수,분석고산력수분협박하적고광보특정적향응특점이급여광보지수지간적관계。결과표명：재수분협박하천전고산력적광보곡선가견광구（VIS）화근홍외구（NIR）균정현명현적추세성변화;불동수분처리하귀일화식피지수NDVI분별여상대함수량（RWC）、등효수후도（EWT）균정현저정상관관계,수분반사지수（WI）여함수량지표RWC、EWT분별균정현저정상관관계,표명NDVI여WI광보지수능구흔호지예측천전고산력협편수분적변화,이광화학반사지수PRI재예측수분함량방면적유효성수협박강도적영향,여수분지표적관계병불은정。통과수분협박후이급수후진행적복수시험,천전고산력광보지수적시간서렬청석현시료선하강후상승적변화특정,병차당협편수분협박체도제42천시,협편상대함수량체도최저치0.31,차시NDVI、WI、PRI분별체도최저림계치0.71、0.98、-0.15,수요립즉복수,부칙천전고산력유수광합등생리특정무법회복。통과비교연구재불동수분협박하,여천전고산력수분변화상황민감적광보지수,가위기우고광보요감기술감측식피수분상황제공삼고。
Detection of plant physiology by using hyperspectral remote sensing technique is one of the recent concerns.By potting Quercus aquifoliodes plants,a long term drought cycle and recovery process had been simulated by withholding water to potted olive plants.Physiological changes as well as spectral reflectance had been observed under varying water regimes during the course of treatment.This study aimed to determine effective spectral reflectance indices that closely track the change of leaf water content of Quercus aquifoliode.The results showed that under water stress,the spectral reflectance increased significantly in the visible region（VIS）and the near-infrared region（NIR）,normalized difference vegetation index（NDVI）was significantly correlated with relative water content（RWC）and equivalent water thickness（EWT）,respectively.Water index（WI）was also significantly correlated with relative water content（RWC）and equivalent water thickness（EWT）.Both NDVI and WI showed highly correlated with leaf water content indices.Comparatively,PRI showed weak correlations with either RWC or EWT.This study showed clear time-course of that under water stress and recovery,the spectral reflectance index（NDVI,WI,PRI）of Quercus aquifoliodes first decreased and then increased as the experiment proceeded.It need to be watered Quercus aquifoliodes when the leaves water stress lasted 42 days,or Quercus aquifoliodes photosynthetic rate and other physiological characteristics couldn＇t be restored.By comparing water-sensitive spectral index under different water stress,this study provided a theoretical basis for detecting vegetation water status based on hyperspectral remote sensing technology.