Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses

Abstract

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species (Quercus glauca) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500–660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca. These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

Indication of Light Stress in Ficus elastica Using Hyperspectral Imaging

“…Thus, Navarro et al [33] showed that ranges 492-504 and 540-568 nm of visible light; 712-720 nm of far-red light; and 855, 900-908, and 970 nm of near-infrared light had the best sensitivity to pathogen-induced stress occurring in Diplotaxis tenuifolia plants. In several studies, other reflectance spectral ranges indicative of different types of stress (not related to photoinhibition) have been proposed, 850, 630, 535, and 465 nm [15]; 500-660 nm [34]; and 690 and 702 nm [9].…”

Resources for image-based high-throughput phenotyping in crops and data sharing challenges

“…The authors observed that multiple trait measurements would be required to correctly assess the plants, whereas with hyperspectral images they were able to score them in a fast noninvasive way, dataset is described in Supplemental Data Set 2 ( Moghimi et al, 2018 ). Multispectral and hyperspectral images have also been employed to identify salt stress in sugarcane ( Saccharum officinarum L. ) and wheat irrigated with saline water ( Hamzeh et al, 2013 ; El-Hendawy et al, 2019 ), acidic and heavy metal stress ( Liu et al, 2011 ; Jin et al, 2013 ; Li et al, 2015 ; Zhang et al, 2017 ; Wang et al, 2018a ), nutrient deficiency ( Pacumbaba and Beyl, 2011 ), heat stress ( Gautam et al, 2015 ; Trachsel et al, 2019 ), and frost ( Fitzgerald et al, 2019 ; Nuttall et al, 2019 ; Murphy et al, 2020 ).…”

Low pH in simulated acid rain promotes the toxicity of copper on the physiological performance in Sargassum horneri

“…Acid rain and heavy metal pollution have become serious environmental problems around the world in recent decades. Acid rain is caused mainly by sulfur dioxide (SO2) and nitrogen oxides (NOx) emission, and the pH of acid rain is usually lower than 5.6 (Li et al 2017, Wang et al 2018. China has become one of the severely acid-rain polluted countries, especially in the southern and southwestern parts (Ma et al 2019).…”