(Press-News.org)
Solar-induced chlorophyll fluorescence (SIF) and the photochemical reflectance index (PRI) have emerged as significant tools in assessing the photosynthetic and carbon sequestration capacities of terrestrial vegetation, particularly for estimating gross primary productivity (GPP). However, the relationship between SIF, PRI, and GPP encounters challenges due to large temporal and spatial variabilities as well as the influence of various observational factors such as canopy structure and physiological state. Despite the potential of multi-angle observations and the Bidirectional Reflectance Distribution Function (BRDF) model to mitigate these issues by accounting for canopy anisotropy and separating physiological signals from environmental influences, the application of these approaches to SIF and PRI for GPP estimation remains underexplored.
In February 2024, Plant Phenomics published a research article entitled by “Establishing a Gross Primary Productivity Model by SIF and PRI on the Rice Canopy”.
In this study, researchers employed a multi-angle spectrometer alongside an eddy covariance (EC) system to enhance the precision of GPP estimation within a subtropical rice field in China, through the utilization of a PRI-boosting SIF-GPP model. They innovatively applied a semi-empirical kernel-driven BRDF model combined with a two-leaf model for an in-depth analysis of both hotspot and total canopy PRI and SIF (PRIhs/SIFhs and PRItot/SIFtot, respectively). This dual-model approach facilitated the construction of hotspot and total canopy PRI+SIF-GPP models, whose efficacy was rigorously tested against a validation dataset. The research findings revealed significant correlations between the PRI/SIF indexes and GPP across various timescales, establishing robust linear models for GPP estimation. Notably, the study uncovered the dynamic responses of PRI/SIF to environmental conditions, quantifying their accuracy through R2, RMSE, and RPD metrics across different models.
The exploration into the temporal dynamics of GPP, LAI, and PAR highlighted the crucial role of clear vs. cloudy weather conditions in determining the strength of these correlations. Particularly, the daily and half-hourly analysis showed that total canopy measures (SIFtot and PRItot) were more effective in mirroring GPP variations than their hotspot counterparts (SIFhs and PRIhs), demonstrating a stronger alignment with GPP's daily and intraday fluctuations. This alignment was further enhanced by distinguishing between shaded and sunlit leaves within the two-leaf model, which significantly improved the correlation between SIF/PRI and GPP, especially for PRI.
The study also examined the impact of environmental stresses, such as PAR, temperature (T), and vapor pressure deficit (VPD), on PRI and SIF performance, revealing that these factors disproportionately affect the estimation capabilities of PRI and SIF. Through detailed modeling and validation efforts, the researchers showed that combining PRI and SIF for GPP estimation substantially outperformed individual index models. This superiority was particularly pronounced after integrating the distinction between shaded and sunlit leaves, marking the PRItot+SIFtot-GPP model as the most effective for GPP estimation.
In conclusion, this study not only advances our understanding of the complex interactions between environmental factors, SIF, PRI, and GPP but also demonstrates the superior estimation capabilities of combined PRI and SIF models, particularly when incorporating nuanced distinctions between canopy components. This work paves the way for more accurate, non-invasive tracking of crop photosynthesis and carbon sequestration processes, offering valuable insights for future research and practical applications in agriculture and climate change mitigation.
###
References
Authors
Zhanhao Zhang1, Jianmao Guo1,2*, Shihui Han1, Shuyuan Jin1, and Lei Zhang3
Affiliations
1School of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
2Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing 210044, China.
3National Meteorological Centre, China Meteorological Administration, Beijing 100081, China.
END
Corvallis, OR — The Alliance of World Scientists (AWS) is pleased to announce the six recipients of the 2024 Planet Earth Award: Dr. S Faizi, Dr. James Hansen, Dr. Denise Margaret S. Matias, Dr. Kimberly Nicholas, Dr. Jamie Pittock, and Dr. Fernando Valladares.
Planet Earth Award
The AWS Planet Earth Award acknowledges individuals who champion life on Earth. These individuals demonstrate exceptional creativity or contributions in their work in science-based advocacy with the public, ...
Computers work in digits — 0s and 1s to be exact. Their calculations are digital; their processes are digital; even their memories are digital. All of which requires extraordinary power resources. As we look to the next evolution of computing and developing neuromorphic or “brain like” computing, those power requirements are unfeasible.
To advance neuromorphic computing, some researchers are looking at analog improvements. In other words, not just advancing software, but advancing hardware too. Research from the University of California San Diego and UC Riverside shows a promising new way to store and transmit information ...
DALLAS (SMU) – What exactly happens at the tiny scale at which individual atoms exist and interact? SMU chemist Elfi Kraka and her colleagues have been working on developing a computational tool aimed at providing answers to that mystery.
Mathematical functions used to calculate the potential energy of a system of atoms are called interatomic potentials. Machine learning interatomic potentials (MLIP)s have become an efficient and less expensive alternative to traditional quantum chemical simulations, which even on today’s high-performance computing often become out of reach for larger ...
Although women have breastfed since the beginning of time, there is very little scientific research on how exercise affects breast milk.
Online forums for pregnant women and new mothers are full of questions about this exact issue:
Can exercise cause breast milk to go sour? What happens to breast milk if you do high-intensity interval training? Will strenuous exercise affect your milk supply?
“There are so many myths about exercise and breast milk. We simply need more knowledge,” says researcher Trine Moholdt at the Norwegian University of Science and Technology (NTNU).
She heads several international research projects ...
The ACMG Foundation for Genetic and Genomic Medicine is proud to present the ACMG Foundation/David L. Rimoin Inspiring Excellence Award to Christiana Wang, BS for her featured platform presentation at the 2024 ACMG Annual Clinical Genetics Meeting, “Antisense oligonucleotide targeting a linked-SNP provides allele-specific and effective knockdown to a dominant negative SPTAN1 pathogenic variant.”
Christiana Wang, BS, is a second-year PhD candidate in the Department of Molecular ...
ATLANTA – New data provided by studying the beluga whales at Georgia Aquarium helps close a key information gap about how much food these whales need to thrive. The information will inform important management decisions for their counterparts in Alaska’s Cook Inlet, which are protected under the U.S. Endangered Species Act (ESA).
A new study released in the Journal of Experimental Biology, led by Terrie M. Williams, Director of the Integrative Carnivore EcoPhysiology Lab, with her graduate student Jason John at the University of California-Santa Cruz in partnership ...
Americans already living in housing supported by federal housing assistance programs have significantly lower blood lead levels than counterparts who would later join these programs, according to new research led by environmental health scientists at Columbia University Mailman School of Public Health and Tufts Medical Center. The findings appear in the peer-reviewed journal Environmental Health Perspectives.
“Living in federally-supported housing—especially public housing—limited opportunities for residents’ exposure to lead,” says first author MyDzung Chu, Ph.D., assistant professor in the Institute for ...
Residential heating by coal has for decades been the major contributor to the high levels of air pollution in Krakow, Poland. New research finds a nearly 40 percent decline in the annual average concentration of respirable particulate matter (PM2.5) in Kraków, Poland, between 2010 and 2019 following the implementation of policies targeting emissions from the burning of coal and other solid fuels. Researchers show the improvement in air quality translated to substantial benefits for children’s outcomes, including fewer cases of asthma and better birth outcomes.
The ...
Nagoya University researchers and their colleagues in Japan have found that middle-age obesity is caused by age-related changes in the shape of neurons in the hypothalamus, a region of the brain that controls metabolism and appetite.
A protein called melanocortin-4 receptor (MC4R) detects overnutrition and regulates metabolism and appetite to prevent obesity. According to their study in rats, MC4Rs were concentrated in primary cilia (antenna-like structures) that extend from a couple of groups of hypothalamic neurons. The study also showed that the primary cilia became shorter with age, which decreased MC4Rs accordingly, ...
Recently, Nano Research announced awardees of the 2023 Nano Research Young Innovators (NR45) Awards in Bio-inspired Nanomaterials. Thirty-three outstanding young investigators under the age of 45 were selected for their extraordinary contributions in developing bio-inspired nanomaterials with applications spanning clean energy, human healthcare, monitoring, and disease treatments. They were selected through a competitive process by an award committee from Nano Research’s editorial board. Congratulations to all the 33 awardees in 2023!
The NR45 Awards ...
