- 标题
- 摘要
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- 实验方案
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Deriving Individual-Tree Biomass from Effective Crown Data Generated by Terrestrial Laser Scanning
摘要： Biomass reflects the state of forest management and is critical for assessing forest benefits and carbon storage. The effective crown is the region above the lower limit of the forest crown that includes the maximum vertical distribution density of branches and leaves; this component plays an important role in tree growth. Adding the effective crown to biomass equations can enhance the accuracy of the derived biomass. Six sample plots in a larch plantation (ranging in area from 0.06 ha to 0.12 ha and in number of trees from 63 to 96) at the Mengjiagang forest farm in Huanan County, Jiamusi City, Heilongjiang Province, China, were analyzed in this study. Terrestrial laser scanning (TLS) was used to obtain three-dimensional point cloud data on the trees, from which crown parameters at different heights were extracted. These parameters were used to determine the position of the effective crown. Moreover, effective crown parameters were added to biomass equations with tree height as the sole variable to improve the accuracy of the derived individual-tree biomass estimates. The results showed that the minimum crown contact height was very similar to the effective crown height, and an increase in model accuracy was apparent (with R2 a increasing from 0.846 to 0.910 and root-mean-square error (RMSE) decreasing from 0.372 kg to 0.286 kg). The optimal model for deriving biomass included tree height, crown length from minimum contact height, crown height from minimum contact height, and crown surface area from minimum contact height. The novelty of the article is that it improves the fit of individual-tree biomass models by adding crown-related variables and investigates how the accuracy of biomass estimation can be enhanced by using remote sensing methods without obtaining diameter at breast height.
关键词： point cloud data,TLS,effective crown,biomass,crown parameters
更新于2025-09-12 10:27:22
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Effect of Different Combinations of Red and Blue LED Light on Growth Characteristics and Pigment Content of In Vitro Tomato Plantlets
摘要： The aim of this study was to evaluate the growth characteristics and pigment content of tomato plantlets grown under various ratios of red (R) (661 nm) and blue (B) (449 nm) LED light. In this study, three di?erent ratios of R and B (RB) light such as 5:01, 10:01, and 19:01 along with R (100%) were used. The photosynthetic photon ?ux density (PPFD), and photoperiod of the growth chamber was 120 ± 5 μmol m?2s?1 and 16/8 h (day/night), respectively. Tomato plantlets were cultured for six weeks in the growth chamber. It was shown that tomato plantlets had higher photosynthesis rate, higher pigments content, higher growth characteristics (e.g., number of leaves, leaf area, shoot number, root number, root length, dry, and fresh mass), and greater surviving rate under the R:B = 10:01 ratio among the treatments. The plantlets showed at least a threefold decrease in photosynthesis rate, as well as a signi?cant abnormal stem elongation when grown under 100% R light. It is concluded that the RB ratio of 10:01 showed excellent performance in all growth parameters. This result has shown that the optimum lighting environment improves tomato plantlet cultures in vitro.
关键词： tomato plantlets,pigments,light-emitting diode (LED),biomass,photosynthesis
更新于2025-09-12 10:27:22
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Growth and glucosinolate profiles of a common Asian green leafy vegetable, Brassica rapa subsp. chinensis var. parachinensis (choy sum), under LED lighting
摘要： Technological advancements in light-emitting diode (LED) technology have led to the production, under controlled indoor conditions, of value-added crops that are high in nutritional or nutraceutical contents. In this study, the growth and glucosinolate (GSL) profiles of a common Asian vegetable, Brassica rapa subsp. chinensis var. parachinensis (choy sum or cai xin) were determined under LED lighting. The growth of choy sum was influenced by both the LED light intensity and spectrum, with plants grown under 160 μmol m?2 s?1 red-blue light (160RB) producing the highest shoot biomass (～100–300 % increment in adult plants). GSL content was found to vary across growth stages regardless of LED treatment. Total GSLs per gram fresh weight were four times higher in one-leafed seedlings than in adult plants. A shift from a high proportion of aliphatic GSLs in one-leafed seedlings to indolic and aromatic GSLs in three-leafed seedlings and adult plants was attributed to an increase in the proportion of glucobrassicin and/or 4-hydroxy-glucobrassicin, and gluconasturtiin which are known to have anti-cancer properties. Our results will be useful for the production of GSL-enhanced vegetables through urban farming.
关键词： Biomass,Glucosinolate,Brassica rapa var. parachinensis,Vegetable,LED,Urban farming
更新于2025-09-12 10:27:22
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Non-destructive tree volume estimation through quantitative structure modelling: Comparing UAV laser scanning with terrestrial LIDAR
摘要： Above-Ground Biomass (AGB) product calibration and validation require ground reference plots at hectometric scales to match space-borne missions' resolution. Traditional forest inventory methods that use allometric equations for single tree AGB estimation suffer from biases and low accuracy, especially when dealing with large trees. Terrestrial Laser Scanning (TLS) and explicit tree modelling show high potential for direct estimates of tree volume, but at the cost of time demanding fieldwork. This study aimed to assess if novel Unmanned Aerial Vehicle Laser Scanning (UAV-LS) could overcome this limitation, while delivering comparable results. For this purpose, the performance of UAV-LS in comparison with TLS for explicit tree modelling was tested in a Dutch temperate forest. In total, 200 trees with Diameter at Breast Height (DBH) ranging from 6 to 91 cm from 5 stands, including coniferous and deciduous species, have been scanned, segmented and subsequently modelled with TreeQSM. TreeQSM is a method that builds explicit tree models from laser scanner point clouds. Direct comparison with TLS derived models showed that UAV-LS reliably modelled the volume of trunks and branches with diameter ≥30 cm in the mature beech and oak stand with Concordance Correlation Coefficient (CCC) of 0.85 and RMSE of1.12 m3. Including smaller branch volume led to a considerable overestimation and decrease in correspondence to CCC of 0.51 and increase in RMSE to 6.59 m3. Denser stands prevented sensing of trunks and further decreased CCC to 0.36 in the Norway spruce stand. Also small, young trees posed problems by preventing a proper depiction of the trunk circumference and decreased CCC to 0.01. This dependence on stand indicated a strong impact of canopy structure on the UAV-LS volume modelling capacity. Improved flight paths, repeated acquisition flights or alternative modelling strategies could improve UAV-LS modelling performance under these conditions. This study contributes to the use of UAV-LS for fast tree volume and AGB estimation on scales relevant for satellite AGB product calibration and validation.
关键词： Above-Ground Biomass (AGB),Forest,UAV,Laser scanning,Quantitative Structure Model (QSM)
更新于2025-09-12 10:27:22
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Feasibility study of gross calorific value, carbon content, volatile matter content and ash content of solid biomass fuel using laser-induced breakdown spectroscopy
摘要： Rapid determination of the solid biomass fuel properties is essential for optimizing the combustion process of biomass. In this work, a feasibility study on using laser-induced breakdown spectroscopy (LIBS) in conjunction with partial least squares (PLS) for simultaneous measurement of gross calori?c value, carbon content, volatile matter content and ash content was carried out for 66 wood pellet samples. The best quantitative analysis results were obtained with the PLS model based on spectra that combined baseline correction with Z-score standardization. The root mean square error of prediction (RMSEP) of the gross calori?c value, carbon content, volatile matter content and ash content were 0.33 MJ/kg, 0.65%, 1.11% and 0.38% respectively, while the average standard deviation (ASD) were 0.08 MJ/kg, 0.15%, 0.43% and 0.16% respectively.
关键词： Gross calori?c value,Carbon content,Solid biomass fuel,Ash content,Volatile matter,Laser-induced breakdown spectroscopy (LIBS)
更新于2025-09-12 10:27:22
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Monitoring the Spatio-Temporal Variations of C3/C4 Grass Species Using Multispectral Satellite Data
摘要： Grass that follows a C3 and C4 photosynthetic pathway represents a fundamental component of grass species functional type, with outstanding services in grassland ecosystems. These grasses differ in morphology, phenology and physiological features, over time, due to varying environmental requirements. These features determine the success of their discrimination using remotely sensed data and their response in Aboveground Biomass (AGB) over time. For decades, the lack of appropriate remote sensing data sources compromised C3 and C4 grasses monitoring over space and time. This has resulted in uncertainties in understanding their potential and contribution to the provision of services. The aim of this study was to determine the optimal period to discriminate C3 and C4 grass species. The study additionally estimated species AGB over space and time. This was achieved, using Sentinel 2 satellite data with Discriminant Analysis (DA) and sparse partial least squares regression (SPLSR) algorithms. The winter peak was shown to present the best temporal window for discriminating C3 and C4 grasses. This period was also associated with higher species AGB (±1.11kg/m2) for both species as they have reached their peak. Although summer period was associated with reasonably high classification accuracies, highest errors (±20%) were encountered and this period had higher AGB, as both species were in their early stages of growth. The discrimination of C3 and C4 and AGB variations were significantly (α = 0.05) contributed by red edge, NIR and SWIR portions of the electromagnetic spectrum. These variables managed to capture species phenological, physiological and morphological contrasts as well as spatial variations over time.
关键词： classification error,seasonal changes,temporal window,aboveground biomass
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Afrisar-Tropisar: Forest Biomass Retrieval by P-Band Sar Tomography
摘要： The objective of this paper is to provide a better understanding of tomographic capabilities to estimate aboveground biomass (AGB) in dense forested areas at P-band. The analysis is carried out on airborne data acquired over sites in French Guyana and in Gabon during the ESA campaigns TropiSAR and AfriSAR 2015, respectively. Over both sites, P-band to-mography allows us to retrieve the vertical structure of the forest, to better characterize the ground and/or volume scattering mechanisms and to provide a unique solution for the AGB retrieval over the full range of biomass. The relationship between AGB and tomography data was found to be highly similar for forests across continents and sites: Paracou (French Guiana), Lope, Rabi and Mondah (Gabon). The developed metrics derived from the tomographic data have been found highly correlated to reference in situ AGB estimates (R2=0.85) and the root mean square error was 16% (for AGB ranging from 0 to 500 t/ha). These results have strong implications for the tomographic phase of the BIOMASS spaceborne mission.
关键词： BIOMASS mission,AfriSAR,Above Ground Biomass,P-band SAR tomography,forest,TropiSAR,forest vertical structure,Synthetic Aperture Radar
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Current status of the ISS-vegetation lidar Mission-MOLI
摘要： Canopy height is a factor to evaluate the above-ground biomass of a forest area by remote sensing techniques. Measurements of canopy height from space progress to understand the carbon budget. JAXA has studied a space-borne vegetation lidar (the Multi-footprint Observation Lidar and Imager: MOLI) that observes canopy height on the new exposed facility of the Japanese Experiment Module (JEM), the IVA-replaceable Small Exposed Experiment Platform (i-SEEP) on the International Space Station (ISS). The MOLI will be the first space lidar for earth environmental observation in Japan; a high-energy pulsed laser with a long operational life is key to the operation of the MOLI mission. The concepts underlying the MOLI and vacuum test of functional model of pulsed laser transmitter will be discussed herein.
关键词： above-ground biomass,space-borne vegetation lidar,MOLI,Canopy height,remote sensing,JAXA,ISS
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - SMOS-IC Vegetation Optical Depth Index in Monitoring Aboveground Carbon Changes in the Tropical Continents During 2010–2016
摘要： Tropical aboveground carbon changes during 2010-2016 were estimated by a newly developed vegetation optical depth (VOD) product retrieved from the low-frequency L-band (1.4 GHz) passive microwave observations from the Soil Moisture and Ocean salinity (SMOS) satellite. The aboveground carbon changes estimated by VOD in the tropical region during 2010-2016 indicate the tropical region acts as a net carbon source of 111 Tg C yr-1 during 2010-2016. The declines in tropical aboveground carbon were found mainly in eastern America, African drylands and Indonesia.
关键词： carbon changes,SMOS-IC,aboveground biomass,vegetation optical depth,tropical region
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - SMOS-IC: Current Status and Overview of Soil Moisture and VOD Applications
摘要： In 2017, the new SMOS-IC retrieval product of soil moisture (SM) and L-band Vegetation Optical depth (L-VOD) was developed. This product relies on a two-parameter inversion of the L-MEB model (L-band Microwave Emission of the Biosphere) which requires little ancillary information and was found to be accurate, making it very well-suited for application in agriculture, hydrology, climate and vegetation monitoring. In this communication we present recent improvements in the SMOS-IC retrieval algorithm and recent applications using the soil moisture or VOD retrievals from the SMOS-IC data set. SMOS-IC SM is available at the French CATDS center.
关键词： carbon stocks,biomass,SMOS,VOD,SMOS-IC,soil moisture
更新于2025-09-10 09:29:36