Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Site and Reference Data
2.2. Quantifying Understory Vegetation Densities using TLS Data
2.3. Modeling Understory Vegetation Density Using ALS Metrics
3. Results
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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ALS Metrics | Description | |
---|---|---|
Height-based (12 metrics) | Mean, relative mean, and standard deviation of heights (HMEAN, RHMEAN, SDH) | The mean and relative mean heights above the ground of all first returns |
Coefficient of variation of height (HCV) | Coefficient of height variation of all first returns | |
Skewness and kurtosis of height (HS, HK) | Skewness and kurtosis of the normalized heights of all first returns | |
Mean and standard deviation of heights within three layers (HM1/3, HM2/3, HM3/3, SD1/3, SD2/3, SD3/3) | Mean and standard deviation of heights lower than 1/3, between 1/3 and 2/3, and higher than 2/3 of the maximum height | |
Density-based (5 metrics) | Percentage of points over the ground (OGP) | The number of first returns classified as no-ground over the total first returns |
Points total number (PTN) | Total number of first returns | |
Percentage of points within three layers (PP1/3, PP2/3, PP3/3) | Percentage of points in three layers: Lower than 1/3, between 1/3 and 2/3, and higher than 2/3 |
Lower Understory (LU) | ||||
Adjusted-R² = 0.51; nRMSE = 20% | ||||
Metric | Estimate | Std. Err. | t value | p-level |
HM1/3 | 0.025 | 0.028 | 1.86 | 0.077 |
SD1/3 | 0.029 | 0.013 | 1.17 | 0.253 |
Upper Understory (UU) | ||||
Adjusted-R² = 0.77; nRMSE = 13% | ||||
Metric | Estimate | Std. Err. | t value | p-level |
HM1/3 | 0.029 | 0.003 | 8.77 | < 0.001 |
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Ferrara, C.; Puletti, N.; Guasti, M.; Scotti, R. Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration. Sensors 2023, 23, 511. https://doi.org/10.3390/s23010511
Ferrara C, Puletti N, Guasti M, Scotti R. Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration. Sensors. 2023; 23(1):511. https://doi.org/10.3390/s23010511
Chicago/Turabian StyleFerrara, Carlotta, Nicola Puletti, Matteo Guasti, and Roberto Scotti. 2023. "Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration" Sensors 23, no. 1: 511. https://doi.org/10.3390/s23010511
APA StyleFerrara, C., Puletti, N., Guasti, M., & Scotti, R. (2023). Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration. Sensors, 23(1), 511. https://doi.org/10.3390/s23010511