Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Field Data Collection
2.3. Lidar Data Collection
2.4. Supplementary Geospatial Data
2.5. Data Analysis
2.5.1. Derivation of Geospatial Layers from Lidar
2.5.2. Extracting Lidar Derived Metrics to Field Data
2.5.3. Random Forest
2.5.4. Statistical Analysis
3. Results
3.1. Differences in Classified Conifer and Deciduous Trees/Shrubs Using Lidar Metrics
3.2. Classification of Conifer vs. Deciduous Shrub/Tree in Post-Fire Peatlands Using Lidar
3.3. Proportion of Conifer and Deciduous Shrubs and/or Trees in Post-Fire Peatlands
3.4. Cumulative Growth of Conifers vs. Deciduous Tree and Shrubs in the Years Since Fire
4. Discussion
4.1. Use of Lidar to Identify Conifers and Deciduous Trees and Shrubs
4.2. Changes in Proportional Coverage of Conifers and Deciduous Tree/Shrubs
4.3. Spatial Variation in Vegetation Height in Bogs and Fens
4.4. Use of Remote Sensing and Possible Limitations
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Type | Lidar Metric | Description |
---|---|---|
Vegetation Structural Metrics | C123_Max_hgt | Maximum height of all returns from all channels with heights > 0.5 m from ground |
C123_Min_hgt | Minimum height of all returns with heights > 0.5 m from ground | |
C123_IQR_hgt | Interquartile range of height using all returns from all channels with heights > 0.5 m from ground. IQR = p75 height − p25 height | |
C123_Ske_hgt | Skewness of height values using all returns with heights > 0.5 m from ground | |
C123_Kur_hgt | Kurtosis of height values using all returns with heights > 0.5 m from ground | |
C123_Cover | Percent cover using all returns from all channels with heights > 0.5 m from ground | |
Vegetation Laser Return Intensity | C1_Min_int | C1 minimum intensity of returns with heights > 0.5 m from ground |
C1_Max_int | C1 maximum intensity of returns with heights > 0.5 m from ground | |
C1_Ske_int | C1 skewness of intensity values using returns with heights > 0.5 m from ground | |
C1_Kur_int | C1 kurtosis of intensity values using returns with heights > 0.5 m from ground | |
NDIR_C1_C2 | Normalized Difference InfraRed index using returns with heights > 0.5 m from ground calculated using the formula (C1 − C2)/(C1 + C2) | |
C2_Min_int | C2 minimum intensity of returns with heights > 0.5 m from ground | |
C2_Max_int | C2 maximum intensity of returns with heights > 0.5 m from ground | |
C2_Ske_int | C2 skewness of intensity values using returns with heights > 0.5 m from ground | |
C2_Kur_int | C2 kurtosis of intensity values using returns with heights > 0.5 m from ground | |
Environmental/Topographic | Slope | 5 m resolution slope generated based on LasTool generated DEM |
Aspect | 5 m resolution aspect generated based on LasTool generated DEM | |
TPI | Topographic position index generated using Jenness topographic position tool having a search radius of 50 m |
Variable Importance (%) | 5 YSF | 18 YSF | 30 YSF | 38 YSF | Unburned |
---|---|---|---|---|---|
IQR height | 19.8 | 19.7 | 19.9 | 18.7 | 18.5 |
NDIR | 17.1 | 15.6 | 16.7 | 15.5 | 17.9 |
Percent Cover | 15.5 | 17.1 | 17.2 | 18.6 | 16.0 |
Aspect | 14.9 | 16.5 | 15.5 | 15.5 | 16.4 |
TPI | 16.6 | 16.2 | 15.9 | 16.1 | 15.8 |
Slope | 16.1 | 15.0 | 14.8 | 16.7 | 15.3 |
Vegetation structural metric | |||||
Vegetation laser return intensity | |||||
Environmental/Topographic |
Training Data | Sensitivity (%) | Accuracy (%) |
Deciduous shrubs | 1.00 | 0.98 |
Deciduous trees | 0.95 | 0.96 |
Conifer trees | 0.96 | 0.96 |
Validation Data | Sensitivity (%) | Accuracy (%) |
Deciduous shrubs | 0.92 | 0.92 |
Deciduous trees | 0.66 | 0.71 |
Conifer trees | 0.62 | 0.71 |
Deciduous Shrubs | Deciduous Trees | Conifer Trees | Commission Error | Omission Error | |
---|---|---|---|---|---|
Deciduous shrubs | 150 | 5 | 7 | 0.07 | 0.15 |
Deciduous trees | 12 | 239 | 102 | 0.32 | 0.27 |
Conifer trees | 14 | 84 | 197 | 0.33 | 0.36 |
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Enayetullah, H.; Chasmer, L.; Hopkinson, C.; Thompson, D.; Cobbaert, D. Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar. Atmosphere 2022, 13, 112. https://doi.org/10.3390/atmos13010112
Enayetullah H, Chasmer L, Hopkinson C, Thompson D, Cobbaert D. Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar. Atmosphere. 2022; 13(1):112. https://doi.org/10.3390/atmos13010112
Chicago/Turabian StyleEnayetullah, Humaira, Laura Chasmer, Christopher Hopkinson, Dan Thompson, and Danielle Cobbaert. 2022. "Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar" Atmosphere 13, no. 1: 112. https://doi.org/10.3390/atmos13010112
APA StyleEnayetullah, H., Chasmer, L., Hopkinson, C., Thompson, D., & Cobbaert, D. (2022). Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar. Atmosphere, 13(1), 112. https://doi.org/10.3390/atmos13010112