## 2 Materials and Methods
### Characteristic Variables Extraction and Selection
#### 2.5.2 GEDI Parameters  
Compared with GEDI L2A level data, L2B standard data products include additional vertical profile indicators such as total cover, total plant area volume density profile, directional gap probability profile, and foliage height diversity. Table 3 contains fourteen modeling indices and six quality screening indices.  
In addition to the vegetation indices extracted from the Landsat 9 images, as well as the canopy cover, leaf area index, and other factors provided by GEDI, this research also used topographic factors (elevation, slope, and aspect) to investigate the layout of _Quercus aquifolioides_ carbon storage on various slopes and aspects.  
\begin{table}
\begin{tabular}{c c c} \hline
**Vegetation Index** & **Full Name** & **Expression** \\ \hline Band reflectance & B1-Coastal, B2-Blue, B3-Green, B4-Red, B5-NIR, & - \\  & B6-SWIR 1, B7-SWIR 2 & \\ NDVI & Normalized Difference Vegetation Index & NDVI = (NIR \(-\) R)/(NIR + R) \\ RVI & Ratio Vegetation Index & RVI = NIR/R \\ DVI & Difference Vegetation Index & DVI = NIR \(-\) R \\ RGVI & Red-green Vegetation Index & RGVI = (R \(-\) G)/(R + G) \\ GNDVI & Green Normalized Difference Vegetation Index & GNDVI = (NIR \(-\) G)/(NIR + G) \\ IPVI & Infrared Vegetation Index & IPVI = NIR/(NIR + R) \\ EVI & Enhanced Vegetation Index & EVI = (2.5 \(\times\) (NIR \(-\) R))/(NIR + 6 \(\times\) R \(-\) 7.5 \(\times\) B + \\ ARVI & Atmospherically Resistant Vegetation Index & ARVI = (NIR \(-\) (2 \(\times\) R \(-\) B))/(NIR + (2 \(\times\) R \(-\) B)) \\ VARI & Visible atmospherically resistant Index & VARI = (G \(-\) R)/(G + R\(-\)B) \\ \hline \end{tabular}
\end{table}
Table 2: Formulas of the vegetation index.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Parameters** & **Description** & **Parameters** & **Description** \\ \hline cover & Total canopy cover & fhd\_normal & Foliage height diversity index \\ \hline pai & Total plant area index. & landsat\_treecover & Landsat tree canopy cover \\ \hline degrade\_flag & Degrade flag & solar\_elevation & Solar elevation \\ \hline lon\_lowestmode & \begin{tabular}{c} Longitude of center of \\ lowest mode \\ \end{tabular} & lat\_lowestmode & Latitude of center of lowest mode \\ \hline pgap\_theta & Total gap between plant & modis\_treecover & \begin{tabular}{c} Percent tree cover from \\ MODIS data \\ \end{tabular} \\ \hline digital\_elevation\_model & \begin{tabular}{c} Digital elevation model height \\ above the WGS84 ellipsoid \\ \end{tabular} & modis\_nonvegetated & \
\begin{tabular}{c} Percent non-vegetated from \\ MODIS data \\ \end{tabular} \\ \hline leaf\_off\_doy & Leaf-off start day-of-year derived & leaf\_on\_doy & Leaf-on start day-of-year derived \\ \hline rg & The ground energy value in the waveform & rv & The vegetation energy value in the waveform \\ \hline rh100 & Height above the ground at the start of the waveform signal & sensitivity & The waveform penetrable to the \\ \hline leaf\_off\_flag &
\begin{tabular}{c} Indicating if the observation was \\ recorded under deciduous \\ forest conditions \\ \end{tabular} & quality\_flag & Flag simplifying selection of most useful data \\ \hline \end{tabular}
\end{table}
Table 3: Description of GEDI parameters.