# Siberian Pine and Larch Response to Warming-Drying Climate in the Southern Boundary of Their Range
## Materials and Methods
### Satellite Data Analysis
#### 2.5.2 MODIS-Based Analysis of the Land Cover Classes in the Tannu-Ola Ridge  
We used the MODIS MOD12Q1 product (v6.1; [[https://lpdaac.usgs.gov/products/mcd12q1v061](https://lpdaac.usgs.gov/products/mcd12q1v061)]([https://lpdaac.usgs.gov/products/mcd12q1v061](https://lpdaac.usgs.gov/products/mcd12q1v061)); accessed on 12 January 2024) to estimate changes in the cover of Siberian pine and larch stands. That dataset represents annual global land cover maps [41]. We used IGBP classification layers to assess changes in land cover. Burned areas were removed from the used land cover maps based on the MODIS MCD64A1 product ([[https://lpdaac.usgs.gov/products/mcd64a1v061](https://lpdaac.usgs.gov/products/mcd64a1v061)]([https://lpdaac.usgs.gov/products/mcd64a1v061](https://lpdaac.usgs.gov/products/mcd64a1v061)); accessed on 12 January 2024). Both products have a 500 m spatial resolution. These datasets were downloaded from NASA's EarthData portal ([[https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)]([https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)); accessed on 12 January 2024).  
The Tannu-Ola Ridge was delineated based on a physical map and the Copernicus GLO30 Digital Elevation Model ([[https://spacedata.copernicus.eu/collections/copercius](https://spacedata.copernicus.eu/collections/copercius)]([https://spacedata.copernicus.eu/collections/copercius](https://spacedata.copernicus.eu/collections/copercius))  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Test** & **Elevation,** & **Tree Species** & **Mean Age, Years** & **Total Length** & **Sample Depth** & **EPS** & **First Order Auto-tocrelation** & **Mean Sensitivity** \\ \hline \multirow{2}{*}{1} & 2030 & _Larix sibirica_ & 14 & 2000–2023 & 26 & 0.93 & 0.63 & 0.26 \\ \cline{2-8}  & (REG) & _Pinus sibirica_ & 21 & 1989–2023 & 25 & 0.93 & 0.80 & 0.20 \\ \hline \multirow{2}{*}{2} & 2030 & _Larix sibirica_ & 80 & 1798–2023 & 23 & 0.97 & 0.75 & 0.24 \\ \cline{2-8}  & \multirow{2}{*}{2030} & _Pinus sibirica_ & 77 & 1894–2023 & 18 & 0.95 & 0.91 & 0.17 \\ \hline \multirow{2}{*}{3} & \multirow{2}{*}{1980} & _Larix sibirica_ & 136 & 1720–2023 & 20 & 0.97 & 0.61 & 0.19 \\ \cline{2-8}  & _Pinus sibirica_ & 85 & 1888–2023 & 17 & 0.93 & 0.62 & 0.12 \\ \hline \multirow{2}{*}{4} & \multirow{2}{*}{1580} & _Larix sibirica_ & 111 & 1850–2023 & 24 & 0.97 & 0.59 & 0.19 \\ \cline{2-8}  & _Pinus sibirica_ & 73 & 1932–2023 & 20 & 0.97 & 0.63 & 0.15 \\ \hline \multirow{2}{*}{5} & \multirow{2}{*}{1360} & _Larix sibirica_ & 130 & 1793–2023 & 24 & 0.98 & 0.60 & 0.27 \\ \cline{2-8}  & & _Pinus sibirica_ & 81 & 1886–2023 & 23 & 0.96 & 0.72 & 0.18 \\ \hline \multirow{2}{*}{6} & \multirow{2}{*}{1210} & _Larix sibirica_ & 178 & 1789–2023 & 21 & 0.97 & 0.78 & 0.22 \\ \cline{2-8}  & & _Pinus sibirica_ & 117 & 1812–2023 & 20 & 0.96 & 0.79 & 0.19 \\ \hline \multirow{2}{*}{7} & \multirow{2}{*}{1090} & _Larix sibirica_ & 55 & 1946–2023 & 36 & 0.99 & 0.55 & 0.37 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Descriptive statistics of tree ring chronologies.  
digital-elevation-model; accessed on 17 January 2024). The GLO30 was obtained from the OpenTopography geoportal ([[https://portal.opentopography.org](https://portal.opentopography.org)]([https://portal.opentopography.org](https://portal.opentopography.org)); accessed on 17 January 2024). We analyzed territories (about 20,060 km\({}^{2}\)) with elevations >1000 m.  
All spatial data were transformed to the UTM projection (zone 46, WGS84) and clipped to the territory of the Tannu-Ola Ridge. We calculated harmonized maps for the two periods (2001-2003 and 2020-2022) using the majority filter cell statistics. We reduced the number of the analyzed land cover classes by merging IGBP classes concerning local ones that are typical for the Tannu-Ola Ridge (Table 3). Changes were detected based on the generated maps and the transformation matrix of land cover classes.