## 3 Results
### Trends of Vegetation GPP, NPP, and VT over the Rajmahal Hills  
The spatial distribution of the long-term (2001-2021) trend of GPP, NPP, and VT over Rajmahal Hills is shown in Figure 6, along with the histogram. Overall, increasing GPP and VT trend over the Rajmahal Hills. Approximately 86% of areas in Rajmahal Hills were found under the increasing VT trend (up to 0.112 mm/day), whereas \(\sim\)46% of areas were found under the increasing GPP trend (up to 0.304 gC/m\({}^{2}\)/day). Still, \(>\)50% of areas over the Rajmahal Hills were found under the decreasing GPP trend. The overall physiographic development of vegetation cover, including leaf area index (LAI) and canopy density, could have influenced increasing GPP and VT trends. On the other hand, comparatively larger \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Periods** & **1990–2000 (D1)** & **2000–2010 (D2)** & **2010–2020 (D3)** \\ \hline Vegetation regrowth in the mining area (@m\({}^{2}\)) & 0.83 & 1.12 & 0.47 \\ GPP (KgC/day) & 2.84 & 3.67 & 1.41 \\ NPP (tC) & 0.30 & 0.37 & 0.22 \\ VT (mm/day) & 1000 & 1340 & 530 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Total increment in vegetation productivity and transpiration due to vegetation regrowth in mining areas during the study periods. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Periods** & **2000–2010** & **2010–2020** & **2000–2020** \\ \hline Mines-induced vegetation loss (km\({}^{2}\)) & 3.06 & 8.10 & 22.29 \\ GPP (tC/day) & 0.01 & 0.04 & 0.09 \\ NPP (tC) & 1.25 & 2.77 & 7.27 \\ VT (mm/day) & 5200 & 13,630 & 30,190 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Total vegetation productivity and transpiration losses caused due to mines-induced vegetation loss during 2000–2020. areas were observed under the decreasing NPP trend was observed over the Rajmahal Hills, wherein very few areas were observed under the increasing NPP trend. About 93% of the area of the Rajmahal Hills was found under decreasing NPP trend (up to 0.03 \(\mathrm{KgC/m^{2}/day}\)) during 2001-2021, while only 7% area of the Rajmahal Hills was found under an increasing NPP trend (up to 0.017 \(\mathrm{KgC/m^{2}/day}\)). The decreasing GPP and NPP trend statistics indicate that both sequestration capacity and carbon stock of Rajmahal Hills were falling, which is a critical issue. The decreasing vegetation NPP trend over the Rajmahal Hills seems to have resulted from the gradual loss of vegetation cover primarily caused by anthropogenic activities (e.g., mining, settlement encroachments, transportation networks, etc.). The higher respiration fluxes of vegetation triggered by environmental, soil, and climatic factors could have also affected the vegetation GPP and trends over Rajmahal Hills. The aspects of higher respiration fluxes of vegetation, climate change (rising temperatures and changing precipitation patterns), etc., impacts on decreasing NPP trend over Rajmahal Hills need to be well understood. It's important to note that these factors may act in combination or independently. Therefore, it's essential to understand the specific context and conduct further research to determine the cause of decreasing NPP. It is distinguishable from Figure 7 that the decreasing GPP, NPP, and VT trends were mainly associated with the mining-induced vegetation cover loss regions over the Rajmahal Hills. All the mining sites (zoomed regions in Figure 6) are noted with persistent decreasing  
Figure 6: Spatial pattern of long-term (2001–2021) (**a**) GPP, (**b**) NPP, and (**c**) VT trend over the Rajmahal Hills. (**d–f**) are the GPP, NPP, and VT histograms, respectively. t trends of all three variables, which indicates that the gradual vegetation cover loss due to stone and coal mining activity has triggered a significant loss in vegetation productivity and transpiration. Apart from the decreasing trend, increasing GPP, NPP, and VT trend pixels were also observed over the vegetation recovery sites in mining areas (highlighted in Z3 using a maroon color dotted circle).