## 3 Results and Discussion
### Annual Changes in GPP
Meanwhile, the average GPP estimation in forests over the past two decades increased dramatically compared to that for the other two types of land use from 1995 to 2014 (544.97 to 846.40 gC m\({}^{-2}\) year\({}^{-1}\)). However, in general, the mean GPP estimated for the settlement and in agriculture and grassland land cover types was almost similar, and that for the forest increased over the past two decades. This study found that the  
Figure 4: Annual gross primary production (GPP) distribution in Denpasar from Landsat satellite data analysis. The grey colour indicates that the area is not counted due to land use types such as water and others. (**a**) 1995; (**b**) 2003; and (**c**) 2014.  
estimated GPP for the settlement region is half of that for agriculture and grassland and that a change of 1 ha of agriculture and grassland into settlement will cause Denpasar city to lose 3 tC ha\({}^{-1}\) year\({}^{-1}\) of carbon uptake carbon by green vegetation (GPP). The region-wide net decrease in GPP was approximately 7793.96 tC year\({}^{-1}\) during the past two decades, a decrease of 12.65% from the GPP value in 1995 (Table 5). The estimated total GPP decreased during the 20-year period with an average decline of 0.63% per year. However, the fastest decline occurred in the first nine years compared to 2003 to 2014 (Table 6), which is similar to the decrease in the agriculture and grassland use type. Interestingly, based on land use data, GPP estimates increased for settlements and forests, although the forest area decreased, while a decline in the value of estimated GPP occurs only in the agriculture and grassland use type. The GPP estimate for settlements increased at a rate of 13.31% per year, while during 2003 to 2014, the increase in the GPP estimate was less than that for the first nine years, and over the past 20 years, the increase has been large, reaching 10.68% per year. The estimated GPP in forests over the past two decades has continued to grow, even though the forest area has declined, with the fastest growth occurring from 1995 to 2003. Decreasing agricultural and grass land use has also led to a decline in the value of GPP estimates, and the decline in the past 20 years reached more than 50%. The fastest change, a value of 3.75% per year, was found from 1995 to 2003, and from 2003 to 2014, the value of estimated GPP loss was approximately 2.57% per year. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Land Use** & **1995 to 2003** & **2003 to 2014** & **1995 to 2014** \\ \hline Settlement & 13.31\% & 3.56\% & 10.68\% \\ Forest & 1.61\% & 0.93\% & 1.36\% \\ Agriculture and grass & \(-\)3.75\% & \(-\)2.57\% & \(-\)2.71\% \\ Total & \(-\)1.08\% & \(-\)0.27\% & \(-\)0.63\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Changes in GPP estimation per year (% year\({}^{-1}\)) for each type of land use from 1995 to 2014. Figure 5: Mean of annual GPP in Denpasar from Landsat satellite data analysis of each land use type. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Land Use** & **1995 to 2003** & **2003 to 2014** & **1995 to 2014** \\ \hline Settlement & 119.76\% & 42.72\% & 213.64\% \\ Forest & 14.47\% & 11.15\% & 27.23\% \\ Agriculture and grass & \(-\)33.72\% & \(-\)30.88\% & \(-\)54.19\% \\ Total & \(-\)9.72\% & \(-\)3.25\% & \(-\)12.65\% \\ \hline \hline \end{tabular}
\end{table} 
Table 5: GPP estimation changes in each type of land use in Denpasar from 1995 to 2014. The current study found that the total value of estimated GPP for the settlement land use type increased dramatically. From the lowest proportion in 1995, this land use type achieved the highest ability to uptake total carbon through vegetation of all land use types in 2014. The average value of estimated GPP is similar in the three observation periods, although the average value is lower than the result obtained by [PERSON] et al. (2019) (390.24 gC m\({}^{-2}\) year\({}^{-1}\)), which may be due to the different methods used in GPP calculation.