## 3 Results Analysis
### Net Ecosystem Services Value
In addition, from the perspective of the ecosystem services type (Figure 7), the regulating service was the most important function of ESs in Ningde City, with a value of CNY 2092.64 \(\times\) 10\({}^{8}\) during the 20 years, accounting for 68.43% of the total ESV; followed by the supporting services, which accounted for 21.39%, while the cultural services had the lowest value, accounting for only 4.31% of the total value. Specifically, the regulating service, supporting service, provisioning service, and cultural service decreased from CNY 751.58 \(\times\) 10\({}^{8}\), CNY 241.41 \(\times\) 10\({}^{8}\), CNY 64.19 \(\times\) 10\({}^{8}\), and CNY 48.36 \(\times\) 10\({}^{8}\) in 2000 to CNY 704.03 \(\times\) 10\({}^{8}\), CNY 212.53 \(\times\) 10\({}^{8}\), CNY 60.76 \(\times\) 10\({}^{8}\), and CNY 43.15 \(\times\) 10\({}^{8}\) in 2020, respectively. The total ecosystem dis-services value in Ningde City showed a continuous increasing trend, with a total increase of CNY 3.25 \(\times\) 10\({}^{8}\) in 20 years, with an average annual increase of CNY 0.181 \(\times\) 10\({}^{8}\) (Figure 8). Apart from land-use-driven carbon emissions, the negative value caused by other negative effects continues to decrease; among them, water consumption accounted for the largest proportion, and its ratio hovered between 21.35 and 38.40%. Meanwhile, the negative value caused by pesticide pollution, plastic \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sub-Type**} & \multicolumn{3}{c}{**ESV (10\({}^{8}\) CNY)**} & \multicolumn{3}{c}{**Change Rate (\%)**} \\ \cline{2-7}  & **2000** & **2010** & **2020** & **2000–2010** & **2010–2020** & **2000–2020** \\ \hline Food production, FP & 24.11 & 20.01 & 20.50 & \(-17.00\) & 2.42 & \(-14.99\) \\ Material production, MP & 31.50 & 26.10 & 27.55 & \(-17.15\) & 5.55 & \(-12.55\) \\ Water supply, WS & 8.57 & 8.43 & 12.71 & \(-1.70\) & 50.80 & \(+48.23\) \\ Gas regulation, GS & 104.75 & 86.78 & 91.55 & \(-17.16\) & 5.50 & \(-12.60\) \\ Climate regulation, CR & 290.82 & 241.13 & 256.24 & \(-17.09\) & 6.27 & \(-11.89\) \\ Purify environment, PE & 88.47 & 73.93 & 79.78 & \(-16.44\) & 7.92 & \(-9.83\) \\ Hydrologic adjustment, HD & 267.53 & 235.19 & 276.46 & \(-12.09\) & 17.55 & \(-3.34\) \\ Soil conservation, SC & 121.90 & 100.96 & 166.90 & \(-17.17\) & 5.88 & \(-12.30\) \\ Maintaining nutrient cycle, MNC & 10.44 & 8.65 & 9.06 & \(-17.20\) & 4.79 & \(-13.23\) \\ Bio-diversity, BD & 109.07 & 90.56 & 96.57 & \(-16.97\) & 6.64 & \(-11.46\) \\ Aesthetic landscape, AL & 48.36 & 40.26 & 43.15 & \(-16.75\) & 7.18 & \(-10.78\) \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Changes in ecosystem services value (sub-type) in Ningde City during 2000–2020. Figure 7: ESV in Ningde City from 2000 to 2020 (by service type). film pollution, and fertilizer loss decreased from CNY 0.825 \(\times\) 10\({}^{8}\), CNY 0.005 \(\times\) 10\({}^{8}\), and CNY 1.804 \(\times\) 10\({}^{8}\) in 2000 to CNY 0.937 \(\times\) 10\({}^{8}\), CNY 0.027 \(\times\) 10\({}^{8}\), and CNY 1.927 \(\times\) 10\({}^{8}\) in 2020, respectively; its ratio declined from 10.91%, 0.07%, and 23.86% in 2000 to 8.67%, 0.25%, and 17.82% in 2020, respectively. It is worth noting that the negative value caused by land-use-driven carbon emissions presented an increasing trend, from CNY 5.179 \(\times\) 10\({}^{8}\) in 2000 to CNY 13.148 \(\times\) 10\({}^{8}\) in 2020, an increase of 153.90%. It can be seen from the comprehensive LUTs that with the conversion of cultivated land and forest land to built-up land, its area expands continuously, and carbon emissions also increase accordingly. As can be seen from Figure 9, the net value of ecosystem services in Ningde City decreased at first and then increased. The net value fell by 16.01% from CNY 1092.86 \(\times\) 10\({}^{8}\) in 2000 to CNY 917.93 \(\times\) 10\({}^{8}\) in 2010, and then rose to CNY 1000.08 \(\times\) 10\({}^{8}\) in 2020, with an increase of 8.95%. Figure 8: Ecosystem dis-services value in Ningde City from 2000 to 2020.