[Evolution Trade-offs and Synergistic Relationships in Ecological Functional Areas Based on Ecosystem Service Bundles： A Case Study of the Turpan-Hami Region].

Clarifying the spatial distribution and compositional structure of the ecological functional zone and understanding the evolution of the trade-offs and synergies among multiple ecosystem services （ESs） are essential for scientific management and restoration of Turpan-Hami Region ecosystems. The objective of this study was to explore the driving forces of the trade-offs/synergies for each ecosystem service bundle （ESB） and to develop differentiated ecological management strategies based on the ecological characteristics. Six ecosystem services （carbon storage （CS）, water yield （WY）, soil retention （SR）, habitat quality （HQ）, food production （FP）, and aesthetic landscape provision （ALP））, were quantified in the Turpan-Hami Region. Based on this, the comprehensive ability of multiple ecosystem services in different regions was quantified by calculating the multiple ecosystem services landscape index （MESLI）. Then, the SOFM algorithm was used to identify the ESBs. According to the ecological structural characteristics of the ESBs, the ecological functional zones were divided. Furthermore, the trade-offs/synergies among the ESs in each ESB were analyzed using Spearman correlation analysis. The results showed that： ① The area of construction land in the Turpan-Hami Region increased the most from 2000 to 2020 at 87.10%, followed by cultivated land （13.47%）, and the area of grassland and unutilized land continued to decrease. ② In terms of temporal distribution, the mean value of FP in the Turpan-Hami Region increased and then decreased, the ALP decreased and then increased, WY showed an increasing trend, HQ and SR showed a gradual increasing trend, and no significant change was observed in the mean value of CS from 2000 to 2020. In terms of spatial distribution, the high value areas of WY, HQ, SR, ALP, and CS were all distributed in a contiguous pattern in the Tianshan Mountains Region. The high value areas of FP were mainly distributed in the croplands in the oases of the pre-mountain plains. ③ The mean value of MESLI in the Turpan-Hami Region was 0.49, indicating that the region as a whole had a weak capacity to provide multiple ecosystem services, and the integrity of the ecosystem structure was low. The overall spatial distribution of MESLI showed high in the center and west and low in the south, with obvious spatial differentiation. The area was dominated by low MESLI values, accounting for 79.46% of the total area. ④ The area was divided into four ESBs based on the clustering analysis： ecological conservation bundle （ECB）, ecological protection bundle （EPB）, food production bundle （FPB）, and ecologically fragile bundle （EFB）. The ECB accounted for 10.55%, which had the strongest ability to provide multiple ecosystem services （MESLI=1.88）. EPB was the smallest, accounting for 2.02% of the total area of the region. FPB accounted for 8.07% of the total area. EFB accounted for 79.36% of the total area of the region, and it had the weakest ability to provide multiple ecosystem services （MESLI=0.2）. ⑤ There were more synergistic relationships than trade-offs in the Turpan-Hami Region across the whole region. There were similarities and differences in trade-offs/synergies for the same combination of services in different service bundles. The research results can provide scientific basis for the sustainable development and ecological environment optimization in the Turpan-Hami Region.