## 3 Results
### Evolution Characteristics of the ESV in Different Landform Types
#### 3.2.1 Temporal and Spatial Variation in the ESV in Different Landform Types
Only shrubland and grassland showed a decreasing trend in the ESV, and the combined decrease in both (USD 1.059 billion) was higher than the combined decrease in the first four (USD 937 million). The decline was due to the decrease of 432,307.60 \(\mathrm{hm}^{2}\) in shrubland and grassland in the pure-karst area. In total, 296,676 \(\mathrm{hm}^{2}\) of grassland was converted to forest, mainly in Dushan County, Huishui County, and Libo County in Qiannan Prefecture, and forest was the main contributor to the ESV in Guizhou Province. In addition, 98,380.20 \(\mathrm{hm}^{2}\) of grassland was converted to forest, which mainly occurred in Weining County in Bijie City, Panzhou City in Liupanshui City, and Xinyi City in Qianyinan Prefecture. As a result, the area of forest in the pure-karst area increased, and the proportion of the forest ESV increased further, from 77.29% in 1985 to 81.74%. The ESV of cropland, shrubland, and grassland declined in the semi-karst area, while the ESV of other land-use types maintained an increasing trend. Shrubland, in particular, had the largest decrease, reaching USD 251 million, a decrease of 57.23%. This was followed by grassland, with a decline of USD 141 million or 56.23%. Cropland had a relatively small decline of USD 40 million. The percentage of ESV in cropland declined from 12.80% in 1985 to 11.69% in 2020. Over the past 35 years, the forest in the ESV increased by USD 666 million, mainly in the northern and central regions of Guizhou Province such as Suiyang County and Zheng'an County in Zunyi City, Qianxi City, and Zhijin County in Bijie City. The contribution of the ESV of forest areas increased from 75.05% to 80.04% in the beginning. The added value of the ESV in water was USD 132 million, which was sporadically distributed in areas such as Qingzhen City, Sinan County, and Weining County. The ESV of shrubland and grassland in the non-karst area decreased by USD 492 million, with both categories decreasing by more than half, at 50.23% and 59.02%, respectively. The decline was due to the conversion of 73.53% of the shrubland in the non-karst area into forest with the implementation of the policy of hillclosing afrorestation and ecological environmental protection, mainly in the regions of Pu'an County, Xinyi City, and Yanhe County. Approximately 90% of the properties of the original grassland also changed. A total of 56.29% of the grassland was transformed into forest and 34.65% was transformed into cropland, and this transformation was concentrated in the western edge in Guizhou Province (Xinyi City, Weining County, and Pu'an County). The ESV of water and forest areas showed an upward trend, with a combined increase of USD 576 million over the past 35 years, mainly because the large cropland areas in Wangmu County, Zhengfeng County, and Ziyun County, located in the non-karst areas, were converted to forest. Meanwhile, the ESV in forest areas accounted for more than 89% of the total ESV during the same period, and the ESV in water increased from 0.83% to 2.74%. The rise in the water ESV was inextricably linked to the fact that Guizhou Province has spent three years building water transportation infrastructure, which had a significant impact, resulting in a significant increase in water.