Paying attention to the ecosystem service value (ESV) of different karst landform types is of great benefit to the green, sustainable, and high-quality development of the ecological environment in Guizhou Province. Based on the eight-period China Land Cover Dataset (CLCD) from 1985 to 2020, we compared and analyzed the ecosystem service value and its temporal and spatial variation characteristics of different karst landforms with the equivalent factor method in the study. The results revealed that the overall ecological environment of Guizhou Province showed a tendency to improve. Over the past 35 years, the net increase in the ecosystem service value in Guizhou Province was USD 385 million, with the largest increase occurring from 2015 to 2020. The overall spatial distribution is characterized by continuous low values in the middle and concentrated high values in the surrounding areas. Some of the local ecological environment in Guizhou Province is still not well-preserved. The ecosystem service value in the pure-karst area has decreased by USD 122 million over the past 35 years, mainly in Dushan County and Libo County, Qiannan Prefecture. The semi-karst area has increased by USD 367 million, concentrated in the northern and central areas of Guizhou Province. The non-karst area increased by USD 140 million, mostly distributed in Pu’an County, Xingyi City, and Yanhe County. In terms of the ecosystem service value per unit area, the results were as follows: non-karst areas > pure-karst areas > semi-karst areas. The ecosystem service value of each geomorphological area varied with the elevation and slope, showing an inverted “V” trend, first increasing and then decreasing. The maximum ecosystem service value in the pure-karst and semi-karst areas was between 800 m and 1100 m above sea level, and the non-karst area was in the range of 500 m to 800 m. The maximum ecosystem service value in the non-karst areas and semi-karst areas was within the gradient of 15° to 25°, and the pure-karst area was between 6° and 15°. The forest contributed most to the ecosystem service value of each karst landform, followed by cropland, and finally shrubland and grassland. Guizhou Province should pay attention to the protection of forest and cropland ecosystems in terms of future land management, especially with regard to ecological construction in pure-karst landform areas.

Karst regions are exceptionally responsive to global change with their harsh natural environment, fragile ecology, and acute human-land conflicts. The reconstruction of cropland spatial pattern in karst areas during the historical period is typical for studying human-land relations in karst areas and has important practical significance for climate study. The ecological environment changes at regional and global scales, primarily to provide essential data and a theoretical basis for studying the inverse evolution of rock desertification in karst areas. Guizhou province, a typical karst area, was selected as the research area in 1820. Based on the correction of historical population data and cropland data, a reconstruction model of cropland spatial pattern in karst areas during the historical period was constructed by selecting factors such as elevation, slope, soil types, organic matter content, climatic productivity potential, distance to river and distance from settlements to reconstruct the spatial pattern distribution of cropland in 1820 of Guizhou. The results show that the data on cropland recorded in Guizhou during the Qing dynasty is too low, mainly due to Yin-Ni and the policy of Tu-Di-Mian-Ke. In 1820, the total area of revised cropland in Guizhou was 1,851,792 hm², with the highest proportion of 14.32% in Dading Fu and the lowest in Songtao Ting at 1.6%. Only 30% of the grid in Guizhou has a cropland distribution. It is mainly concentrated in the central part of Qianzhong District (Anshun and Guiyang Fu), the southern part of Qianbei District (Pingyue Fu and southern Zunyi Fu), the western part of Qiandongnan District, the central and eastern parts of the Qiandongbei District. The overall average reclamation rate of land in Guizhou is 10.93%, the highest reclamation intensity in Qianzhong District, with 8.5% of grids ≥ 50%, and the smallest in Qianxinan District, with only 1.65% of grids ≥ 50%. The analysis is validated by comparing the reconstruction model and the reconstruction results. It can be seen that the reconstruction model and research results of this paper can more objectively reflect the distribution of cropland in karst areas during the historical period, and the reconstruction model is suitable for karst areas with low productivity levels.

Net biome productivity (NBP), which takes into account abiotic respiration and metabolic processes such as fire, pests, and harvesting of agricultural and forestry products, may be more scientific than net ecosystem productivity (NEP) in measuring ecosystem carbon sink levels. As one of the largest countries in global carbon emissions, in China, however, the spatial pattern and evolution of its NBP are still unclear. To this end, we estimated the magnitude of NBP in 31 Chinese provinces (except Hong Kong, Macau, and Taiwan) from 2000 to 2018, and clarified its temporal and spatial evolution. The results show that: (1) the total amount of NBP in China was about 0.21 Pg C/yr¹. Among them, Yunnan Province had the highest NBP (0.09 Pg C/yr¹), accounting for about 43% of China’s total. (2) NBP increased from a rate of 0.19 Tg C/yr¹ during the study period. (3) At present, NBP in China’s terrestrial ecosystems is mainly distributed in southwest and south China, while northwest and central China are weak carbon sinks or carbon sources. (4) The relative contribution rates of carbon emission fluxes due to emissions from anthropogenic disturbances (harvest of agricultural and forestry products) and natural disturbances (fires, pests, etc.) were 70% and 9.87%, respectively. This study emphasizes the importance of using NBP to re-estimate the net carbon sink of China’s terrestrial ecosystem, which is beneficial to providing data support for the realization of China’s carbon neutrality goal and global carbon cycle research.

Karst regions are exceptionally responsive to global change with their harsh natural environment, fragile ecology, and acute human-land conflicts. The reconstruction of the spatial pattern of cropland in karst areas during the historical period is typical for studying human-land relations in karst areas and has important practical significance for the study of climate. The ecological environment changes at regional and global scales, primarily to provide essential data and a theoretical basis for studying the inverse evolution of rock desertification in karst areas. Guizhou province, a typical karst area, was selected as the research area in 1820. Based on the correction of historical population data and cropland data, a reconstruction model of the spatial pattern of cropland in karst areas during the historical period was constructed by selecting factors such as elevation, slope, soil types, organic matter content, climatic productivity potential, distance to river and distance from settlements to reconstruct the spatial pattern distribution of cropland in Guizhou in 1820. The results show that the data on cropland recorded in Guizhou during the Qing dynasty are too low, mainly due to Yin-Ni and the policy of Tu-Di-Mian-Ke. In 1820, the total area of revised cropland in Guizhou was 1,851,792hm², with the highest proportion of 14.32% in Dating Fu and the lowest in Songtao Ting at 1.6%. Only 30% of the grid in Guizhou has a cropland distribution. It is mainly concentrated in the central part of Qianzhong District (Anshun and Guiyang Fu), the southern part of Qianbei District (Pingyue Fu and southern Zunyi Fu), the western part of Qiandongnan District, the central and eastern parts of the Qiandongbei District. The overall average reclamation rate of land in Guizhou is 10.93%, the highest reclamation intensity in Qianzhong District, with 8.5% of grids ≥ 50%, and the smallest in Qianxinan District, with only 1.65% of grids ≥ 50%. The reconstruction results are more reasonable and can objectively reflect cropland distribution in karst areas during the historical period. The reconstruction model is suitable for karst areas with low productivity levels.