The restoration of the ecological environment in rocky desertification areas and economic development go hand in hand. With the support of the national policies from the “Ninth Five-Year Plan” to the “Thirteenth Five-Year Plan”, the related ecological industries and products derived from the control of rocky desertification in karst areas continue to emerge. It not only restrains and repairs the development of rocky desertification but also produces a higher regional economic value than the replaced industry, which has practical significance for targeted poverty alleviation and rural revitalization in rocky desertification areas. The thesis classifies and summarizes the development status of ecological products from the perspectives of the basic theory of ecological products, industrial model construction, industrial demonstration, quality monitoring and evaluation, product sales space, product value realization and improvement research and proposes some scientific problems to be solved. The dual attributes of ecology and economy of ecological products are integrated, and a sustainable industrial model and industrial value-added enlightenment for consolidating the achievements of rocky desertification control is proposed.

The efficient reactivity and mobility of dissolved organic matter (DOM) affect biogeochemical processes. As important components that link aboveground and belowground vertical systems under the binary 3D structure of karst, fissures provide soil–water–nutrient leakage channels and storage spaces. However, reports on DOM properties and drivers in fissured soil are extremely rare. This study characterizes DOM in the fissured soil of different vegetation types under medium-intensity rocky desertification conditions. Soil samples were characterized via ultraviolet (UV)–visible absorption spectroscopy and fluorescence excitation–emission matrix–parallel factor analysis. Five fluorescent fractions were identified. The controlling factors for the optical properties of soil DOM were determined via the redundancy analysis method. Results showed the following: (1) Dissolved organic C/soil organic C < 4.68 + 0.49‰, specific UV absorbance (SUVA)₂₅₄ and SUVA₂₆₀ exhibited low overall performance with the vast majority of the humification index (HIX) < 4, most of the fluorescence index (FI) ≥ 1.7, most of the biological index (BIX) in 0.6 < BIX < 1 and 31.67–41.67% of protein-like fractions. These data indicate that cleaved soil, except for topsoil, has low DOM content, weak aromaticity, and low humification; (2) Rainfall intensity, aperture, and near-surface vegetation type are the major causes of DOM transport and loss; and (3) Most DOM losses are likely to be protein-like and enhance the loss of soil P. In summary, environmental factors and the characteristics of fissures determine DOM content and migration, particularly rainfall intensity and vegetation type. The loss of lighter DOM components will be greater in an area with high karst desertification grade, strong fissure development, weaker soil aromaticity, and lower humification. These results provide a clearer basis for optimizing the fissure nutrient element migration scheme in karst areas.

The purpose of this study was to explore the effects of different vegetation restoration types on soil hydrology characteristics in the Karst Plateau Gorge and to clarify the soil moisture (θ) use characteristics. A barrel experiment was conducted to monitor θ and the water potential ($\Psi$) of three vegetation types (Zanthoxylum bungeanum (ZB), Zea mays L. (ZM), and Sophora tonkinensis (ST), Abandoned land (AL)) was used as a control to explore θ use conditions of each vegetation type. A larger surface permeability led to lower moisture storage. The soil moisture storage showed the law of ZM > ST > AL > ZB. The soil moisture storage also had obvious characteristics in dry-wet seasons. As a typical drought-tolerant crop, ZB responded more obviously to rainfall and had the highest effective replenishment amount and efficiency. Two processes were clearly involved in decreasing soil moisture, which could be divided into three stages of changes: a consumption period (CP), a moisture supplying period (SP), and a relatively stable period (RSP). CP occurred primarily in November to April, when θ was prone to water stress and required proper artificial replenishment. SP was characterized by limited rainfall replenishment in January and May, which significantly increased θ. During the rainy season, corresponding with RSP, θ fluctuated within a relatively stable range. At the end of the CP, the water shortage was more severe. In actual agricultural production, attention should be given to reasonable artificial recharge. This research aims to provide a theoretical basis for karst θ management.

Under extreme drought and climate change, golden pear trees have experienced problems such as yield reduction, dryness and death. This suggests that we know very little about the mechanisms regulating pear tree growth, assuming that meteorological factors positively influence plant sap flow. Based on this, we used the heat ratio method to monitor the sap flow of pear trees from June to December 2020, and recorded the changes in various environmental factors. The results showed that: (1) Sap flow velocity has obvious radial variability in tree sections; the sap flow velocity during the day was significantly higher than that at night (p < 0.05) and was higher in the growing season than in the non-growing season. (2) All environmental factors, except relative humidity and precipitation, were positively correlated with sap flow, vapor pressure deficit and photosynthetically active radiation, which are the key factors affecting daytime flow, and vapor pressure deficit and plant water potential are the key factors affecting nighttime flow. The linear regression results also showed that the daytime sap flow had a significant positive effect on the nighttime sap flow (p < 0.05). (3) The contribution of night flow to total daily flow varied from 17.3% to 50.7%, and most of the non-growing season values were above 40%. The results show that nighttime sap flow accounts for a significant portion of the pear tree’s water budget. Continuous irrigation during fruit enlargement and non-growing seasons will increase fruit yield and maintain plant sap flow activity to avoid death due to drought.

Rocky desertification is a common phenomenon in karst areas. Soil carbon and nitrogen storage is of great significance to the formation and evolution of ecosystems. Soil leakage is one of the important indicators in evaluating ecosystem stability. There are few studies on the response of carbon and nitrogen leakage below the surface of karst critical zones to forest ecosystems. The karst springs in the study area of Shibing Heichong, Bijie Salaxi and Guanling-Zhenfeng Huajiang in Guizhou, China, were selected to determine the variation characteristics of carbon and nitrogen content and karst spring outputs and their response to soil leakage. The results showed the following: (1) The content and output of carbon and nitrogen in karst springs in the three study areas showed obvious spatial differences. The carbon and nitrogen output of karst spring water was mainly concentrated in the rainy season. The carbon and nitrogen contents and output of karst springs in the Shibing Heichong study area were higher than those in the Bijie Salaxi and Guanling-Zhenfeng Huajiang study areas. (2) The carbon and nitrogen outputs of karst springs were mainly affected by flow. Land cover and land use in forests affect the carbon and nitrogen contents of karst springs and thus affect the output. (3) The higher the soil leakage of the karst spring was, the higher the carbon and nitrogen output. The leakage of the overlying soil in the Shibing Heichong study area was high, but the soil decline was small, and the stability of the forest ecosystem was relatively good. In summary, a lower degree of rocky desertification results in higher leakage from karst springs and higher risks of soil leakage; however, the ecosystem was relatively stable. Evaluating forest soil carbon and nitrogen loss and ecosystem stability in karst areas through the nutrient output of karst springs is of great significance for the prevention and control of rocky desertification areas.

Subtropical forests in southwestern karst areas are the top priority for ecosystem restoration, as studying the water absorption strategies of the major plants in these regions is crucial to determining the species distribution and coexistences within these seasonal subtropical forests, which will help us to cope with the forest ecosystem crisis under future climate change. We used the stable isotope ratios (δD and δ¹⁸O) of tree xylem and soil water to assess the seasonal changes in the water use patterns and hydrological niche separations of four dominant tree species in seasonal subtropical forests in southwestern karst areas. The results showed that the soil water’s isotopic composition varied gradiently in the vertical direction and that the variation of the soil water’s isotopic composition was greater in the shallow layer than in its depths. Juglans regia (HT) mainly depended on soil water at a depth of 30–60 cm (41.8 ± 6.86%) and fissure water (32.5 ± 4.21%), while Zanthoxylum bungeanum Maxim (HJ) and Eriobotrya japonica Lindl (PP) had the same water use pattern. In the dry season, HT competed with HJ and PP for water resources, and in the rainy season, HJ and PP competed with Lonicera japonica (JYH), while HJ competed with PP all the time. JYH and HT were in a separate state of hydrologic niche and they did not pose a threat to each other. Coexisting trees are largely separated along a single hydrological niche axis that is defined by their differences in root depth, which are closely related to tree size. Our results support the theory of hydrological niche isolation and its potential responses in relation to drought resistance. This study provides a method for determining more efficient plant combinations within karst forest vegetation habitats and its results will have important implications for ecosystem vegetation restoration.