Plant litter decomposition and its effect on soil nutrients are important parts of the ecosystem material cycle, and understanding these processes is key for species selection and allocation to promote the effective use of litter in ecological tea gardens. In this study, the in situ litter decomposition method was used to examine the decomposition characteristics of leaf litter of Cinnamomum glanduliferum, Betula luminifera, Cunninghamia lanceolata, Pinus massoniana, and Camellia sinensis prunings in the Jiu’an ecological tea garden in Guizhou and their effects on soil nutrients. The results showed that the litter decomposition rate of broad-leaved tree species was higher than that of coniferous tree species, with a half-life of 1.11–1.75a and a turnover period of 4.79–7.57a. There are two release modes of nutrient release from litter: direct release and leaching–enrichment–release. Different litters make different contributions to soil nutrients; Betula luminifera and Cinnamomum glanduliferum litter increased the contents of soil organic carbon, soil total nitrogen, and soil hydrolyzed nitrogen. Betula luminifera litter increased the content of soil total phosphorus, soil available phosphorus, and soil available potassium, and Pinus massoniana litter increased the content of soil total potassium and soil available potassium; therefore, it is concluded that the decomposition of Betula luminifera litter had a positive effect on soil nutrient content. Thus, Betula luminifera is a good choice for inclusion in ecological tea gardens to increase their nutrient return capacity, maintain fertility, and generally promote the ecological development of tea gardens.

The growth and overlay of a large number of bryophytes in the broken soil patches between the exposed bedrocks of karst have an essential influence on the infiltration and runoff process between the exposed bedrocks and even the whole rocky desertification area. The purpose of this study is to explore the effects of moss on the infiltration and runoff of soil patches between karst exposed bedrocks and the processes of rainfall, runoff and infiltration transformation on slopes through rainfall experiments. The results showed that the slopes between the karst outcrops are dominated by subsurface and underground pore runoff. More than 50% of precipitation is lost through underground pores, with surface runoff accounting for only 1–17% of the total. Bryophyte overlay significantly reduced the initial runoff from subsurface and underground pore runoff, and advanced the steady-state time of runoff from subsurface and underground pore runoff, suggesting that bryophyte coverage may reduce the risk of soil erosion caused by short-duration rainfall. Eurohypnum has a significant inhibitory effect on percolation between exposed bedrock and reduces rainfall leakage from subsurface and underground pores. Thuidium has a strong intercepting effect on rainfall, significantly reducing the formation of surface runoff and the risk of surface soil erosion. Moss overlay has an essential role in soil and water conservation between karst exposed bedrock, and Eurohypnum and Thuidium can be considered as pioneer mosses for ecological restoration in the process of rocky desertification control and ecological restoration, which can effectively solve the serious problem of soil and water loss in karst rocky desertification area and improve the benefit of soil and water conservation in karst area.

Soil preferential flow infiltrating rapidly through the rock–soil interface is an important hydrological process in karst rocky desertification area. However, how does the water leakage in the near-surface fissures, especially those filled with soil, proceed? The role of preferential flow at rock–soil interface of those fissures on water leakage process still puzzles us. The goal of this study was to reveal the role of soil preferential flow at the rock–soil interface in the process of water leaking of near-surface fissures. Five typical types of near-surface fissures were selected in an area experiencing severe rocky desertification in Guizhou Province, China. Dye tracer testing was applied, combined with digital image processing techniques. The results indicated that the rock–soil interface flow on both sides of the fissures is the most important preferential flow form in the fissures in karst area. The dyed area ratio of preferential flow varied from 0.12 to 0.48 in the rock + soil profiles, from 0.06 to 0.37 in the soil profiles, and between 0.02 and 0.16 in the rock–soil interface. The rock–soil interface is the smallest in terms of both their variation range of dyed area ratio and preferential flow patterns compared with soil and rock–soil profiles. The soil preferential flow in near-surface fissures mainly occurs in the soil depth range of 0–20 cm. The preferential flow path is mainly affected by the rock–soil interface on both sides and can pass through the clay layer with poor permeability. However, the soil depth of the dyed part was more than 50 cm. The soil preferential flow at the rock–soil interface is the main form of rapid downward leakage of water in near-surface fissures in the karst rocky desertification area, which can flow to the bottom of clay layer with poor permeability.