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(Efimenko and Aleinikov 2019; Noguchi et al. 2011). Madsen reported that under the open canopy (13% light) or closed canopy (5% light), fertilized and irrigated in a mineral soil seedbed have different effects on seedling growth of beech (Fagus sylvatica), and weed competition did not significantly reduce seedling growth (Madsen 1995). These implicated that light intensity, soil water content and nutrient supply effect on natural regeneration of beech. In turn, NR also improves soil fertility, microbial biomass carbon and enzyme activity more than artificial afforestation (Hu et al. 2020; Pang et al. 2018) and also alters compositional and functional shifts in soil seed banks(Medeiros-Sarmento et al. 2021). Additionally, the characteristics of forest gaps have an important impact on light environment, temperature and humidity and micro terrain, and play an important role in forest regeneration, for example, number of beech increased with gap size and light availability; and herbaceous species abundance also significantly effected by gap size (Naaf and Wulf 2007; Qin et al. 2011). These studies have shown that the efficiency of NR is affected by environmental factors. Additionally, the stand factor is another regulatory factor that affects the frequency of NR. For example, in forests, gaps of different sizes and ages have different effects on tree density, dominance, the conversion rate from seedlings to young trees, and spatial pattern of seedlings and young trees (Ugarković et al. 2018; Zhu et al. 2014), which significantly affects the growth of regeneration seedlings (Beckage and Clark 2003). Different shade-tolerant tree species also have certain segmentation in the utility of forest gap ecological resources (Ugarković et al. 2018). In addition, natural forest regeneration is also affected by some special habitats, such as karst scar habitat (Gholami et al. 2018). Studied found that the special habitat of karst scar (except the dissolution corridor) in the karst area can preserve some plant residues and provide a source of propagules for plant regeneration (Hu et al. 2020; Pang et al. 2018). Bryophyte communities affect seed dispersal, seed germination, and seedlings establishment, and also exert a role of the allelopathy on vascular plants (Fukasawa et al. 2019). Platycladus orientalis (L.) Franco (cypress) is an evergreen tree species of the cypress family. Cypress likeswarm and humid climate conditions and has wide adaptability to soil including neutral, slightly acidic and calcareous soil, and particularly prefers the shallow calcareous purple soil and lime soil in the upper layer. Cypress needs sufficient upper light to grow, but they also have a certain resistance to shadein the seedling stage. Cypress can play an important role in the ecological construction of arid and barren forests in mountainous areas. However, the natural NR of cypress plantations used for ecological construction is very difficult, which greatly reduces the efficiency of ecological improvement (Kimambo and Naughton-Treves 2019). Importantly, in cases where cypress dominated forest is aimed/auchtonus forest type, the weakness of NR ability of cypress plantation significantly affects the stability of the ecosystem, which is not conducive to sustainable management. At present, it is known that the NR of cypress plantations is the result of a comprehensive restrictions of many factors. For example, the regeneration of Arizona cypress affected by wildfire (Dos Santos et al. 2019). Cypress seedlings can grow in large numbers due to the release of seeds from serous cones, the exposure of mineral soil, and the increase of solar radiation (Barton and Poulos 2018). Proper thinning intensity can achieve a better regeneration effect of cypress (Olson et al. 2014). Different stand densities, soil water content, and litter cover thickness significantly impact on seed germination and early seedling growth (Islam et al. 2016). However, there is no research on the environmental factors and stand factors limiting cypress regeneration, thus,the strategies for managing and promoting the natural regeneration of cypress plantations are not yet fully understood. As far as we know, the effect of environmental factors and stand factors on cypress regeneration is studied for the first time. In this study, we aimed to explore (1) whether cypress can regenerate naturally; (2) which factors affect NR of cypresses; and (3) how these factors affected NR of cypresses. This study provides an empirical basis for the management and the promotion of NR for cypress plantations. Methods Metode Overview of the study area – Pregled područja istraživanja This study was conducted in Guilin city, located in the Southwest of Guangxi, China (latitude 24° 55´ – 25° 18´, longitude 110 ° 18´ – 110 ° 45´, altitude 115–421 m) (Figure 1). Cypress is one of the major species of artificial vegetation in this area and is mostly distributed in the middle and lower part of the mountains. The climate of the survey region is the subtropical monsoon climate with the characteristic of a mild climate, abundant rainfall, long frost-free period, sufficient light, abundant heat, long summer and short winter, four distinct seasons, and the same season of rain and heat. The climatic condition of survey region is superior with less snow in three winters and frequent flowers in four seasons. The annual average temperature is around 19.4 °C, July and August are the hottest months of the year with an average temperature of about 28.5 °C; January and February are the coldest months of the year with an average temperature of about 8.3 °C. The annual average frost-free period is 309 days, the annual average rainfall is 1974 mm, and the annual average relative humidity is |