Key Factors for the Rapid Cultivation of Lithophytic Moss Crusts and Preliminary Trials in the Ecological Restoration of Rocky Slopes

Abstract

The cultivation and inoculation of lithophytic moss crusts represent a potential pathway for the ecological restoration of rocky slopes. At present, the key factors influencing rapid cultivation are not well understood, and ecological restoration practices remain at the conceptual stage. In this study, based on the investigation of moss diversity in the northern foothills of the Qinling Mountains, we selected Brachythecium plumosum, a dominant moss species, for incubator experiments to explore the inoculation density (20 g·m−2, 60 g·m−2, 100 g·m−2), moss stem and leaf fragment length (1–3 mm, 3–6 mm, 6–9 mm), and substrate type (kaguma soil, peat soil, volcanic rock) on moss crust growth. Meanwhile, an outdoor artificially constructed rocky slope was utilized to examine the response of moss crust restoration on rocky slopes to inoculation methods (dry broadcasting, wet blending), substrate particle sizes (< 1 mm, 1–2 mm, > 2 mm), gauze additions, and exogenous microorganisms (Bacillus megaterium, Chlorella vulgaris). The results showed that (1) in an artificial incubator (constant environment), medium inoculum, short stem and leaf fragments, and volcanic rock substrate were more conducive to the rapid development of moss crusts. Moss coverage, plant height, and plant density reached 50.28%, 5.64 mm, and 52 stems·cm−2, respectively, in the 60 g·m2 + 1–3 mm gametophyte fragments + volcanic rock treatment; (2) Moss coverage, plant height, and plant density of dry broadcast inoculation were significantly higher than those of wet blend inoculation, but the addition of B. megaterium and C. vulgaris did not produce significant differences; the addition of gauze cushion and substrate (particle size < 1 mm) contributed to rapid establishment and improved survival rates of moss crusts on rocky slopes. In summary, we identified the key factors for the rapid cultivation of lithophytic moss crust, preliminarily verified its feasibility as an ecological restoration measure for rocky slopes, and provided methodological references and new perspectives for the restoration of bare rock landscapes.