Research on ecological effects of typical moss crusts in Jiuzhaigou National Nature Reserve

As a pioneer species in the primary succession stage, bryophytes play an important role in water conservation, soil conservation and biodiversity maintenance due to their unique physiological structure and dehydration recovery ability. In this study, three bryophytes including Racomitrium japonicum, Hypnum plumaeforme and Plagiomnium ellipticum in different habitats (grassland, shrub, forest and bare rock) were selected as the research objects. Based on field investigation and laboratory analysis, the ecological effects of dissolution activity, soil and water holding capacities of three typical bryophytes crusts on the post-earthquake restoration in the Jiuzhaigou National Nature Reserve were evaluated. The results showed that R. japonicum had the highest the carbonic anhydrase (CA) activity (50.5 U·g⁻¹ DW), the maximum dissolution rate (4.8×10⁻⁴ t·km⁻²·a⁻¹ CO₂) and carbon sink content (2.12 mg ·m⁻²·a⁻¹). Different mosses in different habitats had different soil consolidation capacity, among which the soil consolidation capacity of H. plumaeforme was the highest (3.1×10³ kg·hm⁻²), and its maximum soil consolidation rate was more than 2 times of its own dry weight. In addition, the water retention capacity of P. ellipticum was higher than that of R. japonicum and H. plumaeforme. The water holding capacity of P. ellipticum was between 1100-1400 kg·hm⁻², and the water retention rate was more than 8 times of its own dry weight. In conclusion, in the process of ecological restoration by using moss crusts, it is suggested to select specific bryophytes according to different stages and different habitat conditions from the perspective of ecological restoration such as soil formation, soil consolidation and water conservation, so as to accelerate the ecological restoration and reconstruction after the earthquake in Jiuzhaigou National Nature Reserve.