九寨沟典型苔藓结皮的生态效应研究

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

苔藓植物作为初生演替阶段的先锋种,其独特的生理结构和脱水复苏能力在水源涵养、土壤保持、生物多样性维持等方面发挥着重要作用。以不同生境下(草地、灌木、乔木林以及空地)东亚砂藓(Racomitrium japonicum)、大灰藓(Hypnum plumaeforme)及阔边匐灯藓(Plagiomnium ellipticum)3种苔藓植物为研究对象,通过野外实地考察与室内分析,评估3种典型苔藓结皮的溶蚀能力、固土以及保水特性对九寨沟国家自然保护区震后恢复的生态效应。结果表明:东亚砂藓具有最高的碳酸酐酶活性(50.5 U·g^(-1) DW),进而具备最大的溶蚀速率(4.8×10^(-4) t·km^(-2)·a^(-1) CO_(2))与碳汇量(2.12 mg·m^(-2)·a^(-1))。不同生境条件下的不同苔藓固土能力不同,其中大灰藓结皮层的固土量最高(3.1×103 kg·hm^(-2)),最高固土率可达到自身干重的2倍以上。此外,阔边匍灯藓的保水能力均高于大灰藓与东亚砂藓,其保水量维持在1100-1400 kg·hm^(-2)之间,保水率可达自身干重的8倍以上。综上,在利用苔藓结皮进行生态恢复过程中,建议从成土、固土、保水等生态修复的角度出发,针对不同阶段、不同生境条件选择特定藓种,以加快九寨沟地区震后的生态恢复与重建。

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) CO_(2))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.