免修、半免修复层防火林带阻火机理研究

利用山沟、小山脊呈"鸡爪型"分布的特点,在沟边和小山脊采取不同措施营建高阻火效能、低维护成本的免修、半免修复层防火林带,并研究其阻火机理.对火环境主要因子调查分析表明:免修复层防火林带衰减光照能力强,降温保湿效果好,挡风能力强,乔木、灌木、草本层和枯枝落叶层以及土壤的含水率高,阻火效果最好;半免修复层防火林带阻火效果次之,山脊单层防火林带阻火效果最差.因此,应充分利用沟边残存阔叶林和沟边小山脊特有的湿润环境,营建免修、半免修复层新型防火林带,并对现有单层防火林带进行改造.

Fire RetardantMechanism of the Non-managed andPartlyManagedMulti-layer Firebreak Forests

Non-managed and partly managed fire retardant multi-layer firebreak forests with high fire retardant efficiency and low management cost were established in mountain gullies and on low ridges using various afforestation measures, and fire retardant mechanism was analyzed by investigating related fire retardant factors. Results showed that non-managed multi-layer firebreak forest belt got the highest fire retardant efficiency with the highest capacity of luminous energy reduction, temperature decreasing, moisture keeping and wind breaking. Humidity ratio in living forest on upper mountain ridges showed the least fire retardant efficiency. Based on these results, suggests were given on non-managed and partly managed fire retardant multi-layer firebreak forest establishment by making use of the moist environment with remained broadleaf forest in mountain gullies and low ridges near the gully. Suggestions were also given on reconstruction of the existing single layer firebreak forest on upper mountain ridges.