The Ecological Benefits Evaluation Of Four Main Coastal Shelterbelt Forests In Pingtan

Taking the main coastal shelterbelt forest in Pingtan as a case, investigate the Ecological Benefits of main coastal shelterbelt forest through field sampling and laboratory analysis. Applying the method Analytical Hierarchy Process (AHP) to establish evaluation index system and evaluation model of comprehensive ecological benefit. By using the "marginal benefit" to seeks maximum of synthesized benefits. The results indicated that:(1) The soil under the coastal shelterbelt forest partial to acidity, and is Widespread poverty, the biomass index of coastal shelterbelt forest were Pinus elliottii 312.16t/hm2)> Casuarina equisetifolia (189.82t/hm2)> Pinus thunbergii (146.28t/hm2)> Acacia confusa (87.71t/hm2); The shelterbelt plays a crucial role in the regulation of temperature, humidity and wind speed, in which the wind speed regulation is the most obvious.(2) Water holding capacity of litter increases with increasing as the soaking time,however moisture rate of litter decrease. The order of water holding capacity were Acacia confusa> Casuarina equisetifolia> Pinus thunbergii> Pinus elliottii Water conservation function in soil(0-60cm) for the coastal shelterbelt were Pinus thunbergii> Acacia confusa> Casuarina equisetifolia> Pinus elliottii。(3) The carbon content and carbon stores decrease with settlement depth of the soil; The average carbon content were Pinus thunbergii (49.2%)> Pinus elliottii (49.07%)> Acacia confusa (48.59%)> Casuarina equisetifolia (45.55%);The effect of carbon fixation and oxygen release were Pinus elliottii> Casuarina equisetifolia> Pinus thunbergii> Acacia confuse.(4) Establish the evaluation index system and evaluation model of comprehensive ecological benefit which consists of four criterion layer and ten indicator layer. The result indicated that comprehensive ecological benefit index of coastal shelterbelt were: Casuarina equisetifolia(1.1623)> Pinus elliottii (1.0758)> Pinus thunbergii.(1.0059)> Acacia confusa (0.7619).(5) Using linear programming model to seek the maximum of synthesized benefits by application of marginal benefits principle. The results showed that ecological benefits will be 13.78%.higher than the existing eco-efficiency in reasonable area ratio of Casuarina equisetifolia (31.03%)、Acacia confusa (17.27%)、Pinus elliottii (51.69%).