广州城市森林涵养水源、固土保肥的功能及价值分析

Function and Value Analysis of Water Conservation,Soil Reinforcement and Fertility Maintenance of Urban Forest in Guangzhou

对广州城市森林涵养水源、固土、保肥的功能及其价值进行评估,结果表明:广州城市森林生态系统每年贮水量比无林地多6.429亿m3,调节径流防洪能力大2.609亿m3;每年植物组织净积累N元素4.949万t,P元素0.428万t,K元素4.400万t;每年凋落物归还林地N元素3.524万t,P元素0.216万t,K元素1.539万t;每年土壤流失减少123万t,有机质流失减少3.905万t,N元素流失减少0.218万t,P元素流失减少0.066万t,K元素流失减少2.368万t;森林贮水效益1.286亿元,防洪效益0.522亿元,储存在植物组织中养分效益3.497亿元,保持土壤效益1.145亿元,改良土壤效益1.872亿元,广州城市森林每年涵养水源、固土保肥的功能价值共8.322亿元。

The functions and values of water conservation, soil reinforcement and fertility maintenance of the urban forest in Guangzhou were assessed. The results showed that the urban forest ecosystem in Guangzhou city could store 6.429 × 10^8 m^3 water and adjust 2.609 × 10^8 m^3 flooding more than that of non-stocked land. The plant annual net accumulation of nutrient for N was 4.949× 10^4 t,for P was 0.428 × 10^4 t,and for K was 4.400 × 10^4 t and the nutrients of annual litter fall returned back to forestland were that for N was 3.524 × 10^4 t,for P was 0.216 × 10^4 t and for K was 1.539 × 10^4 t; The urban forest in Guangzhou city also could reduce soil loss in the amount of 123 × 10^4 t,reduce organic matter loss in the amount of 3.905 × 10^4 t including 0.218 × 10^4 t N,0.066 × 10^4 t P and 2.368 × 10^4 t K; The economic function effect of the system for water storage was 1.286 × 10^8 yuan,for flooding prevention was 0.522 × 10^8 yuan,for fertilizer maintenance was 3.497 × 10^8 yuan, for soil reinforcement was 1. 145 × 10^8 yuan and for soil improvement was 1. 872 × 10^8 yuan. So that the annual urban forest economic function value in Guangzhou city in the areas of water conservation,soil reinforcement and fertilizer maintenance was 8.322 × 10^8 yuan.