森林与生态环境(上)

Forest and Eco-environment (Ⅰ)

本文介绍了目前国际社会注目的10个生态环境问题:温室效应加剧、生物多样性锐减、大气臭氧层损耗、水资源危机、水土流失、沙漠化扩大、土壤退化、噪声污染、大气污染和酸沉降、海洋污染,简述了生态环境恶化带来的严重后果,并重点阐述了森林与温室效应、生物多样性保护、大气臭氧层损耗、水资源危机的关系。

At present, international community understands more and more thatforest plays a significant role in eco-environment. (1) Forest can retard green-house effect in two aspects. Firstly, afforestation can absorb and fix atmosphericCO_2 which is one kind of greenhouse gases in atmosphere. Secondly,deforestation is regarded to release tens and thousands of tons of carbon per yearwhich was stored up in the past. (2) The vanishing of forest is thought as thegreatest menace to biodiversity. Forest district has not only complicatedecosystem, species and genetic diversity, but also a great influence uponbiodiversity of other regions and ecosystems, because deforestation can causeeco-environmental deterioation, such as greenhouse effect aggravation, sharp decrease of biodiversity, water and soil erosion, soil desertification and soil de-generation. (3) Many chemical compounds such as CFC_?, N_2O, NO_2,CH_4 and water steam, especially CFC_?, can lead to decomposition of ozone inthe stratosphere. The correlation between forest and CFC_? has not been clear, butforest is closely interrelated with N_2O, NO_2, and water steam. (4) Forest canalleviate water resources crisis. Green reservoir' (forest) not only can suck up andconserve some of rainfall, but also can prevent soil erosion and reduce sediments inrivers, lakes and reservoirs. Consequently forest can increase available water onearth surface. Air reservoir' (forest) can not only effect water transpiration intoatmoshpere and accelerate water circulation but can also influence atmospheric cir-culation in many ways therefore forest can increase precipitation.