The Comparative Analysis Of The Different Ways Of Forest Vegetation Restoration In Nanniwan

Improve the environment and rehabilitation and reconstruction of damaged ecosystems are becoming a major issue among people.Returning farmland to forest (grassland), aerial seeding afforestation, and closed forest is the main way to restore vegetationArtificial. Through comparative analysis the different ways of Forest vegetation restoration in Nanniwan in Yan'an city, this article explore the important role, restoration effects, existing problem of three restoring forest vegetation in the process of vegetation restoration.The results show as follows:From 1999 to 2006, total area of returning farmland to forest (grassland) is 37,754 acres which include 30,033 acres of farmland to forest and 7,721 acres of afforestation in Nanniwan. Ecological forest is the chief returning farmland to forest (grassland). Tree composition and tree growth increase continuously in abandoned lands. The canopy density of the larch stand and the forest coverage increase significantly in abandoned lands too.From 2002 to 2004 total area of returning farmland to forest (grassland) is 30000 acres in Nanniwan. Sowing area is 2,925 ares in four sowing area. The results of aerial sowing afforestation are not good.By closed forest from 1991 to 2006, forest land area expanded frome 23561 hm2 to 27504.8 hm2, non-forest land reduced from 3430 hm2 to zero, the forest coverage rate increased from 85.2% to 86.2%. Closed forest had a better result.Through the comparative analysis of three ways of we can say that: returning farmland to forest (grassland) can increase the forest area, improve forest canopy density and vegetation cover in a relatively short period; closed forest reduced effectively a variety of activities for the destruction of forests, increased the forest coverage rate; aerial seeding afforestation was high efficiency and the provincial labor advantages, but this situation resulted in the low use rate.we should combine the local site, social and economic conditions, select the appropriate way in the implementation process to this three ways to restore vegetation.