A STUDY OF THE EFFECT OF CLEAR CUTTING AND PRESCRIBED BURNING ON THE MIGRATION OF THE NUTRIENT ELEMENTRESOURCES OF THE FOREST LAND
皆伐炼山对林地养分元素资源迁移影响的研究

his paper studies the migration of nutrient element resources of the forest land after clear cutting and prescribed burning. The results are as follows: the biomass that migrates out of the forest land after clear cutting is above 80% of the total biomass of the forest land, the migration of Ca and Mg is above 60%, and the migration of N,P and K is below 50%. The nitrogen loss rate of clearing residue during burning is above 95%, and the loss rates of P,K,Ca and Mg are relatively lower. N and P reserves decrease and Ca,K and Mg increase slightly in the surface soil layer after prescribed burning. Almost all the biomass and nutrient elements of the forest land which accumulate during the whole growth stage of the forest stand are migrated out of the forest land after clear cutting and prescribed burning.