Abstract:

Absorption and utilization of ³²P of Larix olgensis Henry and Fraxinus mandshurica Rupr, applied by pouring and with tube, were studied in pure and mixed stand. The result showed that absorption and transport of ³²P of trees were very fast, and ³²P reached crown at the date treated. ³²P distributing in higher level of crown was the most; that in middle level of crown came second; and that in lower level of crown was the least.³²P distributing in sun face of crown was more when appling ³²P by pouring; while that in shade face of crown was more when appling ³²P with tube. Absorption of ³²P of trees in mixed stand was more than that in pure stand when appling by pouring; while that in pure stand was more than that in mixed stand when appling with tube. Absorption of ³²P of F.mandshurica was more than that of L.olgensis in differnt stand type. Trees could exchange³²P directly through root system connection, and the mount of exchange of ³²P between different tree species was the most in mixed stand. The nutrition relationship between L. olgensis and F.mandshurica was harmonious, and in mixed stand the root system connected more extensively and distributed more rationally, which improved P nutrition condition of trees and raised productivity.

Key words: Larix olgensis Henry, Fraxinus mandshurica Rupr, ³²P, Nutrition relationship, Mixed stand, The mechanism of increasing production