Shrinkage characteristics of Castanopsis hystrix and Betula alnoides plantation wood.

The transverse shrinkages (tangential and radial shrinkage) of plantation-grown Castanopsis hystrix and Betula alnoides in different directions(north or south), tree heights and radial directions were investigated. The effect of these factors on the transverse shrinkage was analyzed and discussed. The results show that there is no significant difference of shrinkage (tangential and radial) between the samples from north and south directions for both species. There is a marked difference of transverse shrinkage at different heights for Betula alnoides, with no obvious difference for Castanopsis hystrix. There is a remarkable difference of radial shrinkage at different radial positions in Betula alnoides.