Chapter 4. Prediction of Wood Structural Patterns in Trees by Using Ecological Models of Plant Water Relations

摘要

Wood structure varies within parts of plants, among plants, among habitats, and among species. Although we have several models to predict the general patterns of change (such as the juvenile/mature wood model to explain radial and vertical variation), we lack mechanistic models to explain the variation. Recent work in ecophysiology is providing models that link wood structure to environment. This chapter provides an overview of three such models, one linking wood density and cell diameter distribution to the plant's growing season temperature; another linking cell wall thickness and cell diameter to the plant's drought resistance; and the third linking the radial decrease in microfibril angle to the needed increase in water transport as trees get larger. These models, as well as paleobotanical research, suggest that many features of tree's structure are driven by needs for water transport rather than by needs of the xylem to hold the plant up. Such models, if shown to be robust, will help wood scientists predict how environment will affect wood properties, which will be useful in sorting and processing wood. It will help tree breeders avoid production of maladaptive genotypes and help them produce wood with specific structural characteristics.