diameter increment by sustained cell expansion during their development. The
relation of height to dbh shows different growth strategies for Euterpe and Iriartea.
Euterpe palms grow regularly in height and in dbh (Fig. 35). In Euterpe palms, first
diameter growth is prioritized up to a dbh of about 20 cm. After almost reaching their
final diameter, they then grow mainly vertically. This means competitive strength
changes according to age. The smaller Cryosophila palms increase their number of
leaves during an establishment phase, and the stem reaches the final diameter
(Homeier et al. 2002a). After that, the palm continues its vertical growth, with a
diameter sufficient to support a maximum height of up to 10 m.
The reproduction and establishment of the various species is a rather complex
phenomenon. It was only checked with very few species but is very important for
future sustainable soft management of tropical forests, since introduced trees often
suffer nutrient deficiencies (Breckle et al. 2005). The population structures of the
Fig. 34 Abundance of tree fern species along the altitudinal gradient in Sierra de Tilarán, near Rio
Lorencito, Costa Rica (Bittner and Breckle 1995)
36
S.-W. Breckle