Mineral Nutrition

Methods in evaluating mineral requirements The nutritional status of trees is most frequently assessed on the basis of the elemental analysis of leaves (MATERNA 1960 KRAL 1963 FIEDLER et al. 1965 Lavrichenko 1968 Tamm 1968 Zech 1968 Swan 1972 Linder 1995 and others). In spruce, needles sampled for this purpose should be collected be tween mid-August and mid-September (Touzet et al. 1970), preferably from the same sector of the tree crown (JUNG and RIEHLE1966), and separately for each...

Hormonal Regulation Of Growth And Development

Plant growth and development are regulated by phytohormones or growth regulators, low-molecular weight compounds present in cells in relatively low concentrations, acting in tissues remote from the place of their synthesis. Plant hormones may be divided into five basic groups auxins, gibberellins, cytokinins, abscisic acid, and ethylene. Recently, polyamines and brassino-steroids have also been recognized as growth regulators. Of the many studies of plant hormones, studies of forest trees and...

The Spruceless Belt In Central Europe

The determination of the geographic range of Picea abies in central Europe and the origin of a spruceless belt between the mountains of central Europe and northeastern Europe has served as an intriguing puzzle for a number of investigators. Additionally, a natural disjunction in the species range in the western Carpathians has been discussed previously. The problems concerning both disjunctions have been summarized by SRODON 1967a, b and the seminal study of SCHMIDT-VOGT 1977 . The aim of the...