Retranslocation of foliar nutrients in evergreen tree species planted in a Mediterranean environment.

Internal nutrient recycling through retranslocation (resorption) is important for meeting the nutrient demands of new tissue production in trees. We conducted a comparative study of nutrient retranslocation from leaves of five tree species from three genera grown in plantation forests for commercial or environmental purposes in southern Australia--Acacia mearnsii De Wild., Eucalyptus globulus Labill.

Foliar nutrient retranslocation in Eucalyptus globulus.

We measured patterns of change in concentrations and contents of nitrogen, phosphorus, potassium, magnesium and calcium in fully expanded leaves of young Eucalyptus globulus (Labill.) trees growing in a plantation in southeastern Australia, over a 12-month period beginning at the onset of spring. There was significant net retranslocation of mobile nutrients on a seasonal basis from green leaves, coinciding with continued growth and production of foliage.

Effects of compaction and simulated root channels in the subsoil on root development, water uptake and growth of radiata pine.

Effects of subsoil compaction and simulated root channels (perforations) through the compacted layer on root growth, water uptake, foliar nutrient concentration and growth of radiata pine (Pinus radiata D. Don) were studied in a field experiment where a range of treatments were applied in reconstituted soil profiles. Subsoil compaction adversely affected root penetration in deeper parts of the soil and consequently caused greater water stress in trees.

Relationships between nutrient status, carbon assimilation and water use efficiency in Pinus radiata (D. Don) needles.

The productivity of Pinus radiata D. Don plantations can be increased on many soils by N and P fertilization. Foliar analyses are usually taken as a guide for nutrient management, but there is little information about the relationship of foliar nutrient status to foliar physiology.