Review article
WHICH ECOPHYSIOLOGICAL FACTORS INFLUENCE REPRODUCTION OF FOREST TREES AND WHETHER TREES PRODUCED SEED MORE FREQUANTLY AND ABUNDANTLY IN THE PAST?
Krunoslav Sever
; Faculty of forestry University of Zagreb
Željko Škvorc
; Faculty of forestry University of Zagreb
Daniel Krstonošić
; Faculty of forestry University of Zagreb
Maša Zorana Ostrogović
; Croatian forest research institute
Jozo Franjić
; Faculty of forestry University of Zagreb
Abstract
Masting, or an abundant fruiting of forest trees in intermittent intervals in a broader geographical area, represents an evolutionary advantage which has ensured survival of certain forest tree species up till today. Due to the selection pressure, surviving individuals are
the ones which underwent initiation and differentiation of flowers under the influence of strong interactive control of climatic factors and nutrients which a particular individual tree had at its disposal. In other words, initiation and differentiation of a large number of flowers
occurs only under the influence of both, sufficient amount of nutrients and favourable climatic conditions, which is also a basic requirement for the occurrence of masting. The advantage of masting occurrence is reflected in an increased success of pollination, decreased populations of pests affecting reproductive organs of forest trees, and dissemination of particular amounts of seed to greater distances from parent trees. Particular phases of forest tree fruit development take place under the influence of a specific interaction of physiological processes within the plant organism (hormonal control, mineral nutrition and carbohydrate metabolism) which are stimulated, and to a certain degree controlled, by the climatic factors (air temperature,amount of precipitation, relative humidity of air, etc.). Under favourable climatic conditions, a portion of nutrients which
forest trees have at their disposal gets used in fruit development, which is reflected in great amount of initiated anddifferentiated flowers. The amount of nutrients which would be invested
in fruit development depends greatly on the site quality. Trees grown in high quality environment, as opposed to those grown in lower site quality, replenish their nutrient reserves more rapidly despite having identical climatic growth conditions, thanks to a more intensive photosynthetic activity, which in turn results in an increased seed production.
Keywords
forest trees; fruiting; masting; physiological factors; climatic factors
Hrčak ID:
129278
URI
Publication date:
1.3.2014.
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