Studies on Foliar Apparatus Development of the Norway Maple (Acer platanoides) during the Growing Season

Abstract

Studies werw carried out on Norway maple canopy developement during the growing season, which is a very important factor in conducting physiological processes, having a direct impact on tree growth and developement All solar radiation reaching inside tree canopy define photosynthesis procese. Thus, quantitative measurements were carried out on the flow of light radiation inside of the leaf apparatus, solitary trees were subjected in the research in facilities outside the forest. The differences of the existing lighting was recorded inside the canopy according exhibition, the measurements were made for six months, from budding to full expansion of leaves. After processing the experimental data, it was showed the fact that on the western exhibition the light penetration shows a higher value in both years of the study, between 3.1% and 4.1% from the average recorded in the canopy. In March, April, May and June, the light flow inside the canopy is higher, with values ranging between 0.7% and 27.6% compared to the average of the growing season. According to expectations, the northern exhibition presents the lowest values in terms of light penetration, showing very significantly distinct negative values compared to the control variant. Together with the development of the trees foliage mass, in August were recorded the smallest amount of light radiation, were seen a decrease up to 48.1% compared to the mean, which can be explained by the reaching of maximum physiological development of the leaves.