[Morphological-ecological characters and growth patterns of main tree species leaves in urban forest of Shenyang]

Abstract

The study with statistic and multivariate analyses showed that the main meteorological factors affecting the growth and development rhythms of main tree species leaves in urban forest of Shenyang were > or = 5 degrees C accumulated temperature, accumulated sunshine hours, and mean temperature in the middle ten days of each phenological period. The meteorological factors needed by the tree species varied with their phenological period. Necessary low temperature and CI were required in germination period, and suitable WI and HI were needed in the growth period. The major quantitative morphological characters of 10 tree species in Shenyang urban forest were displayed in their leaf morphology and size, which decreased in the sequence of Lespedeza cyrtobotrya > Syringa oblata > Sophora japonica > Populus alba > Cornus alba > Lonicera maackii > Ligustrum obtusifolium > Fraxinus mandshurica > Prunus padus > Phellodondron amurense. As for the leaf area, it was decreased in the order of S. oblata > P. alba > P. amurense > P. padus > F. mandshurica > C. alba > L. cyrtobotrya > L. maackii > S. japonica > L. obtusifolium. The relationships of leaf length with leaf width, perimeter and area accorded with the model of y = ax(k), and the growth trend belonged to allometic type. The k value between leaf length and width of all test tree species except P. alba was lower than 1, and that between leaf length and perimeter was > 1 for P. amuresne, approximately 1 for P. alba, and < 1 for other tree species. As for the k value between leaf length and area, it was > 1 for all the tree species, with that of P. alba being 2. 1028. The increasing rate of leaf area was about 2 times higher than that of leaf length. An optimum regression assessment model of the 10 tree species leaf area was built and tested.