Ranking of individual mountain birch trees in terms of leaf chemistry:
seasonal and annual variation |
| |
Authors: | Email author" target="_blank">Marianna?RiipiEmail author Erkki?Haukioja Ky?sti?Lempa Vladimir?Ossipov Svetlana?Ossipova Kalevi?Pihlaja |
| |
Institution: | (1) Section of Ecology, Department of Biology and Kevo Subarctic Research Institute, University of Turku, 20014 Turku, Finland;(2) Department of Chemistry, Laboratory of Environmental Chemistry, University of Turku, 20014 Turku, Finland |
| |
Abstract: | Summary. The quality of tree leaves as food for herbivores changes rapidly especially
during the spring and early summer. However, whether the quality of an individual
tree in relation to other trees in the population changes during the growing season
and between years is less clear. We studied the seasonal and annual stability of
chemical and physical traits affecting leaf quality for herbivores. Rankings of trees
in terms of the contents of two major groups of phenolics in their leaves, hydrolyzable
tannins and proanthocyanidins (condensed tannins), were very stable from the early
spring to the end of the growing season. There were also strong positive within-season
correlations in the levels of some other groups of phenolics in the leaves (kaempferol
glycosides, myricetin glycosides and p-coumaroylquinic
acid derivatives). The contents of individual sugars and the sum content of protein-bound amino
acids showed patterns of seasonal consistency in mature leaves, but not in young developing leaves.
The seasonal correlations in leaf water content and toughness were also strongest in mature leaves.
The correlations between two years at corresponding times of the growing season were strongly
positive for the major groups of phenolics throughout the season, but were more variable
for the contents of proteins and some sugars. Leaf toughness and water content showed strong
positive correlations in mature leaves. Despite the consistency of tree ranking in terms
of leaf phenolics, the relative resistance status of trees may, however, change during
a growing season because there was a negative correlation between the content of hydrolyzable
tannins (early-season resistance compounds) in leaves early in the season and the content of
proanthocyanidins (late-season resistance compounds) late in the season, and vice versa.
Thus, assuming that phenolics affect herbivore preference and performance, different
plants may suffer damage at different times of the growing season, and the overall
variation between trees in the fitness consequences may be low. In addition, the
adaptation of herbivorous insects to mountain birch foliage in general, as well as
to specific tree individuals, may be constrained by variation in the relative resistance
status of the trees. |
| |
Keywords: | Betula pubescens subsp czerepanovii phytochemistry phenolics plant/herbivore interactions relative resistance temporal variation |
本文献已被 SpringerLink 等数据库收录! |
|