Chemoecology (2008) 18, 85-98

Liisa Huttunen, Pekka Niemelä, Riitta Julkunen-Tiitto, Susanne Heiska, Riitta Tegelberg, Matti Rousi and Seppo Kellomäki (2008)
Does defoliation induce chemical and morphological defenses in the leaves of silver birch seedlings under changing climate?
Chemoecology 18 (2), 85-98
Abstract: We examined the effects of defoliation con-currently with elevated temperature and CO₂ on some chemical and morphological characteristics in the leaves of silver birch seedlings (Betula pendula). We also analyzed the consequent changes in the palatability of leaves for adult blue alder leaf beetles (Agelastica alni). Under the different climatic treatments, the seedlings were subjected to three fertilizer treatments (0 kg, 130 kg and 270 kg N ha^-1) and defoliation treatments (0%, 25% and 50% of the total leaf area). In each climatic treatment, fertilization increased the nitrogen content in the leaves, but decreased total concentrations of soluble phenolics, detected by high-performance liquid chromatography (HPLC), and insoluble condensed tannins. Defoliation, both independently and in combination with elevated temperature and CO₂, decreased the concentrations of the phenolics. Compared to the intact controls, the leaves of the defoliated seedlings were smaller and tougher. Under elevated temperature, the beetles consumed a smaller amount of the leaves of plants subjected to the high fertilization, while under ambient climatic conditions, fertilization increased the feeding. The total leaf consumption was higher under the ambient climatic conditions than under elevated temperature, elevated CO₂ or the combination of elevated temperature and CO₂.
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Link to article at publishers website
Database assignments for author(s): Susanne Heiska

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Agelastica alni	Birch (Betula)