Effects of silicon application on Betula pendula seedlings

: Hassan, Md. Kamrul; Huitu, Otso; Aphalo, Pedro J.; Klemola, Tero; Leppanen, Tuomo; Tervahauta, Arja; Lehto, Tarja

Publisher: CANADIAN SCIENCE PUBLISHING

: OTTAWA

: 2025

: Canadian Journal of Forest Research

: CANADIAN JOURNAL OF FOREST RESEARCH

: CAN J FOREST RES

: 0140

: 55

: 11

: 0045-5067

: 1208-6037

DOI: https://doi.org/10.1139/cjfr-2024-0140

: https://doi.org/10.1139/cjfr-2024-0140

Silicon (Si) is a beneficial element for many plant species, conferring resistance to drought and herbivory, but its effects on trees are less known. We studied responses of silver birch (Betula pendula), grown in peat, to liquid Si supplementation (Si concentration 0.65 mmol/L) on (1) growth, (2) water economy, and (3) element accumulation plus (4) feeding preference of an insect, Epirrita autumnata, and a mammalian herbivore, Microtus agrestis. Plant growth was not affected but control (Si-) plants shed their old leaves earlier. Detached Si+ leaves lost water 11% units less than Si-, and the integrated water-use efficiency based on 13C analysis was higher in Si+. Foliar Se was higher and Mn and S lower in Si+. Root Mg concentrations were higher and Pb lower in Si+. Epirrita autumnata did not prefer either treatment, but M. agrestis preferred Si- stems. Silicon improved birch water relations as indicated by the leaf drying resistance and increased water-use efficiency. The changes in metal accumulation were probably beneficial, but the lower S/Se ratio requires attention. Furthermore, Si decreased palatability to a mammalian herbivore. Using Si as fertilizer in nurseries could be possible to increase birch tolerance to water stress and herbivory.

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Funding information The study was partly supported by the Academy of Finland (decision number 324648).