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Growth, nutrient uptake and ectomycorrhizal function in Pinus sylvestris plants exposed to aluminium and heavy metals

Ahonen-Jonnarth, Ulla (2000). Growth, nutrient uptake and ectomycorrhizal function in Pinus sylvestris plants exposed to aluminium and heavy metals. Diss. (sammanfattning/summary) Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae. Silvestria, 1401-6230
ISBN 91-576-5864-1
[Doctoral thesis]

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Abstract

The potential role of aluminium (Al) toxicity to trees has been of particular concern to forest owners and scientists since the early 1980’s when Ulrich hypothesised that both A1 and heavy metals were involved in forest dieback because of their increased concentrations in soil due to acidfication. Since then, numerous studies have examined the effects of metals upon nutrient uptake by plants. However, most of these investigations have been carried out in the absence of mycorrhizal fungi, which, in most ecosystems, are crucial components in nutrient uptake by plants.
The present work focused on the effects of elevated concentrations of A1 and heavy metals on Scots pine (Pinus sylvestris L.) and the potential role of ectomycorrhiza in modifying these effects.
Ectomycorrhizal colonisation enhanced the growth and nutrient uptake by seedlings. To some extent, colonisation also alleviated reduced nutrient uptake which was a feature of seedlings growing in the presence of the metals. This effect was particularly noticeable with respect to P uptake. In general, mycorrhizal seedlings grew better and had an improved P, K, Mg and S status compared with non-mycorrhizal seedlings. Significant differences were also found in nutrient uptake among seedlings colonised by different fungi. One fungus, Hebeloma cf. longicaudum, was more sensitive to the A1 treatment than the pine seedlings. The use of the base cation / A1 ratio as an indicator of the potential detrimental effects to trees to acidification and A1 is discussed.
The production of oxalic acid was found to increase when mycorrhizal and nonmycorrhizal seedlings were exposed to A1 or Cu. Colonisation by Suillus variegatus or Rhizopogon roseolus, in particular, resulted in a marked increase. These results demonstrate that there is a capacity, especially by certain ectomycorrhizal fungi, for increased production of the metal-chelating oxalic acid when root systems are exposed to increased levels of metals.
In a field experiment, spraying with solutions of Ni/Cu sulphate or acidified water did not affect the growth of small pine trees. As part of the same experiment, defoliation was carried out on the pine trees in order to reduce carbon supply below-ground. Defoliation altered the proportions of different mycorrhizal morphotypes: Tuberculate types decreased and smooth types increased. The treatment did not affect the level of mycorrhizal colonisation of short roots, which was nearly 100%.

Authors/Creators:Ahonen-Jonnarth, Ulla
Title:Growth, nutrient uptake and ectomycorrhizal function in Pinus sylvestris plants exposed to aluminium and heavy metals
Year of publishing :2000
Number:130
Number of Pages:61
Publisher:Swedish University of Agricultural Sciences
ISBN for printed version:91-576-5864-1
ISSN:1401-6230
Language:English
Publication Type:Doctoral thesis
Article category:Other scientific
Version:Published version
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Forest Science
Keywords:aluminium, nickel, cadmium, copper, Pinus sylvestris, ectomycorrhiza, oxalic acid, defoliation
URN:NBN:urn:nbn:se:slu:epsilon-p-107945
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-p-107945
ID Code:17733
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Forest Mycology and Plant Pathology
(S) > Dept. of Forest Mycology and Plant Pathology
Deposited By: SLUpub Connector
Deposited On:07 Oct 2020 08:12
Metadata Last Modified:19 Oct 2020 14:30

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