Meeri Pearson , Markku Saarinen, Juha Heiskanen, Tytti Sarjala, Jukka Laine

Kasvualustan kuivumisen vaikutukset rahkasaraturpeeseen istutettujen männyntaimien ensikehitykseen

Pearson M., Saarinen M., Heiskanen J., Sarjala T., Laine J. Kasvualustan kuivumisen vaikutukset rahkasaraturpeeseen istutettujen männyntaimien ensikehitykseen.

English title: High and dry: Consequences of drought exposure in Scots pine seedlings grown in authentic peat soil

Tiivistelmä

Should the frequency of drought increase in boreal forests due to climate change, seedlings planted in prepared peat mounds could become more susceptible to soil desiccation. The resistance of Scots pine (Pinus sylvestris L.) seedlings to drought will thus be a key factor in the regeneration success of pine-dominated, forestry-drained peatlands. In this study, we evaluated the physiological, metabolic, and morphological responses of year-old seedlings gradually exposed to extreme drought in highly decomposed Sphagnum-Carex peat blocks. Drought clearly suppressed root and shoot growth as well as fractional colonization of ectomycorrhizal fungi. Sustained declines in photochemical efficiency (Fv/Fm) of previous-year and current-year needles did not occur until the volumetric soil water content had dropped to 30% and 10%, respectively. Polyamine analysis revealed that new needles are preferred in protecting the different parts of the seedlings against drought stress. Despite growth losses, the maintenance of rather high photochemical efficiency in current-year needles under severe water stress would appear to indicate a potential for seedling recovery if water availability in the peat improved. Given the high tolerance exhibited by Scots pine seedlings, death by drought seems a lesser concern.

Original keywords
männyntaimet; Pinus sylvestris; kuivuus; rahkasaraturve; fotosynteesin tehokkuus (Fv/ Fm); mykorritsat; polyamiinit; juurten ja versojen kasvu

English keywords
drought; Fv/Fm; mycorrhizal colonization; Pinus sylvestris seedlings; poly-amines; root and shoot growth; Sphagnum-Carex peat

Vastaanotettu 31.10.2017 Julkaistu 1.1.2013

Katselukerrat 2785

Saatavilla http://suo.fi/article/9884 | Lataa PDF

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