Growth and physiological activity in Larix kaempferi seedlings inoculated with ectomycorrhizae as affected by soil acidification

Abstract

To evaluate the effect of ectomycorrhizal colonization on growth and physiological activity of Larix kaempferi seedlings grown under soil acidification, we grew L. kaempferi seedlings with three types of ectomycorrhizae for 180 days in acidified brown forest soil derived from granite. The soil had been treated with an acid solution (0 (control), 10, 30, 60, and 90 mmol H + kg -1 ). The watersoluble concentrations of Ca, Mg, K, Al, and Mn increased with increasing amounts of H + added to the soil. Ectomycorrhizal development significantly increased in soil treated with 10 and 30 mmol H + kg -1 but was significantly reduced in soil treated with 60 and 90 mmol H + kg -1 . The concentrations of Al and Mn in needles or roots increased with increasing H + added to the soil. The total N in seedlings significantly increased with increasing H + in soil and colonization with ectomycorrhiza. The maximum net photosynthetic rate at light and CO 2 saturation (P max ) was greater in soil treated with 10 mmol H + kg -1 than in controls, and was less is soils treated with greater than with 30 mmol H + kg -1 , especially with 60 and 90 mmol H + kg -1 . However, colonization with ectomycorrhiza significantly reduced the concentration of Al and Mn in needles or roots and increased the values of P max and total dry mass (TDM). The relative TDM of L. kaempferi seedlings was approximately 40% at a (BC, base cation)/Al ratio of 1.0. However, ectomycorrhizal seedlings had a 100-120% greater TDM at a BC/Al ratio of 1.0 than non-ectomycorrhizal seedlings, even though the acid treatment reduced their overall growth.

Photosynthetic rate, needle longevity, and nutrient contents in Picea glehnii growing on strongly acidic volcanic ash soil in northern Japan

“…For woody species, ectomycorrhizal fungal symbioses are important for exclusion of Al. Inoculation with ectomycorrhizae can reduce Al uptake, and protect plants from deficiencies in Ca, Mg, and K (Hentschel et al 1993, Lux and Cumming 2001, Choi et al 2008, van Schöll et al 2008. Based on our microscope observation, P. glehnii growing in volcanic ash soil had numerous ectomycorrhizal hyphae around their roots, showing that they have active symbioses with ectomycorrhizal fungi.…”

Ecophysiological responses of the larch species in northern Japan to environmental changes as a basis for afforestation

“…Mg ? K) to Al (i.e., BC/Al ratio) in the soil solution or water extract of soil, the sensitivity of Japanese larch to soil acidification is similar to that of Cryptomeria japonica, Pinus densiflora, and Fagus crenata Choi 2008;Choi et al 2008).…”

“…As shown in Choi et al (2008), severe soil acidification reduces growth and photosynthesis of Japanese larch. At lower level of acidification, ectomycorrhiza will help the larch to maintain growth, but will not help at severe acidification level.…”

“…The role of ectomycorrhizae in growth responses of larch species in acid soil is therefore important in clarifying the effect of soil acidification on larches. Choi et al (2008) studied the growth response of Japanese larch seedlings infected with several ectomycorrhizal fungi and raised under different soil acidification levels (proton concentrations of 10, 30, 60, and 90 mmol H ? kg -1 ).…”

Seed germination and seedling physiology of Larix kaempferi and Pinus densiflora in seedbeds with charcoal and elevated CO2

“…This has happened in, for example, the central part of the Korean peninsula, the Far East of Russia, and northeast China (Makoto 2005(Makoto , 2007bChoi et al 2008). Changes to the environment, such as atmospheric CO 2 levels, are also accelerating, and photosynthetic adjustment is often observed in plants (Choi et al 2006(Choi et al , 2008Farrar and Williams 1991;IPCC 2000IPCC , 2007. It is increasingly important to establish a practical method of forest rehabilitation in such degraded areas.…”