Effects of tree species, water and nitrogen on mycorrhizal C flux
Abstract
Mycorrhiza plays an important role in global carbon cycle, especially, in forest soils, yet the effect of tree species on the amount and timing of C transfer through roots to myccorhiza is largely unknown. We studied the C transport to mycorrhiza under 6 most commonly dominant in boreal forests tree species using the mesh collars installed at the Siberian afforestation experiment. The CO2 flux from mycorrhizal and non-mycorrhizal mesh collars indicated the mycorrhizal C flux. Tree species strongly differed in C flux to mycorrhiza: more C was transferred by deciduous species than by conifers. The mycorrhizal CO2 flux was not linked to soil temperature but rather to trees phenology and to photosynthetic activity. All tree species transfered more carbon to mycorrhiza during the second half of summer and in September, this is because all the carbon photosynthesized earlier is used for building the tree biomass. Seasonal variation in C transfer to mycorrhiza was much larger than hourly variation (within a day). Nitrogen application (50 kg/ha) increased mycorrhizal C flux only under Scots pine, but not under larch, thus the effect of N application is tree species dependent. We found under most tree species that more C was transferred by trees to mycorrhiza in root-free collars, where the soil moisture was higher than in collars with roots. This suggests that trees preferentially support those parts of mycorrhiza, which can gain extra-resources.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.B21F..04M
- Keywords:
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- 0414 BIOGEOSCIENCES / Biogeochemical cycles;
- processes;
- and modeling;
- 0426 BIOGEOSCIENCES / Biosphere/atmosphere interactions;
- 0428 BIOGEOSCIENCES / Carbon cycling;
- 0476 BIOGEOSCIENCES / Plant ecology