Nitrophobic ectomycorrhizal fungi are associated with enhanced hydrophobicity of soil organic matter in a Norway spruce forest
<p>In boreal forests an important part of the photo assimilates are allocated belowground to support symbiosis of ectomycorrhizal fungi (EMF). The production of EMF extramatrical mycelium can contribute to carbon (C) sequestration in soils, but the extent of this contribution depends on the co...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-08-01
|
| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/19/3713/2022/bg-19-3713-2022.pdf |
| Summary: | <p>In boreal forests an important part of the photo assimilates are allocated
belowground to support symbiosis of ectomycorrhizal fungi (EMF). The
production of EMF extramatrical mycelium can contribute to carbon (C)
sequestration in soils, but the extent of this contribution depends on the
composition of the EMF community. Some species can decrease soil C stocks by
degrading soil organic matter (SOM), and certain species may enhance soil C
stocks by producing hydrophobic mycelia which can reduce the rate of SOM
decomposition. To test how EMF communities contribute to the development of
hydrophobicity in SOM, we incubated sand-filled fungal-ingrowth mesh bags
amended with maize compost for one, two or three growing seasons in
non-fertilized and fertilized plots in a young Norway spruce (<i>Picea abies</i>) forest. We
measured hydrophobicity as determined by the contact angle and the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">C</mi><mo>/</mo><mi mathvariant="normal">N</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="24pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="f135772273124e8de131c1d3d27c70de"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-3713-2022-ie00001.svg" width="24pt" height="14pt" src="bg-19-3713-2022-ie00001.png"/></svg:svg></span></span> ratios
in the mesh bags contents along with the amount of new C entering the
mesh bags from outside (determined by C<span class="inline-formula"><sub>3</sub></span> input to C<span class="inline-formula"><sub>4</sub></span> substrate), and related
that to the fungal community composition. The proportion of EMF species
increased over time to become the dominant fungal guild after three growing
seasons. Fertilization significantly reduced fungal growth and altered EMF
communities. In the control plots the most abundant EMF species was
<i>Piloderma olivaceum</i>, which was absent in the fertilized plots. The hydrophobicity of the
mesh bag contents reached the highest values after three growing seasons only
in the unfertilized controls plots and was positively related to the
abundance of <i>P. olivaceum</i>, the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">C</mi><mo>/</mo><mi mathvariant="normal">N</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="24pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="a1fd226718b6fd2378e4d645ff1b8807"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-3713-2022-ie00002.svg" width="24pt" height="14pt" src="bg-19-3713-2022-ie00002.png"/></svg:svg></span></span> ratios of the mesh bag contents and the amount of new C
in the mesh bags. These results suggest that some EMF species are associated
with higher hydrophobicity of SOM and that EMF community shifts induced by
fertilization may result in reduced hydrophobicity of soil organic matter,
which in turn may reduce C sequestration rates.</p> |
|---|---|
| ISSN: | 1726-4170 1726-4189 |