Trees usually associate with different mycorrhizal fungi, which help them take up nutrient from soil.
Meanwhile, trees would re-translocate nutrient from senescing organs to living or storage organs during organ senescence. This process is known as nutrient resorption, which plays an important role for nutrient conservation in plants. It remains unclear whether nutrient resorption would differ between trees associated with different types of mycorrhizal fungi.
To understand the variation of nutrient resorption between trees associated with ectomycorrhizal fungi (ECM) and arbuscular mycorrhizal fungi (AM), an international research group of scientists from Institute of Applied Ecology and Institute of Botany, Chinese Academy of Sciences, Max Planck Institute for Biogeochemistry, and Indiana University, carried out a study with methods of meta-analysis and empirical experiment.
Their results showed that nutrient resorption varied greatly between different mycorrhizal types and among different climate zones.
The amount of foliar phosphorus resorbed in ECM trees was 76% greater than that in AM trees in the boreal forest. In the tropic forests, ECM trees resorbed less N than AM trees.
Those results indicated that the variation of nutrient resorption between AM and ECM trees is largely dependent on climate zone.
The scientists further analyzed the data from 45 forest plots in Indiana of US, within which both AM and ECM trees are co-occurring.
They found that the plots with more ECM trees would resorb more N during leaf senescence.
Results from the study improve our understanding of the role of mycorrhizal fungi in mediating plant nutrient conservation. Trees with different mycorrhizal associations are different in nutrient resorption patterns across local, biome, and even global scales.
The results also highlight the utility of mycorrhizal type as a functional trait to better understand ecosystem nutrient cycling.
This work was published entitled "Foliar Nutrient Resorption Differs Between Arbuscular Mycorrhizal and Ectomycorrhizal Trees at Local and Global Scales" in Global Ecology and Biogeography.
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