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MycoPhen: Linking mycorrhizal network phenology to above- and belowground plant phenology and environmental factors

Active Dates 9/1/2022-8/31/2025
Program Area Environmental Systems Science
Project Description
Mycorrhizal networks and fine roots together represent a critical link between aboveground plant nutrient and water demands and belowground resources. However, the patterns and processes underlying the growth of mycorrhizal networks in soil, their relationships to whole-plant phenology, and their responses to environmental factors are largely unknown. Models are therefore strongly limited in their ability to represent current and predict future productivity in terrestrial ecosystems. To overcome these limitations, studies are needed that can identify the timing and drivers of mycorrhizal network phenology together with the closely related phenology of their plant hosts.

In this project we will address three objectives: 1) identify changes in the growth, abundance, and composition of mycorrhizal fungal networks across the growing season and their responses to stress, ephemeral soil resources, or transient environmental factors; 2) determine the coordination of mycorrhizal network phenology with whole-plant phenology and ecophysiology; and 3) improve the ability of models to represent the timing and magnitude of fine-root and mycorrhizal network growth. To address these objectives, new data regarding mycorrhizal network phenology and composition will be linked with observations of leaf, stem, and fine-root phenology in mature, monospecific forestry plots at The Morton Arboretum (Lisle, IL, USA). These will then be used to guide and parameterize ongoing development of the E3SM Land Model (ELM) in collaboration with colleagues at Oak Ridge National Laboratory.

 This project leverages existing resources at The Morton Arboretum, where 23 plots have been instrumented for repeated, long-term measurements of above- and belowground phenology. Our platform includes minirhizotrons to capture fine-root phenology and aspects of fungal phenology, digital dendrometers for stem-wood growth, phenocams for leaf/canopy phenology, sap flow sensors for whole-tree water movement, and continuous monitoring of abiotic soil and weather conditions. We propose to further augment a subset of 10 plots where we will increase the frequency of our minirhizotron imaging and incorporate repeated sampling of fungal abundance and communities in bulk soil to identify seasonal and short-term fluctuations in mycorrhizal network biomass based on qPCR and community composition using high-throughput sequencing (HTS). The instrumented plots capture a diverse suite of host plants that allow us to experimentally compare patterns and responses of mycorrhizal networks for multiple model-relevant plant functional groupings including deciduous and evergreen species, gymnosperm and angiosperm species, as well as species that dominantly associate with either of the two main mycorrhizal types, arbuscular and ectomycorrhizal fungi.

Our long-term observations and repeated sampling of mycorrhizal fungal networks across the growing season will allow us to quantify patterns of fungal growth and biomass across the season and determine how fungal species dominance within these networks shifts across the growing season and in response to the environment. These results would represent a substantial advance in our understanding of mycorrhizal network functioning in terrestrial systems. Furthermore, the combination of our novel data characterizing mycorrhizal network growth in conjunction with measurements of whole-plant phenology across diverse host tree species gives us the capacity to address fundamental questions regarding coupled above- and belowground ecosystem processes in a transformative manner. Our collaborative work updating representations of belowground processes in ELM also provides an immediate opportunity where our findings can be used to improve predictions of earth’s responses to future climate change and environmental variability in the coming decades.
Award Recipient(s)
  • The Morton Arboretum (PI: McCormack, MichaelLuke)