About

Professor Laura M. Bogar is a researcher at the University of California, Davis, leading the Bogar Lab. Her work focuses on understanding the ecology of roots, fungi, and soil microbes through genetics and physiology. The lab specifically investigates ectomycorrhizal symbiosis between roots and soil fungi, which is essential for the health of most temperate forest trees. Their research aims to elucidate how these interactions function, how they enhance tree stress response, and how ectomycorrhizal fungi interact with other microbes to influence forest soil functioning.

Research topics

• Biology
• Ecology
• Botany
• Geography
• Paleontology

Selected publications

• Functional composition of subsoil microbial communities changes with oak mortality

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Fire severity drives shifts in ectomycorrhizal fungal communities and Pseudotsuga menziesii seedling performance

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-08-19

  preprintOpen accessSenior author

  Abstract Background and Aims High-severity wildfires are increasing in western North America, disrupting soil conditions and mutualisms between plants and ectomycorrhizal fungi (EMF), which support seedling nutrient uptake, stress tolerance, and survival. This study investigates how fire severity and recency affect fungal communities and Pseudotsuga menziesii (Douglas-fir) seedling performance, and whether live-soil inoculation or stress priming improve post-fire outcomes. Methods In a greenhouse experiment, Douglas-fir seedlings were grown in soils from high-severity burns, recent and historic low-severity burns, and unburned sites in the Sierra Nevada. Each soil was applied as a live or autoclaved inoculum. Drought stress and abscisic acid priming treatments were imposed before a final 3-week dry-down. We measured seedling biomass, chlorophyll fluorescence (Fv/Fm), EMF colonization, and fungal community composition using ITS amplicon sequencing. Results High-severity soils reduced seedling growth, EMF colonization, and fungal richness. Low-severity burns supported more rich, diverse fungal communities and greater seedling performance. Stress priming treatments had minimal effects. Fungal community composition varied significantly by burn severity. Conclusion Fire severity drives changes in fungal community structure that influence seedling outcomes. Low-severity soils retain beneficial microbial legacies, supporting stronger mycorrhizal associations that result in seedling performance comparable to unburned soils. Targeted microbial restoration may enhance post-fire forest regeneration in high-severity burn areas

  PublisherOA PDFDOI

• Functional composition of subsoil microbial communities changes with oak mortality

  Soil Biology and Biochemistry · 2024-12-03 · 1 citations

  preprintOpen accessSenior authorCorresponding

  Abstract Tree mortality in oak savannas is increasing under climate change, but its impact on microbial communities and soil carbon below the top 20 centimeters is relatively unknown. Deep tree roots, their ectomycorrhizal fungi, and associated bacteria may have a particularly important effect on landscape carbon storage, as they mediate the transfer of recently fixed plant carbon into deep soil and subsoil layers. To investigate how tree mortality impacts microbes and soil carbon, we sampled under living and recently dead Quercus douglasii trees in a California oak savanna, gathering depth-resolved soil cores to 45 cm below the surface. We captured finely resolved biological detail on these soil samples, comparing living (RNA-based) to potential and historical (DNA-based) microbial communities and assessing microbial biomass with phospholipid fatty acid analysis. Tree mortality greatly reduced the abundance of ectomycorrhizal fungi, particularly in subsoils. Fungal niches were more variable at depth under dead trees than under living ones, and RNA-based profiling captured substantially different communities than DNA, especially under living trees. However, tree mortality three years prior to our study did not impact the overall quantity of carbon stored in the soil. Tree mortality can have profound effects on the interactions between tree roots, mycorrhizal fungi, and soil bacteria, which may shift soil carbon dynamics over long time scales. Understanding the mechanisms of these interactions, and their time scales, will improve our ability to predict and manage soil carbon in savanna landscapes as drought and heat events kill more oaks in arid climates. Highlights Ribosomal RNA, from living cells, revealed different communities than from DNA. Microbial functions changed more with depth and tree health than taxonomy. Differences were most extreme below 20 cm depth. Microbial population distributions changed under living and dead trees. Total microbial biomass and carbon were similar beneath living and dead trees.

  PublisherDOI

• Tree drought physiology: critical research questions and strategies for mitigating climate change effects on forests

  New Phytologist · 2024-12-17 · 28 citations

  reviewOpen access

  Droughts of increasing severity and frequency are a primary cause of forest mortality associated with climate change. Yet, fundamental knowledge gaps regarding the complex physiology of trees limit the development of more effective management strategies to mitigate drought effects on forests. Here, we highlight some of the basic research needed to better understand tree drought physiology and how new technologies and interdisciplinary approaches can be used to address them. Our discussion focuses on how trees change wood development to mitigate water stress, hormonal responses to drought, genetic variation underlying adaptive drought phenotypes, how trees 'remember' prior stress exposure, and how symbiotic soil microbes affect drought response. Next, we identify opportunities for using research findings to enhance or develop new strategies for managing drought effects on forests, ranging from matching genotypes to environments, to enhancing seedling resilience through nursery treatments, to landscape-scale monitoring and predictions. We conclude with a discussion of the need for co-producing research with land managers and extending research to forests in critical ecological regions beyond the temperate zone.

  PublisherOA PDFDOI

• Environmental Fluctuations Promote Host Reward Strategies That Maintain Partner Diversity in Multispecies Mutualisms

  The American Naturalist · 2024-09-21 · 2 citations

  article

  AbstractIn multispecies mutualisms, hosts might be expected to reward only the highest-quality partner in order to maximize benefits and prevent the proliferation of cheaters. In a fluctuating environment, however, partner quality is likely to vary over time, and the maintenance of low-quality partners has been shown to be beneficial in some environmental regimes. Here, we present a model of a simple tree-fungal mutualism with two distinct environmental conditions and a host that can employ reward strategies with varying degrees of preference for higher-quality fungi. We find that in many environmental regimes, the most successful strategy for the host is one that actively maintains equal densities of the two fungal partners, in spite of their immediate differences in quality. This conservative bet-hedging strategy leads to reduced variance in the tree's carbon resources and high resilience to environmental perturbation. An alternative reward strategy, which supports only the highest-quality partner at a time, is most successful under some conditions when fluctuations in the environment are infrequent. Longer periods of environmental stasis thus increase the risk to the tree of losing fungal partner diversity. This theoretical work identifies a mechanism by which biodiversity may be actively maintained in multispecies mutualisms but that may be disrupted as environmental conditions change.

  PublisherDOI

• Ectomycorrhizal fungi alter soil food webs and the functional potential of bacterial communities

  mSystems · 2024-05-08 · 14 citations

  articleOpen access

  ABSTRACT Most of Earth’s trees rely on critical soil nutrients that ectomycorrhizal fungi (EcMF) liberate and provide, and all of Earth’s land plants associate with bacteria that help them survive in nature. Yet, our understanding of how the presence of EcMF modifies soil bacterial communities, soil food webs, and root chemistry requires direct experimental evidence to comprehend the effects that EcMF may generate in the belowground plant microbiome. To this end, we grew Pinus muricata plants in soils that were either inoculated with EcMF and native forest bacterial communities or only native bacterial communities. We then profiled the soil bacterial communities, applied metabolomics and lipidomics, and linked omics data sets to understand how the presence of EcMF modifies belowground biogeochemistry, bacterial community structure, and their functional potential. We found that the presence of EcMF (i) enriches soil bacteria linked to enhanced plant growth in nature, (ii) alters the quantity and composition of lipid and non-lipid soil metabolites, and (iii) modifies plant root chemistry toward pathogen suppression, enzymatic conservation, and reactive oxygen species scavenging. Using this multi-omic approach, we therefore show that this widespread fungal symbiosis may be a common factor for structuring soil food webs. IMPORTANCE Understanding how soil microbes interact with one another and their host plant will help us combat the negative effects that climate change has on terrestrial ecosystems. Unfortunately, we lack a clear understanding of how the presence of ectomycorrhizal fungi (EcMF)—one of the most dominant soil microbial groups on Earth—shapes belowground organic resources and the composition of bacterial communities. To address this knowledge gap, we profiled lipid and non-lipid metabolites in soils and plant roots, characterized soil bacterial communities, and compared soils amended either with or without EcMF. Our results show that the presence of EcMF changes soil organic resource availability, impacts the proliferation of different bacterial communities (in terms of both type and potential function), and primes plant root chemistry for pathogen suppression and energy conservation. Our findings therefore provide much-needed insight into how two of the most dominant soil microbial groups interact with one another and with their host plant.

  PublisherDOI

• Modified source–sink dynamics govern resource exchange in ectomycorrhizal symbiosis

  New Phytologist · 2023 · 27 citations

  1st authorCorresponding
  • Ecology
  • Biology
  • Paleontology

  Ectomycorrhizal symbiosis between roots and fungi is founded on the movement of carbon from plants to fungi, and of soil resources from fungi to plants. Framing this movement as a trade can facilitate an understanding of how this mutualism has developed over evolutionary time, but fails to explain experimental observations of carbon and nutrient movement. Here, I propose that source-sink dynamics are an essential basic model to explain the movement of plant and fungal resources, which may be modified by plant immune response, variability in fungal molecular repertoires, and competition in the soil. Source-sink dynamics provide testable hypotheses to illuminate mechanisms of ectomycorrhizal resource movement and its consequences for mutualism stability and forest function under climate change.

  PublisherOA PDFDOI

• Fungal Fight Club: phylogeny and growth rate predict competitive outcomes among ectomycorrhizal fungi

  FEMS Microbiology Ecology · 2023-09-11 · 7 citations

  articleOpen access

  Ectomycorrhizal fungi are among the most prevalent fungal partners of plants and can constitute up to one-third of forest microbial biomass. As mutualistic partners that supply nutrients, water, and pathogen defense, these fungi impact host plant health and biogeochemical cycling. Ectomycorrhizal fungi are also extremely diverse, and the community of fungal partners on a single plant host can consist of dozens of individuals. However, the factors that govern competition and coexistence within these communities are still poorly understood. In this study, we used in vitro competitive assays between five ectomycorrhizal fungal strains to examine how competition and pH affect fungal growth. We also tested the ability of evolutionary history to predict the outcomes of fungal competition. We found that the effects of pH and competition on fungal performance varied extensively, with changes in growth media pH sometimes reversing competitive outcomes. Furthermore, when comparing the use of phylogenetic distance and growth rate in predicting competitive outcomes, we found that both methods worked equally well. Our study further highlights the complexity of ectomycorrhizal fungal competition and the importance of considering phylogenetic distance, ecologically relevant traits, and environmental conditions in predicting the outcomes of these interactions.

  PublisherOA PDFDOI

• Data for EMSL Project 51394 from March 2022

  OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2022-01-01

  datasetOpen accessSenior author
  PublisherDOI

• Data for EMSL Project 51394 from May 2022

  OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2022-01-01

  datasetOpen accessSenior author
  PublisherDOI

Recent grants

• NSF Postdoctoral Fellowship in Biology FY 2020

  NSF · $138k · 2020–2022

Frequent coauthors

• Kabir Peay

  Stanford University

  1058 shared

• Glade Dlott

  Stanford University

  1051 shared

• Peter G. Kennedy

  University of Minnesota

  5 shared

• Nora C. Duncritts

  University of Wisconsin–Madison

  3 shared

• Holly V. Moeller

  University of California, Santa Barbara

  3 shared

• Marie Duhamel

  2 shared

• Yakir Preisler

  Harvard University Press

  2 shared

• W. Douglas Robinson

  2 shared

Education

• Ph.D., Biology

  Stanford University

  2019

• B.A., Biology

  Lewis & Clark College

  2012