Research

I investigate how forest ecosystems respond to biological and environmental stress, with a focus on the interactions between trees and their associated microbial communities. My work integrates microbial ecology, fungal genomics, and molecular diagnostics to understand how host-microbiome dynamics shape forest health across different ecosystems and disturbance regimes.

Research Themes

Forest Health & Plant-Microbiome Interactions

How do fungal pathogens and microbial communities shape tree health across contrasting forest ecosystems?

To address this question I use a multi-layered approach, looking not only at host-pathogen interactions (HPI), but also how the host interacts with the whole microbial community, including beneficial symbionts.

To address HPI, I have studied the Cypress Canker Disease (CCD) pathosystem, investigating the molecular interactions between Seiridium cardinale and Cupressus sempervirens. CCD is one of the few documented pandemic forest diseases. Therefore, understanding how cypress responds to infection has important implications for forest management. Using dual-RNA seq across multiple climate zones in California, I examine how distinct environmental conditions influence gene expression during infection, and which host genes are associated with resistance. Complementing this, comparative genomics analyses across Seiridium species illuminate the evolutionary basis of pathogenicity and the success of invasive populations.

I also investigate microbial communities associated with the decline of trees, using Screwbean mesquite (Prosopis pubescens) in the Mojave Desert and Death Valley as a study system. This system represents an enigmatic dieback affecting a keystone riparian species in one of North America’s most extreme environments. This work explores how abiotic stress and microbial community shifts interact to drive tree decline in extreme environmental conditions.

Finally, I am involved in a project developing biocontrol strategies against Heterobasidion root rot in West Coast conifer forests — a major threat to standing trees that spreads through root anastomosis from infected stumps. We test how different strains of Phlebiopsis gigantea can suppress or reduce Heterobasidion growth, contributing to more sustainable forest disease management.

Forest Health in Island Ecosystems

Island ecosystems — characterized by high endemism, ecological isolation, and heightened vulnerability to biological invasions — offer powerful natural laboratories for studying how forest communities respond to emerging pathogens and anthropogenic stress. In Hawaiʻi, I investigate fungal communities associated with healthy and diseased ʻōhiʻa lehua (Metrosideros polymorpha) trees affected by Rapid ʻŌhiʻa Death (ROD), a devastating emerging disease caused by Ceratocystis fungi. I also study leaf litter fungal communities along altitudinal gradients on Oʻahu, examining how heavy metal concentrations in pristine versus anthropogenically polluted sites shape mycobiome structure and diversity.

In Sardinia (Italy), I have investigated fungal communities associated with cork oak (Quercus suber) systems, examining how Phytophthora alters soil fungal communities and mycorrhizal networks — with implications for cork quality and oak woodland conservation.

Fungal Diversity, Evolution & Molecular Diagnostics

Understanding fungal diversity and evolution requires both robust molecular tools and access to historical biological material. I apply ancient DNA techniques to herbarium specimens to generate sequence data for taxonomically unresolved fungal groups, with a focus on Laccaria spp. — an ecologically important mycorrhizal genus and a model for understanding mycorrhizal associations. By producing DNA barcodes from historical collections, I expand the genetic resources available for fungal taxonomy and diversity assessments. My broader toolkit includes metabarcoding and eDNA approaches for characterizing microbial communities, reference-quality genome assembly, and molecular diagnostics (qPCR, NGS, Sanger sequencing) for pathogen detection and pop-gen analyses. I am particularly drawn to non-model systems where genomic resources are scarce but ecological and applied stakes are high.