Project title

Death from Above: Microbial communities & disease pressure from forest floor to canopy

Mentor's name(s)

Dr. Erin Spear, STRI Staff Scientist.
SpearER@si.edu

Location of internship. Will mentor be at this location?

Gamboa and Parque Natural Metropolitano

Project summary

Utilizing STRI’s canopy access crane in the seasonally dry forest of Parque Natural Metropolitano (PNM), this multifaceted and multi-year project: (a) assesses whether adult trees are reservoirs of disease for understory juveniles (an assumption of the Janzen Connell Hypothesis); (b) identifies key dispersal mechanisms of micro-fungi; (c) explores the vertical turnover of microbial communities from forest floor to canopy; (d) investigates the role of abiotic factors (e.g., temperature, ultraviolet radiation) in microbial turnover; (e) determines whether a disease gradient is correlated with vertical abiotic gradients; (f) evaluates pathogen sharing between phylogenetically unrelated but sympatric trees; and (g) captures interannual changes in microbial community composition and disease levels. To date, the latter includes a normal precipitation year and the driest year on record. This project involves lab-based work culturing, molecularly identifying fungi, and assessing fungal tolerance of abiotic stressors (e.g., temperature & UV); greenhouse-based inoculation experiments to assess host range and how plant-pathogen interactions respond to elevated temperature; and field-based collections of diseased leaf tissue, airborne and rainwater-dispersed spores, and soil.

Mentorship goals

Interns will gain practical experience with core field, lab, and analytical skills. Interns are encouraged to consider the broader impacts and science communication of the project by developing relevant social media posts and/or a short article for the STRI newsletter. Research and career guidance is available from Dr. Spear as well as other team members in one-on-one and regular lab meetings. Additionally, interns are encouraged to attend weekly STRI seminars, exposing them to a wide range of research topics and providing an opportunity to interact with the broader STRI community. The ultimate goal is that interns’ active participation and unique contributions to the project result in the opportunity to coauthor at least one scientific paper. Finally, interns would be joining an inclusive scientific community (the broader STRI community and our lab), as well as building a network of research mentors at various career stages and potential future collaborators.

Desired background

Understanding of botany, mycology, and biology. No fear of heights
Experience:

• Accurately and effectively entering data in spreadsheets.
• Using the statistical program R, at a minimum for descriptive statistics.
• Using aseptic technique to culture microorganisms and/or extract and amplify DNA.
• Working in the field, particularly in hot and humid conditions with insects.

Intern’s role and expected product

This is a full-time appointment for a 3-month period. Interns are expected to devote ~40 hours per week to research. Expected time allocation: 10% fieldwork (Parque Natural Metropolitano), 75% laboratory work (Dr. Spear’s lab in Gamboa), 15% entering and analyzing data and writing. Each intern is expected to produce and present an informal report on results and outcomes to the lab group. The intention is that the final report will be incorporated into a peer-reviewed scientific publication, with the intern as a co-author.

Suggested background readings

• Gilbert, G. S. (1995). Rain forest plant diseases: the canopy—understory connection. Selbyana, 75-77.
• Lodge, D. J., & Cantrell, S. (1995). Fungal communities in wet tropical forests: variation in time and space. Canadian Journal of Botany, 73(S1), 1391-1398.
• Spear, E. R., & Broders, K. D. (2021). Host‐generalist fungal pathogens of seedlings may maintain forest diversity via host‐specific impacts and differential susceptibility among tree species. New Phytologist, 231(1), 460-474.