Saguaro Water Balance
Tracking changes in volume:surface ratio (V:S) across seasons to understand how saguaros store and lose water, and how much rainfall is required to recharge a desiccated plant.
Saguaro water balance, desert heat, and plant function.
I am a fungal ecologist and desert plant physiologist working on how Carnegiea gigantea (saguaro) and other Sonoran plants respond to heat, drought, and a changing climate.
This site hosts project summaries, figures, opportunities for collaboration, and public engagement.
About
I study the root fungal relationships, physiology and ecology of desert plants, with a focus on water relations, thermal stress, and long-term responses to a warming, drying climate. My work combines field measurements, and quantitative analysis to understand how iconic species like saguaro cacti are changing through time and how they will cope with a changing climate.
I am based in Phoenix, Arizona, and spend my time between fieldwork, lab management, data analysis, and public outreach. This site is a living space for current projects, visualizations, and ways to get involved.
Research Themes
Photosynthetic Performance & Stress
Monitoring FVFM (dark-adapted quantum yield) as a window into photosystem health, and relating it to temperature, humidity, vapor pressure deficit, and plant water status.
Climate & Extreme Heat
Using environmental variables (temperature, humidity, radiation, precipitation) to quantify the conditions saguaros experience.
Fieldwork & Collaboration
Inter-agency surveys, long-term monitoring, and collaborative projects that link fundamental plant physiology with conservation and management decisions in the Sonoran Desert.
Interactive Figures
These figures are built from ongoing analyses of saguaro physiology and microclimate. Hover and zoom to explore the data. New plots will be added as projects develop.
V:S, Daily Max Temperature, and Precipitation Through Time
Size-class averaged V:S with standard errors, overlaid with daily maximum temperature and precipitation.
FVFM, Daily Max Temperature, and Precipitation Through Time
Mean FVFM by size class with uncertainty, shown alongside daily temperature and rainfall.
FVFM vs Relative V:S (Medium Plants)
FVFM as a function of relative V:S (% of maximum), with a log-curved fit to highlight how photosystem performance changes as plants transition between “fat” and “dry” states.
Photos
Field sites, instrumentation, and seasonal conditions across South Mountain and other Sonoran locations. Click any image to view it full-size.
Fieldwork & Outreach
This project is grounded in field measurements across South Mountain and other Sonoran sites, and in sharing what we learn with the public.
- Long-term monitoring of tagged saguaros across elevation bands.
- Nighttime FVFM campaigns to track seasonal stress and recovery.
- Talks to the public in partnership with the Desert Foothills Land Trust.
If you are interested in collaboration, data use, or educational partnerships, please reach out.
Media
A few recent features, interviews, and mentions related to my work in desert plant physiology and fungal ecology.
Podcast
Soli Microves and Desert Plant Restoration / In Defense of Plants
The importance of root fungi in dryland ecology and restoration.
Article
How the foundational riparian tree species Populus fermontii uses water in extreme heat and how it fairs without it.
Blog Post
South Mountain's Saguaros Still Soak up the Rain
How saguaro on South Mountain are responding to rain events and weather patterns.
Contact
For questions about the research, data visualization, or potential collaborations, you can reach me at:
Email: aschuessler@dbg.org
You can also connect with me on LinkedIn and other professional networks (linkedin.com/in/alexandra-schuessler).