The Dryland Plant Ecophysiology Lab | Desert Botanical Garden


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The Dryland Plant Ecophysiology Lab studies plant ecophysiology traits that underlie adaptation to heat waves, drought and other stressors. We use the most up-to-date approaches to study plant water relations, photosynthesis and growth to better understand how plants respond to stressful environmental conditions. We seek to identify solutions for restoring and conserving dryland forests, plant communities, and sensitive species threatened by global environmental change.


Urban landscaping for a cooler future

The heat island effect is extreme in the arid Southwest and are poised to increase in intensity due to population growth and climate change. With collaborators at the School of Earth Sciences and the Environment at Arizona State University, the DPEL is combining...

Plant responses to heat stress

Water loss in plants has commonly been considered only as a cost of photosynthetic carbon gain. However, plants may use water in ways that may not necessarily optimize instantaneous carbon gain, but instead as a strategy for leaf evaporative cooling. The DPEL and...

The distinctive form and function of giant cactus

Giant cactus are among the most charismatic and iconic plant life forms on the planet, but many giant cactus species are threatened by the effects of climate change. At the Dryland Plant Ecophysiology Lab (DPEL) the staff studies the distinctive physiological features...

Tree ecophysiology in dryland riparian ecosystems

Riparian forests are among the most threatened in North America as a consequence of altered hydrological conditions, invasive species and climate change. The Dryland Plant Ecophysiology Lab seeks to identify tree ecophysiological traits that underlie adaptation to...

Meet the Team

Kevine Hultine

Kevin Hultine (Ph.D.)

Lab director / Plant Ecophysiologist

Hultine’s expertise involves studying how plants cope with environmental stress in desert ecosystems in urban, riparian and upland areas. He is focused on the duel effects of drought and thermal stress on plants and ecosystems in dryland regions worldwide. He applies stable isotope methods, measurements in plant water relations and measurements of plant carbon allocation and storage to improve the understanding of how desert plant systems function at multiple scales.

Google scholar:


khultine@dbg.orgphone: 480.481.8195

Lab Director / Plant Ecophysiologist

Natalie Melkonoff

Kelly kerr (ph.d)

Kelly received her PhD from the University of Utah. Her research interests revolve around the resiliency of forest tree species to climate change. She is particularly interested in using tree physiology, genetics and modeling to understand and predict tree species’ responses to the environment.


Postdoctoral Fellow, University of California, Santa Barbara

Ivanna Caspeta

Ivanna Caspeta

BS Conservation Biology & Ecology, Arizona State University
Completion of M.S. by lab member 

Ivanna Caspeta successfully defended her thesis in the School of Life Sciences at Arizona State University. Ivanna’s thesis focused the xylem anatomy of giant cacti, and tested whether allometric scaling equations used characterize the xylem anatomy of trees and shrubs also works for cacti. Congratulations Ivanna!

B.S. Conservation Biology & Ecology, Arizona State University 
Completion of M.S. by lab member


Madeline Moran (M.S.)

M.S. Plant Biology and Conservation, Arizona State University (In progress)
Huizingh Desert Research Fellowship Award

Moran’s background is in plant ecology/conservation and environmental education. Moran’s research interests include how plants physically respond to environmental stress, the implications of those responses within their ecosystem and finding community-based solutions to conservation issues. Currently, she is working on her masters about how the thermal tolerance of cottonwood leaves differs in varying climate conditions and how increasing temperatures might alter the efficacy of photosynthesis in these trees.

Madeline Moran was recently awarded the Huizingh Desert Research Fellowship. The award provides five years of funded to support her PhD program to study the thermal tolerance of plants exposed to heat stress. Madeline becomes the second student to receive this prestigious award. Congratulations Madeline!

Ph.D. Arizona State University/Desert Botanical Garden (In progress)
Desert Research Fellowship Award

Dan Koepke

Dan Koepke (M.S.)

Plant Functional & Physiological Ecology Research Assistant

Koepke assists lab personnel and colleagues with field and laboratory projects. His work focuses on plant hydraulics and seeks to identify morphological and physiological traits that respond to environmental stresses, and how these traits are interrelated. In turn, information about trait expression improves the ability of site managers to restore ecosystems faced with environmental change.

Google Scholar Profile

Senior Research Assistant

Natalie Melkonoff

Natalie Melkonoff (B.S.)

PhD. Biology, Arizona State University/Desert Botanical Garden (In progress)

Melkonoff’s work is focused on the interactions between plants and animals and how the physiological processes of both impact their interdependence on one another and their ability to thrive under different environmental stressors. She is currently working on her Ph.D. with a focus on the interactions between milkweed, monarch butterflies and pollinators in the Sonoran Desert. She also coordinates Desert Botanical Garden’s monarch and pollinator conservation initiative, Great Milkweed Grow Out.


Ph.D. University of Arizona/Desert Botanical Garden (In progress)


Ali Schussler (M.S.)

Ali manages the plant physiology and molecular labs. Where she works with the traits and function of traits in desert and arid riparian plants, along with the genomics and phylogenies of agave, cactus and other desert plants. One of her personal research interests is on dark septate endophytic fungi and how they influence plants in desert and riparian systems, where these fungi are potentially aiding plant growth regulator production, nutrient and water uptake and other positive plant growth responses.  


Lab Managaer

Photo_Mary Chisolm_Update 2
Mary Chisolm (m.s.)
Mary recently completed her Master of Science degree in Plant Biology and Conservation at Arizona State University and in the Dryland Plant Ecophysiology Lab. Mary previously completed her B.S. at the University of Massachusetts, Amherst and will continue studying desert plants at the Desert Botanical Garden.


Research Assistant

Natalie Melkonoff

Brad Posch (Ph.D)

Dr. Posch is a plant ecophysiologist who studies how plants respond to environmental stressors such as heat and drought. Posch received his Ph.D. from the Australian National University and has worked as a postdoc under Dr. Nick Smith at Texas Tech University. Although Posch’s research focuses on leaf gas exchange, he is also interested in the biochemical processes underlying physiological responses to warming.

Google Scholar


Plant Ecophysiologist 


Susan Bush (Ph.D)

Bush is a global change ecologist whose research has largely focused on fluxes of carbon and water in both urban and natural ecosystems. Her research effort has spanned scales from leaf-level gas exchange and xylem vascular hydraulics of individual plants to landscape scale investigations of water and carbon exchange with the atmosphere as impacted by anthropogenic factors (urbanization, invasive species, and climate change).

Google Scholar Profile


Field Ecology Program Director

Natalie Melkonoff

Jessica Guo (PH.D)

Guo is a plant ecologist and data scientist intrigued by plant strategies for surviving arid environments. She is particularly interested in disentangling the temporal patterns of plant responses to environmental extremes and uses Bayesian statistical approaches to evaluate empirical measurements from the field and lab. Guo also loves to teach reproducibility and data science skills in R. 



Data Science Program Director

Natalie Melkonoff


Susan Albor’s background is in soil ecology and environmental science. Albor’s research interests include studying interactions between plants and mycorrhizal fungi and how plant traits are shaped by their relationships with beneficial soil microbes. Currently she is working on her PH.D. studying how plant microbe interactions may increase the thermal tolerance of plants when exposed to heat stress. Susan Albor’s received a prestigious Graduate Research Fellowship from the National Science Foundation to support her doctoral studies.

Ph.D. Arizona State University/Desert Botanical Garden (In progress)

Lab Updates

Completion of M.S. by lab member, Mary Chisholm

Mary Chisholm successfully defended her thesis in the School of Life Sciences at Arizona State University. Mary studied growth rings of box elder trees to determine whether male and female trees respond differently to stress caused by drought and heat exposure. Congratulations Mary!

Welcome New Lab Member Susan Albor

Welcome new PhD student Susan Albor, who is working on her doctorate studying relationships between plant and root fungi in desert ecosystems in the School of Life Sciences at Arizona State University.

Launch of Global Water Potential Network by Lab Member Dr. Jessica Guo and Colleagues

The National Science Foundation funded Global Water Potential Network, PSInet was recently launched by lab member Dr. Jessica Guo and colleague Dr. Kimberly Novick (University of Indiana).

Previous Lab Member Dr. Luiza Aparecido Starts New Faculty Position

Dr. Luiza Aparecido started her new position as Assistant Professor in the Department of Biology at the University of Utah. We look forward to continue our collaboration with Luiza in the future. Congratulations Luiza!

Recent Papers Published by Lab Members in High-Impact Journals

Check out recent papers published by Kelly Kerr, Madeline Moran and Brad Posch

Huizingh Desert Research Fellowship Awarded to Lab Member, Madeline Moran

Madeline Moran was recently awarded the Huizingh Desert Research Fellowship. The award provides five years of funded to support her PhD program to study the thermal tolerance of plants exposed to heat stress. Madeline becomes the second student to receive this prestigious award. Congratulations Madeline!

Heat Advisory: Please be prepared for extreme heat. Bring water, stay hydrated and seek shade when possible.