Associate Professor of Research
Horticulture

Joshua Caplan, PhD

Josh Caplan is an environmental biologist who studies plant and soil dynamics in human-modified settings. With most of his work, he seeks to understand how plants and soils respond to environmental extremes (for example, in salinity, soil moisture, and nutrients). Often, he is interested in determining how their responses affect larger-scale processes like water fluxes, carbon cycling, and plant invasion. Some of his research also investigates ways that plants themselves alter soil and how engineered soil media could be modified to be more effective or sustainable. Josh’s fieldwork takes place in a variety of human-shaped settings, such as urban roadsides, disturbed forests, and coastal wetlands. His research also relies on chemical and hydraulic laboratory analysis as well as computational modeling.

PhD, Environmental Sciences & Resources, Portland State University, 2009
BS, Environmental Science, University of Rochester, 2001

Selected Works

First-authored papers
Caplan JS, Galanti RC, Olshevski S, Eisenman SW (2019). Water relations of street trees in green infrastructure tree trench systems. Urban Forestry & Urban Greening 41: 170-178.

Caplan JS, Meiners SJ, Flores-Moreno H, McCormack L (2019). Fine root traits are linked to population dynamics in a successional plant community. Ecology 100: e02588.

Caplan JS, Giménez D, Subroy V, Heck RJ, Prior SA, Runion GB, Torbert HA (2017). Nitrogen-mediated effects of elevated CO2 on intra-aggregate soil pore structure. Global Change Biology 23: 1585-1597.

Co-authored papers
Ravi S, Law DJ, Caplan JS, Barron-Gafford GA, Dontsova KM, Espeleta JF, Okin GS, Breshears DD, Huxman TE (2022). Biological invasions and climate change amplify each other’s effects on dryland degradation. Global Change Biology 28: 285-295.

Mozdzer TJ, Drew SE, Caplan JS, Weber P, Deegan LA (2021). Rapid recovery of carbon cycle processes after the cessation of chronic nutrient enrichment. Science of the Total Environment 750: 140927.

Choi CS, Cagle AE, Macknick J, Bloom DE, Caplan JS, Ravi S (2020). Effects of revegetation on soil physical and chemical properties in solar photovoltaic infrastructure. Frontiers in Environmental Science 8: 140.