From rain forest to desert
Shreve studied at Johns Hopkins and investigated Jamaican montane rain forest and Maryland vegetation before joining the Desert Laboratory in Tucson, Arizona, in 1908. His later work focused particularly on the Sonoran and Chihuahuan deserts.
He examined plant structure, physiology and natural history under field conditions, asking how regional environments helped explain the occurrence of individual species.
References: [1]
Measuring a mountain environment
In the Santa Catalina Mountains he used rain gauges, evaporation instruments and soil thermographs to compare rainfall, humidity, evaporation and soil moisture with vegetation patterns.
His 1915 study, Vegetation of a Desert Mountain Range as Conditioned by Climatic Factors, brought these observations together. It related continuous environmental variation along slopes to plant distributions rather than relying on named vegetation units alone.
References: [2]
Gradual changes in plant assemblages
Shreve emphasized physical environmental constraints in deserts. His observations supported viewing vegetation as gradually changing assemblages, differing from Frederic Clements’s emphasis on community development and climatic climax.
This was an interpretation developed for particular environments, not a demonstration that competition is unimportant everywhere. His desert studies emphasized climatic conditions and the tolerances of individual plants.
Field research and scientific exchange
From 1911 Shreve edited Plant World, which later passed to the Ecological Society of America and continued as Ecology.
He was also a founding society member and served as secretary-treasurer and president. Editing and society work helped place desert field evidence within a broader ecological discussion.