Responses of Chihuahuan Desert herbaceous annuals to rainfall augmentation

TitleResponses of Chihuahuan Desert herbaceous annuals to rainfall augmentation
Publication TypeJournal Article
Year of Publication1987
AuthorsGutierrez J.R, Whitford WG
JournalJournal of Arid Environments
Date Published1987
Accession NumberJRN00059
Call Number00095
Keywordsannual plant, growth response, annual plant, rainfall simulation, annual plant,soil nutrient, article, articles, Astragalus, water response, Euphorbia, water response, journal, journals, rainfall simulation, rainfall simulation,annual plant response, water,also SEE <RAINFALL SIMULATION>

Densities and biomass of annual herbaceous plants were compared on plots receiving supplemental water of 25 mm at 4-week intervals or 6.6mm per week, and plots receiving only natural rainfall. During the first summer, there were no significant differences in total biomass between treatments, but the density and biomass of two species, Astragalus tephrodes and Euphorbia micormera, were greater on the watered plots. Several spring annuals responded to supplemental water and by late spring (April) there were decreases in biomass on the watered plots, with the greatest decreases on the 6.3 mm per week plots. Few species of summer annuals responded to supplemental water during the second year, possibly as a result of smaller rain events and/or limitation of available nitrogen. Root shoot biomass ratios were between 0.15 and 0.25 for winter-spring annuals and 0.04 and 0.03 for summer annuals.