Distribution of annual plants in North American deserts

TitleDistribution of annual plants in North American deserts
Publication TypeJournal Article
Year of Publication1988
AuthorsLudwig J., Cunningham GL, Whitson P.D
JournalJournal of Arid Environments
Date Published1988
Accession NumberJRN00074
Call Number00188
Keywordsannual plant, c3 and c4, annual plant, distribution, article, articles, journal, journals, plant, also SEE <annual plant>, plant, annual

Early researchers concluded that the winter-annual flora was richest in the California deserts and became relatively poorer towards the east, whereas summer-annuals were richest in the deserts of western Texas and their richness progressively declined in to eastern California. US/IBP Desert Biome and subsequent studies support these trends and add much relevant information. Winter-annuals have the C3 photosynthetic pathway, whereas most summer-annuals have the C4 pathway. While the Sonoran and Chihuahuan deserts have a few C3 'summer' annuals (actually 'winter' annuals which can persist into the summer), the Mojave Desert lacks C3 summer-annuals. The Great Basin Desert has only a few prevalent winter or summer-annuals (mostly introduced species). Studies of the micro-distribution of desert-annuals have shown their close association with perennial shrubs. Some shrubs produce substances that are reportedly toxic to some annuals; the role of such toxins in structuring annual plant communities is unclear. The importance of nutrients associated with shrub canopies on the micro-distribution of many desert-annuals is becoming evident through LTER and other studies.