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Soil moisture and biogeochemical factors influence the distribution of annual Bromus species

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, , , , and
https://doi.org/10.1007/978-3-319-24930-8

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Abstract

Abiotic factors have a strong influence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromusoccurrence. At the more local scale, soil characteristics and climate influence distribution, cover, and performance. In hot, dry, summer-rainfall-dominated deserts (Sonoran, Chihuahuan), little or noBromus is found, likely due to timing or amount of soil moisture relative to Bromus phenology. In hot, winter-rainfall-dominated deserts (parts of the Mojave Desert), Bromus rubens is widespread and correlated with high phosphorus availability. It also responds positively to additions of nitrogen alone or with phosphorus. On the Colorado Plateau, with higher soil moisture availability, factors limiting Bromus tectorum populations vary with life stage: phosphorus and water limit germination, potassium and the potassium/magnesium ratio affect winter performance, and water and potassium/magnesium affect spring performance. Controlling nutrients also change with elevation. In cooler deserts with winter precipitation (Great Basin, Columbia Plateau) and thus even greater soil moisture availability, B. tectorum populations are controlled by nitrogen, phosphorus, or potassium. Experimental nitrogen additions stimulate Bromus performance. The reason for different nutrients limiting in dissimilar climatic regions is not known, but it is likely that site conditions such as soil texture (as it affects water and nutrient availability), organic matter, and/or chemistry interact in a manner that regulates nutrient availability and limitations. Under future drier, hotter conditions,Bromus distribution is likely to change due to changes in the interaction between moisture and nutrient availability.

Additional publication details

Publication type:
Book chapter
Publication Subtype:
Book Chapter
Title:
Soil moisture and biogeochemical factors influence the distribution of annual Bromus species
DOI:
10.1007/978-3-319-24930-8
Year Published:
2016
Language:
English
Publisher:
Springer International Publishing
Contributing office(s):
Forest and Rangeland Ecosys Science Center
Description:
30 p.
Larger Work Type:
Book
Larger Work Title:
Exotic brome-grasses in arid and semiarid ecosystems of the Western US
First page:
227
Last page:
256