Long‐term response of a Mojave Desert winter annual plant community to a whole‐ecosystem atmospheric CO2 manipulation (FACE). (26th January 2014)

• Record Type: Journal Article
• Authors: Smith, Stanley D.; Charlet, Therese N.; Zitzer, Stephen F.; Abella, Scott R.; Vanier, Cheryl H.; Huxman, Travis E.
• Is Part Of: Global change biology. Volume 20:Number 3(2014:Mar.)
• Page Start: 879
• Page End: 892
• Publication Date: 2014-01-26
• Subjects: Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.12411
• Languages: English
• ISSNs: 1354-1013

Abstract

<abstract abstract-type="main" id="gcb12411-abs-0001"> <title>Abstract</title> <p>Desert annuals are a critically important component of desert communities and may be particularly responsive to increasing atmospheric (CO<sub>2</sub>) because of their high potential growth rates and flexible phenology. During the 10‐year life of the Nevada Desert FACE (free‐air CO<sub>2</sub> enrichment) Facility, we evaluated the productivity, reproductive allocation, and community structure of annuals in response to long‐term elevated (CO<sub>2</sub>) exposure. The dominant forb and grass species exhibited accelerated phenology, increased size, and higher reproduction at elevated (CO<sub>2</sub>) in a wet El Niño year near the beginning of the experiment. However, a multiyear dry cycle resulted in no increases in productivity or reproductive allocation for the remainder of the experiment. At the community level, early indications of increased dominance of the invasive <italic>Bromus rubens</italic> at elevated (CO<sub>2</sub>) gave way to an absence of <italic>Bromus</italic> in the community during a drought cycle, with a resurgence late in the experiment in response to higher rainfall and a corresponding high density of <italic>Bromus</italic> in a final soil seed bank analysis, particularly at elevated (CO<sub>2</sub>). This long‐term experiment resulted in two primary conclusions: (i) elevated (CO<sub>2</sub>) does not increase productivity of annuals in most years; and (ii) relative stimulation of invasive grasses will likely depend on future precipitation, with a wetter climate favoring invasive grasses but currently predicted greater aridity favoring native dicots.</p> </abstract>