Elevated CO2 increases productivity and invasive species success in an arid ecosystem

Document Type

Article

Publication Date

11-2-2000

Publication Title

Nature

Volume

408

First page number:

79

Last page number:

82

Abstract

Arid ecosystems, which occupy about 20% of the earth's terrestrial surface area, have been predicted to be one of the most responsive ecosystem types to elevated atmospheric CO2 and associated global climate change. Here we show, using free-air CO2 enrichment (FACE) technology in an intact Mojave Desert ecosystem4, that new shoot production of a dominant perennial shrub is doubled by a 50% increase in atmospheric CO2 concentration in a high rainfall year. However, elevated CO 2 does not enhance production in a drought year. We also found that above-ground production and seed rain of an invasive annual grass increases more at elevated CO2 than in several species of native annuals. Consequently, elevated CO2 might enhance the long-term success and dominance of exotic annual grasses in the region. This shift in species composition in favour of exotic annual grasses, driven by global change, has the potential to accelerate the fire cycle, reduce biodiversity and alter ecosystem function in the deserts of western North America.

Keywords

Climate change; Elevated CO2; Fire cycle; Free-air CO2 enrichment (FACE); Grasses; Invasive species; Mojave desert; Water availability

Disciplines

Environmental Indicators and Impact Assessment | Plant Biology

Language

English


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