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

• Published in: Nature (London) Vol. 408; no. 6808; pp. 79 - 82
• Main Authors: SMITH, Stanley D, HUXMAN, Travis E, ZITZER, Stephen F, CHARLET, Therese N, HOUSMAN, David C, COLEMAN, James S, FENSTERMAKER, Lynn K, SEEMANN, Jeffrey R, NOWAK, Robert S
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 02.11.2000; Nature Publishing Group
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Carbon Dioxide; Climate change; Desert Climate; Deserts; Drought; Ecological function; Ecosystem; Ecosystems; Ecotoxicology, biological effects of pollution; Fundamental and applied biological sciences. Psychology; Global climate; Grasses; Indigenous species; Invasive species; Nevada; Plants; Poaceae; Rosales; Species composition; Surface area; Terrestrial environment, soil, air; North America; America; Nevada; Mojave Desert; USA, California, Mojave Desert; Invasive species; Arid region; Ecosystem; Carbon dioxide; Air pollution; Annual plant; Concentration; Desert; Biodiversity; Climate modification; Biological productivity; Ecological abundance
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35040544

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 ecosystem, 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 CO2 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.