Portal de Periódicos da CAPES

CONTROLS OF GRASS AND SHRUB ABOVEGROUND PRODUCTION IN THE PATAGONIAN STEPPE

2000; Wiley; Volume: 10; Issue: 2 Linguagem: Inglês

10.1890/1051-0761(2000)010[0541

1939-5582

Estéban G. Jobbágy, Osvaldo E. Sala,

Land Use and Ecosystem Services

Ecological ApplicationsVolume 10, Issue 2 p. 541-549 Article CONTROLS OF GRASS AND SHRUB ABOVEGROUND PRODUCTION IN THE PATAGONIAN STEPPE Esteban G. Jobbágy, IFEVA—Departamento de Ecología, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, 1417 Buenos Aires, Argentina Present address: Department of Botany, Phytotron Building, Duke University, Durham, North Carolina 27708 USA. E-mail: e.jobbagy@duke.eduSearch for more papers by this authorOsvaldo E. Sala, IFEVA—Departamento de Ecología, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, 1417 Buenos Aires, ArgentinaSearch for more papers by this author Esteban G. Jobbágy, IFEVA—Departamento de Ecología, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, 1417 Buenos Aires, Argentina Present address: Department of Botany, Phytotron Building, Duke University, Durham, North Carolina 27708 USA. E-mail: e.jobbagy@duke.eduSearch for more papers by this authorOsvaldo E. Sala, IFEVA—Departamento de Ecología, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, 1417 Buenos Aires, ArgentinaSearch for more papers by this author First published: 01 April 2000 https://doi.org/10.1890/1051-0761(2000)010[0541:COGASA]2.0.CO;2Citations: 130 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract We studied the temporal dynamics of aboveground net primary production (ANPP) and senescence in a semiarid steppe representative of the Occidental District of Patagonia. We focused on the association of ANPP and senescence with climatic fluctuations at annual and seasonal scales. We estimated annual ANPP based on biomass harvests of grasses and shrubs (the dominant functional groups) at the peak of the growing season (January). The ANPP and senescence of grasses alone were also estimated for several periods within each year. The mean annual ANPP of the studied community for 10 years was 56 g·m−2·yr−1, and the coefficient of variation was 26%. Grass and shrub mean annual ANPP had similar levels. Annual shrub production was associated with cumulative precipitation for the whole year, whereas annual grass production was not associated with precipitation. The average seasonal dynamics of grass ANPP showed its peak during spring, and there was no grass production during late summer and early fall. The peak green biomass of grass was achieved in early summer. Average senescence rates were more constant throughout the year, except for winter, when senescence was almost interrupted. Winter grass ANPP was positively associated with fall temperature, spring grass ANPP was positively related to winter precipitation, and summer grass ANPP was positively related to spring precipitation. Grass senescence during spring was negatively related to precipitation in the same season. Our results highlight the importance of separating functional types in productivity studies. The differential effect of precipitation on grass and shrub ANPP masked the association when these functional groups were pooled. ANPP association with climatic variables in the Occidental District of the Patagonian steppe shifted from precipitation alone to precipitation and temperature when the temporal scale of analysis changed from annual to seasonal. Citing Literature Volume10, Issue2April 2000Pages 541-549 RelatedInformation