Journal Article

Different growth responses of C<sub>3</sub> and C<sub>4</sub> grasses to seasonal water and nitrogen regimes and competition in a pot experiment

Shuli Niu, Weixing Liu and Shiqiang Wan

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 59, issue 6, pages 1431-1439
Published in print April 2008 | ISSN: 0022-0957
Published online March 2008 | e-ISSN: 1460-2431 | DOI: http://dx.doi.org/10.1093/jxb/ern051

More Like This

Show all results sharing this subject:

  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Understanding temporal niche separation between C3 and C4 species (e.g. C3 species flourishing in a cool spring and autumn while C4 species being more active in a hot summer) is essential for exploring the mechanism for their co-existence. Two parallel pot experiments were conducted, with one focusing on water and the other on nitrogen (N), to examine growth responses to water or nitrogen (N) seasonality and competition of two co-existing species Leymus chinensis (C3 grass) and Chloris virgata (C4 grass) in a grassland. The two species were planted in either monoculture (two individuals of one species per pot) or a mixture (two individuals including one L. chinensis and one C. virgata per pot) under three different water or N seasonality regimes, i.e. the average model (AM) with water or N evenly distributed over the growing season, the one-peak model (OPM) with more water or N in the summer than in the spring and autumn, and the two-peak model (TPM) with more water or N in the spring and autumn than in the summer. Seasonal water regimes significantly affected biomass in L. chinensis but not in C. virgata, while N seasonality impacted biomass and relative growth rate of both species over the growing season. L. chinensis accumulated more biomass under the AM and TPM than OPM water or N treatments. Final biomass of C. virgata was less impacted by water and N seasonality than that of L. chinensis. Interspecific competition significantly decreased final biomass in L. chinensis but not in C. virgata, suggesting an asymmetric competition between the two species. The magnitude of interspecific competition varied with water and N seasonality. Changes in productivity and competition balance of L. chinensis and C. virgata under shifting seasonal water and N availabilities suggest a contribution of seasonal variability in precipitation and N to the temporal niche separation between C3 and C4 species.

Keywords: Chloris virgata; competition; growth; Leymus chinensis; nitrogen seasonality; water seasonality

Journal Article.  4949 words.  Illustrated.

Subjects: Plant Sciences and Forestry

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.