Co-ordinating Editor: Janos Podani
Spatial pattern and process at the plant neighbourhood scale: insights from communities dominated by the clonal grass Elymus repens (L.) Gould
Article first published online: 31 MAY 2011
© 2011 International Association for Vegetation Science
Journal of Vegetation Science
Volume 22, Issue 6, pages 973–982, December 2011
How to Cite
Pottier, J. and Evette, A. (2011), Spatial pattern and process at the plant neighbourhood scale: insights from communities dominated by the clonal grass Elymus repens (L.) Gould. Journal of Vegetation Science, 22: 973–982. doi: 10.1111/j.1654-1103.2011.01304.x
Pottier, J. (corresponding author, firstname.lastname@example.org): Department of Ecology and Evolution (DEE), Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland Evette, A.: (email@example.com) Cemagref, UR EMGR, Grenoble, 2 Rue de la Papeterie BP 76, FR-38042 Saint Martin d' Hères cedex, France
- Issue published online: 5 OCT 2011
- Article first published online: 31 MAY 2011
- Received 18 November 2010, Accepted 8 May 2011
- Elymus repens (L.) Gould.;
Question: How do clonal traits of a locally dominant grass (Elymus repens (L.) Gould.) respond to soil heterogeneity and shape spatial patterns of its tillers? How do tiller spatial patterns constrain seedling recruitment within the community?
Locations: Artificial banks of the River Rhône, France.
Material and Methods: We examined 45 vegetation patches dominated by Elymus repens. During a first phase we tested relationships between soil variables and three clonal traits (spacer length, number of clumping tillers and branching rate), and between the same clonal traits and spatial patterns (i.e. density and degree of spatial aggregation) of tillers at a very fine scale. During a second phase, we performed a sowing experiment to investigate effects of density and spatial patterns of E. repens on recruitment of eight species selected from the regional species pool.
Results: Clonal traits had clear effects – especially spacer length – on densification and aggregation of E. repens tillers and, at the same time, a clear response of these same clonal traits as soil granulometry changed. The density and degree of aggregation of E. repens tillers was positively correlated to total seedling cover and diversity at the finest spatial scales.
Conclusions: Spatial patterning of a dominant perennial grass responds to soil heterogeneity through modifications of its clonal morphology as a trade-off between phalanx and guerrilla forms. In turn, spatial patterns have strong effects on abundance and diversity of seedlings. Spatial patterns of tillers most probably led to formation of endogenous gaps in which the recruitment of new plant individuals was enhanced. Interestingly, we also observed more idiosyncratic effects of tiller spatial patterns on seedling cover and diversity when focusing on different growth forms of the sown species.