How relevant are instantaneous measurements for assessing resource depletion under plant cover? A test on light and soil water availability in 18 herbaceous communities
Article first published online: 29 JAN 2007
Volume 21, Issue 2, pages 185–190, April 2007
How to Cite
VIOLLE, C., LECOEUR, J. and NAVAS, M.-L. (2007), How relevant are instantaneous measurements for assessing resource depletion under plant cover? A test on light and soil water availability in 18 herbaceous communities. Functional Ecology, 21: 185–190. doi: 10.1111/j.1365-2435.2006.01241.x
- Issue published online: 29 JAN 2007
- Article first published online: 29 JAN 2007
- Received 20 September 2006; accepted 27 November 2006 Editor: Ken Thompson
- comparative approach;
- light transmission;
- mechanistic modelling;
- soil water content;
- temporal dynamics
- 1Quantifying the amount of resources remaining under plant cover is essential for assessing plant–plant interactions or biological invasions. Although resource levels fluctuate in time, their quantification is performed mainly by instantaneous measurements. We investigated how instantaneous measurements are related to the amount of resources cumulated throughout one growing season, measuring parameters of both light and soil water depletion.
- 2During a growing season, we measured regularly light and soil water levels under the cover of 18 plant species grown as monocultures in a common garden. The temporal dynamics of light and soil water depletion were assessed within each monoculture using mechanistic modelling approaches.
- 3The total amounts of resources remaining over the year under the range of communities were best predicted by instantaneous measurements performed at critical periods, differing among resources. The significance of prediction decreased dramatically for other dates, including the period of peak production, but without changing the ranking of communities according to ability to deplete resources. We therefore recommend that such measurements should be limited to qualitative studies, and that mechanistic modelling for quantitative assessments should be developed.