Timing of disturbance and vegetation development: how sowing date affects the weed flora in spring-sown crops
Article first published online: 18 JAN 2010
2001 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 12, Issue 1, pages 93–98, February 2001
How to Cite
Milberg, P., Hallgren, E. and Palmer, M.W. (2001), Timing of disturbance and vegetation development: how sowing date affects the weed flora in spring-sown crops. Journal of Vegetation Science, 12: 93–98. doi: 10.1111/j.1654-1103.2001.tb02620.x
- Issue published online: 18 JAN 2010
- Article first published online: 18 JAN 2010
- Received 13 January 2000; Final revision received 25 August 2000; Accepted 29 August 2000.
- Partial CCA;
- Summer annual;
- Variation partitioning;
- Winter annual
Abstract. The number of annual weeds were recorded in 752 field experiments in spring-sown cereal crops conducted in Sweden 1972–1993. Two null hypotheses were tested regarding how the sowing date influenced the weed flora. 1. There is no relationship between the weed flora composition and sowing date. A pCCA (with geographic regions, crop species and soil types as covariables) clearly refuted this hypothesis. Hence, the composition of the weed flora varied depending on sowing date. 2. Species classified as summer annuals, winter annuals and germination generalists (that can germinate substantially in both spring and autumn) do not differ in their placement along the first ordination axis in the pCCA, i.e. according to sowing date. An ANOVA was unable to reject this hypothesis. Hence, germination syndrome classification did not explain the observed community differences related to sowing date. These results illustrate the importance of the date of disturbance for any secondary succession involving a seed bank and also the importance of annual dormancy cycles in seed banks.