Dr. Cavers' Links: Dr. Paul B. Cavers
Weed Seed Ecology
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Position: Professor Emeritus Office: Collip Room 112 Phone: 519 661 2111 x 82640 Fax: 519 661-3935 Email: pcavers@uwo.ca |
Research Statement
Fields with dense populations of weeds can have many thousands of plants of each of several weed species per hectare. Despite these impressive numbers, there can be many more weed plants in those same fields in the form of dormant seeds. Each of these latter plants is nearly or completely invisible to the human eye but it is an individual plant and can be the source of future weed populations. Some dormant weed seeds can remain alive in the soil for many years before they germinate and grow into flowering plants.
For many plant species, especially weeds, the most critical stage in the life cycle is the transition from seed to seedling. If the seedling starts to grow when environmental conditions are highly favourable, and there is minimal competition and predation, then its chances of survival are high. In unfavourable environments, few or no emerging seedlings survive. Timing is everything! One strategy for many weed species is intermittent germination, whereby only a few of the seeds in the soil seed bank germinate at any one time. In our laboratory, we have examined the causes of intermittent germination in detail. At present, our focus is on the role of crop litter, left after harvest on no-till fields, on the weed seed banks in those fields. We are also comparing the vigour of seeds that have persisted for different lengths of time in the seed bank.
