Author
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Forcella, Frank |
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Submitted to: Aspects of Applied Biology
Publication Type: Book / Chapter Publication Acceptance Date: 9/19/2003 Publication Date: 10/1/2003 Citation: FORCELLA, F. DEBITING THE SEEDBANK: PRIORITIES AND PREDICTIONS. BEKKER, R.M. ET AL. EDITORS. ASSOCIATION OF APPLIED BIOLOGISTS, WELLESBOURNE, UK. ASPECTS OF APPLIED BIOLOGY 69. 2003. P. 151-162. Interpretive Summary: Generally speaking, weed seeds in seedbanks have four fates: persistence, germination, death, and emigration. The latter three fates represent losses from the weed seedbank. Of these losses, germination and death are the fates that farmers and other weed managers attempt to encourage. Death of seeds typically is caused by seed-eating animals and seed diseases, but general seed deterioration by simple aging also is important, especially for seeds buried below about four to six inches. Dormant seeds may be more resistant to diseases and less preferred by animals than non-dormant seeds. Losses through seed death can be large, but typically affect < 50% of seeds, unless seeds are buried deeply. Emigration occurs by seeds washing from soil surfaces through runoff and erosion after rainstorms and snow melt, but this probably does not represent a major loss from seedbanks. Generally, seed germination accounts for the majority of seedbank losses. Consequently, understanding the timing and amount of release from seed dormancy, seed germination, and seedling emergence are still critical for future research and increasing weed control by differing management operations. This does not lessen the importance of studying seed death and emigration, but merely lends perspective to these types of research. The information summarized in this report, which was gathered by studying recent literature on losses from seedbanks, will be useful primarily to scientists with interests in weed seedbank ecology. These scientists can use this information to help prioritize their future research activities. Technical Abstract: There are four general fates of seeds in seedbanks: persistence, germination, death and emigration. The latter three fates represent seedbank losses, and they are the topics examined in this paper. Seed death in the seedbank typically is caused by granivores and seed pathogens, but general seed deterioration via aging also is important, especially for deeply buried seeds. Dormant seeds may be more resistant to pathogens and less palatable to granivores than non-dormant seeds. Losses through seed death can be large, but typically affect < 50% of seeds, unless seeds are buried deeply. Emigration occurs through runoff and erosion, but probably does not represent a major loss from seedbanks. Generally, seed germination accounts for the majority of seedbank losses. Consequently, understanding the timing and magnitude of seed dormancy release, seed germination and seedling emergence is still critical for future research and increasing the efficacy of management operations and alternatives. This does not diminish the importance of studying seed death and emigration, but merely lends perspective to such research. |
