Abstract
Seed rain into sites undergoing primary succession on Mount St. Helens was measured from 1982 to 1986 and again from 1989 to 1990. Study sites were devastated in 1980 by pyroclastic flows of pumice, searing blasts, and lahars. Most sites were several km or more from seed sources. Seed rain density averaged 34 seeds 0.1 m -2 yr -1 in mid-elevation barren sites, 1,083 seeds 0.1 m -2 yr -1 in mid-elevation vegetated sites and 2 seeds 0.1 m -2 yr -1 at subalpine barren sites. A total of 33 species was collected in traps. The relative abundance distributions of species were generally similar across years and sites. A few, wind-dispersed species accounted for most of the seed rain: Anaphalis margaritacea, Epilobium angustifolium , E. watsonii (E. ciliatum), Hieracium albiflorum, and Hypochaeris radicata. Seeds of trees and shrubs were virtually absent. The common species in the seed rain were also the most common species in the vegetation, although their absolute abundance is determined by environmental factors. Many uncommon species occurred in the vegetation that were not recorded in the seed rain. Two taxa common in the vegetation, Lupinus lepidus and Salix spp., were rare in the seed rain. For Salix, this is because seed dispersal occurred before traps were in place for the season. Lupinus lepidus is not wind dispersed and seeds are not likely to enter traps. We conclude that the seed rain on Mount St. Helens is apparently sufficient to initiate colonization but is depauperate in species. At present the vegetation generally reflects the incoming seed rain.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Seed rain density differed across barren and vegetated sites.
Not reportedTaxon
Verbatim
e0“Seed rain density averaged 34 seeds 0.1 m -2 yr -1 in mid-elevation barren sites, 1,083 seeds 0.1 m -2 yr -1 in mid-elevation vegetated sites and 2 seeds 0.1 m -2 yr -1 at subalpine barren sites.”
Claim · model-written summary
Traps collected 33 species.
Not reportedTaxon
Verbatim
e0“A total of 33 species was collected in traps.”
Claim · model-written summary
Species relative abundance distributions were generally similar across years and sites.
Not reportedTaxon
Verbatim
e0“The relative abundance distributions of species were generally similar across years and sites.”
Claim · model-written summary
A few wind dispersed species accounted for most seed rain.
- Taxon
- Anaphalis margaritacea
Anaphalis margaritaceae0 - Outcome
- most of the seed raine0
- Qualifier
- wind-dispersed speciese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A few, wind-dispersed species accounted for most of the seed rain: Anaphalis margaritacea, Epilobium angustifolium , E. watsonii (E. ciliatum), Hieracium albiflorum, and Hypochaeris radicata.”
Claim · model-written summary
Tree and shrub seeds were virtually absent.
Verbatim
e0“Seeds of trees and shrubs were virtually absent.”
Claim · model-written summary
Common seed rain species were also common in vegetation.
- Outcome
- most common species in the vegetatione0
- Direction
- most commone0
- Comparator
- common species in the seed raine0
Not reportedTaxon
Verbatim
e0“The common species in the seed rain were also the most common species in the vegetation, although their absolute abundance is determined by environmental factors.”
Claim · model-written summary
Many uncommon vegetation species were unrecorded in seed rain.
- Outcome
- uncommon species occurred in the vegetation that were not recorded in the seed raine0
Not reportedTaxon
Verbatim
e0“Many uncommon species occurred in the vegetation that were not recorded in the seed rain.”
Claim · model-written summary
Lupinus lepidus and Salix were rare in seed rain despite being common in vegetation.
- Taxon
- Lupinus lepidus
Lupinus lepiduse0 - Outcome
- rare in the seed raine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Two taxa common in the vegetation, Lupinus lepidus and Salix spp., were rare in the seed rain.”
Claim · model-written summary
The authors conclude seed rain was sufficient to initiate colonization but species poor.
- Outcome
- seed rain on Mount St. Helens is apparently sufficient to initiate colonization but is depauperate in speciese0
Not reportedTaxon
Verbatim
e0“We conclude that the seed rain on Mount St. Helens is apparently sufficient to initiate colonization but is depauperate in species.”
Claim · model-written summary
Vegetation generally reflected incoming seed rain.
Not reportedTaxonDirection
Verbatim
e0“At present the vegetation generally reflects the incoming seed rain.”