skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The effect of burial depth on removal of seeds of Phytolacca americana.

Abstract

Abstract - Although burial is known to have important effects on seed predation in a variety of habitats, the role of burial depth in affecting the removal of seeds in early successional systems is poorly known. Phytolacca American (pokeweed) is a model species to examine the role of burial depth in affecting seed removal because it is common in early-successional habitats, studies suggest that seed removal is indicative of seed predation, and seed predation is related to the recruitment of mature plants. To determine how burial depth affects P. americana seed removal, 20 seeds of P. americana were buried at depths of 0, 1, or 3 cm in early-successional habitats at the Savannah River Site in South Carolina for over 6 weeks. The frequency with which seeds were encountered (as measured by the removal of at least one seed) and the proportion of seeds removed was significantly greater when seeds were on the soil surface (0 cm depth) compared to seeds that were buried 1 cm or 3 cm; there was no difference in encounter or removal between seeds at 1 cm or 3 cm. Our findings suggest that burial may have important consequences for P. americana population dynamics, becausemore » seed survival depends upon whether or not the seed is buried, and relatively shallow burial can yield large increases in seed survival. Because seed limitation is known to be an important determinant of plant community composition in early successional systems, our work suggests that burial may play an unappreciated role in the dynamics of these communities by reducing predator-mediated seed limitation.« less

Authors:
Publication Date:
Research Org.:
USDA Forest Service, Savannah River, New Ellenton, SC
Sponsoring Org.:
USDOE - Office of Environmental Management (EM)
OSTI Identifier:
903444
Report Number(s):
na
07-02-P; TRN: US201103%%62
DOE Contract Number:
AI09-00SR22188
Resource Type:
Journal Article
Resource Relation:
Journal Name: Southeastern Naturalist.; Journal Volume: 6; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; COMMUNITIES; POPULATION DYNAMICS; REMOVAL; SAVANNAH RIVER PLANT; SEEDS; SOILS; SOUTH CAROLINA; Seed predation; burial depth; Phytolacca americana, pokeweed

Citation Formats

Orrock, John, L.: Damschen, Ellen, I. The effect of burial depth on removal of seeds of Phytolacca americana.. United States: N. p., 2007. Web. doi:10.1656/1528-7092(2007)6[151:TEOBDO]2.0.CO;2.
Orrock, John, L.: Damschen, Ellen, I. The effect of burial depth on removal of seeds of Phytolacca americana.. United States. doi:10.1656/1528-7092(2007)6[151:TEOBDO]2.0.CO;2.
Orrock, John, L.: Damschen, Ellen, I. Sun . "The effect of burial depth on removal of seeds of Phytolacca americana.". United States. doi:10.1656/1528-7092(2007)6[151:TEOBDO]2.0.CO;2.
@article{osti_903444,
title = {The effect of burial depth on removal of seeds of Phytolacca americana.},
author = {Orrock, John, L.: Damschen, Ellen, I.},
abstractNote = {Abstract - Although burial is known to have important effects on seed predation in a variety of habitats, the role of burial depth in affecting the removal of seeds in early successional systems is poorly known. Phytolacca American (pokeweed) is a model species to examine the role of burial depth in affecting seed removal because it is common in early-successional habitats, studies suggest that seed removal is indicative of seed predation, and seed predation is related to the recruitment of mature plants. To determine how burial depth affects P. americana seed removal, 20 seeds of P. americana were buried at depths of 0, 1, or 3 cm in early-successional habitats at the Savannah River Site in South Carolina for over 6 weeks. The frequency with which seeds were encountered (as measured by the removal of at least one seed) and the proportion of seeds removed was significantly greater when seeds were on the soil surface (0 cm depth) compared to seeds that were buried 1 cm or 3 cm; there was no difference in encounter or removal between seeds at 1 cm or 3 cm. Our findings suggest that burial may have important consequences for P. americana population dynamics, because seed survival depends upon whether or not the seed is buried, and relatively shallow burial can yield large increases in seed survival. Because seed limitation is known to be an important determinant of plant community composition in early successional systems, our work suggests that burial may play an unappreciated role in the dynamics of these communities by reducing predator-mediated seed limitation.},
doi = {10.1656/1528-7092(2007)6[151:TEOBDO]2.0.CO;2},
journal = {Southeastern Naturalist.},
number = 1,
volume = 6,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • Orrock, John, L. 2005 The effect of gut passage by two species of avian frugivore on seeds of pokeweed, Phytolacca Americana. Can. J. Bot. 83: 427431. Abstract: Although avian frugivores are known to be important dispersers of seeds of pokeweed, Phytolacca americana L., there are no studies that rigorously examine the effect of gut passage through avian frugivores on P. americana seeds. I examined how passage through avian frugivores affected the proportion of P. americana seeds germinating, the rate of germination (average number of days required for all seeds to germinate), and the total number of viable seeds. Field-collected fruitsmore » were either cleaned of pulp (control seeds), fed to northern Mockingbirds (Mimus polyglottos), or fed to Brown Thrashers (Toxostoma rufum). The proportion of seeds germinating after passage through avian frugivores was greater than control seeds (0.88 vs. 0.67, respectively), but did not differ between Mockingbirds or Brown Thrashers. However, seeds consumed by Mockingbirds germinated significantly faster on average (4.2 d) compared with seeds consumed by Brown Thrashers (4.6 d). Consumption by either species led to faster germination than control seeds (5.5 d). The total number of viable seeds did not differ among seeds consumed by avian frugivores or control seeds. These results suggest that avian frugivores do not change the viability of P. americana seeds. Rather, avian frugivores shifted the timing of germination, such that more seeds germinate more quickly after passage through frugivores. The adaptive implications of accelerated germination following passage through frugivores are briefly discussed.« less
  • Specimens of coalified plant debris in Tully-correlative strata of the Gilboa Formation (uppermost Middle Devonian) within the eastern Catskill Mountains of New York State have been converted to anthracite having a vitrinite reflectance of 2.5%. This implies a level of organic metamorphism (LOM) of 16. The specimens are about 350 m.y. old; if 200 m.y. is taken as the duration of the time of exposure to the maximum geothermal temperature, then the LOM of 16 and other thermal indicators imply a maximum temperature of 190/sup 0/C. Using a geothermal gradient of 26/sup 0/C.km/sup -1/ (17/sup 0/F.1,000 ft/sup -1/), a formermore » depth of burial of 6.5 km is implied. Such former deep burial is not usually inferred for the Catskills, but it is consistent with the idea that the thick (about 6.4 km or 21,000 ft) Carboniferous strata of northeastern Pennsylvania formerly extended northeast far enough to bury the Catskills. The lack of metamorphism of the Paleozoic strata lying about 4.5 km beneath the Tully-correlative rocks and exposed in the adjacent Hudson Valley places low limits on the former geothermal gradient; this supports the concept of great depth of former burial of the Catskills. For example, 6.5 km of former burial and a geothermal gradient of 26/sup 0/C.km/sup -1/ imply a temperature of 307/sup 0/C for the base of the Paleozoic. By contrast, only 1 km of former burial requires a geothermal gradient of 170/sup 0/C.km/sup -1/, which would have subjected the base of the Paleozoic to a temperature of 955/sup 0/GAMMA, which is far higher than the 600 to 650/sup 0/C recently inferred for the Acadian-age metamorphism of the Taconic allochthon in southwestern Massachusetts and adjoining areas.« less