Seed-bank properties of an Appalachian sphagnum bog and a model of the depth distribution of viable seeds

Abstract

Seed banks were examined in four plant communities in a high-elevation sphagnum bog in West Virginia, U.S.A. A germination assay was used to detect germinable seed densities. Vertical depth distributions were determined for one community in which the soil cores were transported intact to the greenhouse. Seed densities ranged from 12 874 in a Sphagnum-dominated community to 377 041 seeds m−2 in a sedge-dominated community. The seed bank in all communities was dominated numerically by Juncus effusus, although this species comprised a minor part of the aboveground vegetation. Three types of depth profiles were observed, including one distribution showing a simple decline in seed numbers with depth, another showing a unimodal peak below the soil surface, and a third with two distinct peaks at depth. A matrix model of seed burial was devised to account for the different depth profiles. By assuming that soil compression occurred and that the rate of compression declined with time, the model showed that either of the first two depth profiles could be produced with no need to invoke a historical change in the seed rain. The model was unable to account for the bimodal depth profile with the assumption of a constant seed rain. However, the fact that the model of seed burial could explain a unimodal peak in the depth profile suggests that simple historical interpretations of past abundance using a buried seed profile are difficult.

Soil seed banks of secondary vegetation on the Port Hills and Banks Peninsula, Canterbury, New Zealand, and their role in succession

“…Juncus was an important constituent of wet seepage areas upstream of both the major sites, and it seems that their seeds were washed down by moving water. A similar soil distribution pattern for various Juncus species was described by Williams (1984), and for J. effusus by McGraw (1987).…”

Relationships between the developments of seedbank, standing vegetation and litter in a post-mined peatland

“…In contrast to these studies, species composition in seedbank is not consistent with the standing vegetation in a lagoon wetland complex (Nicol et al 2003), and dominant species in seedbank do not appear in the standing vegetation of an Appalachian Sphagnum bog (McGraw 1987). Seedbank formation patterns do not correspond with the standing vegetation following intensive disturbances (Thompson 2000).…”

Heathland Seedbanks under BrackenPteridium aquilinum(L.) Kuhn and their Importance for Re-vegetation after Bracken Control

“…The presence of seeds in the mineral soil beneath a considerable depth of bracken litter could be interpretated as the remains of seed deposited in situ before or during the initial period of bracken invasion (Chippindale and Milton, 1934;Hill and Stephens, 1981;McGraw, 1987). In this case the density of seedlings would depend on the time since invasion.…”