Buried, viable seeds in two California bunchgrass sites and their bearing on the definition of a flora

Species Interactions in a Successional Grassland. III. Effects of Canopy Gaps, Gopher Mounds and Grazing on Colonization

“…Because only those species abundant in the local seed rain were found as seedlings in the seedling exclosures, there was no evidence of a functional seed bank of species that formerly occupied sites, as found, for example, by Rabinowitz (1981) and Major & Pyott (1966). In this community, the species composition of the seed rain was a good predictor of the species composition of natural recruitment, at least in the absence of major disturbance.…”

“…The usual method of examining the seed bank is by counting viable seeds in the soil or the seedlings emerging from soil samples (Harper 1977;Thompson & Grime 1979;Thompson 1986). This method is appropriate for characterizing the seed bank community and its potential contribution to the vegetative community (Major & Pyott 1966). However, the actual contribution of the seed bank to recruitment in any one year will be much less than the total number of viable seeds in the soil, because recruitment from the seed bank depends on a complex of environmental factors and the requirements of species for germination and early survival (Silvertown 1980;Thompson & Grime 1983;Gorski, Gorska & Norwicki 1977;Slade & Causton 1979).…”

Journal of Range Management, Volume 53, Number 1 (January 2000)

“…Prince and Hodgdon (1946) also found abundant germination of bluegrass, and detected few economically useful species in their survey of 21 pastures in New Hampshire. Although dominant in the vegetation, perennial grasses are almost universally under represented in the germinable seed bank (Chippindale and Milton 1934, Prince and Hodgdon 1946, Champness and Morris 1948, Major and Pyott 1966, Archibold 1981, Rabinowitz 1981, Hassan and West 1986, Rice 1989, Perez et al 1998. Unlike annual and perennial forbs, most perennial grasses rely on vegetative reproduction and have not evolved seed that remains viable for long periods in soil (Roberts 1981).…”

“…Bluegrass is an exception to most perennial grasses because it forms substantial reserves of viable seed (Chippindale and Milton 1934, Champness and Morris 1948, Jalloq 1975, Roberts 1981. Of course, grazing can also affect seed bank composition (Major and Pyott 1966, Jalloq 1975, Iverson and Wali 1982, Kinucan and Smeins 1992, Bertiller 1992 especially if defoliation interrupts sexual reproduction.…”

Reservoir de graines des sols de sapinieres boreales au nord du Lac Saint-Jean

“…Ceci est dû à la distribution contagieuse des graines de la majorité des espèces (Roberts, 1958;Major et Pyott, 1966;Kellman, 1974;Kellman, 1978). Comme cette méthode permet uniquement l'examen d'une faible surface dans des délais raisonnables, l'analyse des populations de graines des espèces à dispersion faible ou contagieuse est limitée (Goyeau et Fablet, 1982).…”