Defining transient and persistent seed banks in species with pronounced seasonal dormancy and germination patterns

Abstract

The most often used time-line for distinguishing a transient seed bank from a persistent seed bank is one calendar year. Thus, species whose seeds live in or on the soil for <1 year have a transient seed bank, whereas those whose seeds live for ≥1 year have a persistent seed bank. However, dormancy cycling of seeds buried in soil has not been given due consideration in these models. When dormancy cycling is considered, it is shown that seeds of both autumn-germinators and spring-germinators are in the dormant state when they are 1 year old. Thus, unless the seeds live until at least the second germination season (i.e. usually 16–18 months following dispersal), they are, in effect, part of a transient seed bank, having lived through only one germination season. We propose that for seeds of such species to be considered part of a short-term persistent seed bank, they should remain viable and germinable until at least the second germination season, and to be part of a long-term persistent seed bank, until at least the sixth germination season. Our definitions are applicable to seeds with physiological, physical or morphophysiological dormancy, which often require >1 year after maturity to come out of dormancy in nature. We discuss modifications of the seedling emergence method for detection of a soil seed bank, so that they correspond to our definitions of seed-bank strategies.

Responses of Soil Seed Bank and Vegetation to the Increasing Intensity of Human Disturbance in a Semi-Arid Region of Northern China

“…Soil seed bank is defined as the viable seeds that exist on the soil surface or buried in soil [11], which represents the memories of the last plant community and the development of a future plant community in the surrounding area [12]. It is generally considered that the soil seed bank is the seed resources of native vascular plants, and would supply most seedlings for vegetation regeneration [13].…”

The Andean Forest Soil Seed Bank in Two Successional Stages in Northeastern Colombia

“…The fact that the diversity and density of the species found by using the direct separation method was higher compared to the germination method can be explained by three non-exclusive factors: 1) physiological, such as seed dormancy, longevity, and germination traits (Saatkamp et al 2009, Gonzalez & Ghermandi, 2012; 2) ecological, such as storage time, germination requirements and high rates of dispersal/predation (Thompson et al 2003, Daws et al 2005, Walck et al 2005, Bernhardt et al 2008, Esquivel et al 2008, Price et al 2010, Gonzalez & Ghermandi 2012; and 3) morphological, such as seed size and seed coat (De Villiers et al 1994, Facelli et al 2005, Venable 2007, Price et al 2010, Gonzalez & Ghermandi 2012. Similar results were found in a study with seed banks from natural grasslands in Patagonia by Gonzalez and Ghermandi (2012).…”

Effects of shade on germination traits of the endangered cycad Dioon edule (Zamiaceae)

“…Various studies have revealed that some cy- (Frett, 1987;López-Ovando and Treviño-Garza, 2008;Lázaro-Zermeño et al, 2012;Lopez-Gallego, 2013). The ability of seeds to germinate under both shade conditions indicates that D. edule seeds can germinate under the oak canopy or near the mother plant, forming a transient seed bank (seeds live in or on the soil for up to one year) (Walck et al, 2005;Octavio-Aguilar et al, 2009). High germination balances the limited seed production and its high mortality, and elevated seedling mortality may have more impact on population structure (Yáñez-Espinosa et al, 2014).…”