Seed size and shape are good predictors of seed persistence in soil in temperate mountain grasslands of Argentina

Abstract

We tested whether seed mass and shape are good predictors of seed persistence in the soil of subhumid temperate montane grasslands of central Argentina. We plotted seed mass against variance of seed dimensions of 71 herbaceous species and obtained information on their persistence in the soil from a previous experiment on germinable seed banks. We identified a certain seed mass/shape combination beyond which no seed was persistent in the soil, with the exception of the annual Tagetes minuta. Our results confirmed the patterns previously reported for British species: small and compact seeds tend to persist in the soil for a longer time than big and elongated or flattened seeds. We suggest that the value of seed mass and shape as predictors of persistence in the soil can be extended beyond the British flora to herbaceous floras from other humid temperate regions.

Towards an Understanding of Factors Controlling Seed Bank Composition and Longevity in the Alpine Environment

“…There have been few works that studied the significance of seed size in establishing persistent seed bank in alpine landscapes. In Argentinean mountain grassland, the available evidence demonstrated that small seeded species have an increased likelihood of entering the persistent seed bank (Funes et al, 1999;Fig. 2).…”

“…Relationship between seed mass (log scale) in mg and variance of seed dimension adopted from (a) Italian Alps; 114 species (re-drawn only for alpine species from Cerabolini et al, 2003 with permission), (b) Central Austrian Alps (Schwienbacher et al, 2010) after excluding the standard deviation given in the original data set and (c) Argentinean mountain grassland; 71 species (re-drawn from Funes et al, 1999 …”

“…Extending his suggestion to a larger data set of more than 1000 species by reworking the data presented by Ma et al(2010b), Funes et al (1999), Cerabolini et al (2003), Körner (2003), Giménez-Benavides et al (2005), Pluees et al (2005), Shimono and Kudo (2005), Bu et al (2007a), Schwienbacher (2010), Ma et al (Ma et al, 2013) [from the seed size summary data] and Wu et al (2013), we show that 88% of the species have seed mass below 3 mg and nearly 93% have seed mass below 4 mg, reinforcing the selection of small-seeded species in alpine vegetation. Furthermore, in literature where seed mass data are not presented for individual species, those studies have some useful summary of seed mass range.…”

“…maternal environment, heteromorphism etc. Table 4 Seed size of 1011 species collected from the published literature, Ma et al(2010b), Funes et al (1999), Cerabolini et al (2003), Körner (2003) [from the seed size summary data] and Wu et al (2013). For some species, seed mass was determined by searching the seed information database ( …”

“…These studies, although few in number, offer insights suggesting that, owing to the advantage that species with smaller seeds have in entering seed banks (Funes et al, 1999;Cerabolini et al, 2003;Schwienbacher et al, 2010), most alpine species may benefit from the seed banks rather than dispersal. Furthermore, seeds in alpine soil remain frozen most of the year and therefore secondary dispersal could be limited during these periods.…”