Ample germination ability under wide‐ranging environmental conditions in a common understory tropical palm

Abstract

Although palms play an important ecological role in tropical forests, characteristics related to their germinative niche remain largely unknown. We evaluated the seed germination characteristics of Geonoma schottiana, an abundant palm in the understory of different ecosystems of the Atlantic Rain Forest biome and the gallery forests of the Cerrado biome. We conducted experiments under light and dark conditions at Ψ = 0 MPa, and under two low-water-potential conditions and a flooded condition. Seed germination was highest at Ψ = 0 MPa under light (72%) and dark (67%) conditions. We observed moderate (51%) and low (18%) seed germination at Ψ = −0.4 and −0.8 MPa. About 20% of ungerminated seeds subjected to low water potentials for 300 days remained viable. No seeds germinated under flooded conditions; however, 23% of them maintained germinability. A delay in seed germination time was observed at low water potentials and an increase in synchrony occurred at Ψ = −0.8 MPa. G. schottiana seeds did not require specific light conditions to germinate, and the species possesses germinative characteristics to cope with deficit and excess of water. Probably, this wide germination niche allows for its seeds to germinate over a wide range of habitats in different types of ecosystems.

Sensitivity of seed germination to water stress in high‐altitude populations of a threatened palm species

“…2015; Braz et al . 2016). The last situation was observed in the palm species Geonoma schottiana , with germination synchrony increasing when seeds were subjected to low water potentials (Braz et al .…”

“…On the other hand, most water deficit studies have found that decreasing water potentials lead to a decrease in seed germination and an increase in time to germination (Evans & Etherington 1990;Adams 1999;Dürr et al 2015;Braz et al 2016;Fan et al 2020). Seeds of three species occurring in a Brazilian dry forest showed very little or no germination at water potentials below −0.8 MPa (Dantas et al 2020).…”

“…However, very few studies have been conducted on Atlantic Rainforest species (Kolb & Joly 2010; Braz et al . 2016). Seeds of different species may sink or float during flood events, which results in distinct germination capacity.…”

“…To ensure germination under high environmental heterogeneity, species must have characteristics such as a broad germination niche (Braz et al . 2016), germination plasticity (Vayda et al . 2018), adaptation capacity of local populations (Dickman et al .…”

Linking Plant Functional Traits to Demography in a Fragmented Landscape

“…The effects of rainfall reductions could be more pronounced in small fragments because it tends to be drier due to edge effects (Laurance et al, 2002). As Braz et al (2016) stated that Geonoma seeds are sensitive to water scarcity, this might explain the lower seedling survival rate. However, in a climate change scenario, Geonoma may not be endangered in small forest fragments, as an increase in precipitation and temperature is predicted for southeastern Brazil over the coming decades (Vale et al, 2021), along with a probable decrease in the duration of dry spells (Nunes et al, 2018).…”