A research agenda for seed‐trait functional ecology

Abstract

Summary Trait‐based approaches have improved our understanding of plant evolution, community assembly and ecosystem functioning. A major challenge for the upcoming decades is to understand the functions and evolution of early life‐history traits, across levels of organization and ecological strategies. Although a variety of seed traits are critical for dispersal, persistence, germination timing and seedling establishment, only seed mass has been considered systematically. Here we suggest broadening the range of morphological, physiological and biochemical seed traits to add new understanding on plant niches, population dynamics and community assembly. The diversity of seed traits and functions provides an important challenge that will require international collaboration in three areas of research. First, we present a conceptual framework for a seed ecological spectrum that builds upon current understanding of plant niches. We then lay the foundation for a seed‐trait functional network, the establishment of which will underpin and facilitate trait‐based inferences. Finally, we anticipate novel insights and challenges associated with incorporating diverse seed traits into predictive evolutionary ecology, community ecology and applied ecology. If the community invests in standardized seed‐trait collection and the implementation of rigorous databases, major strides can be made at this exciting frontier of functional ecology.

Ready for change: Seed traits contribute to the high adaptability of mudflat species to their unpredictable habitat

“…Seed dispersal traits allow us to better understand how far and in what number seeds disperse to sites optimal for survival, germination and seedling establishment (Saatkamp et al, ). In the present study, we expected high seed production and high seed buoyancy potential among mudflat species to adopt long‐distance dispersal in time and space by water and to facilitate the “escaping” strategy through transportation and deposition in large numbers of seeds in available habitats.…”

“…For example, orthodox seeds of Rumex maritimus (one of our study species) survived well under different hydrological (dry, moist and wet) regimes when exhumed from artificial burial after 1.5 years (Abedi, Bartelheimer, & Poschlod, ) and even after 5.5 years (S. S. Phartyal, unpublished data). As to the latter, the ability of mudflat species to persist in seed banks is likely an adaptation for bridging the long periods of temporarily unsuitable (flooded) environmental conditions of their habitat (Poschlod & Rosbakh, ), which helps populations to recover via persistent seed banks when conditions become favourable for germination and seedling establishment (Saatkamp et al, ).…”

“…Thus, it is now a prevailing view among plant ecologists that environmental factors act like filters that remove plants from local species pools if they lack certain requisite traits (Grime, ; Keddy, ). The ability of seeds of a species to disperse, persist and germinate depends on sets of trait‐based ecological responses of the species (Saatkamp et al, ). Consequently, the inclusion of seed traits can provide significant information about how communities respond to the abiotic and biotic environment (Rosbakh & Poschlod, ; Tudela‐Isanta et al, ).…”

What we (don't) know about global plant diversity

“…While plant scientists may all agree that there are gaps in our knowledge of plants (Meyer et al 2016, Gallagher et al 2019, Saatkamp et al 2019, they are unlikely to know where the most gaping holes occur (as found in systematic surveys of botanical trait knowledge; FitzJohn et al 2014). To quantify and understand these gaps, we present an analysis from our recent downloads of global plant databases.…”

The functional trait spectrum of European temperate grasslands

“…Plant species may be particularly sensitive to environmental filtering at the regeneration stage and this might be more important than other life‐history stages as species could be totally excluded from a habitat due to inappropriate environmental conditions for germination or successful establishment (Grubb, ). However, our knowledge of plant trait ecology is largely focused on few traits concerning aboveground vegetative growth and morphology, and very few studies have assessed the potential role of regeneration traits (Jiménez‐Alfaro, Silveira, Fidelis, Poschlod, & Commander, ; Larson & Funk, ; Poschlod et al., ; Saatkamp et al., ). Regeneration traits have been long acknowledged as relevant to the natural maintenance of biodiversity (Grubb, ), and have been found to be important for both species coexistence and species sorting (Bernard‐Verdier et al., ; Fernández‐Pascual, Pérez‐Arcoiza, Prieto, & Díaz, ; Pierce, Bottinelli, Bassani, Ceriani, & Cerabolini, ).…”