Ontogenetic trait shifts: Seedlings display high trait variability during early stages of development

Abstract

1. Characterizing variation in plant functional traits is often key to understanding community-level processes and predicting ecosystem responses to environmental change. Trait-based ecology has focused on interspecific trait variation, but sources and consequences of within-species ontogenetic trait variation, particularly during early stages of development, remain understudied.2. Using a manipulative greenhouse experiment, we investigated trait variation during early stages of seedling development in seven dominant perennial plant species in the western United States. We examined variability in key trait values (i.e. SLA, root:shoot ratio (RSR), specific root length (SRL) and root dry matter content (RDMC)) of 20-to 62-day-old seedlings grown under low and high levels of water availability. We also compared these to compiled trait databases to assess how representative these readily available data sources are of seedling trait values. 3. Early seedling trait values shifted greatly during early stages of development and generally differed from average plant trait database values. Trait shifts were greatest in forbs versus grasses. Overall, observed trait shifts suggested a transition from fast-growing resource acquisitional strategies towards more slow-growing conservative strategies over time. For example, seedling SLA decreased while RSR and RDMC increased over time. 4. That seedling trait values aconsistently differed from trait database values indicates that plant trait database values may be poor predictors of seedling trait values. Such mismatches in species trait information could result in inaccurate predictions of community assembly outcomes or incongruities between seedling traits and environmental filters experienced by seedlings during early stages of recruitment in applied settings.5. We suggest that additional work is needed to characterize intraspecific trait variation across plant ontogeny, and that this information should be incorporated into studies ranging from understanding early plant growth and survival to evaluating the outcomes of ecological restoration.

Trait ecology of startup plants

“…The unpredictable microsites faced by individual seedlings (but not so much by resprouts) favour plastic adjustment of traits (e.g. Havrilla et al, 2021). In business, the 'lean startup' concept (Ries, 2011) advocates rapid adjustment of business plans as the situation evolves, in contrast to the traditional virtue of designing a sound plan from the outset.…”

Plant water‐use strategies predict restoration success across degraded drylands

“…However, seeding success is low in general in dry years (Copeland et al, 2019), and wet conditions should be targeted for investment in restoration efforts in dryland systems (Bradford et al, 2018; Holmgren & Scheffer, 2001). Traits also tend to shift from acquisitive to conservative as development progresses from a seedling into a mature plant, not the other way around (Havrilla et al, 2021). Nevertheless, recognizing that the conditions and traits that favour germination, establishment and survival may not align perfectly could be critical to illuminating the bigger picture constraints on restoration success.…”

Phenotypic variation of root-system architecture under high P and low P conditions in potato (Solanum tuberosum L.)

“…Other traits, such as specific root length or root diameter, varied only little during seedling development. Trait variation during ontogeny can also differ considerably from species to species [ 52 ]. Studies covering this specific topic are still missing for potato and are an interesting objective for future research activities.…”