Allocation tradeoffs among chaparral shrub seedlings with different life history types (Rhamnaceae)

Abstract

Seedling growth and carbon assimilation rates were divergent among three life history types and were consistent with differences in tolerance to water stress and shade or sun regeneration niches, but not tradeoffs in sprouting-related allocation differences per se.

Fire-mediated disruptive selection can explain the reseeder–resprouter dichotomy in Mediterranean-type vegetation

“…Specifically, on nutrient-poor soils, these are either resprouting or reseeding life-history strategies offer particularly promising opportunities for study. One such case is found in fire-prone plant communities (Bond and Keeley 2005;Keeley et al 2012), where woody plants have evolved two distinct strategies to cope with fire Bond and Midgley 2001;Pausas et al 2004;Higgins et al 2008;Pratt et al 2012). They either have well-protected buds that allow adults to resprout after a fire, or adults are killed by fire and rely solely on their seeds to re-establish in the burnt area (Bond and Midgley 2001;Keeley et al 2012).…”

“…We refer to reseeder as the strategy that involves all adults dying in a fire and reproduction taking place exclusively through seeds that germinate after the fire. This strategy is also known as 'non-sprouter' (Bond and Midgley 1995;Schutte et al 1995;Pratt et al 2012), 'non-persistent semelparous' (Higgins et al 2008) and 'obligate seeder' (Pausas et al 2004;Keeley et al 2012). We refer to resprouter as the strategy where most adults survive a fire and resprout afterwards, but where fire also triggers reproduction from seeds.…”

“…We refer to resprouter as the strategy where most adults survive a fire and resprout afterwards, but where fire also triggers reproduction from seeds. This strategy has also been called 'persistent iteroparous' (Higgins et al 2008), 'facultative sprouter' (Pratt et al 2012) or 'facultative seeder' (Keeley et al 2012).…”

“…At this stage, reseeders require environmental conditions favourable for germination and need predictable rainfall after the fire season to facilitate establishment (Keeley et al 2012). Later in post-fire succession, reseeders likely incur lower costs of investing in and maintaining carbon-rich defensive structures such as bark, buds (particularly basal buds that are well insulated) and storage tissues (particularly lignotubers) required to support post-fire shoot growth (Pausas et al 2004;Pratt et al 2012). Even though the generality of this trade-off is not well established (Bond and Midgley 2003), there is evidence that seedlings of reseeders tend to grow faster than seedlings of resprouters (Pausas et al 2004;Lamont et al 2011), and the latter also tend to show slower shoot development (associated with greater root development tied to drought avoidance; Pausas et al 2004).…”

Contrasting Regeneration Strategies in Climax and Long-Lived Pioneer Tree Species in a Subtropical Forest

“…Plant regeneration is an important ecological process for a forest ecosystem in which the sprouting and seeding of woody species is involved [1]. As a mechanism for shaping community dynamics [2], plant regeneration is important for the succession of forest communities and for the stability and restoration of vegetation in a forest ecosystem following various disturbances.…”