Effects of apical meristem mining on plant fitness, architecture, and flowering phenology in Cirsium altissimum (Asteraceae)

Abstract

Apical meristem mining reduced plant maternal fitness. The shift in the identity of blooming flower heads from terminal to axial positions contributed to this reduction because axial heads are less fecund. Shorter, meristem-mined plants may have been more susceptible to competition, and this susceptibility may explain their higher mortality rates. The kinds of changes in architecture and phenology that resulted from apical damage to C. altissimum have been shown to affect floral visitation in other plant species.

Cumulative herbivory outpaces compensation for early floral damage on a monocarpic perennial thistle

“…Apical damage has led to compensation, and occasionally overcompensation, for herbivore damage in other systems. Haphazard variation in the timing and duration of insect herbivory and flowering delays due to apical damage can, however, reduce the likelihood of successful seed production and limit the reliability of fitness gains from compensation (Huhta et al 2000;Brody and Irwin 2012;Adhikari and Russell 2014). This variability increases the potential value of strong early-season apical investment, relative to fitness costs spread across multiple later flowering heads, when fitness must be realized under cumulative season-long insect pressure.…”

“…The relative advantage of high early investment, that escapes herbivores, compared to that of releasing additional investment to other flowers, likely varies extensively in time and space (i.e., Brody and Irwin 2012;Klimešová et al 2014;Krimmel and Pearse 2016). For instance, Adhikari and Russell (2014) found a greater proportion of flowering heads developed in response to apical damage in another native thistle (Cirsium altissimum), but the fecundity of axillary flower heads was insufficient to provide compensatory seed production. Without apical damage, if ambient herbivory were low, it is a possible preferential apical investment and early-season inhibition of lower-positioned and axillary head development would still reduce seed contributions from later flowering heads.…”

“…This monocarpic perennial species is known to have strong population-level interactions with floral herbivores (Louda and Potvin 1995;Rose et al 2005;Russell and Louda 2005;Rand and Louda 2012), and would be expected to benefit from tolerance strategies. Apical meristem damage is generally a common occurrence imposed by physical or biological factors (Gruntman and Novoplansky 2011;Adhikari and Russell 2014;Klimešová et al 2014) and represents a disproportionately large potential early-season fitness risk for C. canescens. When the apical flower head escapes damage, it contributes substantially to plant fitness (± 50% total seed production, Louda and Potvin 1995).…”

Mayweed chamomile (Anthemis cotula L.) biology and management—A review of an emerging global invader

“…Eigenbrode). Anthemis cotula plants respond to mowing or grazing by producing new branches (Kay, 1971a), sometimes with altered plant architecture and flowering phenology (Erneberg, 1999; Adhikari and Russell, 2014). This plasticity may contribute to A. cotula invasiveness by enabling it to exploit a range of environments and overcome injury.…”

Chamaecrista Fasciculata In Tallgrass And Sand Prairies: The Potential For Differential Responses

“…Biotic factors of the environment can also have a strong effect on the selection of plant traits within prairies (Adhikari & Russell 2014;Ison et al 2014;. Invertebrate herbivore damage can reduce plant height, delay flowering and shorten duration of flowering, resulting in lower seed production (Adhikari & Russell 2014). In addition, invertebrate herbivory from specific insects (i.e.…”