Additive and non-additive effects of simulated leaf and inflorescence damage on survival, growth and reproduction of the perennial herb Arabidopsis lyrata

Abstract

Herbivores may damage both leaves and reproductive structures, and although such combined damage may affect plant fitness non-additively, this has received little attention. We conducted a 2-year field experiment with a factorial design to examine the effects of simulated leaf (0, 12.5, 25, or 50% of leaf area removed) and inflorescence damage (0 vs. 50% of inflorescences removed) on survival, growth and reproduction in the perennial herb Arabidopsis lyrata. Leaf and inflorescence damage negatively and independently reduced flower, fruit and seed production in the year of damage; leaf damage also reduced rosette size by the end of the first season and flower production in the second year. Leaf damage alone reduced the proportion of flowers forming a fruit and fruit production per plant the second year, but when combined with inflorescence damage no such effect was observed (significant leaf × inflorescence damage interaction). Damage to leaves (sources) caused a greater reduction in future reproduction than did simultaneous damage to leaves and inflorescences (sinks). This demonstrates that a full understanding of the effects of herbivore damage on plant fitness requires that consequences of damage to vegetative and reproductive structures are evaluated over more than 1 year and that non-additive effects are considered.

Net neutral effects of a generalist vertebrate predator on seed production result from simultaneous suppression of plant antagonists and mutualists

“…First, we observed that the grasshoppers increased proportional leaf damage by 88% if comparing leaf proportional damage in the frog absent, grasshopper present (F−, G+) treatment with the frog absent, grasshopper absent (F−, G−) treatment. We speculate that the increase in leaf damage must have significantly reduced plant photosynthetic capacity and thus the carbon and nutrient sources were limited for seed production (Delaney & Higley 2006;Pellegrino & Musacchio 2006;Puentes & Ågren 2012). Second, we did observe a markedly negative effect of frogs on grasshopper survival.…”

Pollination, Herbivory, and Habitat Fragmentation: Their Effects on the Reproductive Fitness of Angadenia berteroi, a Native Perennial Plant of the South Florida Pine Rocklands

“…In addition, timing of damage had no significant impact on plant fitness, since pre-flowering and flowering defoliation had similar effects on both growth and reproduction. Negative effects of defoliation on fitness have been reported in other species (Parra-Tabla et al, 2004;Narbona and Dirzo, 2010;Maguire et al, 2011;Irwin and Brody, 2011;Puentes and Ägren, 2012;Zhu et al 2014), where growth and reproduction were reduced as the percentage of defoliation increased.…”

“…Parra-Tabla et al (2004) reported that Cnidoscolus aconitifolius (Euphorbiaceae) compensated in leaf growth after herbivory damage, suggesting strong resource allocation to re-establish photosynthetic capacity and increase plant growth and survival. Narbona and Dirzo (2010) Strauss et al, 2001;Narbona and Dirzo, 2010;Irwin and Brody, 2011;Puentes and Ägren, 2012). Our field observations indicated that flower number may increase pollinator visitations since visitors tend to be more abundant in areas with more flowers (Barrios et al, in review).…”

“…Plants can make up for tissue lost to herbivory via compensatory photosynthesis of remnant photosynthetic tissues (Thomson et al, 2003;Zhu et al, 2014). Defoliation can also negatively affect reproductive success by reducing resources available for reproductive structures such as flowers Puentes and Ägren, 2012). On the other hand, some studies have shown that herbivory may also increase plant productivity and fitness, since some levels of herbivory may result in overcompensatory growth (Thomson et al, 2003;Zhu et al, 2014).…”

“…Though it has been shown in some systems that damage from real herbivores may elicit different responses in plants than damage by artificial means (Baldwin, 1990;Tiffin and Inouye, 2000;Ehrlén, 2003;Zvereva and Kozlov, 2014). Artificial damage to plants grown in a common environment has been often used to assess the effect of herbivory on plant fitness (Strauss et al, 2001;Thompson et al, 2004;Narbona and Dirzo, 2010;Puentes and Ägren, 2012), to avoid the different response to herbivory among genotypes, and to obtain a true estimate of the tolerance (Tiffin and Inouye, 2000) while controlling for genetic differences and growing conditions. In this experiment, we used this approach, to determine the effects of damage to leaves and to flowers of a perennial plant growing in habitats frequently affected by fire.…”