Growing up aspen: ontogeny and trade-offs shape growth, defence and reproduction in a foundation species

Abstract

Background and Aims Intraspecific variation in foundation species of forest ecosystems can shape community and ecosystem properties, particularly when that variation has a genetic basis. Traits mediating interactions with other species are predicted by simple allocation models to follow ontogenetic patterns that are rarely studied in trees. The aim of this research was to identify the roles of genotype, ontogeny and genotypic trade-offs shaping growth, defence and reproduction in aspen. Methods We established a common garden replicating >500 aspen genets in Wisconsin, USA. Trees were measured through the juvenile period into the onset of reproduction, for growth, defence chemistry (phenolic glycosides and condensed tannins), nitrogen, extrafloral nectaries, leaf morphology (specific leaf area), flower production and foliar herbivory and disease. We also assayed the TOZ19 sex marker and heterozygosity at ten microsatellite loci. Key Results We found high levels of genotypic variation for all traits, and high heritabilities for both the traits and their ontogenetic trajectories. Ontogeny strongly shaped intraspecific variation, and trade-offs among growth, defence and reproduction supported some predictions while contradicting others. Both direct resistance (chemical defence) and indirect defence (extrafloral nectaries) declined during the juvenile stage, prior to the onset of reproduction. Reproduction was higher in trees that were larger, male and had higher individual heterozygosity. Growth was diminished by genotypic allocation to both direct and indirect defence as well as to reproduction, but we found no evidence of trade-offs between defence and reproduction. Conclusions Key traits affecting the ecological communities of aspen have high levels of genotypic variation and heritability, strong patterns of ontogeny and clear trade-offs among growth, defence and reproduction. The architecture of aspen’s community genetics – its ontogeny, trade-offs and especially its great variability – is shaped by both its broad range and the diverse community of associates, and in turn further fosters that diversity.

Intraspecific Variation In Plant Economic Traits Predicts Trembling Aspen Resistance To A Generalist Insect Herbivore

“…Rather, they are single components of larger phenotypic expression networks. Patterns of trait covariation are typically complex, with tradeoffs occurring among multiple traits simultaneously (Züst and Agrawal 2017;Cole et al 2021). Accordingly, hypotheses addressing variation in plant defense strategies, especially those that incorporate growth-defense associations, would bene t by considering co-expression of resistance and non-resistance traits alike.…”

“…Trembling aspen (Populus tremuloides) is a foundation tree species with an expansive range across northern and western North America (Mitton and Grant 1996). The species exhibits exceptional levels of phenotypic variation (Mitton and Grant 1996;Cole et al 2021), making it an ideal candidate for assessing leaf economics patterns. The gypsy moth (Lymantria dispar) is an invasive forest defoliator (McManus and Csóka 2007), for which aspen is a preferred host (Liebhold et al 1997).…”

“…This experimental system, therefore, provided an ideal opportunity to assess the utility of the LES at the intraspeci c level. Trembling aspen is known to exhibit growth-defense tradeoffs (Cole et al 2016(Cole et al , 2021 but whether its trait expression is consistent with other LES patterns is unknown. The system also provided a unique opportunity to test the preference-performance linkage with an herbivore underrepresented in prior research.…”

Trait plasticity and trade‐offs shape intra‐specific variation in competitive response in a foundation tree species

“…Color scale matches x axis and proceeds from red (trait responses << 1) to blue (trait responses >> 1). Cole et al, 2020;Kruger et al, 2020). Growth and defense traits may trade-off because of metabolic costs, or because they are transcriptionally or genetically linked (Z€ ust & Agrawal, 2017).…”

Trends of forest and ecosystem services changes in the Mescalero Apache Tribal Lands

“…2005, Cole et al. 2010, 2021), Douglas fir (Kranabetter et al. 2012), ponderosa pine (Davis and Hofstetter 2014), and pinyon pine (Sthultz et al.…”