Evolutionary response to coexistence with close relatives: increased resistance against specialist herbivores without cost for climatic‐stress resistance

Abstract

Why can hosts coexist with conspecifics or phylogenetically proximate neighbours despite sharing specialist enemies? Do the hosts evolve increased enemy resistance? If so, does this have costs in terms of climatic‐stress resistance, or in such neighbourhoods, does climatic‐stress select for resistances that are multifunctional against climate and enemies? We studied oak (Quercus petraea) descendants from provenances of contrasting phylogenetic neighbourhoods and climates in a 25‐year‐old common garden. We found that descendants from conspecific or phylogenetically proximate neighbourhoods had the toughest leaves and fewest leaf miners, but no reduction in climatic‐stress resistance. Descendants from such neighbourhoods under cold or dry climates had the highest flavonol and anthocyanin levels and the thickest leaves. Overall, populations facing phylogenetically proximate neighbours can rapidly evolve herbivore resistance, without cost to climatic‐stress resistance, but possibly facilitating resistance against cold and drought via multifunctional traits. Microevolution might hence facilitate ecological coexistence of close relatives and thereby macroevolutionary conservatism of niches.

What Drives Caterpillar Guilds on a Tree: Enemy Pressure, Leaf or Tree Growth, Genetic Traits, or Phylogenetic Neighbourhood?

“…Trees may thus differ in insect communities at a given time due to variation in the timing of budburst ( [5][6][7][8][9][10][11]; Figure 1, arrow 1). Furthermore, populations of hosts consist of individuals with different microevolutionary backgrounds, causing differences in palatability and defence traits [12][13][14]. Genetic lineages within plant species may hence harbour distinct insect lineages ( [10,[15][16][17][18][19][20][21]; Figure 1, arrow 2), but see [22][23][24].…”

Ectophagous folivores do not profit from rich resources on phylogenetically isolated trees

“…Endophages might have little to no need of choosing trees with a particular leaf quality, because they can strongly improve it locally (Cornell 1989;Hartley 1998;Nyman and Julkunen-Tiitto 2000;Giron et al 2007;Kaiser et al 2010). Perhaps other leaf traits such as toughness that limit oviposition and mine initiation are more important to endophages (Faeth 1985;Pihain et al 2019). Even when endophages do track resources, it might be easier for them to overcome the effect of phylogenetic isolation than it is for ectophages if they i.e.…”

Phylogenetic analysis of secondary metabolites in a plant community provides evidence for trade-offs between biotic and abiotic stress tolerance

“…The optimal solution to these trade-offs might be constrained by the evolutionary history of the species, in a similar way that plant responses to a single stress, such as herbivory, are macroevolutionary constrained (Pearse et al 2017). The balance in the investments to face multiple stresses has received considerable attention within species (Eränen et al 2009;Ariga et al 2017;Berens et al 2019;Pihain et al 2019), for instance showing genetic correlations between alleles related to osmotic stress tolerance, and resistance to aphids and caterpillars (Thoen et al 2017). However, as far as we know, it remains unknown whether the response of plants to multiple stresses is phylogenetically constrained, resulting in speciesspecific combinations of metabolic profiles that tend to resemble between closely related species.…”