Eco-evolutionary processes affecting plant–herbivore interactions during early community succession

Abstract

The quality and outcome of organismal interactions are not only a function of genotypic composition of the interacting species, but also the surrounding environment. Both the strength and direction of natural selection on interacting populations vary with the community context, which itself is changed by these interactions. Here, we test for the role of interacting evolutionary and ecological processes in plant-herbivore interactions during early community succession in the tall goldenrod, Solidago altissima. We use surveys in a large-scale field experiment with repeated plots representing 6 years of early oldfield succession and reciprocal transplant common garden experiments to test for the relative importance of rapid evolution (genetic) and environmental changes (soil quality) in affecting mean plant resistance and growth phenotypes during community succession. While plant growth varied strongly with soil quality over the first 5 years of agricultural abandonment, plant secondary metabolism, and herbivore resistance varied minimally with the soil environment. Instead, mean composition and abundance of plant secondary compound bouquets differed between S. altissima plants from populations collected in communities in the first ("early") and sixth ("intermediate") years of oldfield succession, which was reflected in the feeding preference of the specialist herbivore, Trirhabda virgata, for early succession lines. Moreover, this preference was most pronounced on poorer quality, early succession soils. Overall, our data demonstrate that plant quality varies for insect herbivores during the course of early succession and this change is a combination of altered genotypic composition of the population and phenotypic plasticity in different soil environments.

Shifts in plant–microbe interactions over community succession and their effects on plant resistance to herbivores

“…The tall goldenrod, Solidago altissima (Asteraceae), may be a useful model for studying intraspecific successional shifts in resistance phenotypes because it is an early coloniser, particularly of abandoned agricultural fields (old fields), that can persist for decades as a dominant community member, even as communities become forested (Bazzaz, ). The herbivore resistance of S. altissima has been observed to increase with successional age in independent populations in both the northern (Howard et al , ) and southern United States (Hakes & Cronin, ). This shift in resistance has been attributed to both rapid microevolution and phenotypic plasticity, with the latter associated with changes in soil conditions (Hakes & Cronin, ; Howard et al , ).…”

“…The herbivore resistance of S. altissima has been observed to increase with successional age in independent populations in both the northern (Howard et al , ) and southern United States (Hakes & Cronin, ). This shift in resistance has been attributed to both rapid microevolution and phenotypic plasticity, with the latter associated with changes in soil conditions (Hakes & Cronin, ; Howard et al , ). Thus, changes in the soil structure, chemistry and particularly the microbiome, may play an important role in shifting plant resistance to herbivores over succession.…”

From plants to herbivores: novel insights into the ecological and evolutionary consequences of plant variation

“…Growth is strongly affected by succession, whereas plant secondary metabolism and herbivore resistance varies only little with the soil environment. They find that feeding by a specialist herbivore causes divergent patterns of resistance evolution within short time periods (Howard et al 2018). The results highlight that selective pressures are likely to vary during community succession.…”

“…In an eco-evolutionary approach, Howard et al (2018) investigate the relative importance of rapid evolution and environmental changes in affecting mean plant resistance and growth phenotypes. They report on a soil transplant experiment with plant lines over several years of succession with different herbivore pressures.…”

“…The studies of this special topic cover a broad range of plant life forms, from marine algae in an aquatic system (Ledet et al 2018) to terrestrial herbs (Calf et al 2018;Chiriboga et al 2018;Cuny et al 2018;Howard et al 2018;Humphrey et al 2018;Kergunteuil et al 2018;Quintero and Bowers 2018), to shrubs (Nell et al 2018;Ochoa-López et al 2018), to long-lived trees (Albrectsen et al 2018;Bagchi et al 2018;Cipollini and Peterson 2018;Coley et al 2018;Falk et al 2018;Lämke and Unsicker 2018). In twelve case studies and four review papers, selected aspects of the huge variation in phenomena and underlying mechanisms are highlighted and new research questions opened, which may inspire further research in this exciting field.…”