Phenological shifts of native and invasive species under climate change: insights from the Boechera–Lythrum model

Abstract

One contribution of 18 to a theme issue 'Human influences on evolution, and the ecological and societal consequences'. Warmer and drier climates have shifted phenologies of many species. However, the magnitude and direction of phenological shifts vary widely among taxa, and it is often unclear when shifts are adaptive or how they affect long-term viability. Here, we model evolution of flowering phenology based on our long-term research of two species exhibiting opposite shifts in floral phenology: Lythrum salicaria, which is invasive in North America, and the sparse Rocky Mountain native Boechera stricta. Genetic constraints are similar in both species, but differences in the timing of environmental conditions that favour growth lead to opposite phenological shifts under climate change. As temperatures increase, selection is predicted to favour earlier flowering in native B. stricta while reducing population viability, even if populations adapt rapidly to changing environmental conditions. By contrast, warming is predicted to favour delayed flowering in both native and introduced L. salicaria populations while increasing long-term viability. Relaxed selection from natural enemies in invasive L. salicaria is predicted to have little effect on flowering time but a large effect on reproductive fitness. Our approach highlights the importance of understanding ecological and genetic constraints to predict the ecological consequences of evolutionary responses to climate change on contemporary timescales.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.

Phenological and fitness responses to climate warming depend upon genotype and competitive neighbourhood in Arabidopsis thaliana

“…One possible explanation for this observation is that if phenology is canalized, then increased temperature might raise metabolic rate to permit increased reproductive effort (Dillon, Wang, & Huey, ; Gillooly, Brown, West, Savage, & Charnov, ; Mittler, Finka, & Goloubinoff, ). However, selection for early flowering at smaller sizes under climate warming may reduce population viability (Colautti, Ågren, & Anderson, ), so that slow development might still be important in population persistence under climate change.…”

“…This multilocus loss of 2010; Gillooly, Brown, West, Savage, & Charnov, 2001;Mittler, Finka, & Goloubinoff, 2012). However, selection for early flowering at smaller sizes under climate warming may reduce population viability (Colautti, Ågren, & Anderson, 2017), so that slow development might still be important in population persistence under climate change.…”

Phenological responses to multiple environmental drivers under climate change: insights from a long‐term observational study and a manipulative field experiment

“…The average method for measuring GDDs overestimates daily heat sums on days when minimum temperatures are below the baseline temperature (Arnold, ). In our estimations of GDD, we assign a baseline temperature of 8°C based on a resource allocation model applied to B. stricta (Colautti et al ., ). In our study region, springtime minimum temperatures are consistently below this threshold (Fig.…”

Human influences on evolution, and the ecological and societal consequences

“…if they limit future responses to selection). We suggest that the greatest increases in genetic variation will attend contexts where population sizes increase most dramatically, such as for introduced species experiencing 'enemy release' [35,68] and for native species benefiting from 'disappearing diseases' [38]. Increases are also expected when diverse source populations are brought together in new locations [34,69,70] and in the case of exposure to mutagens (e.g.…”