Plant responses to climatic extremes: within‐species variation equals among‐species variation

Abstract

Within-species and among-species differences in growth responses to a changing climate have been well documented, yet the relative magnitude of within-species vs. among-species variation has remained largely unexplored. This missing comparison impedes our ability to make general predictions of biodiversity change and to project future species distributions using models. We present a direct comparison of among- versus within-species variation in response to three of the main stresses anticipated with climate change: drought, warming, and frost. Two earlier experiments had experimentally induced (i) summer drought and (ii) spring frost for four common European grass species and their ecotypes from across Europe. To supplement existing data, a third experiment was carried out, to compare variation among species from different functional groups to within-species variation. Here, we simulated (iii) winter warming plus frost for four grasses, two nonleguminous, and two leguminous forbs, in addition to eleven European ecotypes of the widespread grass Arrhenatherum elatius. For each experiment, we measured: (i) C/N ratio and biomass, (ii) chlorophyll content and biomass, and (iii) plant greenness, root (15) N uptake, and live and dead tissue mass. Using coefficients of variation (CVs) for each experiment and response parameter, a total of 156 within- vs. among-species comparisons were conducted, comparing within-species variation in each of four species with among-species variation for each seed origin (five countries). Of the six significant differences, within-species CVs were higher than among-species CVs in four cases. Partitioning of variance within each treatment in two of the three experiments showed that within-species variability (ecotypes) could explain an additional 9% of response variation after accounting for the among-species variation. Our observation that within-species variation was generally as high as among-species variation emphasizes the importance of including both within- and among-species variability in ecological theory (e.g., the insurance hypothesis) and for practical applications (e.g., biodiversity conservation).

Genetic differentiation and plasticity interact along temperature and precipitation gradients to determine plant performance under climate change

“…; Malyshev et al . ). Specifically, target conditions explain most of the variation in the growth‐related traits (plant height, number of ramets, above‐ground and below‐ground biomass) in our study, although the plasticity of these traits strongly varies with origin.…”

Integrating plant ecological responses to climate extremes from individual to ecosystem levels

“…seed size) may also partially buffer negative impacts at the population level during or after environmental stress [34]. There is also increasing evidence for high intraspecific variability in species responses to extremes, which has been observed to be of equal or even greater magnitude than interspecific variation [51]. High intraspecific variability may be influenced by ecotypic and genetic variation within a species ( [37,52,53], but see [54]).…”

Plant evolutionary history mainly explains the variance in biomass responses to climate warming at a global scale

“…The importance of intraspecific variation to community dynamics and ecosystem functioning might challenge the conclusions drawn from average species traits (Violle et al ., ; Malyshev et al ., ). This is because the complicated nonlinear relationships could introduce large uncertainty into ecosystem models (Bolnick et al ., ; Moran et al ., ).…”