A hyper‐arid environment shapes an inverse pattern of the fast–slow plant economics spectrum for above‐, but not below‐ground resource acquisition strategies

Abstract

1. The fast-slow plant economics spectrum predicts that because of evolutionary and biophysical constraints, different plant organs must be coordinated to converge in a unique ecological strategy within a continuum that shifts from fast to slow resource acquisition and conservation. Therefore, along a gradient of aridity, taxa with different strategies will be expected to be successful because selection pressures for slow resource acquisition become stronger as the environment becomes drier. In extremely arid and seasonal environments, however, a slow strategy may become disadvantageous because slow traits are costly to maintain.Additionally, as the availability of water decreases, selection pressures increase, reducing the variation in ecological strategies.2. Using shrub assemblages along an aridity gradient in the Atacama Desert, we test the hypothesis that selection pressures imposed by hyper-aridity act simultaneously on the variation and coordination of trait attributes, leading to an inverse pattern in the fast-slow plant economics spectrum, where strategies shift from slow to fast as the environment becomes drier.3. We established 20-22 plots at each of four sites along the gradient to estimate plant community structure and functional variation. For all species recorded, we quantified a set of leaf, stem, and root traits. 4. Results revealed an inverse pattern of the fast-slow economics spectrum for leaf and stem traits, but not for root traits; that is, as aridity further increased, aboveground traits exhibited a shift from a slow to a fast strategy with some level of coordination. Below-ground traits, however, did not shift accordingly with our prediction, rather they showed more complex pattern of shift and coordination with above-ground traits along the gradient. We also found that trait variation showed an idiosyncratic pattern of variation along the gradient, indicating that ecological strategies are driven by local processes within sites. 5. Synthesis. Our results increase our understanding of the fast-slow plant economics spectrum by showing that environmental gradients, as well as local process can K E Y W O R D S Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Carvajal DE, Loayza AP, Rios RS, Delpiano CA, Squeo FA. A hyper-arid environment shapes an inverse pattern of the fast-slow plant economics spectrum for above-, but not below-ground resource acquisition strategies. J

Trait Gradient Analysis for Evergreen and Deciduous Species in a Subtropical Forest

“…We observed negative correlations between wood and leaf traits in both evergreen and deciduous species. Our results were similar to other studies that showed some degree of coordination between leaf and stem traits [46]. The leaf traits showed a negative relationship with wood density, which indicates that fast resource use by leaves is accompanied by fast water conduction by the stem.…”

“…The leaf traits showed a negative relationship with wood density, which indicates that fast resource use by leaves is accompanied by fast water conduction by the stem. Therefore, above-ground traits respond concordantly to the same habitat stresses promoting rapid resource acquisition [46]. The level of coordination between wood and leaf traits can be multidimensional, meaning that certain wood traits coordinate with leaf traits while others vary independently in determining resource acquisition strategies [47].…”

Intraspecific variability drives functional changes in lichen epiphytic communities across Europe

“…Such functional changes at community level were also determined by the covariation between intraspecific trait variability and species turnover, which varied in sign depending on the trait considered. Most studies centered on plants (e.g., Lepš et al 2011, Kumordzi et al 2014, Carvajal et al 2018, Liu et al 2019) and the few including lichens (Roos et al 2019), found that species turnover and intraspecific trait variability tend to positively covary, whereas here we found the opposite; that is, twice as many cases showed a negative covariation (Fig. 2).…”

Global ecosystem thresholds driven by aridity

“…S4). The observed changes could be related to a physiological limit for the existence of stress-tolerant strategies and evergreen vegetation at aridity levels > 0.8, as this vegetation is replaced by stress-avoidant summer deciduous shrub species that may benefit most from the sparse and unpredictable rain events characterizing these environments (21,29) (Fig. S6D).…”