Deschampsia cespitosa and soil acidification: general and trait‐specific responses to acid and aluminium stress in a solution experiment

Abstract

Genetically based adaptation and phenotypic plasticity represent important means of coping with natural or human‐induced increases in soil acidity. In the present study, we examined the role of phenotypic plasticity in the grass Deschampsia cespitosa by testing for general and trait‐specific responses to acid and aluminium (Al) stress. We sampled tussocks (genets) from sites in southern Sweden differing in their exposure to acid deposition, and quantified the performance of each genet under low pH and high Al levels in a solution experiment using the length and biomass of both shoots and roots as response variables. In agreement with results from a previous solution experiment, the overall performance (expressed as total biomass) declined under acid and Al stress, and there was no evidence for local genetic adaptation with respect to acidity. Three Öland populations showed signs of being stimulated by high Al levels, despite originating from relatively basic soils. We observed a significant increase in root length under high Al levels and hypothesize that this response may be adaptive in the natural soil environment, allowing growing roots to “escape” patches of soil with toxic concentrations of this element. Our results for D. cespitosa indicate that phenotypic plasticity has the potential to mitigate the negative effects of soil acidity in this species.

Plant functional traits modulate the effects of soil acidification on above- and belowground biomass

“…One possible explanation for this insensitivity might be that deep-rooted species were much more resistant to changing soil environment than the shallow-rooted species (such as sedge C. duriuscula) (Zhang et al, 2019). We found both species invested more in enhancing SRL under soil acidification, which was in agreement with Göransson et al (2011) that grass species increased root length to avoid acid stress. These results indicated that variation of root morphological traits has the potential to mitigate the negative effects of soil acidity and should be considered as part of stress-avoidance or tolerance strategies (Thomaes et al, 2013).…”

Is there local adaptation in plant species to soil reaction? A lesson from a multispecies experiment

“…Weak local adaptation was found in experiments that focused on abiotic conditions connected with pH such as elevated aluminum or carbonate concentration, rather than on the effect of pH itself (Göransson et al 2009; Terés et al 2019). On the other hand, studies that focused solely on pH did not find any genetically underpinned adaptation, which suggests that phenotypic plasticity may be the most important mechanism for how plants cope with pH differences (Göransson et al 2011; Fazlioglu et al 2017).…”

“…Basic soils often host different sets of species than acidic soils (Lee 1999; Hawkesford et al 2012), and populations of species that grow on both basic and acidic substrate may be adapted to the population‐specific pH. So far, there is not much known about plant adaptation to soil pH and the results of the existing studies are not conclusive (Göransson et al 2009; Göransson et al 2011; Fazlioglu et al 2017; Young et al 2018). In this study, we focused on population adaptation to soil pH across five common species of temperate grasslands in a reciprocal transplant experiment in a common garden environment.…”