Plant growth shapes the effects of elevation on the content and variability of flavonoids in subalpine bilberry stands

Abstract

The study of morphological and physiological responses of shrubs to climate is crucial for the understanding of future scenarios regarding climate change. In this light, studying shrub growth and physiological acclimation along an elevation gradient might be insightful. The phenolic metabolic pathway represents a powerful tool to interpret such processes. In the South‐Eastern Alps, we investigated the relationships between elevation, plant traits (i.e. age, xylem ring width, annual shoot length), plant–plant interaction (i.e. shrub cover) and flavonoids in Vaccinium myrtillus L. (leaves, berries) in stands above the treeline. The relationships were parsed within causal networks using a confirmatory path analysis. Elevation was the main driver of V. myrtillus growth, having both direct and indirect effects on the leaf flavonoid content, but this was less evident for berries. In particular, the content of foliar flavonoids showed a peak at mid‐elevation and where the growth of xylem rings was intermediate, while it decreased in stands with higher shoot length. Flavonoid content variability of both leaves and berries was affected by elevation and shoot length. In berries, flavonoid variability was further related to all growth traits and shrub cover. These findings evidence that flavonoid content is influenced by both elevation and growth traits of V. myrtillus, often showing non‐linear relationships. These results suggest a trait‐mediated response of this plant to climate conditions as a result of trade‐offs between plant growth, plant defence, environmental stress and nutrient/resource availability.

Trends in Phenolic Profiles of Achillea millefolium from Different Geographical Gradients

“…On the other hand, the trend of increasing total flavonoid content in southern latitudes can be explain by increased UV-B radiation at higher elevations compared with northern, suggesting a greater contribution of flavonoids to radical scavenging potential. In this regard, our findings are partially explained by previous studies showing the promotion of flavonoid synthesis at a high altitude due to increased UV-B radiation and oxidative stress [ 37 ].…”

“…However, previous studies on different plant species have shown the variable effects of environmental gradients on phenolic metabolic pathways [ 34 , 35 ]. The opposite trend of accumulation of phenolic compounds, depending on the elevation, was found in Vaccinium myrtillus L. both for groups of compounds and for part of plants [ 36 , 37 ]. Nataraj et al [ 38 ] reported that the concentration of phenolic compounds decreased in the leaves of Artemisia brevifolia Wall ex DC.…”

Nutrient enrichment promotes invasion success of alien plants via increased growth and suppression of chemical defenses

“…Plants often employ mixed anti‐herbivore defense strategies that involve production of various types of secondary metabolites, which vary in their effectiveness against different herbivores but also play a huge role in plant adaptation to adverse environmental conditions (Filippi et al, 2021; Lankau, 2007; War et al, 2012). Carbon‐based metabolites such as tannins and flavonoids (phenolic compounds) are well‐known to act as anti‐herbivore defenses by affecting the feeding behavior and development of insect herbivores (Müller‐Schärer et al, 2004).…”

Transient Effects of Snow Cover Duration on Primary Growth and Leaf Traits in a Tundra Shrub

“…So far, investigations targeting snow cover effects mainly explore single plant’s parameters as radial annual growth or shoot elongation ( Rixen et al, 2010 ; Schmidt et al, 2010 ; Pellizzari et al, 2014 ; Francon et al, 2017 ; Carrer et al, 2019 ), while other key functional traits or physiological parameters crucial for plant fitness, productivity, and survival, as leaf traits or non-structural carbohydrate content, are mostly neglected, especially in shrub-related studies ( Wipf et al, 2009 ; Sedlacek et al, 2015 ; Filippi et al, 2021 ). In fact, leaves and stomata features, driving photosynthesis and transpiration processes, reflect plant functioning in specific growing conditions ( Chapin et al, 2002 ).…”