Testing the correlations between leaf life span and leaf structural reinforcement in 13 species of European Mediterranean woody plants

Abstract

Summary 1.It has been proposed that in longer-living leaves the allocation of biomass to structural components is greater than in shorter-living leaves, leading to a greater leaf mass per area (LMA) and to lower assimilation rates. However, direct evidence in support of this hypothesis is very scarce. 2. In the present work we investigated the relationships between leaf duration and LMA, leaf thickness and fibre concentrations (cellulose, hemicellulose and lignin) in five oak species, five pine species and three additional tree species, differing in leaf life spans. Correlations among leaf life span and the other leaf traits were obtained both across species (TIPs) and as phylogenetically independent contrasts (PICs). 3. Leaf thickness and LMA increased steadily with leaf longevity. No relationship was found between leaf longevity and the lignin concentration per unit leaf mass. Evergreen leaves were found to have higher mean concentrations of cellulose and hemicellulose than deciduous ones. However, no relationship was observed between leaf longevity and the concentration of structural carbohydrates across the set of evergreen species, although PIC correlations revealed increases in cellulose with leaf longevity within particular lineages. 4. Our findings reveal that leaf reinforcement by structural carbohydrates depends on leaf habit (deciduous vs. evergreen) and, within a given lineage, also on leaf longevity. However, among the evergreen species co-occurring in a particular environment, leaf duration may apparently be increased, with no need for increases in the concentration of structural components per unit leaf mass.

Response of Leaf Functional Traits of Cerasus yedoensis (Mats.) Yü Li to Serious Insect Attack

“…Conversely, this negative relationship is not consistent with previous results [32]. As one of the most variable plant characteristics affecting major physiological properties that enable plants to adapt to numerous environmental conditions [9,33], such as defense against pathogens [23] and herbivores [9], leaf shape index was positively correlated with petiole diameter, leaf length, leaf thickness, ratio of leaf length to petiole length, ad single leaf wet and dry weight, but negatively correlated with leaf moisture. Therefore, leaf shape index may be affected by leaf length, leaf thickness, allocated biomass in leaf lamina relative to leaf petiole (the ratio of leaf length to petiole length), a single leaf wet and dry weight (although leaf shape index was calculated as the ratio of leaf length to the corresponding leaf width).…”

“…This high material investment per unit area is necessary to yield low leaf moisture and SLA, but high leaf thickness, single leaf wet weight, and single leaf dry weight compared with the results described in previous studies [7,[14][15]. Furthermore, leaves with low SLA contain more ructural carbohydrates, such as lignin and cellulose in their cell walls , than those with high SLA [23]. Consistent with the first hypothesis, our results showed that leaf moisture and SLA of damaged leaves were significantly lower than those of healthy leaves.…”

Photosynthetic ecophysiology of evergreen leaves in the woody angiosperms – a review

“…The density of leaf lamina is influenced by the packing of cells and by the thickness and composition of the cell walls and, to a lesser extent, by the composition of the protoplasts. Evergreen leaves tend to be both thicker and denser than deciduous leaves (Mediavilla et al 2001;Mediavilla et al 2008;Poorter et al 2009; see Fig. 1 A vs. B, E vs. F) with much interspecific variability (Rotondi et al 2003;Villar et al 2013).…”

“…Chemical analyses of evergreen leaves usually yield higher cellulose and hemicellulose concentrations, and, often but not always, a higher lignin concentration compared to deciduous species (Villar and Merino 2001;Mediavilla et al 2008). The metabolic cost per unit of leaf biomass has been estimated by measuring the heat of combustion corrected for ash content and additionally calculating the cost of protein synthesis (Villar and Merino 2001).…”

Warm and Fertile Sub-Humid Conditions Enhance Litterfall to Sustain High Soil Respiration Fluxes in a Mediterranean Cork Oak Forest

“…for [59] or 155 gC m −2 for [60]). This supports our statement of a well-watered site based on the observed plasticity of this functional trait according to drought [61,62].…”