Leaf morphology of 40 evergreen and deciduous broadleaved subtropical tree species and relationships to functional ecophysiological traits

Abstract

We explored potential of morphological and anatomical leaf traits for predicting ecophysiological key functions in subtropical trees. We asked whether the ecophysiological parameters stomatal conductance and xylem cavitation vulnerability could be predicted from microscopy leaf traits. We investigated 21 deciduous and 19 evergreen subtropical tree species, using individuals of the same age and from the same environment in the Biodiversity-Ecosystem Functioning experiment at Jiangxi (BEF-China). Information-theoretic linear model selection was used to identify the best combination of morphological and anatomical predictors for ecophysiological functions. Leaf anatomy and morphology strongly depended on leaf habit. Evergreen species tended to have thicker leaves, thicker spongy and palisade mesophyll, more palisade mesophyll layers and a thicker subepidermis. Over 50% of all evergreen species had leaves with multi-layered palisade parenchyma, while only one deciduous species (Koelreuteria bipinnata) had this. Interactions with leaf habit were also included in best multi-predictor models for stomatal conductance (gs ) and xylem cavitation vulnerability. In addition, maximum gs was positively related to log ratio of palisade to spongy mesophyll thickness. Vapour pressure deficit (vpd) for maximum gs increased with the log ratio of palisade to spongy mesophyll thickness in species having leaves with papillae. In contrast, maximum specific hydraulic conductivity and xylem pressure at which 50% loss of maximum specific xylem hydraulic conductivity occurred (Ψ50 ) were best predicted by leaf habit and density of spongy parenchyma. Evergreen species had lower Ψ50 values and lower maximum xylem hydraulic conductivities. As hydraulic leaf and wood characteristics were reflected in structural leaf traits, there is high potential for identifying further linkages between morphological and anatomical leaf traits and ecophysiological responses.

Variation in leaf anatomical traits from tropical to cold‐temperate forests and linkage to ecosystem functions

“…One plausible explanation for the increase in ST/LT with increasing latitude is the significantly negative correlation of ST/LT with MAT (Table ), because development at low temperatures may particularly promote cell division (Gorsuch, Pandey, & Atkin, ). Furthermore, a thicker PT indicates a higher photosynthetic capacity (Chen et al., ; Krober, Heklau, & Bruelheide, ) and the accumulation of photosynthetic products, which are beneficial to plants living at higher latitudes.…”

“…This thinner epidermis at high latitude might benefit gas exchanges and improve CO 2 distribution from the stomata throughout tree leaves (Verboven et al., ). In contrast, the thicker epidermis of herbs might decrease leaf transpiration resulting in a higher WUE (Krober et al., ). PT/ST and PT/LT of shrubs also increased with increasing latitude (Figure ), indicating that shrubs tend to increase their PT to optimize photosynthesis, as the regular arrangement of palisade tissue cells with high chlorophyll content have a higher photosynthetic capacity (Chen et al., ; Krober et al., ).…”

Relating Stomatal Conductance to Leaf Functional Traits

“…Similarly, other types of leaf traits as derived from microscopy such as palisade parenchyma structure and epicuticular wax layer structure could be included 28 .…”

Soil organic matter quantity and quality shape microbial community compositions of subtropical broadleaved forests

“…; Kröber et al . ). Evergreen plants appear to have an adaptive advantage in nutrient‐poor habitats, owing to a higher nutrient‐use efficiency than deciduous plants because of their longer leaf‐lifespan (Givnish ).…”