# Twig and Leaf Morphological Traits and Photosynthetic Physiological Characteristics of Periploca sepium in Response to Different Light Environments in Taohe Riparian Forests

## TL;DR

This study explores how the plant Periploca sepium adapts its twig and leaf structures and photosynthesis in different light conditions.

## Contribution

The study reveals a resource investment trade-off strategy in P. sepium's adaptation to varying light environments.

## Key findings

- Plants in shaded areas had long, thick twigs and large leaves with high photosynthetic efficiency.
- Plants in sunny areas showed opposite traits, with lower photosynthetic efficiency and different leaf structures.
- Twig and leaf traits correlated strongly with photosynthetic characteristics across habitats.

## Abstract

Understanding the variations in twig and leaf morphologies and photosynthetic physiological characteristics of riparian forest plants in heterogeneous habitats is of great significance for revealing their phenotypic plasticity mechanisms and ecological adaptation strategies. In this study, the riparian forest plant Periploca sepium Bunge was selected as the research object. According to the canopy light environment experienced by the P. sepium population, three habitats were established: under-canopy, gap, and full-sun areas. We studied the twig and leaf morphological and photosynthetic characteristics of P. sepium under heterogeneous light environments, as well as the relationships between these two aspects. Plants in the under-canopy area developed long and thick twigs with few large leaves, coupled with high actual photosynthetic efficiency of photosystem II (Y(II)) and low non-photochemical quenching (NPQ), whereas those in the full-sun area exhibited the opposite covariation strategy. Significant correlations between twig and leaf morphologies and photosynthetic physiological characteristics were found across all habitats. The coordinated variations in twig and leaf morphologies and photosynthetic physiology of P. sepium embody a resource investment trade-off strategy that plants have evolved through long-term adaptation to heterogeneous light environments.