# Shifting in the shadows: Morphofunctional variations of Miconia sellowiana Naudin (Melastomataceae) associated with cave environments

## TL;DR

This study explores how cave environments shape the leaf traits of Miconia sellowiana, revealing adaptations to low light and nutrient scarcity.

## Contribution

It identifies specific morpho-functional adaptations in plants growing in cave environments compared to adjacent habitats.

## Key findings

- Cave-grown plants have thinner leaves with fewer photosynthetic layers and smaller phloem areas.
- Stomatal density and leaf size are reduced in cave individuals due to environmental constraints.
- Cave conditions act as environmental filters, shaping plant morphology and physiology.

## Abstract

Caves present unique ecological conditions that influence the distribution and adaptation of species, yet studies on cave‐associated vegetation remain limited. This study investigated how cave conditions affect the functional traits of Miconia sellowiana Naudin (Melastomataceae), comparing individuals from the cave interior with those from the adjacent understory. Our objective was to understand how these environments influence the species' morpho‐functional characteristics and ecological relevance, aiming to identify physiological responses to the constraints of each habitat. Based on this, we hypothesize that caves act as distinct environmental filters compared to the understory, selecting for unique morphological and physiological variations.Leaf morpho‐functional traits were evaluated, including macroscopic dimensions (length, width, and leaf area) and microscopic characteristics, such as the anatomy of the central vein, mesophyll, and epidermis. Samples were fixed, processed for histological sections, and analysed by optical and electron microscopy. Statistical analysis included PCA to identify morpho‐functional patterns and Student's t‐tests/Wilcoxon tests to compare variables between habitats.Cave individuals had thinner leaves, with fewer layers of photosynthetic parenchyma, smaller relative phloem area in the central vein, lower stomatal density, and reduced leaf area and length compared to understory individuals.Low light availability, high humidity, shallow soils, and nutrient scarcity in caves likely limit the development of thicker leaves and affect stomatal density, vascular tissue, and leaf size. These results suggest that cave environments drive morpho‐functional and physiological variations in surrounding plants. This study fills gaps in the literature and highlights ecological mechanisms that sustain life in subterranean ecosystems.

Caves present unique ecological conditions that influence the distribution and adaptation of species, yet studies on cave‐associated vegetation remain limited. This study investigated how cave conditions affect the functional traits of Miconia sellowiana Naudin (Melastomataceae), comparing individuals from the cave interior with those from the adjacent understory. Our objective was to understand how these environments influence the species' morpho‐functional characteristics and ecological relevance, aiming to identify physiological responses to the constraints of each habitat. Based on this, we hypothesize that caves act as distinct environmental filters compared to the understory, selecting for unique morphological and physiological variations.

Leaf morpho‐functional traits were evaluated, including macroscopic dimensions (length, width, and leaf area) and microscopic characteristics, such as the anatomy of the central vein, mesophyll, and epidermis. Samples were fixed, processed for histological sections, and analysed by optical and electron microscopy. Statistical analysis included PCA to identify morpho‐functional patterns and Student's t‐tests/Wilcoxon tests to compare variables between habitats.

Cave individuals had thinner leaves, with fewer layers of photosynthetic parenchyma, smaller relative phloem area in the central vein, lower stomatal density, and reduced leaf area and length compared to understory individuals.

Low light availability, high humidity, shallow soils, and nutrient scarcity in caves likely limit the development of thicker leaves and affect stomatal density, vascular tissue, and leaf size. These results suggest that cave environments drive morpho‐functional and physiological variations in surrounding plants. This study fills gaps in the literature and highlights ecological mechanisms that sustain life in subterranean ecosystems.

Cave environments filter plant traits, selecting thinner, smaller leaves with reduced photosynthetic and vascular structures.