Effects of microclimatic variation on plant leaf traits at the community level along a tropical forest gradient

Key message

Communities far from the tide line showed similarity, due to microclimatic similarities. There was a separation of the beach grass community through traits tolerant to environmental stress.

Abstract

It is challenging connections between leaf functional characteristics and environmental changes, especially in systems with high biodiversity, such as the Atlantic Forest that is considered vulnerable to climate change. This study characterizes the leaf morphoanatomy of twelve species that occur in different vegetation types (sandbanks forest formation, Clusia formation, beach grass and shrub formation, and beach grass formation) in sandbanks ecosystem in the Atlantic Forest. We did this to understand how leaf attributes adjust to the microclimatic variation in each vegetation type. Five individuals of each species in the vegetation types were collected. Subsequently, plant anatomy methods, including light and scanning electron microscopy, were used to make observations. Our findings showed a similarity between the vegetational types of sandbanks forest, Clusia formation, beach grass and shrub formation that may be related to the short distance between plant communities and/or being exposed to similar microclimatic conditions. Characteristics such as epidermal cells with straight walls, hypostomatic leaves and thick striated cuticles helped the species acclimate to the high irradiance conditions of these formations. On the other hand, the beach grass community was separate from the others since the species in this community have exclusive characteristics (aquiferous parenchyma, Kranz sheath, epistomatic leaf and large epidermal cells) that allow them to tolerate water and heat stress in this environment. These characteristics are present in vegetation close to sea line, but not in distant vegetation. Our results indicate expected changes in the distribution and functioning of the Atlantic Forest communities, which are characterized by large patches of environmental degradation.