Anatomical adaptations of plants within the Southern Brazil coastal sand dunes

Abstract

Coastal ecosystems play a crucial role in preserving biodiversity and providing essential ecosystem services to society. Among these ecosystems, coastal dunes and Restinga vegetation stand out for their uniqueness and the diversity of species adapted to extreme environmental conditions. This study aims to investigate the adaptations of plants in these ecosystems, with a specific focus on leaf anatomy, to deepen our understanding of the adaptive strategies adopted by these species and to provide an overview of the most common strategies. To achieve this, we analyzed leaves from 47 prevalent species in herbaceous Restinga of Southern Brazil, across four different microhabitat conditions, employing microscopic techniques to address both qualitative and quantitative measurements to evaluate anatomical characteristics. The results yielded insights into the diversity of plant adaptations to different microhabitats. Key findings include the presence of thickened external periclinal walls, the height of epidermal cells, and a predominance of amphistomatous leaves. These characteristics suggest adaptations to minimize water loss through transpiration due to solar radiation protection against damage of radiation, and a better use of the light that arrives from all directions, reflected by the sand. Additionally, specialized water storage tissues such as the hydrenchyma, voluminous epidermal cells, and hypodermis were identified, indicating adaptations to environments with water restriction and high temperatures. Our data contribute to a better understanding of the adaptive strategies of plants in coastal ecosystems, providing insights for more specialized research approaches and the implementation of practical conservation and management measures in these ecosystems.