Survey of Jundu vegetation on the Praia Grande sea edge –State of São Paulo

Abstract

The Jundu plays a fundamental role in retaining and stabilizing sands on the upper beach during storms and/or swells, maintaining natural drainage that allows rainwater to recharge the groundwater table, in addition to preserving biodiversity by providing habitat, breeding grounds, and food for both resident fauna and migratory animals. The objective of this study was to assist with the project to protect the Jundu vegetation being developed by the Environmental Department (SEMA) of Praia Grande, by conducting a survey of the species present in selected sections within the project. The material collection was carried out between June and July 2024 along the coastline of Praia Grande, São Paulo, with processing and identification of the samples taking place at the Herbarium of the Universidade Santa Cecília (HUSC). A total of 24 species and 22 genera belonging to 17 botanical families were found, of which 19 species are native (three endemic to the country) and five are naturalized (exotic), typical of altered environments. Of the 19 native species, only three are not typical of the Jundu: Euphorbia prostrata, Cayaponia racemosa, and Ambrosia artemisiifolia. The species with the highest number of occurrences, in descending order, were: Hydrocotyle bonariensis, followed by Ipomoea pes-caprae, Dalbergia ecastaphyllum, Blutaparon portulacoides, and Eleusine indica. The areas of the beach farther from the center, with fewer tourists (Solemar and Flórida), presented the highest number of exclusive species, diversity, and the largest Jundu patches, indicating the negative impact of high tourist traffic on the establishment of this vegetation. Due to their ability to successfully withstand the various stresses characteristic of the post-beach environment, such as: the action of swell waves, sea spray, wind, sand movement, and significant temperature variations, we recommend the species Hydrocotyle bonariensis, Ipomoea pes-caprae, Dalbergia ecastaphyllum, and Blutaparon portulacoides for the production of seedlings and planting in areas where Jundu is scarce or nonexistent.

Keywords: Restinga vegetation, Jundu, Beaches and Dunes vegetation, Vegetation restoration, Climate change.