EX SITU CONSERVATION: DIAGNOSIS OF THE “GUSTAVO EDWALL” ARBORETUM AND MANAGEMENT RECOMMENDATIONS

Abstract

The arboretum living collections are of great importance among germplasm banks because it preserves genetic material from tree species of different origins in ex situ conditions. The “Gustavo Edwall” Arboretum was implanted in 1914 in the Alberto Löfgren State Park, São Paulo – SP, by Edmundo Navarro de Andrade. The purpose of this study was to document the fora and structure of the arboretum tree community to detect whether the original planting species remaining and if there had enrichment of species from propagules of the natural forests in the surrounding area. In 19,000 m2 of occupied area by the arboretum, trees and palms with PBH ≥ 15 cm were recorded. The species were classifed as native or alien species, and for the last one, among transient alien, potential invader, non-dominant or dominant invader. A total of 829 individuals were recorded in 2018, belonging to 111 species (50% exotic), 89 genres and 38 families. The arboretum houses 32 species from the original planting, but 78 new species were registered, and one is indeterminate. Most of the community results from natural regeneration and/or undocumented further cultivation. The registration of 22 invasive species, which accounts for 27% of the density and 26% of the basal area, deserves attention. Even if almost half of the species are native, the number of invaders regenerating in the area is worrying. The mechanical control of the aliens and bringing back native species of the original planting are recommended, in order to preserve its historical, scientifc and landscape value.