Acácias australianas no Brasil: histórico, formas de uso e potencial de invasão

Abstract

In several countries, species of the genus Acacia, originally from Australia, have presented a consistent history of introduction followed by invasion. In Brazil, these species have started to be registered in areas adjacent to their introduction sites and, given their broad utilization, this fact raises concern. Therefore, it is important to estimate the invasive potential of the species Acacia mangium and A. mearnsii, given that these are the species of the genus most frequently cited in the lists of invasive alien species in Brazil. The risks associated with the introduction and use of these species in Brazil were estimated by compiling and assessing intrinsic and extrinsic information on the species. This information covers the biology, uses, potential impacts, sites of introduction and history of invasion of the species. The main pathways of introduction of the species in Brazil are commercial cultivation for the production of pulp and tannin extraction, and the reclamation of degraded areas. Both species have characteristics that favor their invasiveness, such as the capacity to grow in a wide variety of climates and tolerance to water and nutrient scarcity. The establishment of individuals of both species in areas neighboring commercial cultivation sites has already been recorded in Brazil, indicating that the invasion process is underway. In these areas, changes in soil nutrient concentration, pH and plant community composition have been observed. Introduction records of A. mangium have been found in the north and east of the national territory. Occurrence of A. mearnsii is mainly documented in the south and southeast. Considering that the cultivation of these species is becoming increasingly more popular and more profitable in Brazil, the development of strategies to prevent their invasion has become imperative.