The hydrological performance of Prosopis juliflora (Sw.) growth as an invasive alien tree species in the semiarid tropics of northeastern Brazil

Abstract

The fast-growing tree Prosopis juliflora was introduced into the drought-prone region of Caatinga in Brazil northeast some decades ago, forming now extensive populations that threaten native biodiversity and disrupt the physiognomy of the local flora. Semiarid tropical forests, such as those that occur in the Caatinga, experience periods of seasonal drought which interrupt cambial activity in woody plants, leading to the formation of annual growth rings that can be used to analyze tree age, growth variability over time and its interactions with climate. We produce a tree-ring width chronology of P. juliflora, in order to establish how this plant is linked to local climate variability, which in turn supports its role as an invasive species in the Caatinga forest. Statistical analyses of the potential effects of climatic variables on this chronology is related directly to the wet season (March–July) and torrential downpours occurring during the dry season (January–February). Moreover, the chronology is inversely related to mean temperature and insolation, which could potentially be linked to rapid loss of moisture in soils due to high temperatures. These findings provide important insights into the growth dynamics of this invasive species, which should contribute to the decision-making of managers and environmental agencies on the development of effective exotic forest management practices in the Caatinga region.