The effect of seed ingestion by a native, generalist bird on the germination of worldwide potentially invasive trees species Pittosporum undulatum and Schinus terebinthifolia

Abstract

Invasive alien species are recognized as the second leading cause of biodiversity loss and species extinction worldwide, with zoochoric dispersion being a key factor for the success of invasive organisms as they can favor the germination of these species. We performed a study in the southern Brazil involving three generalist species with abundant and wide amount of distribution in Latin America, with the objective of evaluating seed ingestion by positive criteria about its germination. We investigated the role of bird digestion on the germination of a native pioneer species, the Brazilian pepper—Schinus terebinthifolia, an invasive alien species in many parts of the world. We compared the germination of this native with those of the invasive Australian cheesewood (Pittosporum undulatum) concurrently. Interestingly, the effect of potentiating germination was more intense in the introduced species than for the native species. Pitangus sulphuratus is an important potential disperser for the germination of P. undulatum seeds, enabling the colonization of new areas in the Atlantic Forest of southern Brazil.