A population census approach to conserving the threatened tree Xylopia decorticans (Annonaceae)

Abstract The tree Xylopia decorticans is a rare endemic in the Brazilian Atlantic Forest, a global biodiversity hotspot. Described in 2007 from two protected areas, it was originally categorized as Least Concern but as a result of progressive forest conversion and degradation it is now categorized as Endangered in the Brazilian Red List and IUCN Red List. Ecologically, the search for new populations is important because the species provides resources to a range of wildlife in different forest layers, but there have been no demographic studies on which to base conservation action. To address this lack of information, we surveyed a private protected area in south-eastern Brazil where there was a new record of X. decorticans . We located 121 individuals within a minimum convex polygon area of 4.08 ha (density 29.65 individuals/ha), c. 30% of which were juveniles. Mean tree height was 9 m and diameter at breast height ≤ 10 cm. The species is ombrophilous and sensitive to edge effects, as evidenced by desiccation observed in the field. The findings of this study improve our understanding of the ecological characteristics of species within regions afflicted by ongoing forest degradation, and underscores the pivotal role of Reservas Particular do Patrimônio Natural (private natural heritage reserves) in Brazil in the conservation of threatened species such as X. decorticans .