Livestock and agriculture affect recruitment and the structure of a key palm for people and an endangered bird in semi-arid lands

Abstract

The palm Syagrus coronata is a key non-timber forest products (NTFP) resource for the livelihood and income of people and is the main food item of the threatened endemic Lear's Macaw (Anadorhynchus leari) in semi-arid Brazil. To contribute to the planning conservation and management of this resource, we assessed how environmental and anthropogenic factors affect the natural regeneration and population structure of S. coronata and identified the relative importance of these factors in the abundance of life stages. We found that (1) recruitment failure occurs mostly in populations in agricultural and intensive grazing areas; (2) regeneration density was positively associated with the density of reproductive plants; and (3) current leaf or fruit harvesting levels were not detected to affect population density and recruitment. Populations subject to chronic anthropogenic disturbance, which lead to poor natural regeneration and recruitment bottlenecks, are likely to become locally extinct. Although populations of S. coronata are locally threatened, the persistence of the species in the landscape is currently ensured by its management and protection in different land uses by local populations that have this species as an important source of food and financial resources.