Guidelines for seed collection of Araucaria angustifolia (Bertol.) Kuntze: A genetic, demographic and geographic approach

Abstract

Restoration of degraded ecosystems is essential for the conservation of global biodiversity. In southern Brazil, the Araucaria forest is a highly reduced and fragmented ecosystem of the Atlantic Forest Biome, and restoration is recommended for the conservation of both Araucaria forest and Araucaria angustifolia, an endangered conifer of this ecosystem. Thus, knowledge about seed collection sites, criteria for the maintenance of genetic diversity, and adaptive potential of seeds is crucial to restoration success. Therefore, this study aimed to identify priority areas for seed collection of A. angustifolia based on its previously known genetic, demographic and geographic characteristics. To accomplish this, the density of reproductive individuals of A. angustifolia associated with a probability of reproduction (50% or 90%) was extrapolated to all the Araucaria forest fragments from Santa Catarina state (SC), Brazil. Then, we estimated which forest fragments would be suitable for seed collection based on average values of fine scale genetic structure (FSGS) and the number of sampled seed trees for which different effective population sizes (100 or 1000) could be retained. Despite high fragmentation, some forest fragments remain suitable as seed source for restoration. However, using strict criteria, only 4.1% of the fragments could be deemed suitable. Collectively, our results represent a starting point for policymakers concerned with identifying restoration areas for endangered species, in particular, the criteria for seed collection of A. angustifolia.