Design of seed transfer zones and assessment of germplasm collections of Neltuma alba for reforestation and afforestation purposes in Argentina

The multipurpose tree Neltuma alba is widely distributed in forests of north-central Argentina but overexploitation and deforestation have led to forest transformation and endangered genetic diversity of this species. Thus, developing germplasm management strategies for the conservation and use of the species is crucial. In this context, the availability of georeferenced ecogeographic information along with multivariate analysis techniques facilitates the characterisation, classification and prediction of adaptive patterns, providing a framework for decision-making. In the present study, an Ecogeographic Land Characterisation (ELC) map was generated to assess the ecogeographic representativeness of N. alba germplasm collections and design seed transfer zones (STZs). Adaptive trait data recorded for different plant materials from several provenances across the species’ range in Argentina were used to validate the methodology. The germplasm collections were ecogeographically representative of the occurrence observed; however, some ecogeographic gaps were identified. Of the 45 ecogeographical categories generated in the ELC map, 12 provisional STZs were established. The STZs showed consensus with the morphological groups generated using adaptive traits. This study demonstrates the usefulness of ecogeographic analyses as a preliminary tool to develop strategies for the collection and use of native plant genetic resources. Furthermore, the validation of models with genetic data ensures their effectiveness for restoration and/or afforestation activities.