Alnus lusitanica

The species was described in 2017, and the major threats affecting the taxon have not yet been evaluated. Recently, there is a new threat for Alnus lusitanica stemming from a disease caused by an oomycete, Phytophthora × alni Brasier & S.A.Kirk (Brasier et al. 2004), which is reported also from the Iberian Peninsula. Trees growing on riverbanks or flood plains are more vulnerable because of the water transport of the pathogen. For more details and reports from the Iberian Peninsula see Pintos Varela et al. (2010), Aguayo et al. (2013) and Kanoun-Boulé et al. (2016). Due to the unique set of haplotypes and spatial isolation preventing genetic admixture in this species, subpopulations could be more at risk to climate change in the future. There may also be an impact from humans on the abundance of A. lusitanica because Alnus spp. yield economically important wood.

Alnus lusitanica is not recorded in any ex situ collections (BGCI 2019). There is a need for long term study focused on the ecology of Alnus lusitanica. There should also be further research into the threats, distribution and population trends of this species. As noticed by Lepais et al. (2013), the distinctiveness of Moroccan tetraploids, such as A. lusitanica, may justify a high-priority conservation status. The species should be included in local lists of rare plant species. Moreover, only regional landraces rather than imported seedlings should be planted in the areas of the recognized tetraploid species.