Larridon, I. | bioRxiv Science

bioRxiv2020

An analysis of Species Conservation Action Plans in Guinea

To achieve conservation success, we need to support the recovery of threatened species. Yet, <5% of plant species listed as threatened on the IUCN Red List have Species Conservation Action Plans (CAPs). If we are to move from a Red List to a Green List for threatened plant species, CAPs need to be devised and implemented. Guinea is one of the most botanically diverse countries in West Africa. Recent research found that nearly 4000 vascular plants occur in Guinea, a 30% increase from previous estimates. 273 of these plant species are now assessed as threatened with global extinction. There is increasing pressure on the environment from the extractive industry and a growing population. In parallel with implementation of an Important Plant Area programme in Guinea, CAPs were developed for 20 threatened plant species. These plans elaborate conservation efforts needed first to safeguard threatened species both in situ and ex situ and then to support their recovery. We document the approach used to assemble the Species Conservation Action Plans, and we discuss the importance of having up to date field information, IUCN Red List assessments, and use of a collaborative approach. The need for these plans is increasingly important with recent calculations suggesting a third of African plants are threatened with extinction. This paper outlines initial detailed plant conservation planning in Guinea and offers a template for conservation practitioners in other tropical African countries to follow.

ecology↗

bioRxiv2019

Introgression in Brownea suggests that reticulate evolution contributes to Amazonian tree diversity

Hybridization has the potential to generate or homogenize biodiversity and is a particularly common phenomenon in plants, with an estimated 25% of species undergoing inter-specific gene flow. However, hybridization in Amazonias megadiverse tree flora was assumed to be extremely rare despite extensive sympatry between closely related species, and its role in diversification remains enigmatic because it has not yet been examined empirically. Using members of a dominant Amazonian tree family (Brownea, Fabaceae) as a model to address this knowledge gap, our study recovered extensive evidence of hybridization among multiple lineages across phylogenetic scales. More specifically, our results uncovered several historical introgression events between Brownea lineages and indicated that gene tree incongruence in Brownea is best explained by introgression, rather than solely by incomplete lineage sorting. Furthermore, investigation of recent hybridization using [~]19,000 ddRAD loci recovered a high degree of shared variation between two Brownea species which co-occur in the Ecuadorian Amazon. Our analyses also showed that these sympatric lineages exhibit homogeneous rates of introgression among loci relative to the genome-wide average, implying a lack of selection against hybrid genotypes and a persistence of hybridization over time. Our results demonstrate that gene flow between multiple Amazonian tree species has occurred across temporal scales, and contrasts with the prevailing view of hybridizations rarity in Amazonia. Overall, our results provide novel evidence that reticulate evolution influenced diversification in part of the Amazonian tree flora, which is the most diverse on Earth.

evolutionary biology↗