Floristic data to support conservation in the Amazonian canga

Abstract

Canga is an environment of great natural and economic value because it harbours a considerable number of endemic species on a substrate that is rich in iron ore. In the Amazon, this open vegetation type grows on top of isolated outcrops in a dense forest matrix found in the Carajás region, in southeastern Pará. Of these outcrops, the Parque Nacional dos Campos Ferruginosos (PNCF) is the only area of Amazonian canga with a strict protection status. Therefore, industrial activity in the region needs to implement mitigation actions to ensure species and habitat conservation. The objective of this study is to complement and review the floristic list of this recently created protected area, enabling us to compare the floristic similarity between it and other 14 Amazonian canga outcrops found outside the conservation units of full protection in the region. This data provides a basis to understand the floristic and phylogenetic complementarity of those patches to support conservation action. For this, six field trips were carried out in the Serra da Bocaina and two in the Serra do Tarzan, respectively, in order to increase the sampling efforts in PNCF and to obtain a more comprehensive plant list. Floristic composition was investigated using multivariate analyses (non-metric multidimensional scaling and unweighted pair group method with arithmetic mean) and phylogenetic structure across studied areas. We added 159 species to the floristic list of the PNCF and the results of the analyses showed that all 16 areas (n.b. PNCF comprises two of these sites) have an overall floristic similarity of 42%, with the least similar areas at 35% and the most similar at 50%. The different micro-habitats found in each study site highlight the high beta diversity of the Amazonian canga sites, making each area unique. Therefore, even if the Parque Nacional dos Campos Ferruginosos does not harbour all the species found in the other Amazonian canga sites, it is strategic for the conservation of the vegetation on ferruginous outcrops in the Amazon, protecting its biodiversity, different habitats, and associated ecosystem services.