RESUMEN
Inselbergs are azonal formations found scattered in different biomes globally. The first floristic list focusing on an inselberg in the Brazilian Amazon is presented here. We aimed to investigate floristic and phylogenetic connections among Neotropical inselbergs and analyze whether environmental variables act as a filter of plant lineages. We used a database compiled from 50 sites spanning three main Neotropical biomes (Amazon, 11 sites, Atlantic Forest, 14 sites, and Caatinga, 25 sites) comprising 2270 Angiosperm species. Our data highlight the vastly different inselberg flora found in each biome. The inselberg floras of the Atlantic Forest and Caatinga show closer phylogenetic ties than those seen in the other biome pairs. The phylogenetic lineages found in all three biomes are also strongly divergent, even within plant families. The dissimilarity between biomes suggests that distinct biogeographical histories might have unfolded even under comparable environmental filtering. Our data suggest that the inselberg flora is more related to the biome where it is located than to other factors, even when the microclimatic conditions in the outcrops differ strongly from those of the surrounding matrix. Relative to the other biomes, the flora of the Caatinga inselbergs has the highest level of species turnover. There is a possibility that plants colonized these rather distant inselbergs even when they were found under very different climatic conditions than those in the Amazonian and Atlantic Forest biomes. It is worth noting that none of the studied inselbergs found in the Caatinga biome is protected. In view of the uniqueness and drought-resilient lineages present in each group of inselbergs, along with their vulnerability to destruction or disturbance and their strong connection with water availability, we stress the need to protect this ecosystem not only to conserve plants potentially useful for ecological restoration but also to preserve the balance of this ecosystem and its connections.
RESUMEN
As deforestation and fire move forward over pristine vegetation in the Amazon, many species remain undiscovered and may be threatened with extinction before being described. Here, we describe two new species of Utricularia (Lentibulariaceae) collected during recent fieldwork in an area of white-sand vegetation in the eastern Amazon Basin named Campos do Ariramba. Further herbarium revision revealed that both species were first collected over 60 years ago in the same area, remaining unnamed until now. The new species, named U. ariramba sp. nov. and U. jaramacaru sp. nov., are placed in U. sect. Aranella and U. sect. Setiscapella, respectively. We provide full descriptions, illustrations, photographs, a distribution map, and taxonomic discussion for both species. Additionally, we provide a preliminary list of Lentibulariaceae from the Campos do Ariramba. Both new species are assessed as Vulnerable, however, yet known only from a few collections each, highlighting the urgency and importance of fieldwork and taxonomic revisions in the Amazon biogeographic region in order to provide essential data for the conservation of both known and still unknown biodiversity.
RESUMEN
The world's largest mineral iron province, Serra dos Carajás, is home to an open vegetation known as canga, found on top of isolated outcrops rising out of the Amazon rainforest. Over one thousand vascular plants species have been recorded in these canga sites, including 38 edaphic endemics. A new survey adds to our investigation of biogeographic relationships between sixteen canga outcrops and the effect of the distance between site pairs on the number of shared species, regional species turnover and species distribution patterns. Plant collecting expeditions to the westernmost site, the Serra de Campos of São Félix do Xingu (SFX), were carried out followed by the identification of all collected specimens and the creation of a species database, built to perform biogeographical analyses. Floristic relationships among the sites were investigated regarding their similarity, using multivariate analyses. The correlation between canga areas and species richness was tested, as well as the geographical distance between pairs of outcrops and their shared species. Vascular plants at SFX total 254 species including 17 edaphic endemics. All canga sites are grouped with 25% of minimum similarity, and the SFX falls within a large subgroup of outcrops. The total species number shared between site pairs does not change significantly with geographical distance but is positively correlated with the area of each outcrop. Meanwhile, shared endemic species numbers between site pairs decline when geographical distance increases, possibly imposed by the barrier of the rainforest. Our data suggest higher shared similarity between the largest and species-richest sites as opposed to geographically nearby sites, and provide useful insight for drafting conservation and compensation measures for canga locations. The size of the canga outcrops is associated to higher floristic diversity but connectivity among islands also plays a role in their similarity.