Palm species richness, latitudinal gradients, sampling effort, and deforestation in the Amazon region

Abstract

Palms are most diverse in warm and humid regions near the equator. Though palms remain relatively well conserved, they are under increasing pressure from deforestation. Here, we analyze patterns of palm species richness relative to latitudinal gradient, sampling effort, and deforestation in the Amazon, and compare patterns of richness and floristic similarity among Amazonian sub-regions. We built a database of 17,310 records for 177 species. The areas with the greatest richness were in the western, central and northeastern Amazon, principally at latitudes 0-5ºS. Species richness and the number of records were highly correlated (R 2 =0.76, P<0.005). The highest rates of deforestation (>2000 km 2) were found in the southern and eastern Amazon of Brazil, which coincide with low richness and gaps in records. Similarity analyzes resulted in two groups of sub-regions: the first included the Amazon s.s., the Andes and the Guiana, while the second included the Plateau and Gurupi. We conclude that the highest species richness is at low latitudes, and observed richness is affected by sampling effort and is vulnerable to deforestation. Therefore, areas with low species richness, especially areas with data deficiency, need to be further studied for a better understanding of their patterns of diversity and richness.

Taxonomy, distribution, and conservation status of <i>Geonoma</i> (Arecaceae, Arecoideae): new records for the Maranhão state, Brazil

“…weddelliana, and G. poiteauana. These new data reinforce the existence of taxonomic knowledge gaps in this region, as pointed out by Alvez-Valles et al (2018) and Lima and Almeida Jr (2020), and also they show the importance of taxonomic studies in improving knowledge.…”

“…The genus has a greater diversity of species in forest formations associated with the Amazon and Atlantic Biomes, but few representatives in open vegetation (Lorenzi et al 2010). Nevertheless, Geonoma is sparely collected in the Eastern Amazon (Henderson 2011), a region that stands out due to the low density of samples and studies related to palms (Pintaud et al 2008, Alvez-Valles et al 2018. About the conservation status of the genus, data are still scarce, and most taxons of Geonoma that occur in Brazil have not been evaluated (Elias et al 2019.…”

PREDICTION OF THE GEOGRAPHIC DISTRIBUTION AND CONSERVATION OF AMAZONIAN PALM TREES Astrocaryum acaule MART. AND Astrocaryum aculeatum MART.

“…Such an inclusion would facilitate population genetics studies and assist in the characterization and demarcation of conservation units. Concerns about conservation also extend to other palm species of the Astrocaryum genus, which are predominantly found in the Amazon domain and exhibit greater diversity (Khan et al, 2008;Alvez-Valles et al, 2018).…”

Brazilian Amazonian palm-stem types and uses: a review

“…The greatest diversity is known from the Amazon region, where 148 native species have been listed (Soares et al 2020). Several Amazonian species are endemic and under increasing pressure due to deforestation (Alvez-Valles et al 2018).…”