Distribution and population status assessment of the endemic grass-like palm Butia marmorii (Arecales: Arecaceae) in Paraguay

The palm Butia marmorii Noblick was described in 2006 and has been found to date in only two populations in Paraguay. It is a species threatened mainly due to habitat loss and its ecology is largely unknown.  Here we performed a potential distribution analysis, providing data about its distribution and ecology.  This work was carried out in the Alto Parana Department, eastern Paraguay, South America.  We analyzed satellite images, in conjunction with a multi-temporal analysis using the sensors Landsat 1-MSS,5-TM,8-OLI, of the years 1973, 1984, 2002, 2012 and 2013; and a posterior visual interpretation of an ASTER ASTGTM2 radar image.  The final step was an in situ visual verification.  We registered 27 potential sites of distribution for Butia marmorii , finding it present in four sites, two of them with limited anthropogenic impacts.  We found a density of 0.0054 to 0.11 individuals/m 2 , and associations with the congener B. paraguayensis .  These new Paraguayan populations of Butia marmorii provide verifiable data demonstrating that anthropogenic impact is the principal threat to the species.  Here we found that the situation of B. marmorii is even worse than supposed before, and hence we consider the species to be Critically Endangered.