AbstractExtinction risk assessments are important tools for plant conservation. However, misinterpretations can lead to negative consequences for survival of species. Inconsistent categorization as extinction, when the species is still extant, constitutes a Romeo error, and annuls all and any mechanism of existing legal protection. But precisely determining the extinction of a plant species is a challenging task, in that the plants can portray characteristics that permit survival in a state of dormancy. To circumvent this problem, specialists frequently adopt precaution and a comprehensive approach that consider biological, ecological, and geographical parameters as inputs for the assessments. It is also important to include explicit logic arguments, as building-blocks of the rational that will support the assessment. Transparent interpretation of the available data can minimize inconsistent categorization. In Brazil, 23% of the plant species assessed as Extinct or Extinct in the Wild, comprise Romeo errors. The other 77% are cases of Data Deficient. Countries that succeeded in minimizing problems arising from this error developed specific legislation to protect threatened species, including mechanisms to annul an erroneous categorizations. Anyhow, the use of categories Extinct (EX) and Extinct in the Wild (EW) according to IUCN definitions should be avoided when no effort has been made to provide evidence of extinction in the wild.

Para entender a ocorrência de P. glomerata na várzea amazônica, investigamos as respostas morfo-fisiológicas a longo período de inundação. Durante seis meses, plântulas de P. glomerata foram submetidas a dois tratamentos de inundação (parcial e total) para análise da assimilação fotossintética líquida (A), eficiência quântica do fotosistema II (referido como Fv/Fm), altura, número de folhas, diâmetro do colo do caule (DCC), área foliar e biomassa da planta. Encontramos um decréscimo da atividade de trocas gasosas, das taxas de crescimento e danos foliares com o aumento do nível de inundação. Após seis meses de experimento, a área foliar, a biomassa dos órgãos vegetativos (raiz, caule e folha) e a biomassa total das plântulas inundadas foram menores que das plântulas controle, plântulas não-inundadas. De acordo com o aumento do nível de inundação, a biomassa fotoassimilada foi alocada principalmente para o caule. Somente área foliar específica, razão raiz / parte aérea e massa seca de raiz não apresentaram diferenças entre os tratamentos. As plântulas totalmente inundadas foram fortemente comprometidas, demonstrando ser esta à condição mais crítica para a manutenção do metabolismo fisiológico. P. glomerata foi afetada pelo longo período de inundação, no entanto a espécie revela adaptações morfo-fisiologica que justifica a sua ocorrência em florestas de várzea.

To understand the occurrence of P. glomerata in the Amazonian várzea we investigated the morpho-physiological responses to long-term flooding. Seedlings of P. glomerata were subjected to two flooding treatments (partial and total) for six months. Following flooding treatments, we examined light-saturated photosynthesis (A), the potential quantum yield of photosystem II (inferred as the Fv/Fm ratio), height, number of leaves (NF), stem diameter at the base of the plant (DCC), leaf area and plant biomass. We found a decrease in gas exchange parameters and growth rates, whereas leaf damage increased with flooding. After six months of flooding, leaf area, and the total plant biomass as well as the biomass of the vegetative organs (leaf, stem and root) were lower in flooded seedlings than in control, non-flooded plants. As flooding level increased assimilated carbon was mainly allocated to stems. However, flooding treatments had no significant effect on specific leaf area, the root/shoot ratio and dry mass of roots. Totally submerged roots of flooded seedlings were strongly affected, showing to be the most critical condition for maintenance of physiological metabolism. P. glomerata was affected by long-term flooding. Thus, P. glomerata exhibited adjusts morpho-fisiological which makes it possible for this species to occur in the Amazon floodplain forest.