Toward a better understanding of the subtropical Atlantic Forest in the state of Santa Catarina, Brazil: tree sampling accuracy, species richness and frequency of rare species

Abstract

Accurate knowledge of floristic composition is crucial when planning and designing research projects and public policies. In this study, our goal was to assess tree sampling accuracy and to identify sites with higher concentrations of rare tree species, as well as those with the highest tree species richness, in the state of Santa Catarina, Brazil. We determined sampling accuracy using the first-order jackknife and Chao 2 estimators, calculated the number of rare species (singletons and doubletons) and applied sampled-based rarefaction. We found that sample accuracy (estimated vs. observed values) was over 90% for the state as a whole, the best estimates having been obtained for the areas of rain forest (first-order jackknife: 91%; Chao 2: 95%). Of the tree species identified, 16.6% were considered rare in the state and only 4% were found in all forest types. Among the various forest types, semideciduous forests showed the highest proportions of rare tree species. Tree species richness was highest in the rain forests and lowest in the dwarf cloud forests. Our results make an important contribution to the conservation of tree species within one of the "hottest" biodiversity hotspots in the world.

Improving collection efforts to avoid loss of biodiversity: lessons from comprehensive sampling of lycophytes and ferns in the subtropical Atlantic Forest

“…ese surveys made Santa Catarina a region with an even distribution of samples for angiosperms (Sousa-Baena et al 2014); for lycophytes and ferns, we here found areas with high sampling e ort, but others with few collections. e overall study area was well-sampled, as could be expected for a large study area with standardized sampling units (Jiménez-Valverde & Hortal 2003;Rezende et al 2014). When all data were analyzed together, we found 95% (ACE), 93% (C1), 88% (C2), 87% (J1) and 82% (J2) of t between estimated and predicted values, thereby indicating that Santa Catarina is well-sampled.…”

“…Another concern is the time interval between these projects, because during this interval the forest loss increased (Fundação SOS Mata Atlântica & Instituto Nacional de Pesquisas Espaciais 2009). Because of these kinds of initiatives, and also due its physiognomic gradients, Santa Catarina constitutes an excellent environmental model for investigation of oral distribution and sampling su ciency (see also Rezende et al 2014;.…”

Riqueza e endemismo de Lauraceae no Paraná: aspectos fitogeográficos e áreas prioritárias para a conservação

“…O número de espécies comuns às três formações florestais é baixo, assim como para as demais famílias no sul do Brasil (Scheer & Blum 2011;Higuchi et al 2013;Rezende et al 2014). Os nove táxons com essa característica apresentaram constância relativa intermediária (20<CR<80%), representando apenas 12% das espécies florestais.…”

“…Atualmente no Paraná existe uma demanda pelas mesmas informações, particularmente para subsidiar a atualização da lista estadual de espécies ameaçadas de extinção, publicada há mais de 20 anos (Hatschbach & Ziller 1995). Além disso, trabalhos recentes têm dispendido esforços na tentativa de classificar com mais clareza as tipologias florestais na porção subtropical do Bioma Mata Atlântica, bem como, detectar riqueza de espécies e endemismos, que são informações de vital importância para a conservação (Marques et al 2011;Rezende et al 2014Rezende et al , 2015aRezende et al , 2015bOliveira-Filho et al 2015).…”