Effects of forest degradation on Amazonian ferns in a land-bridge island system as revealed by non-specialist inventories

Background: Tropical deforestation and degradation worldwide have rapidly outpaced biodiversity field sampling. No study to date has assessed the effects of insular habitats induced by hydroelectric dams on Amazonian understorey plants. Fern community responses to anthropogenic effects on tropical forest islands can be efficiently revealed through simple and cheap, yet informative protocols that can be applied by non-specialists. Aims: This study seeks to both understand the drivers of fern and lycophyte assemblages on forest islands and investigate the relative costs and effectiveness of a simplified sampling protocol that can be implemented by non-specialists and has potential to be used to crowdsource ecological field data acquisition. Methods: Fern and lycophytes species were sampled by a non-specialist in 17 quarter-hectare plots on 10 forest islands at the lake of Balbina Hydroelectric Dam, central Amazonia. Sampling was carried out opportunistically during a field expediti...