Effects of oil palm plantations on anuran diversity in the eastern Amazon

Abstract

The extent of land use for oil palm plantations has grown considerably in the tropics due to climate, appropriate soil conditions for cultivation and its profitability. However, oil palm plantations may endanger biodiversity through reduction and fragmentation of forest areas. Herein we analyzed the effects on anuran species richness, composition and total abundance in oil palm plantations and surrounding forests in eastern Amazon. We installed seven plots in oil palm plantations and seven plots in surrounding forests, which we surveyed for the presence of anurans through active visual and acoustic surveys during periods of high and low rainfall levels. Anuran assemblages found in forests and oil palm plantations differed in species richness and composition, with a loss of 54% of species in oil palm plantations. No difference was observed in total abundance of anurans between both environments. While conversion of forests to oil palm plantations may result in less negative impacts on anuran diversity than other types of monocultures, such loss is nevertheless high, making the maintenance of relatively greater forested areas around oil palm plantations necessary in order to conserve anuran diversity.

Effects of Oil Palm Plantations on the Habitat Structure and Biota of Streams in Eastern Amazon

“…The tropical Amazonian forests are being increasingly threatened by the ongoing expansion of large‐scale oil palm plantations (Carvalho, ). A number of studies have evaluated the impacts of this type of plantation on local biodiversity (Savilaakso et al ., ; Correa et al ., ; Cunha et al ., ; Shimano and Juen, ), but few have focused on the evaluation of the environmental variables that are most affected by the conversion of primary forest in these areas. Of all the impacts caused by the establishment of oil palm plantations, like decrease of structure complexity, decrease of canopy cover, increase of undergrowth spacing, less stable microclimates (Fitzherbert et al ., ) and others, our results showed instream cover for aquatic organisms, substrate and human influences were the blocks of variables that are the most affected by oil palm plantations.…”

“…The conversion of natural forests to monoculture has a number of direct and indirect effects (Savilaakso et al ., ), generally resulting in the loss of both terrestrial species, such as mammals (Azhar et al ., ), birds (Azhar et al ., ), reptiles (Glor et al ., ; Correa et al ., ), arthropods (Turner and Foster, ), butterflies (Koh and Wilcove, ), ants (Fayle et al ., ) and termites (Vaessen et al , 2011), as well as the aquatic ones that inhabit streams, such as macroinvertebrates (Mercer et al ., ; Cunha et al ., ) and fish (Nahum and Santos, ). However, most of the studies with aquatic fauna are essentially descriptive, leaving gaps in our knowledge of the real impact on most aquatic organisms, such as the fish that inhabit streams in oil palm plantations.…”

Comparison of dung beetle communities (Coleoptera: Scarabaeidae: Scarabaeinae) in oil palm plantations and native forest in the eastern Amazon, Brazil

“…The functional diversity of bird communities in oil palm was greatly reduced, in spite of evidence that birds protect oil palms against herbivorous insects (Koh, 2008). Other groups affected in the same way include anurans (Corrêa et al, 2015), aquatic Hemiptera (Cunha and Juen, 2017), bees (Brito et al, 2017), and aquatic insects (Juen et al, 2016).…”

Efecto de la cobertura vegetal de ribera en las comunidades ícticas en el bosque húmedo premontano y muy húmedo premontano del Alto Magdalena, Colombia

“…Por el contrario, la poca diversidad en los mosaicos de cultivos se debe a la inestabilidad de los microclimas (Correa, et al 2015;Shimano & Juen, 2016), a lo que habría que sumar los procesos de erosión que llevan a la sedimentación (Mercer, et al 2014), la disminución de la cobertura de dosel (Fitzherbert, et al, 2008) y sus efectos negativos sobre el suelo y los ecosistemas acuáticos (Allan, 2004). Asimismo, los plaguicidas y fertilizantes asociados a las distintas prácticas agrícolas también están relacionados con los cambios en la concentración de nutrientes y la pérdida de diversidad (Beltrão, et al, 2009).…”