Structure of bird communities in eucalyptus plantations: nestedness as a pattern of species distribution

Abstract

Replacement of native habitats by tree plantations has increased dramatically in Brazil, resulting in loss of structural components for birds, such as appropriate substrates for foraging and nesting. Tree plantations can also reduce faunal richness and change the composition of bird species. This study evaluated the structure of avian communities in eucalyptus plantations of different ages and in a native forest. We classified species as habitat specialists or generalists, and assessed if the species found in eucalyptus plantations are a subset of the species that occur in the native forest. Forty-one sampling sites were evaluated, with three point counts each, in a native forest and in eucalyptus plantations of four different ages. A total of 71 bird species were identified. Species richness and abundance were higher in the native forest, reflecting the greater heterogeneity of the habitat. The composition of bird species also differed between the native forest and plantations. The species recorded in the plantations represented a subset of the species of the native forest, with a predominance of generalist species. These species are more tolerant of habitat changes and are able to use the plantations. The commercial plantations studied here can serve as a main or occasional habitat for these generalists, especially for those that are semi-dependent on edge and forest. The bird species most affected by silviculture are those that are typical of open grasslands, and those that are highly dependent on well-preserved forests.Keywords: avian fauna, subsets, eucalyptus plantations, native forest. Estrutura de comunidades de aves em plantios de eucalipto:aninhamento como padrão de distribuição de espécies Resumo A substituição de ambientes nativos pela silvicultura está se tornando uma prática cada vez mais comum no Brasil, resultando na perda de componentes estruturais para as espécies de aves, como substratos específicos de forrageamento e nidificação. Esta prática pode reduzir a riqueza e alterar a composição das comunidades de aves. O objetivo deste estudo foi avaliar diferenças na estrutura de comunidades de aves em plantios de eucalipto de diferentes idades e em floresta nativa. Além disso, teve como objetivo classificar espécies em especialistas ou generalistas de habitat e avaliar se espécies encontradas nos plantios de eucalipto representam subconjuntos da floresta nativa. Quarenta e um sítios de amostragem foram avaliados, com três pontos de contagem cada, em uma floresta nativa e em plantios de eucalipto de quatro diferentes idades. Foi identificado um total de 71 espécies de aves. A riqueza de espécies e abundância foram maiores na floresta nativa refletindo a maior heterogeneidade desse habitat. A composição de espécies de aves também diferiu entre a floresta nativa e os plantios. As espécies registradas nos plantios representam um subconjunto das espécies da floresta nativa, o que é explicado pelo predomínio das espécies generalistas. Essas espécies são mais tolerantes às alterações de habitat e...

A preliminary study on bird diversity and abundance from Wabe fragmented forests around Gubre subcity and Wolkite town, Southwestern Ethiopia

“…The low species richness and abundance of birds in the human planted eucalyptus and other exotic plant species is also reported in other studies; conifer plantations in southwestern Turkey 17 and eucalyptus plantation in Brazil 19 and Northwest Portugal. 20 This might be due to exotic plants leads to loss of structural components for birds, such as appropriate substrates for foraging and nesting requirements associated with the plant properties and homogeneity habitat creation nature of these plants.…”

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“…20 This might be due to exotic plants leads to loss of structural components for birds, such as appropriate substrates for foraging and nesting requirements associated with the plant properties and homogeneity habitat creation nature of these plants. 17,19 Among the 15 species identified from the plantation habitat, 12 (24%) of them were also occurred in bushland habitats. Similar result is also reported by Jacoboski et al, 19 plantations are functional habitats for a subset of local native forest species which serve as an occasional habitat predominantly for generalist species.…”

“…This is determined by the tolerance or adaptation of the particular species in those changed or modified habitats as some species are build their nests, while other species are used as a migratory corridors/ route to other habitats. 19 According to Sreekar et al, 21 natural forests are irreplaceable for biodiversity conservation as more than half of the local bird species do not occupy monoculture rubber plant species even when in close proximity to natural forests with in less than 100 meter distance.…”

How do diversity and functional nestedness of bird communities respond to changes in the landscape caused by eucalyptus plantations?

“…Only species with certain traits are adapted to the habitat conditions of silviculture areas, in other words, are independent of structure and amount of vegetation. Thus, species traits can determine their presence in plantations, as main or occasional habitats for refuge, landing site (Jacoboski et al 2016). This result is consistent, because silviculture supplies fewer resources for species, such as appropriate substrates for nesting and foraging (Motta-Junior, 1990;Kowk and Corlett, 2000), benefiting species traits of habitat generalists and of those associated with forest edges.…”

“…We tested two hypotheses: 1) both functional diversity and taxonomic diversity are higher in the native forest because of the higher structural heterogeneity in native habitats; 2) species traits in eucalyptus plantations represent a subset of traits in relation to species from the native forest, resulting in functional nestedness, because some species of plantations are shared with the native forest (Jacoboski et al 2016). …”