ABSTRACT The Atlantic Forest is highly heterogeneous, with successional stages inducing shifts in food resources for birds. We investigated fruit and flower availability across two different successional stages in a continuous forest and the implications for bird communities. We sampled three sites in primary forest and three in second-growth forest. We established four plots (10 x 10 m) in each site and estimated the availability of zoochorous fruits and ornithophilous flowers and the occurrence of fruit-eating birds and hummingbirds. Unexpectedly, the availability of zoochorous fruits was similar for primary and second-growth stages, but the abundance of ornithophilous plants was higher in primary forest. Specialized frugivores were more abundant in primary forest, whereas abundance and richness of hummingbirds did not differ between the two successional stages. Frugivores responded to fruit availability in both successional stages, while hummingbirds varied according to ornithophilous plants only in the primary forest. Our results stress that the occurrence of bird species can vary according to resources availability in continuous areas, which contributes to high diversity in forests. These findings highlight the importance of preserving large continuous tracts of forests that promote a spatio-temporal distribution of resources, which maintains bird diversity and their interactions with plants.

中文翻译：

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水果和花卉的可用性影响大西洋森林两个演替阶段的鸟类组合

摘要大西洋森林具有高度异质性，其演替阶段导致鸟类食物资源发生变化。我们调查了连续森林中两个不同演替阶段的水果和花卉可用性以及对鸟类群落的影响。我们在原始林中采样了三个地点，在次生林中采样了三个地点。我们在每个地点建立了四个样地（10 x 10 米），并估计了动物性水果和嗜鸟花的可用性以及食果鸟类和蜂鸟的出现。出乎意料的是，初级和次级生长阶段的动物杂草果实的可用性相似，但原始森林中嗜鸟植物的丰度更高。原始森林中专门的食果动物更为丰富，而蜂鸟的丰度和丰富度在两个演替阶段之间没有差异。食果动物在两个演替阶段都对水果的可用性做出反应，而蜂鸟仅根据原始森林中的亲鸟植物而变化。我们的结果强调，鸟类物种的出现会根据连续区域的资源可用性而有所不同，这有助于森林的高度多样性。这些发现强调了保护大片连续森林的重要性，这些森林促进了资源的时空分布，从而保持了鸟类的多样性及其与植物的相互作用。我们的结果强调，鸟类物种的出现会根据连续区域的资源可用性而有所不同，这有助于森林的高度多样性。这些发现强调了保护大片连续森林的重要性，这些森林促进了资源的时空分布，从而保持了鸟类的多样性及其与植物的相互作用。我们的结果强调，鸟类物种的出现会根据连续区域的资源可用性而有所不同，这有助于森林的高度多样性。这些发现强调了保护大片连续森林的重要性，这些森林促进了资源的时空分布，从而保持了鸟类的多样性及其与植物的相互作用。