Idiosyncratic responses of Amazonian birds to primary forest disturbance

Moura, Nárgila; Lees, Alexander Charles; Aleixo, Alexandre; Barlow, Jos; Berenguer, Erika; Ferreira, Joice; Nally, Ralph Mac; Thomson, James Robertson; Gardner, Toby

doi:10.1007/s00442-015-3495-z

Cited by 34 publications

(33 citation statements)

References 72 publications

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“…An important implication of this result is that even from a functional perspective, which is often assumed to provide great potential for extracting general insights (Mouillot et al 2013), inferences on land use and biodiversity relationships derived from one region cannot necessarily be applied to another. birds; Moura et al 2016), indicating that endogenous regional characteristics such as topography and geology, as well as the differing deforestation histories and disturbance time lags may play significant roles. The authors concluded that, although having higher predictive performance than taxonomic indices, most functional indicators were context-dependent; and caution is needed when generalizing them across distinct regions.…”

Section: Conservation Implications Of Inter-regional Variability In Bmentioning

confidence: 99%

Disentangling the pathways of land use impacts on the functional structure of fish assemblages in Amazon streams

et al. 2017

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Agricultural land use is a primary driver of environmental impacts on streams. However, the causal processes that shape these impacts operate through multiple pathways and at several spatial scales. This complexity undermines the development of more effective management approaches, and illustrates the need for more in-depth studies to assess the mechanisms that determine changes in stream biodiversity. Here we present results of the most comprehensive multi-scale assessment of the biological condition of streams in the Amazon to date, examining functional responses of fish assemblages to land use. We sampled fish assemblages from two large human-modified regions, and characterized stream conditions by physical habitat attributes and key landscape-change variables, including density of road crossings (i.e. riverscape fragmentation), deforestation, and agricultural intensification. Fish species were functionally characterized using ecomorphological traits describing feeding, locomotion, and habitat preferences, and these traits were used to derive indices that quantitatively describe the functional structure of the assemblages. Using structural equation modeling, we disentangled multiple drivers operating at different spatial scales, identifying causal pathways that significantly affect stream condition and the structure of the fish assemblages. Deforestation at catchment and riparian network scales altered the channel morphology and the stream bottom structure, changing the functional identity of assemblages. Local deforestation reduced the functional evenness of assemblages (i.e. increased dominance of specific trait combinations) mediated by expansion of aquatic vegetation cover. Riverscape fragmentation reduced functional richness, evenness and divergence, suggesting a trend toward functional homogenization and a reduced range of ecological niches within assemblages following the loss of regional connectivity. These results underscore the often-unrecognized importance of different land use changes, each of which can have marked effects on stream biodiversity. We draw on the relationships observed herein to suggest priorities for the improved management of stream systems in the multiple-use landscapes that predominate in human-modified tropical forests.

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Section: Conservation Implications Of Inter-regional Variability In Bmentioning

confidence: 99%

Disentangling the pathways of land use impacts on the functional structure of fish assemblages in Amazon streams

et al. 2017

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“…; Moura et al. ). We are aware of only 2 studies reporting on targeted comparisons of biodiversity in primary forest and smallholder mosaics of the western Amazon (Andrade & Torgler ; Korasaki et al.…”

Section: Introductionmentioning

confidence: 99%

“…These studies suggest the biodiversity value of slash‐and‐burn mosaics of the western Amazon may be high; however, Moura et al. () included a limited amount of smallholder agriculture from the eastern Amazon and reached the opposite conclusion.…”

Section: Introductionmentioning

confidence: 99%

“…Remarkably few data are available to determine the biodiversity value of smallholder agriculture anywhere in the lowland tropics. In the Neotropics, most assessments of biodiversity in smallholder landscapes have been conducted in highland regions (Hudson et al 2014), whereas most studies from lowland regions have focused on intensive land-use change in the eastern Amazon (e.g., mechanized agriculture, large-scale ranching, silviculture, or fire) (Barlow et al 2007;Mahood et al 2011;Moura et al 2016). We are aware of only 2 studies reporting on targeted comparisons of biodiversity in primary forest and smallholder mosaics of the western Amazon (Andrade & Torgler 1994;Korasaki et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Overlooked biodiversity loss in tropical smallholder agriculture

Socolar

Sandoval

Wilcove

2019

Conservation Biology

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Smallholder agriculture is the main driver of deforestation in the western Amazon, where terrestrial biodiversity reaches its global maximum. Understanding the biodiversity value of the resulting mosaics of cultivated and secondary forest is therefore crucial for conservation planning. However, Amazonian communities are organized across multiple forest types that support distinct species assemblages, and little is known about smallholder impacts across the range of forest types that are essential for sustaining biodiversity. We addressed this issue with a large‐scale field inventory of birds (point counts) and trees (transects) in primary forest and smallholder agriculture in northern Peru across 3 forest types that are key for Amazonian biodiversity. For birds smallholder agriculture supported species richness comparable to primary forest within each forest type, but biotic homogenization across forest types resulted in substantial losses of biodiversity overall. These overall losses are invisible to studies that focus solely on upland (terra firma) forest. For trees biodiversity losses in upland forests dominated the signal across all habitats combined and homogenization across habitats did not exacerbate biodiversity loss. Proximity to forest strongly predicted the persistence of forest‐associated bird and tree species in the smallholder mosaic, and because intact forest is ubiquitous in our study area, our results probably represent a best‐case scenario for biodiversity in Amazonian agriculture. Land‐use planning inside and outside protected areas should recognize that tropical smallholder agriculture has pervasive biodiversity impacts that are not apparent in typical studies that cover a single forest type. The full range of forest types must be surveyed to accurately assess biodiversity losses, and primary forests must be protected to prevent landscape‐scale biodiversity loss.

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“…Many studies have shown that responses to habitat fragmentation at the assemblage level are often hard to detect, but that there are often marked responses at the population level (Meyer et al., ). Responses at the population level are highly species and ensemble specific (Avila‐Cabadilla, ; Chambers, Cushman, Medina‐Fitoria, Martínez‐Fonseca, & Chávez‐Velásquez, ; Galitsky & Lawler, ; Klingbeil & Willig, ; Moura et al., ), highlighting the need for studies to focus on the level of individual species. Although many studies across the neotropics have assessed the impacts of fragmentation on bats at the population and assemblage level, few were conducted over longer periods and consequently seasonal variation in species responses were rarely considered (Meyer et al., ).…”

Section: Introductionmentioning

confidence: 99%

Season‐modulated responses of Neotropical bats to forest fragmentation

Ferreira

Rocha

López‐Baucells

et al. 2017

Ecology and Evolution

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Seasonality causes fluctuations in resource availability, affecting the presence and abundance of animal species. The impacts of these oscillations on wildlife populations can be exacerbated by habitat fragmentation. We assessed differences in bat species abundance between the wet and dry season in a fragmented landscape in the Central Amazon characterized by primary forest fragments embedded in a secondary forest matrix. We also evaluated whether the relative importance of local vegetation structure versus landscape characteristics (composition and configuration) in shaping bat abundance patterns varied between seasons. Our working hypotheses were that abundance responses are species as well as season specific, and that in the wet season, local vegetation structure is a stronger determinant of bat abundance than landscape‐scale attributes. Generalized linear mixed‐effects models in combination with hierarchical partitioning revealed that relationships between species abundances and local vegetation structure and landscape characteristics were both season specific and scale dependent. Overall, landscape characteristics were more important than local vegetation characteristics, suggesting that landscape structure is likely to play an even more important role in landscapes with higher fragment‐matrix contrast. Responses varied between frugivores and animalivores. In the dry season, frugivores responded more to compositional metrics, whereas during the wet season, local and configurational metrics were more important. Animalivores showed similar patterns in both seasons, responding to the same group of metrics in both seasons. Differences in responses likely reflect seasonal differences in the phenology of flowering and fruiting between primary and secondary forests, which affected the foraging behavior and habitat use of bats. Management actions should encompass multiscale approaches to account for the idiosyncratic responses of species to seasonal variation in resource abundance and consequently to local and landscape scale attributes.

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Idiosyncratic responses of Amazonian birds to primary forest disturbance

Cited by 34 publications

References 72 publications

Disentangling the pathways of land use impacts on the functional structure of fish assemblages in Amazon streams

Disentangling the pathways of land use impacts on the functional structure of fish assemblages in Amazon streams

Overlooked biodiversity loss in tropical smallholder agriculture

Season‐modulated responses of Neotropical bats to forest fragmentation

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