Use este identificador para citar ou linkar para este item: https://repositorio.inpa.gov.br/handle/1/18207
Título: Disentangling the drivers of reduced long-distance seed dispersal by birds in an experimentally fragmented landscape
Autor: Uríarte, Ma?ia
Anciães, Marina
Silva, Mariana T.B. da
Rubim, Paulo
Johnson, Erik I.
Bruna, Emilio M.
Palavras-chave: Abundance
Biological Invasion
Biotic Factor
Bird
Frugivory
Fruiting
Habitat Fragmentation
Herb
Patch Size
Population Dynamics
Radio Telemetry
Rainforest
Seed Dispersal
Songbird
Understory
Vertical Movement
Animals
Biological Model
Bird
Demography
Fruit
Heliconiaceae
Physiology
Seed Plant
Time
Tree
Animal
Birds
Demography
Fruit
Heliconiaceae
Models, Biological
Seeds
Time Factors
Trees
Amazonas
Animalsia
Aves
Heliconia
Heliconia Acuminata
Turdus
Turdus Albicollis
Data do documento: 2011
Revista: Ecology
É parte de: Volume 92, Número 4, Pags. 924-937
Abstract: Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largestbodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities of Turdus albicollis, the largest-bodied disperser and the only one to both regurgitate and defecate seeds. This change in Turdus abundance acted together with lower numbers of fruiting plants in small fragments to decrease the probability of long-distance dispersal events from small patches. These findings emphasize the importance of foraging style for seed dispersal and highlight the primacy of habitat size relative to spatial configuration in preserving biotic interactions. © 2011 by the Ecological Society of America.
DOI: 10.1890/10-0709.1
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