Effective Seed Dispersal Across a Fragmented Landscape

Science ◽  
2006 ◽  
Vol 311 (5761) ◽  
pp. 628-628 ◽  
Author(s):  
C. F. E. Bacles
Plant Biology ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 522-532 ◽  
Author(s):  
M. Kotilínek ◽  
T. Těšitelová ◽  
J. Košnar ◽  
P. Fibich ◽  
L. Hemrová ◽  
...  

Ecology ◽  
2011 ◽  
Vol 92 (4) ◽  
pp. 924-937 ◽  
Author(s):  
María Uriarte ◽  
Marina Anciães ◽  
Mariana T. B. da Silva ◽  
Paulo Rubim ◽  
Erik Johnson ◽  
...  

2019 ◽  
Author(s):  
Carine Emer ◽  
Pedro Jordano ◽  
Marco A. Pizo ◽  
Milton C. Ribeiro ◽  
Fernanda R. da Silva ◽  
...  

ABSTRACTSeed dispersal interactions involve key ecological processes in tropical forests that help to maintain ecosystem functioning. Yet this functionality may be threatened by increasing habitat loss, defaunation and fragmentation. However, generalist species, and their interactions, can benefit from the habitat change caused by human disturbance while more specialized interactions mostly disappear. Therefore changes in the structure of the local, within fragment, networks can be expected. Here we investigated how the structure of seed-dispersal networks changes along a gradient of increasing habitat fragmentation. We analysed 16 bird seed-dispersal assemblages from forest fragments of a biodiversity-rich ecosystem. We found significant species-, interaction- and network-area relationships, yet the later was determined by the number of species remaining in each community. The number of frugivorous bird and plant species, their interactions, and the number of links per species decreases as area is lost in the fragmented landscape. In contrast, network nestedness has a negative relationship with fragment area, suggesting an increasing generalization of the network structure in the gradient of fragmentation. Network specialization was not significantly affected by area, indicating that some network properties may be invariant to disturbance. Still, the local extinction of partner species, paralleled by a loss of interactions and specialist-specialist bird-plant seed dispersal associations suggests the functional homogenization of the system as area is lost. Our study provides empirical evidence for network-area relationships driven by the presence/absence of remnant species and the interactions they perform.RESUMOInterações de dispersão de sementes formam um processo ecológico chave em florestas tropicais onde colaboram na manutenção do funcionamento do ecossistema. Porém, esta funcionalidade pode estar ameaçada pelo aumento na perda e fragmentação do habitat. Enquanto espécies generalistas e suas interações podem se beneficiar da mudança de habitat causada por distúrbios antrópicos, interações envolvendo espécies mais especialistas são, na maioria, eliminadas. Desta forma, mudanças nas redes locais, dentro de fragmentos florestais, são esperadas. Neste trabalho nós investigamos como a estrutura de redes de dispersão de sementes mudam em um gradiente de fragmentação do habitat. Nós analisamos 16 comunidades de dispersão de sementes espacialmente explícitas e distribuídas em fragmentos florestais de um ecossistema rico em biodiversidade. Nós encontramos relações significativas entre a área do fragmento e espécies, interações e estrutura das redes, sendo que o último foi determinado pelo número de espécies remanescentes em cada comunidade. O número de espécies de aves frugívoras e plantas e as interações entre eles, bem como o número de links por espécie diminuíram significativamente conforme a área dos fragmentos é perdida. Por outro lado, o aninhamento da rede mostrou uma relação negativa com a área do fragmento, sugerindo um aumento da generalização da estrutura das redes com a fragmentação do habitat. No entanto, o grau de especialização das redes não foi afetado pela área, indicando que algumas propriedades de rede podem ser resistentes à perturbação. Sendo assim, a extinção local de espécies parceiras, conjuntamente com a perda das interações e associações planta-dispersor mais especializadas, sugere uma homogeneização do sistema conforme a área do fragmento é perdida. Nosso estudo fornece evidências empíricas para as relações rede-área, sendo estas direcionadas pela presença e/ou ausência das espécies remanescentes bem como das interações que estas realizam.


2013 ◽  
Vol 50 (4) ◽  
pp. 220-228 ◽  
Author(s):  
Caio Castro Freire ◽  
Melissa Bars Closel ◽  
Erica Hasui ◽  
Flavio Nunes Ramos

2009 ◽  
Vol 18 (13) ◽  
pp. 3357-3365 ◽  
Author(s):  
E. Figueroa-Esquivel ◽  
F. Puebla-Olivares ◽  
H. Godínez-Álvarez ◽  
J. Núñez-Farfán

2019 ◽  
Vol 62 (2) ◽  
pp. 157
Author(s):  
Carlos Seoane ◽  
Vinicius Diaz ◽  
Paulo Kageyama ◽  
Maria Moreno ◽  
Evandro Tambarussi ◽  
...  

2019 ◽  
Vol 15 (7) ◽  
pp. 20190264 ◽  
Author(s):  
Juan P. González-Varo ◽  
Sarah Díaz-García ◽  
Juan M. Arroyo ◽  
Pedro Jordano

Juvenile animals generally disperse from their birthplace to their future breeding territories. In fragmented landscapes, habitat-specialist species must disperse through the anthropogenic matrix where remnant habitats are embedded. Here, we test the hypothesis that dispersing juvenile frugivores leave a footprint in the form of seed deposition through the matrix of fragmented landscapes. We focused on the Sardinian warbler ( Sylvia melanocephala ), a resident frugivorous passerine. We used data from field sampling of bird-dispersed seeds in the forest and matrix of a fragmented landscape, subsequent disperser identification through DNA-barcoding analysis, and data from a national bird-ringing programme. Seed dispersal by Sardinian warblers was confined to the forest most of the year, but warblers contributed a peak of seed-dispersal events in the matrix between July and October, mainly attributable to dispersing juveniles. Our study uniquely connects animal and plant dispersal, demonstrating that juveniles of habitat-specialist frugivores can provide mobile-link functions transiently, but in a seasonally predictable way.


2002 ◽  
Vol 12 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Bente Jessen Graae

A domestic dog was used in two experiments to elucidate the role of epizoochorous seed dispersal of forest plants. First, the dog was walked through forest vegetation at different times of year and its coat analysed for seeds retained within it. The seed content of the coat was compared to seed frequencies in the vegetation. Secondly, seeds of 11 plant species were placed in different positions on the dog, and their persistence in the coat analysed with respect to distance subsequently travelled. The experiments demonstrate that seeds with morphological adaptations to seed dispersal and small seeds of tall species can be caught effectively by a dog’s coat. The morphologically adapted seeds can be dispersed over large distances as long as the dog moves steadily along a road. The same is true for species with small and smooth seeds if they are deposited on the back of the dog, but not if they are placed on its side. Comparisons of these results with the distribution of forest species in a fragmented landscape, indicated that tall species with small seeds and species with morphological adaptations for epizoochorous dispersal are good at colonizing new forest habitats.


2011 ◽  
Vol 278 (1716) ◽  
pp. 2257-2264 ◽  
Author(s):  
Johanna Lenz ◽  
Wolfgang Fiedler ◽  
Tanja Caprano ◽  
Wolfgang Friedrichs ◽  
Bernhard H. Gaese ◽  
...  

Frugivorous birds provide important ecosystem services by transporting seeds of fleshy fruited plants. It has been assumed that seed-dispersal kernels generated by these animals are generally leptokurtic, resulting in little dispersal among habitat fragments. However, little is known about the seed-dispersal distribution generated by large frugivorous birds in fragmented landscapes. We investigated movement and seed-dispersal patterns of trumpeter hornbills ( Bycanistes bucinator ) in a fragmented landscape in South Africa. Novel GPS loggers provide high-quality location data without bias against recording long-distance movements. We found a very weakly bimodal seed-dispersal distribution with potential dispersal distances up to 14.5 km. Within forest, the seed-dispersal distribution was unimodal with an expected dispersal distance of 86 m. In the fragmented agricultural landscape, the distribution was strongly bimodal with peaks at 18 and 512 m. Our results demonstrate that seed-dispersal distributions differed when birds moved in different habitat types. Seed-dispersal distances in fragmented landscapes show that transport among habitat patches is more frequent than previously assumed, allowing plants to disperse among habitat patches and to track the changing climatic conditions.


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