Antagonistic and mutualistic interactions alter seed dispersal of understory plants at forest edges

Abstract T. jasminoides is a fast-growing liana often grown as ornamental that has escaped from cultivation to become invasive in forest edges and disturbed sites near cultivation. Even when this species does not produce seeds when growing in cultivation, it spreads vegetatively by cuttings, stem fragments, and lateral extensions of the stems. This species rapidly colonies new areas by self-layers, sending out roots from leaf nodes and stem tips wherever they touch the ground (Gilman, 1999; Clifford and Kobayashi, 2010; PFAF, 2017). It climbs high into the canopy of mature forests smothering native trees, out-competing understory plants, and reducing plant diversity (BEST, 2003; BEST, 2013).

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Simplified Communities of Seed-Dispersers Limit the Composition and Flow of Seeds in Edge Habitats

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.655441 ◽

2021 ◽

Vol 9 ◽

Author(s):

Onja H. Razafindratsima ◽

Nasandratra Nancia Raoelinjanakolona ◽

Rio R. Heriniaina ◽

Rindra H. Nantenaina ◽

Tianasoa H. Ratolojanahary ◽

...

Keyword(s):

Species Richness ◽

Seed Dispersal ◽

Seed Size ◽

Species Interactions ◽

Species Coexistence ◽

Seedling Recruitment ◽

Forest Edge ◽

Forest Edges ◽

Opposite Pattern ◽

Adult Trees

Edge effects, driven by human modification of landscapes, can have critical impacts on ecological processes such as species interactions, with cascading impacts on biodiversity as a whole. Characterizing how edges affect vital biotic interactions such as seed dispersal by frugivores is important for better understanding potential mechanisms that drive species coexistence and diversity within a plant community. Here, we investigated how differences between frugivore communities at the forest edge and interior habitats of a diverse tropical rainforest relate to patterns of animal-mediated seed dispersal and early seedling recruitment. We found that the lemur communities across the forest edge-interior gradient in this system showed the highest species richness and variability in body sizes at intermediate distances; the community of birds showed the opposite pattern for species richness. Three large-bodied frugivores, known to be effective dispersers of large seeds, tended to avoid the forest edge. As result, the forest edges received a lower rate of animal-mediated seed dispersal compared to the interior habitats. In addition, we also found that the seeds that were actively dispersed by animals in forest edge habitats were smaller in size than seeds dispersed in the forest interior. This pattern was found despite a similarity in seed size of seasonally fruiting adult trees and shrubs between the two habitats. Despite these differences in dispersal patterns, we did not observe any differences in the rates of seedling recruitment or seed-size distribution of successful recruit species. Our results suggest that a small number of frugivores may act as a potential biotic filter, acting on seed size, for the arrival of certain plant species to edge habitats, but other factors may be more important for driving recruitment patterns, at least in the short term. Further research is needed to better understand the potential long-term impacts of altered dispersal regimes relative to other environmental factors on the successional dynamics of edge communities. Our findings are important for understanding potential ecological drivers of tree community changes in forest edges and have implications for conservation management and restoration of large-seeded tree species in disturbed habitats.

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Spatial heterogeneity in white-tailed deer activity increases seed dispersal of shade-intolerant plants near forest edges in fragmented forests

The Journal of the Torrey Botanical Society ◽

10.3159/torrey-d-16-00045.1 ◽

2017 ◽

Vol 144 (4) ◽

pp. 371-378

Author(s):

Peter W. Guiden

Keyword(s):

Seed Dispersal ◽

Spatial Heterogeneity ◽

Forest Edges ◽

Fragmented Forests

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FRUGIVORIA E DISPERSÃO DE SEMENTES POR PEIXES

Scientific Magazine UAKARI ◽

10.31420/uakari.v1i1.2 ◽

2008 ◽

Vol 1 (1) ◽

pp. 7-18

Author(s):

Luciane Lopes de Souza

Keyword(s):

Sustainable Development ◽

Seed Dispersal ◽

Tropical Forests ◽

Natural Regeneration ◽

Main Species ◽

Fishing Gears ◽

Solimões River

Biotic or abiotic processes of seed dispersal are important for the maintenance of the diversity, and for the natural regeneration in tropical forests. Ichthyochory is one of the fundamental mechanisms for seed dispersal in flooded environments, as the igapó forests. A study on the ichthyochory of the igapós was conducted at Amanã Sustainable Development Reserve, in the middle Solimões river, from June 2002 to September 2004. Monthly samples of frugivorous fish were taken, with the main fishing gears used locally. Guts of 1,688 fish caught were examined. The main species were Myloplus rubripinnis (29.21%), Hemiodus immaculatus (18.96%),Colossoma macropom um (16.23%) and Mylossoma duriventre (16.05%). The diet was made of vegetables (fruits, leave and flowers), and animals (arthropods). 53.02% of all fish caught ingested fruits. The total number of intact seeds in the stomachs and intestines were 8,069 and 5,763 respectively. About 61.9% of the Brycon melanopterus (matrinchão), 46.34% of the Brycon amazonicus (mamuri) and 30.22% of M . rubripinnis (parum ) analysed had intact seeds in their guts. Seeds of Nectandra amazonum and Genipa spruceana ingested proved to be more viable than those non-ingested by fish. The high rates of frugivory, the presence of intact seeds in the guts of fish and the greater viability of ingested seeds all suggest that these animals are important seed dispersors in the igapó forests of Amanã Reserve.

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