The role of dung beetles as secondary seed dispersers and their effect on plant regeneration in tropical rainforests.

AbstractMegafaunal frugivores can consume large amounts of fruits whose seeds may be dispersed over long distances, thus, affecting plant regeneration processes and ecosystem functioning. We investigated the role of brown bears (Ursus arctos) as legitimate megafaunal seed dispersers. We assessed the quantity component of seed dispersal by brown bears across its entire distribution based on information about both the relative frequency of occurrence and species composition of fleshy fruits in the diet of brown bears extracted from the literature. We assessed the quality component of seed dispersal based on germination experiments for 11 fleshy-fruited plant species common in temperate and boreal regions and frequently eaten by brown bears. Across its distribution, fleshy fruits, on average, represented 24% of the bear food items and 26% of the total volume consumed. Brown bears consumed seeds from at least 101 fleshy-fruited plant species belonging to 24 families and 42 genera, of which Rubus (Rosaceae) and Vaccinium (Ericaceae) were most commonly eaten. Brown bears inhabiting Mediterranean forests relied the most on fleshy fruits and consumed the largest number of species per study area. Seeds ingested by bears germinated at higher percentages than those from whole fruits, and at similar percentages than manually depulped seeds. We conclude that brown bears are legitimate seed dispersers as they consume large quantities of seeds that remain viable after gut passage. The decline of these megafaunal frugivores may compromise seed dispersal services and plant regeneration processes.

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Wood Pastures: A Transitional Habitat between Forests and Pastures for Dung Beetle Assemblages

Forests ◽

10.3390/f12010025 ◽

2020 ◽

Vol 12 (1) ◽

pp. 25

Author(s):

László Somay ◽

Viktor Szigeti ◽

Gergely Boros ◽

Réka Ádám ◽

András Báldi

Keyword(s):

Functional Group ◽

Animal Health ◽

Habitat Type ◽

Dung Beetle ◽

Dung Beetles ◽

Livestock Grazing ◽

Pitfall Traps ◽

Assemblage Composition ◽

Beetle Assemblages

Wood pastures are home to a variety of species, including the dung beetle. Dung beetles are an important functional group in decomposition. Specifically, in terms of livestock manure, they not only contribute to nutrient cycling but are key players in supporting human and animal health. Dung beetles, however, are declining in population, and urgent recommendations are needed to reverse this trend. Recommendations need to be based on solid evidence and specific habitats. Herein, we aimed to investigate the role of an intermediate habitat type between forests and pastures. Wood pastures are key areas for dung beetle conservation. For this reason, we compared dung beetle assemblages among forests, wood pastures, and grasslands. We complemented this with studies on the effects of dung type and season at three Hungarian locations. Pitfall traps baited with cattle, sheep, or horse dung were used in forests, wood pastures, and pasture habitats in spring, summer, and autumn. Dung beetle assemblages of wood pastures showed transient characteristics between forests and pastures regarding their abundance, species richness, Shannon diversity, assemblage composition, and indicator species. We identified a strong effect of season and a weak of dung type. Assemblage composition proved to be the most sensitive measure of differences among habitats. The conservation of dung beetles, and the decomposition services they provide, need continuous livestock grazing to provide fresh dung, as well as the maintenance of wood pastures where dung beetle assemblages typical of forests and pastures can both survive.

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Species functional traits and abundance as drivers of multiplex ecological networks: first empirical quantification of inter-layer edge weights

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.2127 ◽

2020 ◽

Vol 287 (1939) ◽

pp. 20202127

Author(s):

S. Hervías-Parejo ◽

C. Tur ◽

R. Heleno ◽

M. Nogales ◽

S. Timóteo ◽

...

Keyword(s):

Species Traits ◽

Abundant Species ◽

Modular Organization ◽

Vertebrate Species ◽

Multilayer Network ◽

Functional Roles ◽

Different Types ◽

Seed Dispersers ◽

Natural Communities

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.

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Fruit-eating fishes of Banara arguta (Salicaceae) in the Miranda River floodplain, Pantanal wetland

Biota Neotropica ◽

10.1590/s1676-06032011000400033 ◽

2011 ◽

Vol 11 (4) ◽

pp. 373-376 ◽

Cited By ~ 8

Author(s):

Raul Costa-Pereira ◽

Francisco Severo-Neto ◽

Tamires Soares Yule ◽

Ana Paula Tinti Pereira

Keyword(s):

Seed Dispersal ◽

Fish Assemblage ◽

Scientific Literature ◽

Ecological Studies ◽

Dispersal Strategy ◽

Ecological Consequences ◽

River Floodplain ◽

Seed Dispersers ◽

Pantanal Wetland

The role of fish as frugivorous and its ecological consequences are often neglected in ecological studies. However, the importance of the interaction between fish and plants is gaining force in scientific literature, and fish has been considered effective seed dispersers. The fruit-eating fish assemblage of Banara arguta (Salicaceae) was evaluated in Southern Pantanal wetlands. Nine species were reported consuming fruits, with different strategies to capture them. The distribution of B. arguta associated with the Pantanal floodplain and the presence of several species of fruit-eating fish, suggest that ichthyochory can be an important seed dispersal strategy to B. arguta.

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