scholarly journals Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands

2016 ◽  
Vol 283 (1837) ◽  
pp. 20161267 ◽  
Author(s):  
Sandra Bibiana Correa ◽  
Joisiane K. Arujo ◽  
Jerry Penha ◽  
Catia Nunes da Cunha ◽  
Karen E. Bobier ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Binary Data ◽  
Species Loss ◽  
Small Species ◽  
Network Stability ◽  
Frugivorous Birds ◽  
Neotropical Wetlands ◽  
Using Data

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence–absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore–fruit interactions.

scholarly journals Potential role of frugivorous birds (Passeriformes) on seed dispersal of six plant species a restinga habitat, southeastern Brazil

2006 ◽  
Vol 56 (1) ◽  
Author(s):  
Verónica Souza da Mota Gomes ◽  
Maria Célia Rodrigues Correia ◽  
Heloisa Alves de Lima ◽  
Maria Alice S. Alves
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Potential Role ◽  
Southeastern Brazil ◽  
Frugivorous Birds

The effects of defaunation on plants’ capacity to track climate change

Science ◽  
2022 ◽  
Vol 375 (6577) ◽  
pp. 210-214
Author(s):  
Evan C. Fricke ◽  
Alejandro Ordonez ◽  
Haldre S. Rogers ◽  
Jens-Christian Svenning
Keyword(s):  
Climate Change ◽  
Seed Dispersal ◽  
Plant Species ◽  
Ecosystem Functioning ◽  
Species Traits ◽  
Vital Function ◽  
Long Distance ◽  
Animal Populations ◽  
Using Data ◽  
Number Of Seeds

Seed dispersal in decline Most plant species depend on animals to disperse their seeds, but this vital function is threatened by the declines in animal populations, limiting the potential for plants to adapt to climate change by shifting their ranges. Using data from more than 400 networks of seed dispersal interactions, Fricke et al . quantified the changes in seed disposal function brought about globally by defaunation. Their analyses indicate that past defaunation has severely reduced long-distance seed dispersal, cutting by more than half the number of seeds dispersed far enough to track climate change. In addition, their approach enables the prediction of seed dispersal interactions using species traits and an estimation of how these interactions translate into ecosystem functioning, thus informing ecological forecasting and the consequences of animal declines. —AMS

scholarly journals How does the functional diversity of frugivorous birds shape the spatial pattern of seed dispersal? A case study in a relict plant species

2016 ◽  
Vol 371 (1694) ◽  
pp. 20150280 ◽  
Author(s):  
Jessica E. Lavabre ◽  
Luis J. Gilarranz ◽  
Miguel A. Fortuna ◽  
Jordi Bascompte
Keyword(s):  
Seed Dispersal ◽  
Spatial Pattern ◽  
Functional Diversity ◽  
Seed Rain ◽  
Local Network ◽  
Modular Organization ◽  
Long Distance ◽  
Frugivorous Birds ◽  
Dispersal Events

Genetic markers used in combination with network analysis can characterize the fine spatial pattern of seed dispersal and assess the differential contribution of dispersers. As a case study, we focus on the seed dispersal service provided by a small guild of frugivorous birds to the common yew, Taxus baccata L., in southern Spain. We build the spatial networks of seed dispersal events between trees and seed-plots within the studied population—local network—and the spatial network that includes all dispersal events—regional network. Such networks are structured in well-defined modules, i.e. groups of tightly connected mother trees and seed-plots. Neither geographical distance, nor microhabitat type explained this modular structure, but when long-distance dispersal events are incorporated in the network it shows a relative increase in overall modularity. Independent field observations suggested the co-occurrence of two complementary groups, short- and long-distance dispersers, mostly contributing to the local and regional seed rain, respectively. The main long-distance disperser at our site, Turdus viscivorus , preferentially visits the most productive trees, thus shaping the seed rain at the landscape scale and affecting the local modular organization. We end by discussing how DNA barcoding could serve to better quantify the role of functional diversity.

scholarly journals Similar seed dispersal systems by local frugivorous birds in native and alien plant species in a coastal seawall forest

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11672
Author(s):  
Bin Liu ◽  
Guohai Wang ◽  
Yuting An ◽  
Dandan Xue ◽  
Libo Wang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Bird Species ◽  
Alien Plant Species ◽  
Frugivorous Birds ◽  
Alien Plant ◽  
Bird Foraging

Frugivorous birds play an important role in seed dispersal. Alien plant species’ seeds are dispersed by local birds in order to establish populations in new habitats. Alien plant species that produce fruits similar to that of native species have the potential to attract local birds, creating new mutualistic systems that are similar to the local ones. In autumn 2018 and 2019, we studied the seed dispersal systems of an alien plant species, Phytolacca americana, and a native species, Cayratia japonica, in a coastal seawall forest. Both plant species’ fruit, frugivorous bird foraging behaviors, seed germination rates, and seedling microhabitats were examined to determine whether the alien species had a similar seed dispersal system to that of the native species. Our results showed that P. americana and C. japonica had similar fruit type, color, and ripening period. There was a positive correlation between the percentage rate of fruit ripening and the percentage rate of fruit missing for both plant species, indicating that local frugivorous birds have the potential to sufficiently disperse the alien seeds to enable its spread in the coastal seawall forest (simple linear regression, P. americana: β = 0.863 ± 0.017, R2adj = 0.978, P < 0.01; C. japonica: β = 0.787 ± 0.034, R2adj = 0.898, P < 0.01). Eleven bird species consumed the fruits of the alien species or native species during the study period. Similar results were shown across alien and native species in bird foraging behavior (feeding frequency, feeding duration and first stop distance) indicating that a similar seed dispersal relationship had been established between local frugivorous and both plant species. The alien plant had a higher number of fruits carried by birds, suggesting that P. americana had a slightly higher fruit consumption than that of C. japonica (t-test, P < 0.01). Alien plant seedlings grow more abundant in forest gap microhabitat (t-test, P < 0.01). Our results confirmed that bird digestion promotes seed germination success in both plant species. Our study suggests that in a narrow coastal seawall forest, alien plant species can successfully establish their populations by relying on similar seed dispersal systems as the local species.

A case study of global ULF pulsations using data from space-borne and ground-based magnetometers and a SuperDARN radar

2011 ◽  
Vol 17 (6) ◽  
pp. 54-67
Author(s):  
A.S. Potapov ◽  
◽  
E. Amata ◽  
T.N. Polyushkina ◽  
I. Coco ◽  
...  
Keyword(s):  
Using Data

The Interactional Foundations of Economic Forecasting

2018 ◽  
Author(s):  
Werner Reichmann
Keyword(s):  
Economic Forecasting ◽  
Political Actors ◽  
Social Legitimacy ◽  
Using Data ◽  
Economic Future ◽  
Economic Forecasts ◽  
Epistemic Process

How do economic forecasters produce legitimate and credible predictions of the economic future, despite most of the economy being transmutable and indeterminate? Using data from a case study of economic forecasting institutes in Germany, this chapter argues that the production of credible economic futures depends on an epistemic process embedded in various forms of interaction. This interactional foundation—through ‘foretalk’ and ‘epistemic participation’ in networks of internal and external interlocutors—sharpens economic forecasts in three ways. First, it brings to light new imaginaries of the economic future, allowing forecasters to spot emerging developments they would otherwise have missed. Second, it ensures the forecasts’ social legitimacy. And finally, it increases the forecasts’ epistemic quality by providing decentralized information about the intentions and assumptions of key economic and political actors.

scholarly journals Extending Geodemographics Using Data Primitives: A Review and a Methodological Proposal

2021 ◽  
Vol 10 (6) ◽  
pp. 386
Author(s):  
Jennie Gray ◽  
Lisa Buckner ◽  
Alexis Comber
Keyword(s):  
Social Dynamics ◽  
Feature Space ◽  
Social Processes ◽  
Multiple Time ◽  
Current State ◽  
Cluster Label ◽  
Static Data ◽  
The Social ◽  
Using Data

This paper reviews geodemographic classifications and developments in contemporary classifications. It develops a critique of current approaches and identifiea a number of key limitations. These include the problems associated with the geodemographic cluster label (few cluster members are typical or have the same properties as the cluster centre) and the failure of the static label to describe anything about the underlying neighbourhood processes and dynamics. To address these limitations, this paper proposed a data primitives approach. Data primitives are the fundamental dimensions or measurements that capture the processes of interest. They can be used to describe the current state of an area in a multivariate feature space, and states can be compared over multiple time periods for which data are available, through for example a change vector approach. In this way, emergent social processes, which may be too weak to result in a change in a cluster label, but are nonetheless important signals, can be captured. As states are updated (for example, as new data become available), inferences about different social processes can be made, as well as classification updates if required. State changes can also be used to determine neighbourhood trajectories and to predict or infer future states. A list of data primitives was suggested from a review of the mechanisms driving a number of neighbourhood-level social processes, with the aim of improving the wider understanding of the interaction of complex neighbourhood processes and their effects. A small case study was provided to illustrate the approach. In this way, the methods outlined in this paper suggest a more nuanced approach to geodemographic research, away from a focus on classifications and static data, towards approaches that capture the social dynamics experienced by neighbourhoods.

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