The form of direct interspecific competition modifies secondary extinction patterns in multi-trophic food webs

Oikos ◽  
2013 ◽  
Vol 122 (12) ◽  
pp. 1730-1738 ◽  
Author(s):  
Mike S. Fowler
2020 ◽  
Author(s):  
Robert Veres ◽  
Zoltán László

AbstractStability is a key attribute of complex food webs that has been for a long time in the focus of studies. It remained an intriguing question how large and complex food webs are persisting if smaller and simple ones tend to be more stable at least from a mathematic perspective. Presuming that with the increasing size of food webs their stability also grows, we analyzed the relationship between number of nodes in food webs and their stability based on 450 food webs ranging from a few to 200 nodes. Our results show that stability increases non-linearly with food web size based both on return times after disturbance and on robustness calculated from secondary extinction rates of higher trophic levels. As a methodologic novelty we accounted for food web generation time in the return time calculation process. Our results contribute to the explanation of large and complex food web persistence: in spite of the fact that with increasing species number the stability of food webs decreases at small node numbers, there is a constant stability increase over a large interval of increasing food web size. Therefore, in food web stability studies, we stress the use of food web generation times.


Author(s):  
Marco Scotti

Food webs are schematic representations of who eats whom in ecosystems. They are widely used in linking process to pattern (e.g., degree distribution and vulnerability) and investigating the roles played by particular species within the interaction web (e.g., centrality indices and trophic position). First, I present the dominator tree, a topological structure reducing food web complexity into linear pathways that are essential for energy delivery. Then, I describe how the dominance relations based on dominator trees extracted from binary food webs may be modified by including interaction strength. Consequences related to the skewed distribution of weak links towards the trophic chain are discussed to explain higher risks of secondary extinction that characterize top predators dominated by basal species. Finally, stochastic simulations are introduced to suggest an alternative approach to static analyses based on food web topology. Ranking species importance using stochastic-based simulations partially contradicts the predictions based on network analyses.


2019 ◽  
Vol 613 ◽  
pp. 49-66 ◽  
Author(s):  
VN de Jonge ◽  
U Schückel ◽  
D Baird
Keyword(s):  

2015 ◽  
Vol 6 (3) ◽  
pp. 167
Author(s):  
Hyun-Seon Shin ◽  
Amahashi Nozomi ◽  
Young-Eun Na ◽  
Hong-Hyun Park ◽  
Kwang-Jin Cho ◽  
...  

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