Ecological Networks Flashcards
How are mutualistic networks useful?
They can be used to study processes like pollination -which species pollinate which flowers etc.
What are ‘multiplex’ networks?
They show a range of interaction types. Can combine antagonistic and mutualistic networks. Different interaction types are colour coded.
What do circles represent in ecological networks?
Nodes - represent one species.
What do lines represent in ecological networks?
Links - represent an interaction.
What is a bipartite network?
A network with 2 separate communities that do not interact with each other. 2 levels and species only appear on 1 of those levels.
How is an ecological network constructed?
An interaction matrix is produced from field data.
What is a connectance web?
The simplest network - it only shows how species are connected and not the strength or type of connection.
How can you identify the main energy channels in an ecological network?
These have the most interactions.
What is the ‘brown’ part of food webs?
Detritus > Detritivores > Predators
What is the ‘green’ part of food webs?
Primary producer > Herbivore > Predators
How do quantitative webs work?
They use thicker links to show more significant interactions/energy flow.
What are the 3 levels of network description?
Network level.
Species level.
Link level.
What are some examples of network level description?
Species richness, food chain length and connectance.
What are some examples of species level description?
Degree, link diversity and generality.
What are some examples of link level description?
Interaction strength and interaction frequency.
What is the difference between niche type and neutral type network mechanisms?
Niche type focuses on ecology and the preferences of individual species. Neutral type assumes all species are the same.
How can body size be used to calculate trophic height?
There is typically an upwards trend with body size and trophic level.
What did the ‘Allometric diet breadth model’ (Petchey 2008) show?
Species feed primarily on smaller species and that profitability is a trade-off between prey size and handling time.
What does higher overall connectance influence food web robustness?
It results in greater robustness.
How can networks adapt?
Either by rewiring - new links forming - or by reweighting - reweighting existing links.
