Ecological communities are more than the sum of their parts

#ESA2016

Transcript

1. cb Ecological communities are more than the sum of their parts Timothée Poisot ESA 2016, Ft. Lauderdale, FL Université de Montréal – @tpoi / tim@poisotlab.io
3. The "building blocks" of food webs
4. The "building blocks" of food webs
5. The "building blocks" of food webs
6. Measuring dissimilarity
7. Measuring dissimilarity G1 → x = f (m1, . . . , m16)
8. Measuring dissimilarity G1 → x = f (m1, . . . , m16) G2 → y = f (m1, . . . , m16)
9. Measuring dissimilarity G1 → x = f (m1, . . . , m16) G2 → y = f (m1, . . . , m16) d(G1, G2) = i (xi – yi)2 = d(G2, G1) → δ
10. Putting the blocks together δ
11. Putting the blocks together δ δ
12. Putting the blocks together δ δ if δ < δ, accept if δ ≥ δ, reject
13. Want to try? Computing resources provided by Compute Canada and Université Laval. http://poisotlab.biol.umontreal.ca/tpoisot/mpna C, GNU GPLv3, uses igraph and gsl
14. Some networks are easier to simulate than others 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Step Distance · 23 food webs from Interaction Web Database · 400 replicate runs (averaged) · Total runtime: 36 years
15. Simulated networks are wider 0.0 0.2 0.4 0.6 0.8 1.0 0 2 4 6 8 Step Diameter
16. Simulated networks have less top predators 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Step Top predators
17. Simulated networks have more intermediate consumers 0.0 0.2 0.4 0.6 0.8 1.0 0 1 2 3 4 5 6 7 Step Intermediate consumers
18. Simulated networks have slightly less primary producers 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Step Primary producers
19. Larger networks are easier to reproduce 0 200 400 600 800 1000 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Numger of interactions Distance q q q q q q q q q q q q q q q q q q q q q q q 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.1 0.2 0.3 0.4 0.5 Distance Top predators q q q q q q q q q q q q q q q q q q q q q q q
20. Take-home messages · Motifs are a poor predictor of food web structure · Food web structure has additional constraints · We need to understand this as it its into ecosystem functions – Eva Delmas et al. COS 75-2 Funding: NSERC, FRQNT