1 / 14

Coloured noise affecting single-species populations in a spatial setting

Coloured noise affecting single-species populations in a spatial setting. Frida Lögdberg. Single-patch populations. Over compensatory : reddening of noise ( increase in autocorrelation ) will decrease extinction risk.

tolla
Download Presentation

Coloured noise affecting single-species populations in a spatial setting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Colourednoiseaffectingsingle-species populations in a spatial setting Frida Lögdberg

  2. Single-patch populations • Over compensatory: reddening of noise (increase in autocorrelation) willdecreaseextinction risk. • Under compensatory:reddening of noisewillincreaseextinction risk.

  3. Twomodels Model 1: Landscape implicit Model 2: Landscape explicit

  4. Model 1 • Discrete population process (Ricker): • Dispersal is a mass-actionmixing process:

  5. Environmentalnoise • 1/f noise in 2D: • Time, noisecolor • Space, synchrony

  6. Model 1 • Noiseaffecting K: • Noiseaffecting r (indirect):

  7. Model 1: Results • Over comp., noise in K: as the single-patch system. • Undercomp ., noise in K: hump-shapedresponse. • Over comp., noise in r: small hump-shapedresponse. • No interaction effectsbetweensynchrony and colour. Noise in K, over comp. Noise in K, under comp. Noise in r, over comp.

  8. Model 2 • Discrete population process (Ricker): • Dispersal isdistancedependent and follows a negative exponential distribution. • Environmentalnoise (colour and synchrony) as in Model 1.

  9. Model 2 Landscapes: generated with spectralmethod. Landscape characteristics: Continuity Contrast Continuity = 0 Continuity = 1 Continuity = 5 Contrast = 1 Contrast = 3 Contrast = 5

  10. Model 2: Results Pop. dynamics is over compen-satory. Noiseenters in K. Continuity = 0 Continuity = 1 Continuity = 5 Contrast = 1 Contrast = 3 Contrast = 5

  11. Model 2: Results Pop. dynamics is under compen-satory. Noiseenters in K. Continuity = 0 Continuity = 1 Continuity = 5 Contrast = 1 Contrast = 3 Contrast = 5

  12. Model 2: Results Pop. dynamics is over compen-satory. Noiseenters in r. Continuity = 0 Continuity = 1 Continuity = 5 Contrast = 1 Contrast = 3 Contrast = 5

  13. Conclusions • No complex interaction effectsbetweenany of landscape, synchronyand colour. • Aggregation versusrandom landscape affects the extinction risk quantitatively. Men ar du tydlig effekt/markerad effekt • Population dynamicsmatter, alsowhenincreasing the complexity by addingspace.

  14. Implications • To determineextinction risk onehave to consider: dynamics, colour, synchrony, continuity, contrast. • Besidesmean and varinace of resources. • On the other hand most of thesehave the same effectregardless of the others • If you want to improve the survival of the populationYou should: • Redder the noise or whiter the noise (be careful with dynamics) • Reducesynchrony • Increasecontrast • Reducecontinuity • (and of courseincrease man and reducevariance) • I f you have to choose: Which is the best to do? Depends on what system, what parameters value you have.

More Related