Food-web Algerian desert

1 collaborator

Revetement-adhesif-bois-brun-marron-0-67-x-2-m

WHAT IS IT?

This model explores the stability of predator-prey ecosystems. Such a system is called unstable if it tends to result in extinction for one or more species involved. In contrast, a system is stable if it tends to maintain itself over time, despite fluctuations in population sizes.

HOW IT WORKS

HOW TO USE IT

Adjust the slider parameters or use the default settings.
Press the SETUP button.
Press the GO button to begin the simulation.
Look at the monitors to see the current population sizes
Look at the POPULATIONS plot to watch the populations fluctuate over time

THINGS TO NOTICE

THINGS TO TRY

Try adjusting the parameters under various settings. How sensitive is the stability of the model to the particular parameters?

Can you find any parameters that generate a stable ecosystem

NETLOGO FEATURES

Note the use of breeds to model five different kinds of "turtles": Cheetah, Snake, Fennec, Bird, Rabbits. Note the use of patches to model Plants.

References

1.aggoun, A. (n.d.). حماية البيئة والتراث. Retrieved from http://tioutwaha1.blogspot.com/2001/02/blog-post_7732.html

2.Boulder, U. o. (2015). Teach. Retrieved from https://www.teachengineering.org/view_activity.php?url=collection/cub_/activities/cub_bio/cub_bio_lesson03_activity1.xml 3.Carwardine, M. (2008). Animal Records. New York. 4.Dave, J. A. (n.d.). Retrieved from http://www.tigerhomes.org/animal/cheetah-facts.cfm 5.Eugenio Picano, E. V. (2014). The appropriate and justified use of medical radiation in cardiovascular imaging: a position document of the ESC Associations of Cardiovascular Imaging, Percutaneous Cardiovascular Interventions and Electrophysiology. European Heart Journal. 6.Ganora. (2015). Research of the African Rock Pipit. Retrieved from http://www.ganora.co.za/page/african_rock_pipit_klipkoester 7.Kostas Karamanos, A. G. (2012). Ecosystem Food-webs as Dynamic Systems:Educating Undergraduate Teachers in Conceptualizing Aspects of Food-webs’. Advances in Systems Science and Application, 49-68. 8.Krisnain, K. B. (n.d.). Slide Share. Retrieved from http://fr.slideshare.net/KesavartiniiBalaKrisnain/simulation-powerpoint-lecture-notes 9.Miscellany, u. (2011). Bird watching. Retrieved from http://sbpoley.home.xs4all.nl/ukrb/age.html 10.Oxford. (n.d.). Oxford dictionaries. Retrieved from http://www.oxforddictionaries.com/ 11.PHET. (n.d.). Interactive simulation. Retrieved from https://phet.colorado.edu/en/simulation/balloons 12.Rezhdo, A. (2011). Buffon’s Needle Problem. 13.SIMULATION AND MODELING. (2013). 14.Stafford, P. (1986). Pythons and Boas. Neptune City, New Jersey, USA: T.F.H. Publications, Inc. Ltd. 15.Volunteers, R. G. (2005). Fennec Fox.

Comments and Questions

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Click to Run Model

globals [plants cheetahs-nb snakes-nb fennecs-nb rabbits-nb birds-nb ]  ;; keep track all inividuals

breed [cheetahs cheetah]
breed [snakes snake]
breed [fennecs fennec]
breed [rabbits rabbit]
breed [birds bird]
turtles-own [energy age] 
patches-own [countdown]


;;@@@@@@@@@@@@@@@ TO SETUP @@@@@@@@@@@@@@@@@@@@@@@@@@

to setup
  clear-all
  
    ask patches [
      set pcolor one-of [green white]
      if pcolor = green
        [ set countdown plants-growth-level ]
    ]
  
  ;;@@@@@@@@@@@@@@@@@@@@@@@@@@@ breed shapes @@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 
   set-default-shape cheetahs "cheetah"
  create-cheetahs Initial-number-Cheetah  ;; create cheetah then initialize their variables
  [
    set color brown
    set size 3  
    set label-color blue - 5
    set energy random 100
    set age random 100
    
    setxy random-xcor random-ycor
  ]
  
  ;;@@@@@@@@@
  set-default-shape snakes "snake"
  create-snakes Initial-number-Snakes  ;; create snakes, then initialize their variables
  [
    set color red
    set size 2.4
    set energy random 100
    set age random 60
    setxy random-xcor random-ycor
  ]
  ;;@@@@@@@@@@@@@@@@@@@@
  set-default-shape fennecs "fennec"
   create-fennecs Initial-number-Fennecs  ;; create fennec, then initialize their variables
  [
    set color brown + 2
    set size 2.5
    set label-color blue - 2
    set energy random 100
    set age random 10
    setxy random-xcor random-ycor
  ]
  ;;@@@@@@@@@@@@@@@@@
  set-default-shape rabbits "rabbit"
   create-rabbits Initial-number-Rabbits  ;; create  rabbit, then initialize their variables
  [
    set color grey 
    set size 1  
    set label-color blue - 2
    set energy random 60
    set age random 10
    setxy random-xcor random-ycor
  ]
  
  
   ;;@@@@@@@@@@@@@@@@@
  set-default-shape birds "bird side"
   create-birds Initial-number-Birds  ;; create bird, then initialize their variables
  [
    set color black
    set size 1  
    set label-color blue - 2
    set energy random 50
    set age random 10
    setxy random-xcor random-ycor
  ]
  
  
  
  
  ;;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  
  display-labels
  set plants count patches with [pcolor = green]
  reset-ticks
end    ;;@@@@@@@@@@@@@@@END TO SETUP @@@@@@@@@@@@@@@@@@@@@@@@@@

to go
   if not any? turtles [ stop ]
  go1
  
  ask patches [ grow-plants ] 
  set plants count patches with [pcolor = green]   
   
  display-labels
  tick ; time move one month 
end   
;;@@@@@@@@@@@@@@@@@@@@@ TO  GO   @@@@@@@@@@@@@@@@@@@@@@@@@@@

to go1 
 
;;@@@@@@@@@@@@@@@@@@@@@@@@
  ask cheetahs [
    move
    set age age + 1  ;;growing
    set energy energy - 1  ;; deduct energy
    catch-fennecs
    catch-rabbits
    catch-snakes
    reproduce-cheetahs
    cheetah-death
    
  ]
;;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  ask fennecs [
    move
    set age age + 1
    set energy energy - 1  ;; deduct energy
    eat-plans
    catch-birds
    catch-rabbits
    fennecs-death
   ;; reproduce-fennecs
    
  ]
  
 ;;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  ask snakes [
    move
    set age age + 1
    set energy energy - 1  ;; deduct energy
    catch-birds
    catch-rabbits
    catch-fennecs
    snakes-death
    reproduce-snakes
  ]
  
 
 ;;@@@ @@@@@@@@@@@@@@@@@@
 
   ask rabbits [
    move
    set age age + 1
    set energy energy - 1  ;; deduct energy
    eat-plans
    rabbits-death
    reproduce-rabbits
  ]
  
 ;;@@@@@@@@@@@@@@@@@@@@@@@
 
  ask birds [
    move
    set age age + 1
    set energy energy - 1  ;; deduct energy
    eat-plans
    birds-death
    reproduce-birds
  ]
 ;;@@@@@@@@@@@@@@@@@@@@@@@
end 
;;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

to move  ;; turtle procedure
  rt random 50
  lt random 50
  fd 1
end 

to eat-plans
  ;; animals eat plants color changes
  if pcolor = green [
    set pcolor green + 2 
    set energy energy + 1   ;; To be verified@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  ]
end 

to reproduce-fennecs  
  
  if random-float 100 < fennec-growth-rate
   [  
    set energy (energy / 2)                
    hatch 1 [ rt random-float 360 fd 1  set age 0 ]  

   ]
end 

to reproduce-snakes 
 if random-float 100 < snake-growth-rate
   [  
    set energy (energy / 2)                
    hatch 1 [ rt random-float 360 fd 1 set age 0 ]  

   ]
end 

to reproduce-birds  
 if random-float 100 < bird-growth-rate
   [  
    set energy (energy / 3)               
    hatch 1 [ rt random-float 360 fd 1 set age 0 ]  

   ]
end 

to reproduce-cheetahs 
if random-float 100 < cheetah-growth-rate
   [  
    set energy (energy / 2)                
    hatch 1 [ rt random-float 360 fd 1 set age 0  ]  

   ]
end 

to reproduce-rabbits
 if random-float 100 < rabbit-growth-rate
   [  
    set energy (energy / 2)               
    hatch 1 [ rt random-float 360 fd 1 ]  

   ]
end 

;;@@@ hunting  process

to catch-rabbits  
  let prey one-of rabbits-here                    ;; grab 
  if prey != nobody                             ;;  we get one
    [ ask prey [ die ]                          ;; kill it
      set energy energy + 3 ];;  To be verified@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
end 

;;@@@@@@

to catch-fennecs
  let prey one-of fennecs-here                    ;; chatch a fennec
  if prey != nobody                             ;; if it get one,
    [ ask prey [ die ]                          ;; kill it
      set energy energy + 4 ];;  To be verified@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
end 

;;@@@@@

to catch-birds  
  let prey one-of birds-here                    ;; grab bird
  if prey != nobody                             ;;  if it get one
    [ ask prey [ die ]                          ;; kill it
      set energy energy + 3 ];;  To be verified@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
end 

;;@@@@@

;;@@@@@@@@@@@@@@@@@@@@@@@@@@@ catch-bird@@@@@@@@@@@@@@@@@@@@@@@

to catch-snakes
let prey one-of snakes-here
if prey != nobody                             
    [ ask prey [ die ]                         
      set energy energy + 5 ]
end 
;;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

to cheetah-death  
  if (energy <= 0)
   [ die ]
  if (age >= 132) ;;normal cheetah life time 11 years in months  132
  [ die ]
end 
;;@@@@

to fennecs-death  
  if (energy < 0) or (age >= 120) ;; fennec livespant to 10 years
 [ die ]
end 

to birds-death  
  if (energy < 0) or  (age >= 36) ;average life 3 years
  [ die ]
end 

to rabbits-death  
  if (energy < 0) 
  [ die ]
  if (age >= 90) 
  [ die ]
end 

to snakes-death  
  if (energy < 0) or (age >= 132) ; lifespan 13 years
   [ die ]
end 
;to death
  
 ;; ask snakes [
   ;; let limit count turtles-here 
;;    let a ( 0.95 * snakes-nb )
  ;;  ask n-of min [ 5 limit] turtles-here [ die ] ]
  ;
 ; ask patches [
;  repeat 5 [
  ;  if any? turtles-here [
;      ask one-of turtles-here [
        
;      ]
;    ]
;  ]
;]
;end

to grow-plants  ;
  if pcolor = (green + 2) [
    ifelse countdown > 90
      [ set pcolor green
        set countdown plants-growth-level ]
      [ set countdown countdown + 1 ]
  ]
end 

to display-labels
  set cheetahs-nb count cheetahs
  set birds-nb count birds
  set snakes-nb count snakes
  set fennecs-nb count fennecs
  set rabbits-nb count rabbits
  ask turtles [ set label "" ]
  if Show-Enargy [
    ask birds [ set label round energy ]
    ask rabbits [ set label round energy ]
    ask fennecs [ set label round energy ]
    ask snakes [ set label round energy ]
    ask cheetahs [ set label round energy ]
  ]
  
  if Show-age [
    ask birds [ set label round age ]
    ask rabbits [ set label round age ]
    ask fennecs [ set label round age ]
    ask snakes [ set label round age ]
    ask cheetahs [ set label round age ]
  ]
end 




;;@@@ created by Kouidrat Amel @@@

There is only one version of this model, created over 10 years ago by Amel Kouidrat.

Attached files

File	Type	Description	Last updated
Food-web Algerian desert.png	preview	Preview for 'Food-web Algerian desert'	over 10 years ago, by Amel Kouidrat	Download

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