Rebecca wants to see if water plants with salt water affects plants. she waters 3 sunflowers with varying amounts of salt water, plant A get regular water plant B get 25% salt water and plant C 50% salt water . During the experiment she records the number of petals each flower has. Which one is independent variable for my line graph

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process. 

1-taiga 2-desert 3-desert 4-taiga