Answer;
-Decrease
if the producer population decreased then the size of the herbivore population will consequently decrease.
Explanation;
Producers
are organisms that make make their own food through a process known as photosynthesis, e.g. plants such as grasses. Herbivores are the organisms which feed on producers. Examples of herbivores are rabbits, giraffes etc.
-An increase in producer population means that there will be a a corresponding increase in the population of herbivores while a decrease in the size of producers will cause a decrease in the population of herbivores.
