Students are given the opportunity to build a three tropic level model in which snakes eat rodents, rodents eat acorns, and acorns grow and occasionally mast. While we do not offer any data for validation of student models yet, students are challenged to do reality checks and reasonableness tests and model adaptability to add features which reflect sudden increases in acorn numbers, so called masting of oak trees.
In forests there are many species of plants and animals. As an example, consider the temperate forests around West Point NY and in the Black Rock Forest where there are dens of northern timber rattle snakes. These snakes live by eating a few rodents per season. The rodent prey are found principally while the snakes are laying in ambush in sunny areas and wandering about their den area. The rodents eat many things, but a principle diet component is acorns from oak trees. Oak trees produce acorns in some regularity, but occasionally there will be a season in which the oaks mast, i.e. produce an enormous number of acorns. There are also leaner acorn production years. You may have experienced walking in the woods some years in which there is lots of crunching from stepping on a matte of acorns under foot and other seasons when the forest floor is smooth and almost clean of acorns. This is due to masting. It is believed that masting is a propagation mechanism. For if the oak trees produced the same (predictable) number of acorns each seasons the rodents who consume them would come to a population level at which there were just enough rodents to eat all the acorns. However, when the acorns mast they get way ahead of the rodents and the acorns (which are the seeds of the oak) germinate, take root, and begin the cycle of growth to the canopy that keeps the oak tree population alive in the woods.