A population of Tree Frogs is introduced into southern Georgia in 1986?

[decatur052005]

Twenty years later, the frogs are spread across the southern half of Georgia, Alabama, and Mississippi. Discuss the forces affecting the population of tree frogs, including:
-the four types of limits that could be responsible for stopping the spread of the frogs northward
-possible population-dependent controls that limit the population density of these frogs
-a description of the logistical growth model and the basic factors that go into it

 

[emucompboy]

> the four types of limits that could be responsible for stopping the spread of the frogs northward
1. Abiotic: temperature. These tropical frogs can thrive only in warm climates.
2. Abiotic: availability of ponds. Frogs need ponds to reproduce in.
3. Biotic: predation of larval forms. In the larger deeper bodies of water northward, there are more predators in the water such as fish and turtles.
4. Biotic: predation of adult frogs. Northward there are more opossums and skunks and weasels, and predatory birds, that can eat adult frogs.

> possible population-dependent controls that limit the population density of these frogs
1. There's only so much available food.
2. The species spaces itself out through its loud calls. There're only so many prime sitting spots.
3. Cannibalism. The larger older adults can and do eat younger smaller frogs.

> a description of the logistical growth model and the basic factors that go into it
I have absolutely no clue because I don't even know what that is. Check your textbook and see if there's something about "exponential" or "S curve" or "J curve" or "exponential with plateau" or "simple Malthusian" or something like that, and read up on them and pick the one you think fits the situation best. I don't even know what I'm talking about and I'm really glad I'm not you right now.

As for basic factors, we've already mentioned availability of food, availability of "sitting places for adults," availability of ponds suitable for growth of tadpoles, temperature, predators, blah blah.