Population ecology is the study of populations and their interactions with the environment. A population is a group of individuals of a species in a particular area. Population ecology studies things like population growth, selection strategies, population distribution, demographics and how populations evolve and adapt.
Once a branch of ecology is called population ecology and this is basically the study of a population and how it interacts both within itself and with the environment around it. Now I want to make sure you understand what a population is, a population is a group of individuals of the same species who happen to be in a particular area, for example we have squirrels here in San Francisco that maybe just like squirrels 20, 30 miles away from here but the squirrels that are in Golden Gate Park are not going to go and be part of the population of squirrels else where so we may study what they are doing and seeing how they change and how they interact with the various trees in other things and their particular environment. Now population ecology cover a number of different areas including how the populations grow what's their birth rate, what's their death rate and things like. You can also get into something called K selection versus R selections strategies. R selections organisms are those that maximize the number of progeny, the number of off springs they have on giving very little resources to each individual off spring. The opposite of that is K selection of organisms the one that tend to have much fewer number of offsprings but each offspring they have winds of getting a greater amount of resources dedicated to it. For example we humans are K selectors we tend to give a lot of resources to our offspring your parents gave you lots of resources it may not have seem like it you may have wanted to get that X box and the play station at the same time, they were so mean to you. But actually if you think about the amount of resources they gave to you compared to say when Bonaco sprays out it's sperm and sprays out eggs into the environment just hopes that they would find each other you came off a little bit better than those Bonaco babies did. Population distribution demographics can be a very interesting thing for ecologist to study, they may look at two different populations and see well this population and that one they both are roughly the same size but this one has a lot younger individuals in it well this one there is a greater preponderance of older individuals into it and trying to figure out why is that. And last they take a look at the long term how do populations evolve and adapt to the changes that are going on in their environment.