Pancake, you're making the first mistake of all job seekers. Looking only at the advertised market. That is about 10% of the job openings out there. Do some research to find companies like Bartlett and Davey and what their research departments do. Find a contact person (like the manager of that department) and call them to learn more about them and their criteria for hiring. Explain to him your interest with a quick background of your reasons for investigating the field. DON'T ask if they're hiring! This is a market research call. If they ask you if you're looking then great you can tell them. You really want to build a resume specific to this type of work.
I would think they recruit from universities but will just as likely hire internally and from outside.
If you want, pm me to discuss the "art" of job hunting. One of my past vocations was a career manager.