There is not a specific camera that should be used for anything. There are many brands available and any of them will shoot landscapes and wildlife. Normally when shooting landscapes, a wider agle lens is preferred and when shooting wildlife, a telephoto lens is preferred (and most times, required). Most people invest in DSLR cameras when they get serious about photography, but most people use "point and shoot" cameras. It really depends on how much of an investment you are willing to make and what results you expect. Photography can become very expensive.
Here is a link to a site that reviews most cameras and even have a buyer's guide program that helps you find the features that are important to you:http://www.dpreview.com/
Hope this helps and good luck in the contest.