This link has some great biome lesson ideas. The world has different biome system and presenting the a world map with different color coded biomes will help your students see the variety of ecosystems.
Also, this is good time to introduce topographic maps, since elevation
can help determine the ecosystem of a biome.
Lines close together depict a hill, lines wide apart depict a flat surface.
An Atlas has good examples of different maps, such as topographic map.
You can check one out online or at the library .