This PowerPoint goes over some basic definitions of ecosystems, species, populations, and habitat. This makes for a great science and conservation lesson. I usually would suit this one for grades 3rd through 8th. This lesson is designed to get the student thinking about their personal environment.
The terms discussed in this presentation:
habitats
biotic factors
abiotic factors
species
population
communities
ecosystem
Both the presentation and the work page can be found within the zip file. Th