The first year I taught 7th grade, which was three years ago, I had no idea how to teach biodiversity and invasive species. I was stumbling around the internet when I discovered a website that had great science modules for the topics I needed to teach. This website is from the University of Florida Center for Precollegiate Education and Training. It is known as SPICE. Spice is a five year project funded by the National Science Foundation. Many of the modules have an ecosytem theme. Most have various lessons complete with powerpoints and printables. The modules I use are Biodiversity, who cares? and Invasive Species. If you are a science teacher I would definitely check it out here at the link below.