The U.S. Forest Service offers an on-line science journal in PDF format. One volume of this journal focuses on the Northern United States, with articles about why leaves change color, ozone and tree growth, and soil activity in the winter time. There are discussion questions, charts to fill out, and interviews with the scientists who wrote the articles. Included are lesson plans and assessment ideas as well as links to further resources. Download the PDF journal here or visit the website homepage.
courtesy of Knovation