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http://participatoryscience.org/curriculum-activity/introduction-nitrogen-cycle
http://thecarboncycledio.weebly.com/the-carbon-cycle-steps.html
http://www.sciencelearn.org.nz/Contexts/Soil-Farming-and-Science/Science-Ideas-and-Concepts/The-phosphorus-cycle
http://www.epa.gov/acidrain/effects/
http://www.newworldencyclopedia.org/entry/Biogeochemical_cycle
http://www.informaecon.com/sacd.asp
http://www.kew.org/science-conservation/plants-fungi/acacia-mangium-brown-salwood
http://news.mongabay.com/2010/0923-rspo_smart_palm_oil.html#sthash.WQwMHaky.dpbs
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Case Study 1: Inagaki, M., & Ishizuka, S. (2011). Ecological Impact on Nitrogen and Phosphorus Cycling of a Widespread Fast-growing Leguminous Tropical Forest Plantation Tree Species, Acacia mangium. Diversity. Retrieved from www.mdpi.com/journal/diversity
Case Study 2: Carbon storage and release in Indonesian peatlands since the last deglaciation. (2014).Quaternary Science Reviews, 97, 1-32.