A study recently published in Forest Ecology and Management examines the carbon stock value of forests in Guyana, finding dramatic differences between different kinds of cover and land-use types. Tropical forests are among the most valuable in terms of carbon stocks. Globally, tropical forests sequester about 2.4 billion metric tons, according to a study published in Proceedings of the National Academy of Sciences in 2011. The new research found that carbon values differ according to forest type and usage pattern; for instance, carbon values from undisturbed forests cannot be applied in inhabited community lands.