The Hubbard Brook Experimental Forest is located in West Thornton, New Hampshire. It is an experimental area established in 1955 within the White Mountains National Forest in New Hamphire's central plateau and is administered by the U.S. Forest Service. Hubbard Brook was the site of many important ecological studies beginning in the 1960s which established the extent of nutrient losses when all the trees in a watershed are cut.

Hubbard Brook is a north temperate watershed covered with a mature forest, and it is still accumulating bio-mass. In one early study, vegetation cut in a section of Hubbard Brook was left to decay while nutrient losses were monitored in the runoff. Total nitrogen losses in the first year were twice the amount cycled in the system during a normal year. With the rise of nitrate in the runoff, concentrations of calcium, magnesium...