John Roper Tropical forests have a special role in the conservation of biodiversity. In tree species alone, tropical rain forests are extremely diverse, often having more than 200 species per hectare. Boreal forests, on the other hand, are biologically much simpler, with as few as one species per hectare for fire-regenerated stands like lodgepole pine in North America.
Forests influence the local and probably global climates.
They moderate the diurnal range of air temperatures and maintain atmospheric humidity levels. Forests absorb atmospheric carbon and replenish the oxygen in the air we breathe. The conservation of forest resources in the watersheds that supply water for irrigation, sanitation, and human consumption is an important component of water supply strategies. When tropical watersheds have balanced land use, their forests absorb excessive rainfall that is gradually released later. Forests regulate stream flows by intercepting rainfall, absorbing the water into the underlying soil, and gradually releasing it into the streams and rivers of its watershed.