Grainger also found an association between declining forest cover and increasing population density in 43 countries in the humid tropics. 58 Population growth and density were the most important factors contributing to deforestation in northeast Thailand, according to another study, mainly because of increasing demand for agricultural land. 59 Richard Bilsborrow found that forest loss in Indonesia could be traced to both population growth and government policies to encourage migration to Indonesia's outer islands. The management of logging in forested areas could protect more of the area needed to support the Earth's species. Forest management is hampered by a lack of knowledge about how much logging a forest can sustain without endangering the area's ecosystems.
Fragmented forests are often too small to support a full complement of species, for example.
Determining how best to manage the world's forests is also affected by philosophical questions. Overriding these philosophical differences, however, is an increasing international consensus about the importance of forests in storing the world's carbon supply. When trees are burned, carbon is released back into the atmosphere, where it recombines with oxygen to form CO2, increasing the atmospheric concentration of carbon dioxide and contributing to global warming. Recent international agreements encourage countries to protect their forests from overcutting. This text may not be reproduced or reprinted in any form without the express written permission of the Population Reference Bureau.