This issue explores the "vital signs" of parks. The National Park Service's Inventory and Monitoring (I&M) Network studies broad ecological trends throughout parks, and uses those trends, or vital signs, to gauge the health of a park's ecosystem.
In an area the size of New Jersey, scientists study Dall's sheep. They are one of 28 vital signs monitored by the Arctic Network Inventory and Monitoring Program (ARCN I&M) because of their importance to the public and in assessing the overall health of the regional ecosystem. Read more
Changes in shallow lakes throughout central Alaska illustrate the effects of our rapidly changing climate. Read more