Forest Health Monitoring by the Canadian Forest Service: Now and the Future

Abstract

In 1984, the Canadian Forest Service initiated a national forest health monitoring program, the Acid Rain National Early Warning System (ARNEWS), to monitor the health of the forest and determine the effects of acid rain and regional air pollutants on the forest. Monitoring is done by personnel of the Forest Insect and Disease Survey, who are experienced in the evaluation of forest health. They assess trees in permanent sample plots for forest damage and identify the causes. Causes of tree mortality are also determined. If damage is found for which no apparent cause is evident, research is initiated to determine the source of the damage.

To date, ARNEWS has reported on the health of 18 conifer and 9 hardwood species from across Canada, including areas known to receive some of the highest levels of atmospheric pollution in Canada. Results indicate that there is no large-scale decline in the health of our forests and, where pollution-like symptoms were observed, they could usually be accounted for by natural factors. Tree mortality in these natural stands is also normal.

However, the monitoring system depends on being able to recognize damage and to determine the cause. The more easily this can be done, the more efficacious is the system. As our researchers assess the trees, they need to know what all type of damage looks like since many pollution symptoms are easily confused with natural effects. The research done on leaf cuticles should help expand this knowledge base.