Ecological change and the challenges for monitoring.

Anthropogenic activities are changing the chemical composition of the global atmosphere. This results in changes to the physical properties as well, such as the radiation balance. These properties are important input variables for biospheric processes. This paper discusses a number of documented ecological changes that have occurred in response to the changing atmosphere. Much of the information has been derived from data collected at integrated monitoring sites. The changing atmosphere is expected to result in many more ecological changes to resources of economic as well as environmental value. Defining and understanding these changes will be necessary for managing sustainable development and poses major challenges for monitoring programs in general and for integrated sites in particular.