COMMENTARY Carbon Metabolism of the Terrestrial Biosphere: A Multitechnique Approach for Improved Understanding

Understanding terrestrial carbon metabolism is criti-cal because terrestrial ecosystems play a major role in the global carbon cycle. Furthermore, humans have severely disrupted the carbon cycle in ways that will alter the climate system and directly affect terrestrial metabolism. Changes in terrestrial metabolism may well be as important an indicator of global change as the changing temperature signal. Improving our understanding of the carbon cycle at various spatial and temporal scales will require the integration o