Global awareness of environmental issues has increased on an unprecedented scale. Deforestation, land degradation, desertification, loss of biodiversity, global warming and climate change are some of the environmental issues linked directly to t- restrial ecosystems, both natural and human-managed. Forests, grasslands and c- plands constitute over 63% of the global land area. Terrestrial ecosystems play a critical role in the global carbon cycle. Global rise in demand for food, fodder, fuel and roundwood is increasing the pressure on land-use systems, and conservation and sustainable development of land-use systems are critical for meeting those demands sustainably and stabilizing CO concentration in the atmosphere to miti- 2 gate global climate change. My interest in carbon flows in forest ecosystems was initiated about 15 years ago with the global concern about the contribution of the growing CO emissions 2 to climate change. My first paper about carbon flows was published in 1996 in Climatic Change; since then my interest and the global interest have only increased (R).