Investigating the balance between timber harvest and productivity of global coniferous forests under global change

A widely used assumption in forestry is that the demand for timber will exceed the maximum level available from forests on a sustainable basis. In this study, measurements of extracted timber and modeled forest productivity were used to investigate the relationship between harvested timber and natural forest productivity for current conditions, and under global change scenario. The analysis was confined to coniferous forests and countries that have coniferous forests within their territories. Annual roundwood production from the database of Food and Agriculture Organization was used as an approximation of annual timber harvest for each country. Annual stem primary productivity of coniferous forests was estimated using the BIOME-BGC model. Based on the current rates, annual timber extraction was extrapolated for each country for the next 80 years. Then, on a country basis, the timber harvest was related to the modeled forest stem productivity, assuming that the area of coniferous forest would stay unchanged for the next 80 years. The results of this study suggest that global coniferous forests currently produce more wood than people consume, but that this gap will narrow in the future. The results also suggest that wood extraction may reach forest regrowth by the middle of the next century, even though most coniferous forests are located in high latitudes and may have an accelerated stem growth associated with the joint effect of climate change and elevated carbon dioxide concentration in the atmosphere. [References: 63