Solomon, Allen M.1997. Maximum natural migration rates of tree species: global terrestrial carbon cycle implications. In: B. Huntley, W.P. Cramer, A.V. Morgan, H.C. Prentice and J.R.M. Allen, editors, Past and Future Rapid Environmental Changes: The Spatial and Evolutionary Responses of Terrestrial Biota. Springer-Verlag, NY, pp. 455-468.
The paper documents the forest-ecological processes which constrain the rate of response by forests to rapid future environmental change. It establishes a minimum response time by natural tree populations which invade alien landscapes and reach the status of mature, closed canopy forests when maximum carbon storage is realized. It considers rare long-distance and frequent short-distance seed transport, seedling and tree establishment, sequential tree and stand maturation, and spread between newly established colonies. An absolute minimum of 100 to 200 years (with a likely average value closer to an order of magnitude greater) is required for natural development of forests composed of tree species previously exotic but recently permitted by ameliorating climate. The analysis demonstrates that standard practice is insufficient to estimate future carbon stocks from static vegetation models. The universally applied assumption of instant forest migration and development must be replaced by an assumption of no forest migration during the next century. As a result, previously simulated increases in terrestrial carbon stocks become declines under doubled greenhouse gas-induced warming.