how disturbance processes may interact with climate change to drive future vegetation dynamics of boreal forest and tundra ecosystems how are changes in disturbance regimes, such as altered fire frequency and severity, likely to influence forest responses to directional climate change the effects of climate warming on plant regeneration and colonization processes after a disturbance has occurred Are disturbances likely to create windows of opportunity for southern species to invade northern communities as the climate warms? management of human disturbances

My main research interest is focused on how disturbance processes may interact with climate change to drive future vegetation dynamics of boreal forest and tundra ecosystems. In particular, how are changes in disturbance regimes, such as altered fire frequency and severity, likely to influence forest responses to directional climate change? Once a disturbance has occurred, what are the effects of climate warming on plant regeneration and colonization processes? Are disturbances likely to create windows of opportunity for southern species to invade northern communities as the climate warms? What do these interactions mean for management of human disturbances, or predicting future changes in forest cover over coming decades or centuries?

Johnstone, J. F., F. S. Chapin, III, T. N. Hollingsworth, M. C. Mack, V. Romanovsky, and M. Turetsky. 2010. Fire, climate change, and forest resilience in interior Alaska. Canadian Journal of Forest Research 40:1302-1312. Johnstone, J. F., T.N. Hollingsworth, M.C. Mack, and F.S. Chapin, III. 2010. Changes in fire regime break the legacy lock on successional trajectories in Alaskan boreal forest. Global Change Biology 16: 1281-1295. Johnstone, J. F., L. Boby, E. Tissier, M.C. Mack, D. L. Verbyla, and X. Walker. 2009. Post-fire seed rain of black spruce, a semi-serotinous conifer, in forests of interior Alaska. Canadian Journal of Forest Research 39: 1575-1588. Johnstone, J. F. and S.V. Kokelj, 2008. Environmental conditions and vegetation recovery at abandoned drilling mud sumps in the Mackenzie Delta region, NWT, Canada. Arctic 61: 199-211.