Samantha Ykema

Climate change in Minnesota has caused increases in temperature, extreme precipitation events, and droughts; these trends are highly likely to continue under current projections (USEPA 2016). Consequences of these environmental changes include an increase in the density of tree species such as northern red oak (Quercus rubra) in northern Minnesota. The Lake Superior lake effect causes coastal forests to have higher rainfall with warmer winters and cooler summers, while inland forests have more extreme seasons and lower rainfall. Minnesota foresters currently choose non-coastal acorns for reforestation plantings because trees along Lake Superior fail to establish when planted inland. To find whether there are significant differences in how coastal and non-coastal populations of northern red oak will respond to climate change, I conducted a garden experiment. I planted coastal and non-coastal acorns in a combination of elevated temperature or ambient conditions and normal watering conditions or drought. I hypothesized seedlings would grow best in ambient temperature, normal-watering conditions, and that the coastal populations would not grow well in high temperature, low-water conditions due to their adaptation to the cool, rainy coastal environment. Results showed non-coastal populations had a greater seed mass, germinated more, germinated earlier, and had a higher growth rate than coastal populations. Although there are differences between regions, coastal and non-coastal populations responded similarly to the projected climate. This research will help State foresters develop practices to manage our forests, one of our most important buffers against climate change.