| In the northern lower peninsula of Michigan, landscape-level variation in tree species composition is associated with glacial landforms which represent an increasing gradient of soil nutrient and water availability (i.e. outwash < ice contact < moraine). To investigate causes species associations, we conducted a reciprocal seedling transplant experiment using Acer saccharum, Fraxinus americana, Quercus alba, Prunus serotina and Q. velutina. Fertilizer additions of calcium and nitrogen were included to test for limitation of these nutrients. One year after transplanting, for seedlings grown in higher light plots, a trade-off was found between survival on outwash (poorer soil resource site) and relative growth rate (RGR) on moraine (richer soil resource site). Our results suggest this trade-off may be underpinned by variation in size and morphology among species. At low light, a trade-off between tolerance to ice-contact and growth on moraine was not supported by our results. Fertilizer additions were not found to effect survival or growth. |
