Interspecific and intraspecific variation in leaf toughness of Arctic plants in relation to habitat and nutrient supply

Leaf toughness is an important functional trait that confers resistance to herbivory and mechanical damage. We sought determine how species composition, climate, seasonality, nutrient availability influence leaf in two types of tundra northern Alaska. measured as force punch for 11 Arctic plants tussock dry heath at 17 sites distributed along a latitudinal gradient. Rubus chamaemorus L. the graminoids occupied opposite ends spectrum, with requiring least punch, whereas one graminoids, Eriophorum vaginatum L., required most. increased mean summer temperature Betula nana it declined warmer temperatures other species. Toughness mature leaves did not vary through growing season but significantly after senescence. Application N P fertilizer experimental site decreased three had no effect on four others. out five was greater than same tundra, there difference community-weighted between heath.