As a response to recent warming, land cover on the North Slope of Alaska is shifting from tundra grasses to shrubs.  This shift will likely increase organic matter inputs of litter to aquatic systems. The River Continuum Concept predicts that as the form of available particulate organic matter varies longitudinally, so will the functional feeding groups of benthic macroinvertebrates. In this scenario, unshaded tundra streams are assumed to be supported by autochthonous production and dominated by scrapers. However, as shrubs colonize riparian zones, it is unclear how subsidies of terrestrial organic matter to stream foodwebs as well as shading will affect insect communities. To address this question, we conducted leaf litter addition and shading experiments on a first order tundra stream. The addition of leaf litter lowered diversity and led to shredder dominance of the insect community within three weeks. This suggests that macroinvertebrates may respond more rapidly than previously thought to shrub-derived organic matter.  While shading the stream lowered chlorophyll values, it did not significantly alter the invertebrate community. It now seems increasingly feasible that tundra streams will undergo a shift in community structure as dramatic as the shift from grasses to shrubs on the tundra landscape.