The Tschierva Glacier, Swiss Alps, has receded dramatically over the past decade, adding nearly 500 meters length to its runoff stream since 1997.  We asked whether this added stream length has resulted in a simple upward shift of the physical and biological stream gradient, or if there is evidence of other system-wide differences related to climate change.  We compared water temperature and benthic community patterns in 1997 and 2007-2008 during three seasons (spring, summer, autumn) to test the null hypothesis that longitudinal patterns are the same between years, except shifted upward ca. 500m.  Results reject the null hypothesis, revealing instead an interaction between an upward shift and the downstream influence of a lake-outlet tributary.  Above the tributary confluence, species found near the 1997 glacial snout have colonized the newly-exposed stream section, and the temperature gradient has shifted upwards as expected.  Below the confluence, summer/autumn temperatures and overall taxonomic diversity are greater now (2007-8) than expected under the null hypothesis, likely due to increased lake temperatures.  Climate change has caused lake warming throughout Switzerland.  Because lakes are common components of glacial watersheds, lake temperature changes may be interacting on a broad spatial scale with glacial recession to influence glacial stream communities.