Understanding the effects of climate change via disturbance on pristine arctic lakes—multitrophic level response and recovery to a 12‐yr, low‐level fertilization experiment

Effects of climate change-driven disturbance on lake ecosystems can be subtle; indirect effects include increased nutrient loading that could impact ecosystem function. We designed a low-level fertilization experiment to mimic persistent, disturbances (deeper thaw, greater weathering, or thermokarst failure) delivering nutrients arctic lakes. measured responses pelagic trophic levels over 12 yr in fertilized deep with fish and shallow fishless lake, compared paired reference lakes, monitored recovery for 6 yr. Relative prefertilization the we observed maximum response chl (+201%), dissolved oxygen (DO, −43%), zooplankton biomass (+88%) during period (2001–2012). Other fertilization, such as water transparency relative abundance, were delayed, but both ultimately declined. Phyto- community composition shifted fertilization. The less pronounced because natural failure likely impacting lake. In there was (a) moderate resistance change functions at all levels, (b) eventual often nonlinear, (c) postfertilization (return) times most rapid base food web (2–4 yr) while higher failed recover after timing magnitude these lakes similar other suggesting modify inputs may affect many future.