As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, water was diverted to a relict stream channel in order to reactivate the streamflow. The purpose of this experiment was to quantify the time scales of response to the arrival of water after many years of dessication. This table contains data showing the chlorophyll, carbon, nitrogen, and hydrogen concentrations of algal communities and some mosses from the relict channel. The data constitutes the reactivated channel's algal and moss biomass data, along with measurements of the amount of carbon and nitrogen associated with algal mats for construction of nutrient budgets.