This dataset comprise biogeochemical data of Nardus stricta snowbed grassland and Empetrum nigrum heath during a controlled environment drought-rewetting mesocosm experiment. The mesocosms were collected from Allt a'Mharcaidh catchment (3°50′ W, 57°5′ N), in the western Cairngorm mountains, Scotland. Data includes carbon and nitrogen gas and leachate fluxes in the oceanic-alpine ecosystems, and soil and vegetation characteristics of the habitats. The data were collected by The James Hutton Institute and Lancaster Environment Centre in order to determine impacts of drought and rainfall intensity on carbon and nitrogen fluxes in Nardus snowbed grassland and Empetrum shrub heath, two widespread alpine habitats. Full details about this dataset can be found at https://doi.org/10.5285/4673cd44-b3f5-41e7-bd84-1c18bb1c0c9a