Many mountain ecosystems are experiencing coincident increases
in temperature, levels of atmospheric carbon dioxide (CO2) and
atmospheric nitrogen (N) deposition. All are important controls
on rates of plant growth, soil microbial activity, nutrient cycling,
and stream N export. It is difficult for experimental studies to
explore ecosystem responses to more than one or two treatments
at plot, let alone catchment, scale. One might expect, however,
ecosystems to respond differently to the combined global change
drivers than to climate, CO2, or N alone. We explored this
question for nine mountain catchments over the period 1980-
2075 with a simulation model.