Effects on Ecosystems

In general, the effect that increased UV-B will have on ecosystems is the disruption of relative balance in the cycling of chemicals (we will look mainly at nitrogen and carbon here, but other elements such as phosphorous and sodium are important and may be disrupted as well) through earth materials and organisms (see biogeochemical cycling).  On this site, the cycling impacts are broken up into several processes:

1. The incorporation of carbon into ecosystems from the atmosphere by plants and algae, or Effects on primary producers;
2. The recycling of organic inputs that result from plant productivity, or Effects on bacteria and fungi;
3. Direct effects UV-B has on ecosystem processes independent of organisms, or Abiotic Effects.

By teasing each of these groups of processes apart and examining how changes might affect biogeochemical cycling, we can start to look at how the ecosystem as a whole might respond to increased radiation.

To first get a general idea about how all of these categories interact, below is a picture from Johnson, 2003 showing ecosystem responses to increased UV-B exposure:

Potential pathways of UV-B effects on terrestrial ecosystems (adapted from Johnson, 2003)