Making a living in dryland ecosystems: An introduction to pulse dynamics

Drylands experience low and unpredictable precipitation, with each event followed by a burst of biologic and chemical activity. Unpredictable conditions are difficult to adapt to, and low, infrequent water requires fast response times. Being controlled by water rather than light or biotic factors has many implications. Most rain events are small and only activate surface organisms, resulting in a temporal and spatial decoupling of production and uptake (e.g., nitrogen inputs versus plant uptake). Future changes in climate and disturbance regimes will also alter how these systems respond to water availability.