Riparian Zones

• Alders often grow in shrub and small-tree form along rivers and streams.Alder image by Valeriy82 from Fotolia.com
  
  Shrubs often mark watercourses, favoring the moist, sometimes waterlogged zone along streams. Common riparian shrubs in North America include willows and alders.
  
  

Montane Shrublands

• In semi-arid country, hardy shrubs may form in transition landscapes between lower grasslands or desert and higher montane forests. In highlands of the Columbia Plateau, shrubs like black hawthorn and mountain mahogany prosper in rocky foothills.
  
  

Steppe and Desert

• Shrub-steppe covers much of the Intermountain West of North America.Eastern Oregon image by pearlguy from Fotolia.com
  
  Many kinds of shrubs are well adapted to water-stressed plains and deserts. Sagebrush flourishes on the steppes of the Intermountain West, while creosote bush is one of the most widely distributed shrubs of the Sonoran Desert.
  
  

Forest Understory

• Shrubs able to contend with more limited light also are common in forests and woodlands. In many parts of North America, various kinds of berry shrubs, such as blackberry, huckleberry and thimbleberry, are major parts of the understory layer.
  
  

Successional Landscapes

• Shrubs are often opportunistic species, colonizing habitat newly disturbed by fire, storm or human activity. Oldfields in North America frequently convert to shrublands before young forest develops.