Alder

Alnus sp

Characteristics

• Alternate toothed leaves, sometimes doubly serrate

• Catkins

• Ash grey bark

• Up to 100 ft

• Riparian species

Ecology

• Important to stream ecology• Leaves start food chain in lotic systems• Canopy of alders is important in temperature

regulation of streams• Nitrogen fixation by symbiotic bacteria is crucial

to nitrogen cycle• Riparian trees provide important food and cover

for a variety of mammals and birds on our list