Juneau Nature

Natural & cultural history of Juneau & Southeast Alaska

Juneau Nature - Natural & cultural history of Juneau & Southeast Alaska

Alluvial landforms & processes

How streams & rivers shape land & interact with forests

When we started the Landmark Trees project in 1996, it quickly became obvious that our search for giant trees was mostly a search for a special kind of stream and river deposit, called alluvium. You can approach the study of alluvial landforms and processes from the perspective of a geologist (the “abiotic” angle). Or, as we did, from the perspectives of forest ecology (the “biotic” angle). Given how important this globally important substrate is to forest productivity and riparian energy flow, I assumed a lot had been written about it.

I was wrong. For example, I could find nothing on why exceptionally large trees cluster where streams approach the heads of lakes. Maybe it’s because so little undeveloped alluvial surface remains throughout the world. I guess it’s up to us Southeast Alaskans!

Above: As a geologist sees alluvial landforms. Below: As a naturalist sees them.

Above: As a geologist sees alluvial landforms. Below: As a naturalist sees them.