Last week’s Question:
Today, there are about 10 million beavers in North America. In the early 1600s, approximately how many beavers were busy damming up the “free flowing” rivers and streams of America?
A. Twice as many – 20 Million
B. 50 Million
C. Ten times as many – 100 Million
D. 250 Million
E. 400 Million
The Answer is “E” – 400 million.
This is a staggering number and double earlier estimates. The latest studies are also at odds with the perception that, before Europeans began trapping beavers, the rivers and streams of America were free flowing. More beavers equals more beaver dams, more beaver ponds and more beaver meadows. (When beavers abandon an area, their pond slowly reverts to forest, changing first to a bog, then a beaver meadow and finally back to forest.) One study describes the hydrology of North America’s streams before European colonization as a series of beaver ponds arranged like “pearls on a string”. In those days, beaver dams were multi-generational efforts and typically measured hundreds of yards in length. Until the last few years, the historical impact of omnipresent beaver dams on both surface water hydrology and ground water hydrology was vastly under estimated or ignored. The new thinking is that approximately 85% of North America’s streams were dammed up and those beaver works mitigated both flooding and droughts. For at least 12,000 years, beavers radically altered the watersheds of North America. Our failure to recognize the extent beaver impacted the environment is a case of ecological amnesia.
This weeks question:
What is a groyne? (Alternate spelling is “groin”.) Example: Look at that groyne!
A. A vegetarian substitute for pork loin
B. A type of watercraft built by native Americans
C. A manmade hydraulic structure
D. A glacial artifact similar to an erratic
E. A medieval torture device