“Reintroducing wolves to Yellowstone has triggered a resurgence of aspen trees. A new study found that one-third of aspen groves in the park now have healthy young trees—something not observed since the 1940s—thanks to the reduced elk population,” reports The Doomslayer.
Live Science adds:
Gray wolves had disappeared from Yellowstone National Park by 1930 following extensive habitat loss, human hunting and government eradication programs. Without these top predators, populations of elk grew unfettered. At their peak population, an estimated 18,000 elk ranged across the park, chomping on grasses and shrubs as well as the leaves, twigs and bark of trees like quaking aspen. This stopped saplings from establishing themselves, and surveys in the 1990s found no aspen saplings…
When wolves were reintroduced in 1995, the picture began to change. As wolf numbers rose, the elk population in the park dropped sharply, and it is now down to about 2,000.
The new study, published Tuesday (July 22) in the journal Forest Ecology and Management, surveyed aspen stands — specific areas of the forest where these trees grow.
The team returned to three areas surveyed in 2012 to examine changes to aspen sapling numbers. Of the 87 aspen stands studied, a third had a large number of tall aspen saplings throughout, indicating the trees are healthy and growing. Another third of the stands had patches of tall saplings…”We’re seeing significant new growth of young aspen and this is the first time that we’ve found it in our plots.” These are young aspen with a trunk greater than 2 inches in diameter at chest height — which haven’t been seen there since the 1940s…
This means a boost to berry-producing shrubs, insects and birds and also species like beavers, because the trees are a preferred food and building material for the semi- aquatic rodents, along with the willows and cottonwoods that grow near to water in the region.
Beavers recently returned to Portugal after being absent for 600 years.
Brazil’s rarest parrots have made a comeback, avoiding extinction.
In Florida, populations of manatees and sea turtles have rebounded.
Fish species are rebounding off the coast of California due to their young finding a sanctuary in abandoned oil rigs.
Scientists recently discovered that the world’s coral reefs are more plentiful than previously thought.
