Eastern hemlock is facing extinction.A little fly can save them


Deciduous forests are made up of many different types of trees, which shed their leaves every winter-oak, birch, ash, maple, and poplar. When an ash tree disappeared from the deciduous forest—perhaps because it was killed by the emerald gray borer—other tree-lined trees were crowded with slaughter. Hemlock forest is dominated by one type of tree. They grow in huge, undulating, homogeneous green forests, full of vitality 365 days a year. When the hemlock disappeared from the hemlock forest, not much remained.

Tsuga is a basic species, which means that they play a key role in building ecological communities. Their greatest contribution is the deep shadow they created. Only 1% of the sunlight hits the hemlock canopy to reach the forest floor. The feathery branches of the tree slope down to the ground instead of upward, forming a low dome. The temperature under this green tent may be 10 degrees Fahrenheit lower than the outside world at the top of the tree, and the temperature at the top of the tree is 5 to 10 degrees lower.

In winter, the snow in the tent will not fall to the ground. Deer gather around the branches of hemlock, away from the deep snow under the deciduous trees. The wrinkled grouse and spotted owl nest in the upper canopy of the hemlock. Snow hare gnaws on the green branches. Porcupines gnaw on bark rich in tannins. In spring, when the sun is shining and melting snow and ice elsewhere, hemlocks retain a ring of snow on their trunks, and this snow slowly dips into nearby streams and creeks to keep them cool. Brook trout relies on this ice water for cooling, as do many species of salamanders, frogs, toads, and flies.

Humans know it, even if they don’t.Hemlock with water More conservative Compared to hardwood species, because their dense branches create a humid and cool microclimate.Harvard forest ecologist Ovig said: “If the hemlocks in the streams are replaced by hardwoods that consume more water, then at least in the summer, the streams may dry out.” These streams are used for swimming, fishing and recreation— —The main part of the Northeast Regional identity. Regardless of where they grow, hemlocks can provide economic and aesthetic benefits for humans.A sort of learn A five-year study of the decline in hemlocks in nine counties in central Connecticut and Massachusetts found that the resulting real estate value fell by $105 million.

“Most people just think of hemlock as this green thing,” said Whitmore of Cornell University. “But when you delve deeper, you will see a variety of truly important ecosystem functions that are related to the cooling and climate they create.”

Hemlock is not only beneficial to small animals and humans living nearby. They are also very good at capturing carbon dioxide.

According to a study, hemlock can absorb about 12 metric tons of carbon dioxide for every two and a half acres. Research in 2002 Compare hemlock with other tree species.This is more carbon dioxide2 Compared with the oak and ponderosa pine studied and analyzed. But the furry adelgid can transform hemlock from a carbon sink into a carbon source. This already happened in the Harvard Forest in 2014. The researchers documented a hemlock forest that began to produce carbon instead of sequestering it. “With the disappearance of hemlock, forests can act as a source of carbon,” Orwig, who helped document the transition from carbon source to carbon source Study in 2020, Say.

Harvard before learn It shows that between 2000 and 2040, the long-haired Adjid can reduce the carbon storage capacity of northeast forests by 8%. But the study and other studies predict that hardwood species, particularly an opportunistic tree called black birch, will eventually replace dead and dying hemlocks—researchers have spotted a trend in the forests of the Northeast. By 2040, Harvard’s research predicts that these black birch trees will capture 12% more The carbon is better than the hemlock they replace. Audrey Barker Plotkin, a senior scientist at Harvard Forest, has been studying the effects of intrusions on hemlocks for many years, she said, but in the short term, a reduction of 8% in carbon sequestration is one thing. event.


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