Global climate change could make the Arctic a very different place by the year 2100. Barren tundra stretching across large expanses of northern Canada, Europe and Asia is vanishing. In its place, scientists are finding trees.
Researchers studying spruce trees in Northern Canada found that tree lines have moved northward and into higher altitudes over the last 300 years.
Movement during the mid twentieth century was really fast for trees. Tree lines on warm, south facing slopes moved upslope as much as 250 feet. In cooler areas, movement wasn't as quick, but tree density increased.
American and South Korean climatologists looked at sixteen global climate models and 100 years of climate observations to project the Arctic's future. They estimate that surface temperatures in 2100 could be from 5.6 to 9.5 degrees Fahrenheit warmer than today. It's no wonder that trees are on the move.
Northern Canada and Alaska could warm fast enough that shrubs and trees will replace tundra by 2059. Shrubs are expected to take over first. They have been known to spread by seed dispersal within a decade's time. Trees will not be far behind. Hot, dry summers trigger spruce trees to mass produce seed, and help seeds germinate. But that's not all.
Trees Create Trees
Just the presence of trees can help more trees grow. Forests are darker in color and reflect less sunlight than snow covered tundra, so forested areas get warmer. A cycle of warmth and tree growth begins.
Having more forests doesn't seem like a bad thing. But as trees move in, tundra plants such as lichens, mosses, and sedges are pushed out. Animals that eat those plants, including caribou, arctic hares and migratory birds, become endangered.