When we think about deforestation, we think about the Amazon rainforest: iconic images of towering jungle trees being cleared to make room for ranching operations, and statistics about how many football fields per minute are being lost.
We may also think about the Canadian boreal forests, huge swathes of which are being leveled so that fossil fuel companies can extract the tar sands oil that lies buried beneath them.
And we may think of America’s Pacific Northwest, where it seems that environmentalists and loggers are constantly at odds over whether old-growth trees should be harvested for commercial use or preserved to provide wildlife habitat and inspire awe in each new generation of humans.
What most of us don’t think about is urban areas. But American cities are losing trees at an alarming rate. One study found that between 1975 and 2006, Minnesota’s Twin Cities region lost 14% of its forest cover. Percentage-wise, that’s actually more tree loss than the Amazon rainforest experienced over an equivalent period.
And a study published this past spring estimated that urban areas of the United States, taken as a whole, are losing 36 million trees a year. That’s net loss – the total decrease in the number of trees after adding back newly-planted trees. Dividing up the data by state, the researchers found that in recent years, only three states have seen a net increase of urban trees, and then only by tiny increments.
As explained in an earlier post, that’s a problem because trees in cities aren’t optional. When there aren’t enough trees around to absorb stormwater, clean air, moderate extreme temperatures, and give people a little relief from the stresses of modern life, providing all of those services through other methods ranges from expensive to impossible. The end result is that we pay more in taxes and get back a lower quality of life.
We can reverse this trend. First, we can demand that our local officials respect and protect our urban trees, instead of damaging or destroying trees that pose minor inconveniences. Second, we can actively work to plant a healthy next generation of trees. No matter how well we care for mature trees, they will eventually die. When that happens, it is too late to plant a replacement tree – it could be decades before the new, young tree is able to provide benefits equivalent to what its adult predecessor was doing. Instead, we need to nurture an urban forest in which every canopy tree has a younger companion nearby, ready to quickly take over the older tree’s duties when its life inevitably comes to an end.