In a North Carolina national park, about 11 percent of the trees have withered in the past 30 years. Hardly any leaves, hardly any branches. Like so many others on the US east coast, they made their acquaintance with the salty Atlantic. What can you do?
On the North Carolina coast in the southeastern United States there are “Wooden Graves”. Graves, because they are the remnants of what once stood there: large, healthy trees. Now they are just gray and pale. The trunks have few branches and hardly any leaves. You ate wrongly. “You can think of it as if we humans were eating a portion of salt water,” says ecologist Constantin Zohner from ETH Zurich, explaining the problem in the ntv podcast “Learned again”. “Salt water removes more water from the body. It is a cell poison that causes you to die.”
The dead trees in North Carolina are one of the clearest signals of the effects of climate change on global ecosystems. Because they stand right on the Atlantic coast and with their roots suck up more and more salt water due to the rising sea level, which they then slowly poison. In the “Alligator River National Wildlife Refuge”, a national park, there used to be beautiful green forests. In the past 30 years, however, 11 percent of the trees have withered. This is the result of several researchers who have examined forest decline in North Carolina and have collected specific data for the first time.
Their conclusion is particularly bleak because the problem affects not just one state, but the entire US east coast. From Maine in the north on the border with Canada to Florida in the south. The rising Atlantic is gradually poisoning huge areas of forest. Mainly because storms wash the salty floods far inland with increasing frequency. Normal forests could not cope with this at all, says ecologist Zohner: “The trees simply die.”
Half the life expectancy
Nienhagen in Mecklenburg-Western Pomerania is also familiar with the problem: The gray, knotless trees of the ghost forest on the steep coast of the small community in the Rostock district are popular with tourists, but appear just as sad as their conspecifics in the USA. The strong Baltic breeze blows away the few nutrients that are on the ground. Instead, beeches drink the salty sea water every time they flood and slowly perish. Healthy beeches usually live up to 300 years. In Nienhagen, their life expectancy is only half as high.
Ecologists see saltwater death as another cause of global forest death that has so far been given little or no consideration. It is well known that man destroys forests. Hurricanes and cyclones also play their part. More and more often due to climate change.
This also applies to forest fires: if the average temperature rises, trees, bushes and other plants gradually dry out. One spark is enough and everything is on fire. In regions like Australia and California now almost all year round.
Natural Barriers to Dying Trees?
Climate change creates another problem. More and more water evaporates due to the high temperatures and heat waves. The dry periods are increasing, the plants have too little to drink and are susceptible to diseases such as fungal attack. 10,000 years ago, forests covered more than half of the land surface, now only a third. And it gets a little less every year.
“It is difficult to express this in numbers because we do not know which direction climate change is headed in,” replied Constantin Zohner when asked how much forest cover could be reduced. “But huge and above all extremely important areas are affected, such as the Amazon. There, especially in peripheral areas, it will be much too hot and the risk of forest fires will increase.”
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If you want to prevent forest death, you have to stop climate change. It will be many decades before this succeeds, if at all. By then, it will be too late for many forests. This is why North Carolina and other coastal regions with dying trees are considering protecting them from the Atlantic with natural barriers. A kind of dike made of sand, stones and plants that can cope better with the salt water.
Mangroves for the coast
A more radical approach is to plant completely new forests on the affected coasts with trees that are more salt-tolerant. Few ecologists consider this solution to be ideal because they want to preserve nature as it is. Especially in the long-term fight against climate change, however, every healthy forest is a welcome companion.
What could such a forest look like? In the very south of Florida, where Miami Beach meets the wetlands of the Everglades, nature has adapted perfectly to the salty Atlantic. Mangrove trees grow and flourish there, they can easily take root in low-oxygen layers of the earth and can secure sufficient nutrients – and would be a very useful tool in the fight against climate change, as Constantin Zohner explains. “The first thing I jokingly thought when I read the study was: Maybe this will give us a few more mangrove forests,” the ecologist tells the podcast. “They are excellent for nature because they bind a lot of CO2 and protect the coast against waves.”
Bavarian forest as a model
A tropical mangrove forest in Mecklenburg-Western Pomerania? Presumably it would attract no less tourists than a ghost forest. Or maybe it would just be best to leave nature to its own devices. Especially when it looks like it’s too late. Like the Bavarian Forest. “They said there: we will no longer intervene. We will let nature run free,” says Zohner. “Now you can see that robust mixed forests have emerged over the last ten years, which can cope much better with stressful conditions.”
In the Bavarian Forest, the air used to be so dirty, the ground so acidic and the temperature so high that many trees became sick. Then the bark beetle attacked him. The first time 40 years ago, then again and again every few years. The dying trees attracted him, he killed them and thus paved the way for new, healthy descendants. They are also worth a visit. It is then beautiful, however, no longer creepy.