It is a long-held belief that forests act like carbon sinks since trees absorb carbon and prevents it from ending up in the atmosphere and worsen the greenhouse effect. But a group of researchers found that not all forests help fight climate change. In fact in Europe planting some types of trees over the past 250 years has worsened climate change, scientists claim.
The study revealed that forest management decisions taken between 1750 and 2015 failed to tackle climate change and they might even contributed to it even though there were a lot more reforestations efforts to offset deforestation over that period.
Researchers used computer models to simulate how forested land in Europe has been managed over the past 250 years. The team took into account data on both deforestation and reforestation activities, and types of tress that were planted by humans to compensate for the harvested wood.
Computer models revealed some issues that escaped scientists’ attention over the past two centuries or so. First, they revealed that although the net gain in forest gain obtain through forest management decisions was quite significant, the amount of stored carbon was lower than natural forests’ was before reforestation efforts.
Second, the models revealed that during reforestation Europeans preferred conifer trees because of their higher commercial value though the land was previously populated with broad-leaved forests such as oaks.
Finally, computer models also showed that in the last 250 years, about 85 percent of European forests were affected by forest management decisions such as deforestation, reforestation tree thinning and so on.
As a result, European forests produced 3.1 billion metric tons since 1750 instead of reducing the levels of extra carbon in the atmosphere. Scientists noted that these forests now have a huge ‘carbon debt’ that might have contributed to climate change.
Kim Naudts, a researcher at University of Versailles and lead author of the research, noted that forest in Europe were less efficient in storing the harmful greenhouse gas because humans brought most wild forests under their management.
Naudts explained that past research had shown that wild forest store carbon more efficiently than their managed counterparts. Furthermore, opting for conifers to reforestate land previously occupied by broadleaved trees had an unwanted consequence.
Scientists argue that since conifer leaves are tinted in a darker tone than broadleaved trees’ leaves, they also attracted more sunlight worsening global rising temperatures. Plus, conifers tend to retain more water and prevent it from evaporating thus promoting a dry environment around them which has also contributed to climate change.