Not all forest management practices aid climate change mitigation as per the findings of an extensive study published in the Science journal on Thursday.

Not all forest management practices aid climate change mitigation as per the findings of an extensive study published in the Science journal on Thursday.

Forests are crucial for the global carbon cycle. In addition to the ocean, forests are large carbon sinks. Through the key role they play in storing carbon, their role in mitigating climate change is crucial. Against this background, sustainable forest management should maximize forests’ ability to remove carbon from the atmosphere, thus becoming vital carbon sinks.

Yet, according to one research team with the Laboratory of Climate Science and Environment – Gif-sur-Yvette, France – not all forest management practices aid climate change mitigation. The study analyzed forest management in Europe, looking at historical data and using data to construct models showing the effects of deforestation, reforestation and afforestation over carbon removal and carbon release. The timeframe of the study spanned 260 years, starting with 1750.

Forests are generally perceived as miracle workers when it comes to cooling our planet. However, this perceived notion fails to take into account the type of forests and practices they are subject to. Depending on the region of the world where the forests are located, they could be more or less effective carbon sinks. Overall, forests stock about 2.4 billion metric tons of carbon per year. It would stand to reason that the more trees are planted, the more carbon is absorbed.

Here is the European forests scenario. Over a period of 260 years, the forested surface of the continent grew by 10 percent. Despite the increase in forested surface, the temperature on the continent also increased by 0.12 degrees Celsius.  

This seemingly paradoxical finding is pinned to forest management practices. Rapid industrialization and meeting the needs of a growing population meant cutting down forests at a rapid pace. 200,000 square kilometers of forests were lost. Economic reasoning replaced the lost forested surface and even made up for it. However, the type of forests which replaced the lost ones were less effective carbon sinks. Following the economic reasoning, commercially valuable conifer tree forests replaced the broadleaf tree forests which were lost.

During the 260 years under scrutiny, conifer tree forests gained 633,000 square kilometers. At the other end of the spectrum, the broadleaf tree forests lost 436,000 square kilometers. Reforestation and afforestation efforts clearly favored the former. According to Kim Naudts, the lead author of the study and environmental scientist:

“By changing the forest, we also make changes to the amount of radiation, water and energy that the forest releases”.

Conifer tree forests, while commercially valuable, are darker than other forest types. Due to their color, heat is trapped here. Moreover, conifer tree forests release less water through evaporation. As these types of forests are exploited for their commercial value, more carbon is released in the atmosphere. Altogether, these factors contributed to the temperature increase of 0.12 degrees Celsius.

Against this background it’s clear that not all forest management practices aid climate change mitigation.

Photo Credits: Wikipedia