Increasingly frequent and intense periods of drought pose a serious threat to forest ecosystems and trees around the world. According to recent studies, some species are increasingly at risk of dying as a result of repeated heat waves and droughts.
How do trees cope with drought?
During periods of drought and heat, even seemingly healthy trees can die. Recent scientific studies indicate that frequent extreme weather conditions increase the vulnerability of some tree species to damage and withering, with different species showing varying levels of sensitivity. The research was conducted in the Netherlands on 20 species of coniferous trees that were planted a century ago in one place. Analysis of annual growth rings from 1970 to 2013 was used for the study. With this approach, the researchers were able to assess how each species coped with the drought by analyzing its growth rate based on the distance between jars.
Additional observations after the extremely dry and hot years of 2018 – 2020 showed that some trees not only stunted their growth, but died completely. These species were so unresponsive that as many as seven out of ten trees withered away. Significantly, the key factor influencing tree mortality was not their ability to extract water, but leaf damage. Pine species that renew their needles every year have been shown to be more resilient, as opposed to those that retain their needles for a decade, which usually saves energy. In times of drought and heat, the ability to quickly replace damaged leaves has proven crucial to survival.
Tree planting vs. carbon emissions
Planting trees is widely considered one of the tools for mitigating climate change, mainly due to their ability to sequester carbon dioxide. Indeed, mass tree planting has the potential to remove significant amounts ofCO2 from the atmosphere, but to have a significant effect on a global scale, you would need to reforest areas the size of large countries.
There are also a number of arguments against the mass planting of trees about which we have already written in the pages of Water Matters. Critics point out that it does not take into account the full complexity of forest ecosystems and can lead to unintended ecological consequences, such as reduced biodiversity or negative impacts on local ecosystems, especially when monocultures are planted. In addition, there are concerns that focusing solely on tree planting could divert attention from more effective measures, such as reducing fossil fuel emissions and protecting existing forests from deforestation.
In light of current research, although tree planting has many advantages, it cannot be considered a one-size-fits-all solution to climate change. Rather, it is one of many components of a broad climate protection strategy that requires balancing different methods of protection.
Forest fires – risks are increasing
One of the main effects of forest fires is the emission of large amounts ofCO2. Trees, which are stores of carbon, release the stored carbon back into the atmosphere when they burn. Forest fires also emit other greenhouse gases, such as methane and nitrogen oxides, which also contribute to the greenhouse effect. In contrast, the destruction of vegetation during fires reduces the amount of water that enters the atmosphere through transpiration. Local disturbances to the hydrological cycle can lead to reduced precipitation in the region and alter the ecosystem.
Researchers at the University of Utah have modeled the risk of tree death in the United States from wildfires, climate stress and insect attacks, predicting an increase in these threats in the 21st century. The results of the study indicate that the risk of wildfires could increase up to 14 times by 2099, depending onCO2 emission scenarios.
Protection of forest stands – necessary actions
Preservation of forest stands is essential to the global ecological balance, especially to preserve biodiversity and protect natural resources. Trees play a key role in regulating hydrological and climatic cycles, sequestering carbon dioxide, and providing habitat for numerous species of flora and fauna. Sustainable forest management is not only an ecological imperative, but also a critical element in combating climate change and biodiversity loss at the global level.
Over the past few years, a number of measures have been taken and many strategies have been developed around the world that emphasize the importance of forest ecosystems, focusing on effectiveness in preventing forest degradation and promoting sustainable management. One of the more important initiatives is Climate-Smart Forestry (CSF), which involves integrating forest management with climate action. It is a set of strategies and management actions that enhance the benefits of carbon storage from forests and the forestry sector, in a way that also supports ecosystem services and cultural values.
In addition, analytical methods and research on forest ecosystem services are also important to assess their value in a sustainable way. Only broad case studies from different regions of the world help to understand what factors lead to the loss of forest ecosystems, enabling the development of effective conservation policies. The studies cited in the introduction demonstrate that effective forest conservation strategies must take into account both the physiological heritage of trees and the dynamic changes in the environment that can affect their ability to survive and thrive.
It is important to remember that a global and holistic approach to forest conservation that takes into account the diversity of forest ecosystems and local specificities is key. This, combined with advanced monitoring and research technologies, enables effective forest management and protection.
Main Photo: Maksim Shutov/Unsplash