Neotropical Forests under Risk: How Climate Change alters Timber and Carbon Storage
Neotropical forests, the lush and biodiverse ecosystems of Central and South America, are a cornerstone of our planet's health. These forests are not only home to an astonishing 10% of the world's known species but also act as the Earth's lungs, storing an estimated 86 billion tons of carbon. They are vital carbon sinks, absorbing carbon dioxide from the atmosphere and helping to mitigate climate change. Additionally, these forests are a significant source of timber, supporting local economies and global industries. However, a new study reveals a troubling trend: climate change is altering the very nature of these forests, threatening their ability to provide timber and sequester carbon.
The Role of Neotropical Forests
Neotropical forests are a key part of the fight against climate change. Trees absorb carbon dioxide through photosynthesis and then store it in their wood, roots, and leaves. This process, called carbon sequestration, is key to regulating the Earth's climate. These forests also provide valuable timber resources, which are used for construction, furniture, and countless other products. It's important to manage these forests in a sustainable way for both environmental and economic reasons.
The Impact of Climate Change
Climate change, which is mainly caused by human activities, is leading to some pretty big changes in weather patterns around the world. In neotropical forests, we're seeing changes like rising temperatures, altered rainfall patterns, and more extreme weather events like droughts and wildfires. These changes are really affecting the dynamics of these ecosystems.
As temperatures rise, trees are under more stress, making them more vulnerable to pests and diseases. Changes in rainfall patterns are disrupting the water cycle, which is leading to both droughts and floods. Droughts can weaken trees, making them more susceptible to fire, while floods can damage roots and soil, hindering tree growth. Wildfires are becoming more common and intense as a result of dry conditions, releasing stored carbon back into the atmosphere.
The Research Findings
A recent study by Hiltner et al. (2021) published in the journal Forest Ecology and Management has given us a better understanding of the extent of these impacts. The researchers used the dynamic forest model FORMIND to simulate the effects of climate change on neotropical forests in French Guiana. The results are pretty alarming.
The study found that if greenhouse gas emissions keep rising, the biomass of these forests could drop by as much as 25% by the end of the century (Figure 1). This means that the forests will be much less able to store carbon. On top of that, the study also found that climate change could lead to a 40% decrease in the volume of timber that can be sustainably harvested from these forests (Figure 2).
Key insights from figure 1
The figure illustrates the projected impact of climate change on the aboveground biomass (AGB) of neotropical forests in French Guiana, both with and without logging. AGB serves as a crucial indicator of a forest's carbon storage capacity, as well as its potential for timber production.
Unlogged Forests (Panel a): In the absence of logging, climate change is projected to cause a decline in AGB across all climate scenarios. The most severe scenario (RCP 8.5) shows the steepest decline, with AGB decreasing by roughly 25% by the year 2300. This signifies a significant loss in the forest's ability to store carbon, potentially exacerbating climate change.
Moderately Logged Forests (Panel b): When moderate logging is introduced every 65 years, the overall trend of AGB decline persists under climate change. However, the cyclical nature of logging creates fluctuations in AGB, with temporary increases after each harvest followed by gradual declines until the next logging event.
Climate Change Intensifies Impacts: The figure emphasizes that the negative impacts of climate change on AGB are amplified under more severe climate scenarios (RCP 8.5). This suggests that urgent action to mitigate climate change is crucial for preserving the carbon storage capacity of these forests.
Logging and Climate Change Interaction: While logging itself causes temporary reductions in AGB, the interaction between logging and climate change seems to exacerbate the long-term decline in AGB. This highlights the need for sustainable forest management practices that consider the compounding effects of both logging and climate change.
Relevance to the Blog
This figure directly supports the blog post's central theme: climate change poses a significant threat to the ecological integrity of neotropical forests. It visually demonstrates the projected decline in AGB, which translates to reduced carbon storage and potential timber yields. The figure reinforces the urgency of adopting sustainable forest management practices and mitigating climate change to safeguard these vital ecosystems.
Key insights from figure 2
The figure illustrates the complex interactions between logging frequency (cutting cycle) and climate change scenarios on timber yield in a neotropical forest. Timber volume (TV) is a key indicator of the economic potential of forests, and its sustainable management is essential for balancing ecological and economic needs.
Timber Volume Decline Under RCP 8.5 (Panel a): The graph shows a consistent decline in timber volume over time under the most severe climate change scenario (RCP 8.5). This indicates that as climate change intensifies, the forest's capacity to produce timber is significantly reduced, regardless of the logging frequency.
Cutting Cycle Influence (Panel b): The average timber volume harvested per logging event increases with longer cutting cycles. This suggests that less frequent logging allows trees to grow larger, resulting in higher timber yields per harvest. However, this benefit seems to diminish under the most severe climate scenario (RCP 8.5).
Total Timber Volume Over Time (Panel c): The total timber volume harvested over the long term shows a nuanced relationship with cutting cycles and climate scenarios. While longer cutting cycles generally lead to higher total timber volumes, this trend is less pronounced under the RCP 8.5 scenario. This implies that the negative impacts of climate change on forest productivity may outweigh the benefits of longer cutting cycles.
Relevance to the Blog
This figure directly supports the blog post's key message: climate change poses a significant threat to the economic potential of neotropical forests by reducing their timber yields. The figure highlights the complex interplay between logging frequency and climate change, demonstrating that sustainable forest management strategies need to consider both factors. It also underscores the urgency of mitigating climate change to preserve the long-term productivity of these forests and the economic benefits they provide.
Consequences for the Environment and Economy
The consequences of these changes are far-reaching. With less carbon being stored, more carbon dioxide will stay in the atmosphere, making climate change worse. This could also lead to more extreme weather, rising sea levels, and other serious problems.
With less timber around, local communities and businesses that depend on these forests for their income could be hit hard. It could also lead to more deforestation as people look for timber from other sources, which would contribute even more to climate change.
What Can We Do?
The future of neotropical forests hangs in the balance, but it's not too late to act. There are several things we can do to mitigate the impacts of climate change on these vital ecosystems:
- Support sustainable forest management practices: Encourage and support logging practices that prioritize the long-term health of forests over short-term profits.
- Advocate for climate policies: Support policies that aim to reduce greenhouse gas emissions and transition to a clean energy economy.
- Reduce your carbon footprint: Make changes in your daily life to reduce your carbon emissions, such as driving less, conserving energy, and eating a more plant-based diet.
- Support conservation organizations: Donate to or volunteer with organizations working to protect and restore neotropical forests.
A Call to Action
The fate of neotropical forests is linked to our own. It's important to remember that the health of these forests is crucial for the health of our planet and the well-being of future generations. If we take action to address climate change and protect these forests, we can make sure they keep providing the essential ecosystem services we all depend on.
Reference
Hiltner, U., Huth, A., Hérault, B., Holtmann, A., Bräuning, A., Fischer, R., 2021. Climate change alters the ability of neotropical forests to provide timber and sequester carbon. For. Ecol. Manag. 492, 119166. https://doi.org/10.1016/j.foreco.2021.119166
