Could Nitrogen Pollution Give Tropical Flora a Much Needed Boost?

Global warming and subsequent climate change is directly linked with human activity on our planet. The greenhouse effect is amplified by our need for energy, burning fossil fuels and pumping vast quantities of CO₂ into our atmosphere. To make things worse, the plants that form the Earth’s “lungs” in the tropics are being destroyed on a massive scale, so less carbon dioxide can be scrubbed from the air. However, it’s not all bad news. Industry and agriculture also generate large amounts of excess nitrogen pollution and scientists now believe that this nitrogen (a main ingredient for fertilizer) may help to increase tropical plant growth by up to 20%…

From our high school classes, we all know that green plants, through photosynthesis, absorb atmospheric carbon dioxide. It is essential for plants to flourish. By far the largest absorbers of carbon dioxide are the tropical rainforests in the Amazon basin, central Africa and southern Asia. They are often referred to as the “lungs” of Earth, as they absorb much of the atmospheric CO₂ and provide balance to the carbon budget of our climate. If this resource is removed through wholesale deforestation, more CO₂ collects in the atmosphere and global warming is amplified by the increase of this greenhouse gas.

However, help may be at hand. Taking the results from over 100 previously published studies, David LeBauer and Kathleen Treseder from the University of California Irvine, believe they have found a trend that suggests a strong link between nitrogen pollution and increased plant growth in tropical regions. Increased plant growth is a welcomed consequence of human activity, as faster plant growth means more plants to absorb more CO₂. Although deforestation is a global catastrophe (much of the ancient forests will never recover and a vast proportion of plant and animal species are now extinct), the new research published in Ecology may influence future climate change models.

“We hope our results will improve global change forecasts.” – David LeBauer, UCI graduate student researcher of Earth system science and lead author of the study.

Nitrogen pollution comes in many forms, the most obvious being from agricultural activity (fertilizer) polluting water supplies and industrial burning emitting nitrogen into the air. What’s more, nitrogen pollution is on the increase, especially in developing countries.

Nitrogen pollution has often been ignored as a possible growth agent in the tropics, as other fertilizing elements are in short supply (typically, if one element is low, no matter how high the other element is, it will have little or no effect on plant growth). Phosphorus for example, is low in tropical regions, but according to the new research, this doesn’t seem to factor and plant growth is increased by 20% regardless.

LeBauer adds: “What is clear is that we need to consider how nitrogen pollution interacts with carbon dioxide pollution. Our study is a step toward understanding the far-reaching effects of nitrogen pollution and how it may change our climate…” It may only be a step, but at least it’s a positive one.

Source: Physorg.com