What Nitrogen Can Tell Us about Climate Change

When we think of air, we think of oxygen, but in fact, 78 percent of the air we breathe is nitrogen and only 21 percent is oxygen. Nature’s nitrogen cycle, where nitrogen is taken from the air, put to good use by living organisms, and then released back into the air again, has kept this level in check for millions of years. But in recent times, this delicate balance is under threat by human activities such as burning fossil fuels and intensive farming, which release nitrogen pollutants into the atmosphere.

Daniel Minikaev, an early-stage researcher at the Faculty of Science and Technology at the Free University of Bozen-Bolzano (unibz), is looking at the effects of this excess nitrogen on forests in South Tyrol, in northern Italy. He’s studying nitrogen deposition, where nitrogen is absorbed by plants and used to make essential components like DNA, protein, and chlorophyll – essential for photosynthesis and giving plants their green colour. “Air pollution is rising and also nitrogen compounds in the air,” he says. “This could lead to a positive impact on plants [such as stimulate growth], but could also have some negative impacts [e.g., poor soil conditions]. It could potentially go either way, depending on the particular ecosystem, the amounts of nitrogen, and whether certain thresholds are reached.”

South Tyrol, where unibz is located, is a picturesque mountainous area covered in forests, perfect for this type of study. Daniel says that this is a long-term project, which aims to spot trends and predict what might happen in 10 or 20 years’ time. Many nitrogen-deposition experiments done by researchers in the past have applied fertiliser (which contains nitrogen) just to the soil, but in reality, some nitrogen is absorbed by the tree canopy before it ever reaches the soil. Daniel and his colleagues are trying to mimic what happens in nature and are using a novel approach to simulate nitrogen deposition. “We have a system that releases the nitrogen-containing fertiliser in an aerial mist at the canopy level,” he explains. “We also treat plots on the ground to show there’s a difference between the methods, and we have untreated plots as a control.” Then, they carry out measurements to see how each method affects tree growth and the surrounding area.

After a stint living in the US and working at farmers’ markets, Daniel developed a passion for agriculture and nature. He went back to his native Israel to do a master’s degree in desert agroecology, and now this project has taken him in a different direction to work on forest ecology. His interest in climate change meant he was thrilled to be offered the chance to be part of a prestigious EU-funded PhD programme (ETN Skill-For.Action) on forest ecology and engineering at unibz. He says, “The programme involves 12 researchers from 12 different universities. We have some joint training sessions, and last month I spent a week training in Spain. It is all about sharing ideas, knowledge, and experience.” Having the chance to work on a multidisciplinary project was important to Daniel, and he enjoys the cooperation with other teams and universities.

Daniel is also collaborating with other Italian universities working on similar forest ecology projects, and he’s taking measurements on their sites too. He comments that when you’re working in natural field settings, you’re not in a controlled environment, so results are often quite tied to the place where you’re doing the experiment. “It could be a very similar forest elsewhere, with a very similar climate, the same tree species, but the soil could be different, and then a whole different array of results can happen,” he says. Even though results are very location-specific, they can also give ideas in a broader sense about what’s happening elsewhere. This acquired knowledge may give some insight on trends and processes by which climate change could affect other forests around the world.

Daniel joined unibz in December last year and relishes the idea of working on a new project area and expanding his skill set. He’s excited about what lies ahead and feels welcomed by the unibz community. He appreciates the fact that everyone in the university speaks English, so it’s easy to communicate with people. He joined unibz with a greater purpose in mind and says, “A big part of my decision to study ecology and continue with this type of research, especially in these days with climate change, is to hopefully have some positive impact on the planet and on nature.” Working at unibz will help him fulfil this ambition. “Don’t fear leaving your comfort zone to explore your curiosities and the unknown.”