ubbing up. Each of these methods negatively affects the environment in some way.
PAP: The very human presence affects the spread of alien species. Even scientists carry part of plants on the soles of their shoes and on their clothes, allowing them to settle in previously unreachable areas.
MD: It is impossible to completely eliminate our negative impact on the environment, but it can be minimized. We already have procedures that require scientists to disinfect and change clothing on boats that take them to naturally valuable areas. We also do that when combating the effects of climate change. We know that the return to gas emissions from pre-industrial times is impossible, but we try to strongly reduce these emissions to do as little harm to the planet and ourselves as possible.
PAP: In grocery stores, there are a lot of vegetables and fruits brought from different parts of the world. Are they also 'alien species'?
MD: Vegetables and fruits are settled or non-settled alien species, but usually not invasive ones. But it also depends on the climate zone. In the Polish climate, mango will not be an invasive species, but it can be one in the tropical zone. We are working on analysing the impact of climate change on changes in the range of invasive trees and shrubs in Poland. This analysis shows that even under the influence of the greatest climatic changes, many invasive species from the tropical zone will still be unable to permanently settle in Poland.
PAP: But this does not mean that bringing seeds of fruits, vegetables and flowers in a suitcase from a long journey is a good idea...
MD: This is illegal. The import of plants and their parts from outside the EU requires permission. This is also because the spread of alien species often begins in areas around communication centres - railway stations, ports and airports. Then they appear in the city and if are not contained in time, they can 'escape' to suburban territories and further, to more natural areas. Another way is the purposeful introduction of alien species, for example in forests. We did that with black cherry and black locust. We can not get rid of them anymore, we can only limit their negative impact.
PAP: Which alien species of trees and shrubs are the most widespread in Poland?
MD: The black cherry and black locust. I am running a project financed by the National Science Centre concerning the impact of these species on the functioning of forest systems, including the circulation of carbon and nitrogen. I want to find out how a specific amount of invasive species will affect the mass of the accumulated carbon and whether it will be advantageous from the point of view of the atmospheric carbon dioxide capture balance. This effect may vary depending on the species and habitats. For example, in South America, invasive shore pine is a very widespread species that binds a lot of carbon in its biomass, because it grows very quickly. On the other hand, it consumes a lot of water and dries adjacent areas. In addition, the tree is filled with a high amount of essential oils and sap, which promotes fires that cause even greater carbon dioxide emissions.
PAP: Are invasive species used to fight climate change?
MD: Such attempts are made in some places in the world. I have seen research results that indicate a large potential for the absorption of carbon dioxide by invasive species. But the climate is not only carbon, it's also water. Nothing is free in nature: a fast growing tree carries a photosynthesis process faster and while dong that, it consumes water. This also causes environmental conflicts between people. In Spain, a very popular species is eucalyptus. Its wood can be used after 8-10 years of growth, but it consumes so much water that it ruins the surrounding olive and citrus plantations. In Chile, desperate farmers often intentionally burn the eucalyptus.
PAP: At what stage are we in Poland? Do we fight invasive species, or do we try to work on two fronts and check which of them could help fight the effects of climate change?
MD: In Poland, we mainly fight invasi