Butterflies are key elements of biodiversity – an important part of food webs and the health of ecosystems. These insects are among the most climate-sensitive living beings – warming disrupts their rhythm of life and threatens their existence. Why are we losing butterflies…Pavel Vassilev, who is completing a master's degree in "Biodiversity" at the Technical University of Dresden, speaks to FACT. He has a bachelor's degree in ecology and environmental protection at the University of Applied Sciences Zittau/Görlitz, Germany, speaks.
- Mr. Vassilev, why are butterflies disappearing? Is human activity or climate killing them more?
- The extinction of butterflies is due to a combination of many factors. This rule applies to almost all extinctions - a set of problems that occur at the same time. There has been a significant decrease in the number of butterflies, as well as many other insects, for years. Human activity is a very serious factor, and climate change is further worsening the situation. It should also be borne in mind that human activity is the one that increases the amount of heat-trapping gases in the atmosphere the most. At the moment, the biggest threat to butterflies is pesticides, artificial fertilizers and the destruction of suitable habitats, but the negative effects of climate change are about to reach this level.
- What indicator are butterflies for the state of nature?
- Butterflies are a very important part of nature - they allow various ecosystems to exist. If a green area is home to many different butterflies and moths, it means that the area is not polluted and has good vegetation. Butterflies are needed by flowering plants so that they can reproduce sexually and produce genetically rich offspring that are resistant to negative external factors. Most caterpillars are herbivorous, and they allow for a high plant species richness because they do not allow one type of plant to become dominant and take over the others. Many butterflies also mean many birds, lizards, amphibians and insectivorous mammals - that is, good biodiversity.
- Is their disappearance simply a biological loss or an important warning?
- Their disappearance must be urgently counteracted. It will affect everyone if it is not stopped. Without pollinators, there will be economic consequences, ecosystems will collapse, and this will lead to even more serious ecological disasters. Human survival is linked to these insects, as strange as it may sound.
- Climate change, intensive agriculture and habitat loss are already negatively affecting dozens of species on the map of Europe. Where is this most pronounced?
- There are still no accurate studies in Bulgaria, but if you look at the map with areas rich in butterflies, you can see that large areas of the Danube Plain and the Thracian Lowland are not marked. And these are territories with intensive land cultivation. Bio-cultivation of fields gives certain types of flowers, such as poppies, a chance to grow between planted crops. This is not the case with intensive agriculture. And in Bulgaria, agriculture is mainly intensive and not in harmony with nature. In all of Europe, the populations of animal species and plants that live in fields and meadows are decreasing the most. It is important for farmers to use part of their income to create conditions for nature. Concepts for a tandem of man and nature exist and have proven successful, a good example is the UNESCO biosphere reserves. There are extinct swamp species in Bulgaria. A very large part of the swamps in the country have been destroyed. There are no measures for their re-creation, and the few that exist - such as the Boyana and Dragoman swamps - are under constant threat. Swamps are one of the most important tools for saving the climate and species.
- What is the diversity of butterflies in Bulgaria?
- Bulgaria is in the top 5 in terms of species diversity in the EU - 211 documented species. This is due to the rich diversity of ecosystems, the diverse relief and climate. Many species of butterflies are “narrow specialists“ - dependent on very specific conditions and are often adapted to only one type of forest or to a small number of plants.
- Butterflies are key elements of biodiversity - an important part of food webs and ecosystem health, and this declines as they disappear. What's next?
- Urgent measures are needed for their conservation. The good thing is that butterflies are small, harmless animals that reproduce quickly and in large numbers. This means that measures for their conservation can be implemented much faster and cheaper, unlike, for example, large mammals. We need landscaping in populated areas, which will strengthen the populations of local butterfly species. This means stopping frequent mowing, ending spraying with glyphosate and other pesticides and quickly planting European species of trees, shrubs and flowers. It is important to include people who are not experts here. Anyone who owns land can create a kind of mini reserve. In reserves and nature parks, the zoning scheme is often applied - one zone is left untouched, where nature can develop on its own, and another zone is maintained in order to save certain species. This can be done at home - one corner of the yard can be left to go wild, and another - to be adapted for butterflies by planting different flowers that bloom all year round, creating a small area of bare soil, piling up branches and stones and planting trees such as linden, hazel, hornbeam, elm and oak. It is also important for zoos, museums and botanical gardens to do pedagogical work and work closely with kindergartens, schools and universities on this topic. And state institutions should develop national plans for the conservation of as many species as possible and implement them.
- Climate change is pushing high-altitude species higher and higher. Butterflies are looking for coolness, is this how they feel the warming?
- This is one of the effects. Another is the newly created competition between species due to the change of seasons. Mild winters also prevent the survival of caterpillars until next year. Drought also harms.
- Southern and Southeastern Europe, including Bulgaria, are in the risk zone. Why could the most butterfly species be lost here?
- The risk is high all over the world. The Balkans are a special area because they have many endemics – species that are not found elsewhere. These species have no reserve populations. If they disappear in our country – they will disappear forever. Butterflies are part of the Bulgarian landscape and it would be very sad and a great shame if we were left without them.