A team of WWF specialists and partners conducted the third consecutive year of monitoring of biodiversity in forests threatened by climate change. The study is part of the project “Climate-smart Forest Management in Central and Eastern Europe” (CLIMAFORCEELIFE) and includes collecting information on species of birds, insects and bats with high conservation value and inhabiting areas affected by climate change.
Biodiversity monitoring is part of the measures to adapt to climate change in one of the most vulnerable forests in our country – Scots pine plantations. The forest sites where the fieldwork is being carried out cover an area of 800 ha. They were carefully selected by experts from WWF and the Southwestern State Forest Enterprise (SWSFE), according to specific criteria, taking into account factors such as climate, type and density of the forest, geographical location, etc.
For the results of the monitoring to be reliable, it must be conducted over a long period of time and follow a certain methodology. The monitoring is planned to continue until 2027 in order to build a rich database.
“As early as early 2025, we will publish a report with the mid-term results of the monitoring in Bulgaria and Slovakia. One of the leading conclusions so far in it is that the greatest diversity of bird, insect and bat species inhabit natural and old forests. We at WWF hope that in a few more years, some of the artificial pine plantations in the areas where we work will begin to acquire the character we are striving for. This way, we will begin to observe an increasingly greater diversity of species in them,” commented Yana Barzova, Senior Expert in the WWF Forests Program.
The monitoring is carried out in three types of forest sub-compartments:
– in artificially created Scots pine forests, where the SWSFE conducts the thinning activities;
– in Scots pine forests with similar characteristics, but in which there will be no intervention to increase their sustainability. These forest sub-compartments will serve as a reference;
– in natural forests – again they will serve as a reference, because by definition they are the richest in species diversity.
Birds
The specific sites selected for the study of animal species fall within the territory of Vitosha (State Hunting Unit “Vitoshko-Studena”) and the area around Logodazh (State Forest Unit “Nevestino”). The target groups include birds, insects and bats, and among the most interesting species that the experts encountered this year were: the white-backed woodpecker, saproxylic beetles and Bechstein’s nightjar. They are typical inhabitants of old forests and are an indicator of healthy and sustainable habitats. In the last two years, WWF specialists had doubts about the presence of the white-backed woodpecker (Dendrocopos leucotos) in one of the forest sub-compartments, but only this year were they able to prove it. It is important to note that in bird surveys, different species are registered visually or by sound by walking pre-selected transects. This is done early in the morning, when the birds are most active.
Insects
Entomologist Assoc. Prof. Dr. Rostislav Bekchiev plays a key role in the field monitoring of insects. With his help, the WWF team came across one of the rarest and most beautiful beetles – the Rosalia longicorn (Rosalia alpina). Other interesting species that were registered include: Morimus asper, Carabus intricatus and others.
Bats
The most time, effort and attention is required for bat monitoring. It keeps experts awake all night to check the stretched nets with which they catch them. This year, seven species were caught in them, including: Plecotus auritus, Myotis bechsteinii, Nyctalus lasiopterus), and Barbastella barbastellus.
The study is done in the evening, but the nets are set up during the daylight hours. The individuals caught in them are carefully released and the experts determine their species. Everything is done quickly so that the bats can be released back into the wild. In addition to being caught, the bats are also identified using echolocators. The recorded sounds are subsequently processed with special software that allows the experts to identify the specific species. Echolocation detectors detected species such as: Pipistrellus pipistrellus, Pipistrellus pygmaeus, Nyctalus noctula. For the study of bats, WWF relies on the expert knowledge of Elena Stoeva.
“Each year, one volunteer joins the bat monitoring. Often these are students who study biological sciences and have a keen interest in nature. We at WWF are happy to be able to encourage their interest, satisfy their curiosity about the environment and provide them with the opportunity to build on their knowledge with practical experience in the field,” says Barzova.
Other measures for adapting forests to climate change
The monitoring of biodiversity is just one of the measures for adapting forests to new climate conditions. The others include:
– preparing an analysis of the health of forests using satellite images;
– conducting experimental afforestation with drought-resistant tree species;
– conducting thinning in Scots pine forests, which are already largely affected by various natural disturbances. Many of these forests are artificially created in atypical places for them, and this, together with climate change, are among the main reasons why they are increasingly becoming victims of damage and drying out. It is believed that the thinning will support the development of natural vegetation, which is more resistant to climate change.
