On 13-14 October 2021, in the cosy surroundings of the U Krobiána inn in Hostim by Berounn, in the heart of the Bohemian Karst, a seminar on traditional forest management took place. It attracted a diverse mix of people working in nature conservation and forestry. Discussions were held on how the reintroduction of previously common practices (leaf fall raking, low and medium forests, forest grazing) can contribute to the conservation of the biodiversity of today’s forests. The large turnout of more than sixty people from conservation practitioners, government employees and scientists only confirmed how topical this topic is in society. The seminar was organised within the framework of the ROTATE1 project, funded by the Norwegian Funds and the Technology Agency of the Czech Republic with an amount of EUR 1.05 million. The project aims to raise awareness on the topic of enhancing biodiversity in forests using traditional management methods.
The morning was devoted to an excursion to the nearby Vysoká stráň, where scientists from the Czech University of Agriculture (ČZU) have been monitoring plant diversity in areas regularly cleared of leaf litter for a long time. Pavel Skala, the Trávníček brothers from the Třesina2 association and Jindřich Prach from the Administration of the Czech Karst Protected Landscape Area guided the seminar participants through places where the association carries out forest grazing with Shetland ponies and primitive breeds of goats and sheep. Thanks to the established grazing and especially to the tireless work of the association in cutting down the scrub, they maintain a valuable mosaic of forest patches and forest-free areas. Josef Mottl (Bohemian Karst Protected Landscape Area) showed the participants how they plan to use various old stands of oak-birch to restore the stumps.
The afternoon belonged to a busy block of lectures.
Péter Szabó from the Botanical Institute of the Academy of Sciences of the Czech Republic (Institue of Botany of the Czech Academy of Sciences) spoke about the historical context of fallow raking in forests. In the 19th century, around 168,000 tonnes of leaves were still harvested, but in 1960 this form of management was completely banned by a new forest law. The reason for this was the depletion of the forest of nutrients, which had a negative effect on timber production, but also the gradual introduction of artificial fertilisers. The archives brought to light an event that took place in Horka nad Moravou in 1845 and reflected the social importance of raking forest litter at that time3.
It was followed up by a lecture by Jeňýk Hofmeister from the Faculty of Forestry and Wood Technology of the Czech University of Life Sciences in Prague (FLD ČZU) on the influence of litter removal on soil nutrient supply. Raking and removal of biomass from the forest significantly reduces the amount of nutrients in the forest soil, which is more pronounced on poor substrates4. Today, nitrogen also enters the ecosystem in the form of precipitation from increased emissions from industry and agriculture. Raking fallow land could therefore be one way to reduce eutrophication.
Jana Doudová from the Faculty of the Environment of the Czech University of Life Sciences in Prague (FŽP ČZU) presented the results of a ten-year experiment from Vysoké hillside in the Bohemian Karst in her lecture on the impact of raking in the forest5: “Raking not only increases the diversity of species associated with light forests, but in dry years it can even protect species that are particularly sensitive to lack of precipitation. Thus, burrowing can promote some species of conservation value and, conversely, help to eliminate ruderal species.”
In the following lecture, Petr Karlík and his colleague Tomáš Černý (both FLD ČZU) described the experience of re-establishing central forest from four experimental sites in the Czech Karst. They focused on stump regeneration in the areas in PR Na Voskopa, where they introduced the central forest and monitored its development and effect on biodiversity of fenced and unfenced areas. This is also where the excursion led the following day. The lightening of the vegetation has led, for example, to a significant expansion of the population of the endangered Gentiana bravita, which was not observed on the site before the intervention and now numbers about a hundred flowering plants.
Petr Karlík also presented the results of the repetition of vegetation records of the forests in the Karlice Valley from the thesis of the recently deceased botanist Dr. D. Blažková. Since 1956 many rare species have disappeared and the invasive Asian small-flowered buttercup has spread. This is mainly due to the high numbers of game (especially mouflon) and, more recently, to the decay of the tree cover due to climate change.
Tereza Kočárková from the Agency for Nature and Landscape Conservation (AOPK ČR) introduced the participants to the Integrated LIFE One Nature project. This project evaluates the impact of traditional forest management methods on biodiversity in forests and verifies their applicability for forest owners and managers. Thanks to this project, for example, the Bohemian Karst Protected Landscape Area can restore biodiversity in oak forests for the benefit of light-loving species.
After the break there was a lecture by Pavel Šebek and Lukáš Čížek (both ENTÚ BC CAS) with a slightly provocative title When, where and how to bother trees? Pavel Šebek drew attention to an apparent paradox: “Although our country has seen an increase in forest area in the last century, some once common light-loving forest species have, on the contrary, drastically declined.” Entomologists from the BC CAS are vocal advocates of thinning lowland forests and have shown in experimental plots in Podyjí NP how important connections to surrounding habitats, mosaicism and the dynamics of vegetation change are in restoring insect diversity in light forests.6 They also briefly discussed the conservation importance of tree head-pruning.
Karel Kříž (ZO ČSOP Vlašim) and Hanka Pánková (BÚ AV ČR) presented the project “Butterflies of the Vltava Slopes “7, where they presented the method of targeted tree damage as a suitable option for creating habitats for saproxylic insects and other invertebrate species. The tree ringing method may be a drastic method for some, but it is very effective if we want to lighten the site while leaving dead wood on the site.
Robert Stejskal (Podyjí National Park) informed the audience about how they are restoring coppice forests in Podyjí National Park. He showed that the disputes between conservationists and some naturalists about the preservation of light-loving insect species due to the absence of stumping are perhaps already a thing of the past.
In his presentation, Ondřej Vild with Radim Hédl (IB CAS) said: “We have been monitoring the impact of stumping on vegetation in Podyjí NP since 2015. We show a clear increase in the number of species of the herbaceous floor in the first years after the intervention. Initially, especially for ruderal species, but these are gradually receding.”
Jiří Rom (Prague City Council) in his pictorial presentation presented a range of regime interventions with a link to traditional management in the city of Prague. These include cattle, sheep and goat grazing, central forest and hill farming. He stressed the issue of public information and education.
Petr Kjučukov (FLD ČZU and Lesy ČR, s.p.) concluded the evening with a talk on ecological forestry and showed an example of transferring the experience from American stands (structural complexity enhancement) to ours, where the spatial and age structure of the forest is prioritized to promote the preservation of old trees and dead wood. Using the example of the Samechov forest or the NPR Ve Studené, we agreed that the current forestry policy should focus, among other things, on the issue of preserving abundant sterile stands.
After dinner, the participants were treated to two engaging lectures by Jaroslav Vojta from the Silva Tarouca Research Institute for Landscape and Ornamental Horticulture (VÚKOZ) and Jan Šebesta and Tomáš Koutecký from the Mendel University in Brno (MENDELU), focusing on the diversity of scrub pasture plants and the effect of fire on stumpage in Czech settlements in the Romanian Banat8,9. It shows that when restoring treeless forests, it is necessary to maintain a certain percentage of shrubs to maintain biodiversity. The well-known fact about the importance of the central forest for the diversity of the herbaceous understory was also confirmed.
1 https://starfos.tacr.cz/cs/project/TO01000132
2 https://spolektresina.weebly.com/
3 https://www.ibot.cas.cz/cs/2021/08/23/pripad-neopravneneho-hrabani-lesniho-steliva/
4 https://doi.org/10.1007/s10533-008-9201-z
5 https://doi.org/10.1111/1365-2664.12801
6 https://doi.org/10.1111/1365-2664.14019
7 https://motyli.csopvlasim.cz/
8 https://doi.org/10.1007/s12224-016-9279-3
9 https://ziva.avcr.cz/2020-1/pavel-kovar-ed-prenesena-krajina-cesky-venkov-v-rumunskem-banatu.html
Written by Petr Petrik, petrik@ibot.cas.cz