Overview

Human Impact on the Forest

The forests of Bohemian and Saxon Switzerland that you see today are not untouched wilderness. They are the result of thousands of years of interaction between people and nature in this remarkable sandstone landscape. Originally, the region was covered by Norway spruce in the cool gorges as a natural relict, while the dominant species were acidophilous beech and fir forests. In the Saxon Switzerland, these beech forests covered approximately 80% of the area, including submontane beech-fir forests and oak-beech forests. Silver fir was then a key tree species of the entire region, particularly in sandstone gorges, where under optimal conditions it accounted for 12-17% of the forest stand. On dry rocky ridges, pine forests were naturally common as a relict vegetation type, shaped by the special sandstone climate and soils.

A major turning point came in the High Middle Ages (12th-14th centuries), when people began clearing forests more intensively. In Saxony, large areas were cut for farms, pastures and villages, reducing forest cover significantly. In the area of the Bohemian Switzerland, people began selectively harvesting high-quality trees such as oak, fir and pine for economic activity. This selective pressure on both sides of the border fundamentally changed the species composition. The decline of the preferred oak and fir favoured the beech, which was not being used so intensively at that time.

From the 16th century onwards, forest use intensified further. Activities like charcoal production, litter removal, forest grazing and tar distillation put heavy pressure on the ecosystem.  In the 18th and 19th centuries, during the Industrial Revolution, forests continued to be managed mainly for timber production, resulting in degraded stands and the emergence of open heathlands. This brought the definitive end of natural diversity across the entire region. Pine and spruce were planted widely because they grew quickly, even on sites where they were not naturally well suited. For example spruce was planted even on dry and rocky sites. This led to dense, even-aged conifer stands replacing the older, more diverse forests that had existed for centuries.

The 20th century sealed this development in both parks. Large insect outbreaks, like the so-called Nun Moth calamity in the 1920s, caused extensive damage and led to widespread reforestation with more conifers. Thus arose vast, even-aged spruce monocultures. By the 1920s, broadleaved trees made up only a tiny fraction of the forest, while conifers dominated. In 1924, deciduous trees covered only 1-2% of the Saxon Switzerland, while conifers occupied around 86%. In the Czech Republic around 1995, spruce dominated with over 60%, pine accounted for 25% and deciduous trees less than 5%. A specific factor in Bohemian Switzerland was the post-war transformation associated with the expulsion of the original population and the abandonment of settlements, which led to secondary overgrowth and an increase in forest cover to 59% by 2005. On both sides of the border, reforestation has resulted in large areas of forests of the same age and simple structure, making them more vulnerable to drought, pests and fire.

A Turning Point: Declaration of the National Parks

The establishment of Saxon Switzerland National Park in 1990 and Bohemian Switzerland National Park in 2000 marked a transition toward the protection of natural processes: forests were no longer seen primarily as economic resources, but as living ecosystems to be protected. However, both parks inherited forests that were far from natural. In Bohemian Switzerland, 60% of the forest consisted of artificially planted monocultures, and only 2% were truly uneven-aged stands. In Saxony, spruce still dominated with 46% in 1998, followed by pine (15%), birch (13%), and beech (12%).

A problem on both sides of the border was the tree age homogeneity. Many stands dated back to large post-nun moth replanting in the 1920s. By the 2000s, trees older than 75 years covered more than half of the forest in both parks, while young stands accounted for less than 10%. The forest became a "ticking bomb" with the same date of birth and likely demise. This made the forests extremely vulnerable: when individual trees started to fail, large areas could collapse at once.

Initial management plans were cautious. In Bohemian Switzerland, the goal was a century-long transformation: keep the unstable stands standing as long as possible while a new, naturally diverse forest grew underneath. In Saxony, the focus was on gradually converting pure conifer stands into more stable mixed forests. Nature, however, did not respect this schedule. A series of extremely dry years after 2015 revealed the weakness of the even-aged forests, with widespread dieback in both parks.

Today, the situation has significantly improved. Forests in Bohemian Switzerland are recovering, with about 60% of the area in the early stages of natural development. Instead of compact, shady spruce stands, a young and spatially open forest is emerging. In Saxony, nearly half of the forest has seen a change in dominant tree species since 1924, and the share of broadleaves has increased to 16%.

Since the parks were established, forests on both sides of the border have been gradually returning to a more natural state, with greater structural diversity, more deciduous trees, and a stronger role of natural regeneration processes. Former “factory‑type” even-aged conifer plantations are transforming into mosaics of different ages and species, creating landscapes that are closer to the dynamic, ever-changing forests that existed long before humans began to intervene.

The Forest as a Living System Shaped by Processes

The current transformation of forests in both national parks represents a return to the dynamics that natural forces have governed here for millennia: drought, bark beetles, fire, water, and wind.

Drought and Bark Beetle

The European spruce bark beetle is a natural and permanent inhabitant of the forests in Saxon and Bohemian Switzerland. Normally it only attacks weakened trees, but in large, even-aged spruce plantations on unsuitable sites, it has become a destructive factor. Prolonged dry periods in Central Europe make trees more stressed and vulnerable, especially in spruce-dominated forests.

Between 2018 and 2022, extreme drought affected the entire region, particularly the sandstone areas. This was followed by a massive outbreak of bark beetles, destroying large areas of spruce and leaving behind both standing and fallen deadwood. On the Bohemian side, nearly half of the park’s spruce forests were affected, with satellite data showing the greatest crown collapse between 2019 and 2021.

While these dead trees may look alarming, they are actually valuable for the ecosystem. They provide habitat for insects and birds and add structural diversity to the forest. However, large amounts of deadwood also increase the risk of fire and wind damage. Research from the 2022 fire shows that areas affected by bark beetles burned more intensely than unaffected forests, because dry, stressed vegetation and fallen branches create more fuel for flames.

Fire

Fire has been an integral part of the landscape dynamics over the past 11.500 years, with paleoecological evidence indicating periodic fire activity that interacted with climate and vegetation patterns. In certain periods, fire helped maintain more open, fire-tolerant forest types such as pine-dominated communities, while influencing the distribution and regeneration of broadleaf trees. A significant historical milestone was the fire in summer 1842, which occurred in almost the same locations and under very similar extreme drought conditions as the 2022 fire. This fire, which took 17 days to extinguish, affected a total of 185 hectares (89.9 ha on the Czech side and 95.2 ha on the Saxon side) and was the largest recorded fire in the region at that time.

Another unique opportunity to observe natural regeneration was provided by the fire at Havraní Rock near Jetřichovice in 2006, which affected 17.92 hectares and created a “natural laboratory.” This scientifically monitored site was left without human intervention to study the natural return of plants, animals, and fungi. Just three weeks after the fire, the first rare fungi, such as the scarlet elf cup, appeared, and fauna gradually changed as species typical of coniferous forests were replaced by animals preferring open habitats with dense undergrowth, such as the bluethroat and common shrew.

The wildfire in summer 2022 affected over 1.000 hectares of the Czech park and about 113 hectares on the Saxon side. Its intensity was amplified by large amounts of dead spruce from previous bark beetle outbreaks, dry fuels, drought conditions, steep slopes, and complex terrain. Wind carried spot fires over long distances, and areas with accumulated beetle-damaged spruce burned most severely. The “chimney effect” in narrow sandstone ravines also aided spread. The heat was so extreme that it caused surface destruction of sandstone and deep soil degradation in many areas. The fire removed acidic humus layers, released nutrients, and allowed birch and pine regeneration. Despite extreme heat, many seeds stored in the soil survived, enabling both parks to recover quickly with diverse new vegetation on burned areas.

Long-term monitoring at Havraní Rock confirms that after initial dominance by aspen and willow, silver birch became the main dominant species over fifteen years. Today, it makes up 80% of all trees over 1.3 meters tall, while the return of beech and fir is significantly suppressed by browsing wildlife.

Water

Water availability and movement are key factors shaping vegetation patterns in the Elbe Sandstone landscape. The highly permeable sandstone allows rain to infiltrate quickly, creating generally dry plateaus and ridges. In contrast, deep gorges and valley bottoms retain cooler, and more humid microclimates that support refugial species such as spruce and silver fir. Stream floodplains with periodic or permanent water host specialized communities, including alder and ash.

Climate change is now altering this delicate water balance. Warmer temperatures and longer dry periods reduce soil moisture and increase water stress for trees, making forests more vulnerable to drought and other disturbances. Changes in rainfall patterns and increased evaporation mean less water is available during the growing season, especially on water-limited sandstone soils. This has consequences for forest health, tree growth and species composition, because water availability directly influences how well seedlings establish and how resilient forests are to stress.

Historical records from the Czech side show that wetlands in the region shrank drastically from 119 to just 56 hectares, reflecting long-term shifts in water availability and land use. Today, dead trunks from collapsing stands help slow runoff and maintain moist conditions of the canyons, benefiting mosses, ferns, and other moisture-loving plants. These remnants of natural water retention highlight the close link between hydrology, forest structure and climate dynamics in the Elbe Sandstone landscape.

Wind

Wind shapes the forest like a natural architect, creating openings and diversity in the landscape. Historically, strong winds have caused windthrows that opened gaps in the canopy and contributed to forest dynamics. In recent decades, major storm events, such as Storm Herwart 2017 and Storm Friederike 2018, caused extensive wind damage, throwing a lot of  wood to the ground and significantly reshaping forest structure. These large windthrows are not isolated. Severe windstorms regularly affect forests across Central Europe and are among the most common natural disturbances recorded in the region since the late 20th century.

These fallen trees form microrelief that protects young seedlings from deer browsing and desiccation, turning standing deadwood into a horizontal protective layer for new life. Wind thus plays a key role in renewing the forest and maintaining structural complexity across both national parks.

Natural Regeneration and Succession

Where humans have stepped back, nature takes the initiative. In both national parks, the principle "let nature be nature" is now applied. In Saxon non-intervention zones, regeneration proceeds exclusively through processes of aging and decay, while in development zones temporary measures are applied to support beech and fir. In Bohemian Switzerland, pioneer trees - birch, aspen, rowan, and pine - have rapidly spread on areas affected by bark beetles and fire. These trees grow quickly, create shade, and prepare the ground for more demanding species.

Regeneration on burned areas is proving more vigorous than on sites that were artificially logged after bark beetle outbreaks. A shared and fundamental problem for both national parks remains the high density of deer. Their selective browsing eliminates young broadleaves and fir, making game regulation essential in both parks if the future forest is to be truly diverse and resilient. The exact number of deer in the Saxon and Bohemian Switzerland is not yet known, and current monitoring efforts, including planned surveys of browsing intensity, aim to better understand how and where deer affect regeneration (see Interreg project “Increasing the effectiveness of deer management using transboundary approaches  (REDEMA)“). Deer feeding behaviour is also shaped by the landscape context, including adjacent agricultural and settled areas that provide additional food resources and influence movements and densities. Moreover, changes in predator populations, for example, the potential return of carnivores such as wolves, could in the long term help moderate deer pressure on forests.

The development of Bohemian and Saxon Switzerland tells the shared story of how forests that were once heavily influenced by humans are increasingly transforming into dynamic, near-natural ecosystems in which natural processes determine the ongoing growth, change and future of this landscape.