The Black Forest in southwestern Germany is under significant stress. Decades of climate change, recurring droughts, bark beetle outbreaks, and legacy soil damage have left measurable marks on one of Europe’s most iconic woodland regions. The forest is not dying in the dramatic, visible way it appeared to in the 1980s acid rain crisis, but long-term monitoring data shows declining tree growth, rising mortality, and a landscape in transition.
Drought Is the Primary Threat
A 2023 study analyzing over 120 years of tree growth data and 140 years of water balance records in the Black Forest identified the climatic water balance, essentially the difference between rainfall and evaporation, as the single most important driver of both tree death and growth decline across the region. As the water balance has trended downward over that period, tree mortality has climbed and annual growth rings have narrowed.
The problem compounds over time. Consecutive hot, dry summers don’t just cause immediate damage; they create drought “legacies” that weaken trees for several years afterward. A tree that survives one bad summer enters the next in a depleted state, with less stored energy and a compromised root system. The research also found that trees become more sensitive to water deficits as the long-term trend gets drier, meaning each new drought hits harder than the last. The extreme European summer of 2018 was a turning point, triggering large-scale Norway spruce mortality across central Europe, including in Baden-Württemberg, the state that contains the Black Forest.
Norway Spruce Is Most Vulnerable
The Black Forest gets its name partly from the dark canopy of its conifer stands, and Norway spruce has historically been the dominant species. That dominance is now a liability. Research comparing spruce and silver fir across central European forests found that spruce is consistently less resistant and less resilient to drought. During mild droughts, silver fir actually grew faster than in normal years, while spruce experienced growth reductions even under moderate water stress. During severe droughts, both species suffered, but spruce losses were substantially worse.
Silver fir also recovers faster. After mild droughts, fir bounced back to pre-drought growth levels more quickly, while spruce struggled to regain momentum. Interestingly, spruce fared even worse when growing alongside fir and beech, likely because of competition for limited soil moisture during dry periods. These findings have major implications for the Black Forest, where foresters are increasingly converting pure spruce plantations into mixed stands of fir, beech, and oak in hopes of building a more climate-resilient forest.
Bark Beetles Follow the Drought
Drought-weakened spruce trees are prime targets for the European spruce bark beetle. Healthy trees can fight off beetle attacks by flooding bore holes with resin, but water-stressed trees produce less resin and lose that defense. Warm winters also allow more beetle larvae to survive, and hotter summers let the beetles complete an extra breeding cycle each year. Modeling research projects that bark beetle timber losses could increase by up to 219% under climate change scenarios compared to historical baselines.
Across all of Germany, damaged timber (from beetles, storms, and drought combined) accounted for 27.3 million cubic meters of the 61.2 million cubic meters logged in 2024, according to the German Federal Statistical Office. That means roughly 45% of all timber harvested nationally was salvage logging rather than planned forestry. While that figure covers all German forests, the Black Forest’s heavy reliance on spruce means it contributes disproportionately to those losses. Salvage logging floods the market with low-value timber, depressing prices and straining the economic viability of forest management at a time when active management is needed most.
Soil Recovery Is Slow and Uneven
The Black Forest was one of the landscapes most visibly damaged by acid rain in the 1970s and 1980s, when sulfur and nitrogen pollution from coal-burning power plants acidified soils and thinned canopies. Acid deposition has dropped sharply since then, thanks to emissions regulations, but soil recovery has been partial at best.
Germany’s two national forest soil inventories, conducted roughly 15 years apart, show that topsoils (the upper 30 centimeters) have improved in pH and base saturation, especially where lime has been spread by helicopter. Limed soils recovered meaningfully, particularly under deciduous trees. But unlimed soils showed little detectable change, and deeper soil layers (60 to 90 centimeters down) continued to acidify on acid-sensitive substrates even as the surface improved. This matters because deep roots draw water and nutrients from those lower layers, and continued acidification there can limit a tree’s ability to weather drought.
Liming programs in Baden-Württemberg have treated hundreds of thousands of hectares over the past few decades. The interventions work: they raise the base saturation of the soil, buffering against further acid damage. But liming is expensive, requires repeated application, and doesn’t reverse decades of nutrient leaching overnight. The forest’s soils are better than they were in the 1980s, but still far from their pre-industrial condition.
What the Forest Looks Like Now
If you hike through the Black Forest today, you’ll see a landscape in various stages of change. In some areas, dead spruce stands have been cleared, leaving open patches where young mixed plantings are taking root. In others, large brown-needled spruce still stand among green neighbors, casualties of beetle attacks or drought that haven’t yet been salvaged. The northern Black Forest, at lower elevations with sandstone soils that hold less water, tends to show more visible damage than the higher, wetter southern portions.
Forest managers in Baden-Württemberg have been shifting strategy for years, moving away from spruce monocultures toward diverse stands that include silver fir, European beech, Douglas fir, and sessile oak. The goal is a forest that can absorb disturbances without collapsing. Mixed stands lose fewer trees to bark beetles (beetles are species-specific, so a mixed canopy limits outbreak spread), handle drought better, and recover faster from storms. But forest conversion is a generational project. Trees planted today won’t form a mature canopy for decades, and the spruce that remains is increasingly vulnerable in the interim.
The Black Forest is not in collapse. It still covers roughly 6,000 square kilometers, supports a major timber industry, and draws millions of visitors annually. But the data is clear: the forest is losing ground to a drier, warmer climate, and the species that defined it for centuries is the one least equipped to handle what comes next.