Acid Rain in the Black Forest in southwestern Germany

Baden-Württemberg’s forest condition survey showed modest improvement, with average crown defoliation declining to 26.4% and 42% of surveyed trees classified as clearly damaged. Although acid pollution has fallen substantially since the 1980s, forests continue to face the combined effects of historically degraded soils, drought, heat, and pests.

Decades after acid rain peaked, legacy soil acidification remained a concern in Baden-Württemberg’s forests. Targeted forest-soil liming continued to restore calcium and magnesium, reduce harmful aluminium concentrations, and improve the ability of soils to neutralize future acidic inputs.

Research on acidified forest soils in southwestern Germany showed that natural recovery was occurring after major reductions in acid deposition, but the process remained slow. Forest liming continued to be used to restore soil chemistry and replenish nutrients lost during decades of acid rain.

Nearly half of the trees in the Black Forest were damaged by acid rain. 

The West Germans have taken steps to ward off further damage. They are adding fertilizer and lime to stricken areas in an effort to reverse the decline. 

Measures to reduce the amount of sulfur dioxide emissions in the region had begun.
They have passed new laws to cut pollution from power plants and automobiles. They are pushing for a continentwide agreement to reduce emissions that travel across national boundaries. They are planning to breed trees that are resistant to pollution. And they hope to improve the mix of trees found in the Black Forest, so that the destruction of any one species will be mitigated by the survival of others.  

Reports issued by the federal Government and the State of Baden-W"urttemberg estimate that almost 80 percent of the silver fir acreage and almost half of the spruce tree acreage hereabouts is suffering some degree of damage, ranging from moderate needle loss in most cases to terminal illness in a small percentage of trees. 

Trees that are over 200 years old have been lost.
Surveys have found extensive damage to very young trees as well, threatening the future survival of the forest

The Black Forest suffered severe subnormal rain for a decade, very heavy snow that broke many trees in 1981-82 and drought again. 

Baden-W"urttemberg suffered an $80 million loss in wood production from forest damage, and that further damage disrupt ground water, soil fertility, wildlife and local climate.

In the crown of a tree that should be bushy and impenetrable but has lost so many needles that the sky shows through. It is on the innermost portions of a branch, next to the trunk, where the needles should be green but have instead turned yellow or have fallen away. It is in the unexpected appearance of lichens, which normally colonize old trees, on young trees as well, a sure sign that their growth rate has slowed. 

The Black Forest suffered severe drought.

Growth rings inside the trunks of silver fir trees show normal growth until the 1950's or 1960's, but greatly reduced growth thereafter.

The damage, first detected in aging silver firs in the mid-1970's.

The trees began losing as much as 25 percent of their leaves and needles when compared to previous years. This is one of the most easily observed effects.