How does acid rain affect trees and plants

Effects of Acid Rain | US EPA

On this Page:

  • Effects of Acid Rain on Ecosystems
  • Effects of Acid Rain on Materials
  • Other Effects of SO2 and NOX
    • Visibility
    • Human Health

The Effects of Acid Rain on Ecosystems

This figure illustrates the pH level at which key organisms may be lost as their environment becomes more acidic. Not all fish, shellfish, or the insects that they eat can tolerate the same amount of acid.

An ecosystem is a community of plants, animals and other organisms along with their environment including the air, water and soil. Everything in an ecosystem is connected. If something harms one part of an ecosystem – one species of plant or animal, the soil or the water – it can have an impact on everything else.

Effects of Acid Rain on Fish and Wildlife

The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife. As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes. The more acid that is introduced to the ecosystem, the more aluminum is released.

Some types of plants and animals are able to tolerate acidic waters and moderate amounts of aluminum. Others, however, are acid-sensitive and will be lost as the pH declines. Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acidic lakes have no fish. Even if a species of fish or animal can tolerate moderately acidic water, the animals or plants it eats might not. For example, frogs have a critical pH around 4, but the mayflies they eat are more sensitive and may not survive pH below 5.5.

Effects of Acid Rain on Plants and Trees

Dead or dying trees are a common sight in areas effected by acid rain. Acid rain leaches aluminum from the soil.   That aluminum may be harmful to plants as well as animals. Acid rain also removes minerals and nutrients from the soil that trees need to grow. 

At high elevations, acidic fog and clouds might strip nutrients from trees’ foliage, leaving them with brown or dead leaves and needles. The trees are then less able to absorb sunlight, which makes them weak and less able to withstand freezing temperatures.

Buffering Capacity

Many forests, streams, and lakes that experience acid rain don’t suffer effects because the soil in those areas can buffer the acid rain by neutralizing the acidity in the rainwater flowing through it. This capacity depends on the thickness and composition of the soil and the type of bedrock underneath it. In areas such as mountainous parts of the Northeast United States, the soil is thin and lacks the ability to adequately neutralize the acid in the rain water. As a result, these areas are particularly vulnerable and the acid and aluminum can accumulate in the soil, streams, or lakes.

Episodic Acidification

Melting snow and heavy rain downpours can result in what is known as episodic acidification. Lakes that do not normally have a high level of acidity may temporarily experience effects of acid rain when the melting snow or downpour brings greater amounts of acidic deposition and the soil can’t buffer it. This short duration of higher acidity (i.e., lower pH) can result in a short-term stress on the ecosystem where a variety of organisms or species may be injured or killed.

Nitrogen Pollution

It’s not just the acidity of acid rain that can cause problems. Acid rain also contains nitrogen, and this can have an impact on some ecosystems. For example, nitrogen pollution in our coastal waters is partially responsible for declining fish and shellfish populations in some areas. In addition to agriculture and wastewater, much of the nitrogen produced by human activity that reaches coastal waters comes from the atmosphere.

  • Learn more about Nitrogen Pollution
  • EPA's Chesapeake Bay Program Office

Effects of Acid Rain on Materials

Not all acidic deposition is wet. Sometimes dust particles can become acidic as well, and this is called dry deposition. When acid rain and dry acidic particles fall to earth, the nitric and sulfuric acid that make the particles acidic can land on statues, buildings, and other manmade structures, and damage their surfaces. The acidic particles corrode metal and cause paint and stone to deteriorate more quickly. They also dirty the surfaces of buildings and other structures such as monuments.

The consequences of this damage can be costly:

  • damaged materials that need to be repaired or replaced,
  • increased maintenance costs, and
  • loss of detail on stone and metal statues, monuments and tombstones.

Other Effects of SO

2 and NOX


In the atmosphere, SO2 and NOX gases can be transformed into sulfate and nitrate particles, while some NOX can also react with other pollutants to form ozone. These particles and ozone make the air hazy and difficult to see through. This affects our enjoyment of national parks that we visit for the scenic view such as Shenandoah and the Great Smoky Mountains.

  • Learn more about Visibility and Regional Haze

Human Health

Walking in acid rain, or even swimming in a lake affected by acid rain, is no more dangerous to humans than walking in normal rain or swimming in non-acidic lakes. However, when the pollutants that cause acid rain —SO2 and NOX, as well as sulfate and nitrate particles— are in the air, they can be harmful to humans.

SO2 and NOX react in the atmosphere to form fine sulfate and nitrate particles that people can inhale into their lungs.  Many scientific studies have shown a relationship between these particles and effects on heart function, such as heart attacks resulting in death for people with increased heart disease risk, and effects on lung function, such as breathing difficulties for people with asthma.

Learn more about:

  • Sulfur Dioxide
  • Nitrogen Oxides
  • Particulate Matter (PM)
  • Asthma

In addition, NOX emissions also contribute to ground level ozone, which is also harmful to human health.

  • Learn more about Ground Level Ozone

Learn more about:

  • Acid Rain
  • Clean Air Markets
  • Clean Air Status and Trends Network (CASTNET)
  • National Atmospheric Deposition Program (NADP)
  • Long-Term Monitoring (LTM) Network

Why is acid rain harmful?

Acid Rain Can Cause Health Problems in People
Air pollution like sulfur dioxide and nitrogen oxides can cause respiratory diseases, or can make these diseases worse. Respiratory diseases like asthma or chronic bronchitis make it hard for people to breathe. The pollution that causes acid rain can also create tiny particles. When these particles get into people’s lungs, they can cause health problems, or can make existing health problems worse. Also, nitrogen oxides cause ground-level ozone. This ground-level ozone causes respiratory problems, like pneumonia and bronchitis, and can even cause permanent lung damage. The health effects that people have to worry about are not caused by the acid rain, but are caused when people breathe in these tiny particles or ozone. Swimming in an acidic lake or walking in an acidic puddle is no more harmful to people than swimming or walking in clean water.

Acid Rain Harms Forests
Acid rain can be extremely harmful to forests. Acid rain that seeps into the ground can dissolve nutrients, such as magnesium and calcium, that trees need to be healthy. Acid rain also causes aluminum to be released into the soil, which makes it difficult for trees to take up water. Trees that are located in mountainous regions at higher elevations, such as spruce or fir trees, are at greater risk because they are exposed to acidic clouds and fog, which contain greater amounts of acid than rain or snow. The acidic clouds and fog strip important nutrients from their leaves and needles. This loss of nutrients makes it easier for infections, insects, and cold weather to damage trees and forests.

Acid Rain Damages Lakes and Streams
Without pollution or acid rain, most lakes and streams would have a pH level near 6.5. Acid rain, however, has caused many lakes and streams in the northeast United States and certain other places to have much lower pH levels. In addition, aluminum that is released into the soil eventually ends up in lakes and streams. Unfortunately, this increase in acidity and aluminum levels can be deadly to aquatic wildlife, including phytoplankton, mayflies, rainbow trout, small mouth bass, frogs, spotted salamanders, crayfish, and other creatures that are part of the food web.

This problem can become much worse during heavy downpours of rain or when the snow begins to melt in the spring. These types of events are known as episodic acidification.

Acid Rain Damages Buildings and Objects
Acid rain can also have a damaging effect on many objects, including buildings, statues, monuments, and cars. The chemicals found in acid rain can cause paint to peel and stone statues to begin to appear old and worn down, which reduces their value and beauty.

Acid rains and their impact on the environment - Taimyr Museum of Local Lore

Mikhailets M.A.

Acid rains and their impact on the environment

This leads to a violation of the equilibrium processes occurring in the biosphere, which is manifested by a whole range of environmental problems.

One of the most pressing environmental problems of recent decades is acid precipitation. The term "acid rain" was originally introduced back in 1882 by R. Smith; its impact on the state of natural and artificial ecosystems was discussed only at the end of the last century.

Acid precipitation and its consequences are a serious socio-economic problem. They have an extremely negative impact on the biocenoses of closed water bodies, causing a decrease in fishing. They reduce the fertility of agricultural land, contribute to the spread of heavy metals, cause the destruction of building structures, as well as monuments of architecture and architecture.

The basis of the mechanism of formation of acid precipitation is a violation of the natural cycles of substances, primarily sulfur, due to intensive human activities (Fig. 1).

Fig. 1. Mechanism of acid rain formation

1. Emissions of acid-forming compounds

2. Interaction of acid-forming substances with water vapor

3. Acid precipitation

destruction of buildings, monuments of architecture and architecture

Sulfur dioxide is produced in large quantities when sulfur-rich fuels such as coal and fuel oil are burned (sulfur content ranges from 0. 5 to 5-6%). Other sources are power plants (~40% of anthropogenic emissions into the atmosphere), metallurgical production, various chemical technological processes, and a number of machine-building enterprises [1].

In the atmosphere, sulfur dioxide, as a result of photochemical oxidation, is partially converted into sulfur trioxide (sulfuric anhydride) SO3: 2SO2 + O2 = 2SO3.

The main part of the emitted sulfur dioxide with sufficient atmospheric humidity forms the acidic polyhydrate SO2•nh3O, or sulfurous acid: SO2 + h3O = h3SO3. Aerosols of sulfuric and sulphurous acids are considered the main cause of acid precipitation.

In our country, the problem of acid rain was first raised only in the late 1980s, and the first attempts to solve it began in the 1990s.

In recent years, the average annual background concentrations of sulfur dioxide over the territory of Russia remained at a low level - about 0.3 µg/m3, slightly increasing in the cold season (about 2. 5 µg/m3 on average). In the long-term dynamics, there is a stabilization of the level of sulfur dioxide concentrations after some decrease during the previous 10 years. The average annual background concentrations of nitrogen dioxide in the air also remained at the level of previous years, varying from 1.2 to 4.8 µg/m3 [4].

However, there are regions in the Russian Federation that are extremely unfavorable in terms of these indicators. An example is Norilsk and NPR, where the main source of emissions of acid-forming compounds is the Norilsk Nickel plant. It consists of three plants - nickel, copper plants and Nadezhda metallurgical plant. As is known, metallurgical enterprises make a significant contribution to air pollution with acid-forming compounds. In this regard, acid precipitation is regularly recorded on the territory of the Norilsk industrial region (Table 1), which leads to a pronounced degradation of forest biocenoses.

Table 1. Daily values ​​of atmospheric precipitation in Norilsk in 2012-2013*

(critical pH - below 4. 0)


Q1 2012


Q2 2012


Q3 2012


Q4 2012


Q1 2013


Q2 2013


Q3 2013


*(Materials provided by the Head of the Territorial Center for Environmental Pollution Monitoring N.S. Shlenskaya).

The area of ​​the damaged forests of Taimyr is mostly located south of Norilsk, which is associated with the prevailing winds. According to eyewitnesses, the drying of forest stands began in the 50s of the last century. By the end of the 60s, the area of ​​dead forests was 5 thousand hectares. Zone of complete destruction of forest stands at 1993 stretched for 90 km to the south from Norilsk, and noticeable man-made forest damage was observed at a distance of up to 170 km from the city. The area of ​​dead and damaged plantations from 1976 to 1990 increased from 322 to 550 thousand ha, and the area of ​​dead in 1989 was 283 thousand ha [3] (Fig. 2).

Fig. 2. Dynamics of the value of claims against Norilsk Nickel enterprises for damage to forest plantations

(according to the Ecomir portal)

It should be noted that the main danger to natural and artificial ecosystems is not so much the acid precipitation itself, but the processes occurring as a result of environmental acidification. Acid precipitation leads to the leaching of nutrients vital for plants, as well as toxic heavy and light metals such as lead, cadmium, etc., from the soil. Such metals and their toxic compounds are actively absorbed by plants and other soil organisms, which leads to negative consequences. . With increased soil acidity, exchangeable calcium, magnesium and other elements are removed from the upper horizons, and metabolic processes between the abiotic and biotic parts of the ecosystem are activated. In particular, an increase in the absorption of aluminum by trees associated with acid precipitation leads to a pronounced decrease in wood growth [4]. The direct impact of acid precipitation leads to disruption of the leaf surface, transpiration and photosynthesis processes.

In general, it can be concluded that the impact of acid precipitation on forest biocenoses is complex, affecting primarily soils and vegetation (Fig. 3).

Soil acidification is considered one of the negative factors leading to the degradation of forests in the temperate zone of the northern hemisphere. In this case, the effect can manifest itself long after acid precipitation.

Fig. 3. The complex nature of the impact of acid precipitation on forest biocenoses [6]

T. F. Tarasova and O.V. Chalovskaya identifies several main stages that are characteristic of the process of transformation of the forest ecosystem of the northern hemisphere under the influence of acid precipitation [5].

1. Loss of species most sensitive to environmental conditions while maintaining the main parameters of the ecosystem. Lichens are the first to disappear when environmental parameters deteriorate.

2. Structural changes in the ecosystem. The sanitary condition of trees is deteriorating, while maintaining the density of the forest stand and its reserves. The grass-shrub layer changes, where sensitive species of forest forbs fall out. The processes occurring with the participation of soil microorganisms are slowed down. The thickness of the litter increases slightly. The diversity and abundance of epiphytic lichens is decreasing.

3. Stage of partial destruction of the ecosystem. There is marked oppression and thinning of the tree layer, a violation of its renewal. In the grass layer, forest species are replaced by meadow and explerent species. The biological activity of the soil is sharply reduced. Large soil saprophages are absent. The rate of destruction of leaf litter decreases, resulting in its accumulation in the form of a thick layer of litter. The lichen cover is preserved only at the very base of the trunks and is represented by one to three resistant species. Large forest bird species are being eliminated, and the density of the avifauna is decreasing. There is an invasion of synanthropic species and species confined to open habitats (typical for the population of birds, small mammals and ants).

4. The stage of complete destruction of the ecosystem. The tree layer is completely destroyed, only separate, strongly oppressed specimens of trees are preserved. The herbaceous layer is represented by one or two types of grasses; horsetail is found in moist places. Lichen cover is absent. The litter and upper soil horizons were completely washed away. The biological activity of the soil is reduced to zero. Soil animals are absent. Groupings of birds and small mammals exist due to the influx of migrants from neighboring areas of the territory.

Measures to protect forest biocenoses from acid rain at the first stage were reduced to the development and implementation of organizational measures, which included the tightening of environmental legislation, the regulation of emissions of harmful substances, and the increase in fines. These actions had a certain environmental effect, but they could not completely solve the problem. The main methods for reducing air pollution with acid-forming emissions today are the development and implementation of various treatment facilities and the legal protection of the atmosphere [2].

To reduce emissions of oxidized sulfur into the atmosphere through chimneys, various gas scrubbers (electric filters, vacuum, air or liquid scrubber filters) are used. Thus, in scrubbers, combustion gases are passed through an aqueous solution of lime, resulting in the formation of insoluble calcium sulfate CaSO4. This method can remove up to 95% SO2, but its main disadvantage is its high cost. Equally expensive is the method of cleaning flue gases from nitrogen oxides using isocyanic acid HNCO. Due to the chemical interaction in this case, up to 99% nitrogen oxides.

Liming is also used to protect forests from acid rain. To do this, freshly ground dolomite (CaCO3 • MgCO3) is sprayed from aircraft, which reacts with acids to form harmless substances: Ca(NO3)2 + Mg(NO3)2 + 2CO2 + 2H2O.

All of the above measures are the implementation of the "outlet control" method, that is, the reduction of the concentration of pollutants at the stage of their release into the atmosphere.

More efficient from an environmental point of view is the “input control” method, which provides for the purification of fuel from potential pollutants, the use of cleaner energy sources and the creation of so-called zero-waste technologies, that is, technological processes comparable to natural cycles in the biosphere.

Thus, the problem of acid precipitation remains relevant both for Russia and for the whole world, affecting primarily countries with a developed industrial complex.

The acidification of precipitation is primarily based on the chemical interactions of sulfur and nitrogen oxides with atmospheric water vapor, resulting in the formation of sulfuric and nitric acids. Intensive industrial emissions of acid-forming compounds disrupt the natural cycles of substances and lead to precipitation with a pH of less than 5.6.

Acid precipitation has a wide range of negative effects on both natural and man-made objects. The biocenoses of lakes and forests are most susceptible to the action of acid precipitation, which, as a result of acidification, can undergo complete or partial degradation.

Solving this problem requires efforts to develop measures to reduce acidic emissions. Promising are technologies that allow cleaning fuel and raw materials from potential atmospheric pollutants at the initial level.

1. Borovsky E.E. Acid rain // ECOTECO, No. 6. - Electronic journal. – URL:

2. Dubrovin T., Dubrovin E. "Acid from the sky" // Energy and Industry of Russia. - 2008, No. 20. - URL:

3. Ziganshin R.A., Voronin V.I., Karbainov Yu.M. Monitoring of forest ecosystems of Taimyr // Bulletin of the Krasnoyarsk State Agrarian University. 2011. No. 8. S. 117-123.

4. Ilkun G.M. Air pollution and plants. - Kyiv: Naukova Dumka, 1978. - 147 p.

5. Overview of the background state of the environment in the territory of the CIS countries for 2009-2010. / Edited by Yu.A. Israel. - Roshydromet, 2011. - 128

6. Tarasova T.F., Chalovskaya O.V. Assessment of the impact of acid rain on the elements of the ecosystem of an industrial city // Bulletin of the OSU. - 2005. - No. 10. pp. 80 - 84.

Effect of acid rain on plant growth and development

Ministry Education and Science Republic of Buryatia

Mukhorshibirsky district

GOU "Ust-Altachey secondary boarding school"

International competition of creative works

“Save and save our wonderful planet »

Nomination - Best research work or project

Influence impact influence influence influence acid rain

Plant growth and development

Author works:

Nimaev Stanislav, 9th grade student,


Buholtseva Tatiana Gennadievna,

history teacher

Ulus Ust-Altasha


Contents works:

1. Introduction.

Acid rain problem---------------------------------3 page

2.Main areas of research:--------------------------3 page

v Overview information on acid rain _________ 4 pp

v Setting experiments._____________________5 pp

v Observation for plants in nature ____________ 6 pp

v Study sources of pollution in the village _________ 7 pp

3.Conclusions__________________________________________ 8 page

4. Results of work _________________________________ 8 line

5. Offers ______________________________________ 8 page

6. Literature _______________________________________________9


In my work I raise the question of about effect of acid rain on plants. The point is that the last time, the following picture is observed more and more often: in the summer on poplar leaves, apple, bird cherry and other plants appear brown or red dots, among green crown of trees you can see branches with dry foliage, bare tops pines, pines with dried needles. It turns out that this may be due to acid rain . When performing work, the following target was set

- find out what effect acid rain has on vegetation organism.

To achieve this goal, it was necessary solve the following problems:

Study literature on the topic

· Carry out an experiment to find out effect of acid rain on plant growth and development

Make observations in nature and find out signs of acid impact on plants in our area

Find out the sources of air pollution substances that cause acid rain.

Place of study: the vicinity of the villages of the Moscow Region "Podlopatinskoye" (Ust-Altash, Podlopatki village), school.

Research time: summer-autumn 2017

Research object:

Plant objects in nature,

indoor plant Spurge ribbed

plant changes as a result of the action of simulated "acid" rain and changes found in plant objects in nature.

Methods used in the execution works :

experiment and observation.


Main areas of research.

1. Overview information about acid rain.

2. Setting experiment "Imitation of acid rain".

3. Setting experiment "Liming of acidic soil".

4. Clarification sources of acid rain in our area.

Reasons occurrence of acid rain and its consequences

From the literature sources, I learned that the term "Acid Rain" was first mentioned in a book English engineer Robert Smith "Air and rain." (4) Acid rain formed as a result of the interaction of sulfur oxides and nitrogen oxides with vapors water in the air. Nitrogen oxides are formed during the combustion of fuel in internal combustion engines of automobiles and during the combustion of solid fuels in boiler installations.

Acid base rainfall is more often sulfuric acid. During the combustion of coal, solid household waste produces sulfur dioxide, in the air it is oxidized and turns into sulfuric gas, which interacts with water, giving at the same time weak solution of sulfuric acid.

The matter is getting more complicated the fact that CHP pipes are getting higher and higher and reach 200-250 meters and even 400 meters. Atmospheric emissions spread over huge distances. Acid rain falls where there is practically no industrial enterprises.(2)

Effects of acid rain are.(4)

ü Acidic rains contribute to the destruction of buildings, structures of monuments.

ü Large acid rain damages forests, forests dry up,

develops dry top.

Acid increases the mobility of aluminum in the soil, and it is toxic and small roots plants die. This leads to oppression of foliage, needles, fragility of branches.

ü Especially coniferous trees suffer, because the needles are replaced less often than the leaves and for needles absorb a lot of harmful substances during their life. Coniferous trees turn yellow.

u deciduous trees, the color of the leaves changes, the foliage falls off faster, plants become less disease resistant.

ü Large damage is caused by acid rain to agricultural crops, as they have integumentary tissues are damaged, metabolism changes, plants slow down growth and development, their resistance to diseases and parasites decreases, productivity.

ü Process Deoxidation of the soil requires large financial costs.

acidification reservoirs causes the death of fish and aquatic vegetation.

For to reduce the impact of acid rain, it is necessary to drastically reduce emissions into the atmosphere nitrogen compounds and especially sulfur oxides.

Results research

Subject No. 1. Study of the effects of acid rain on plants .

Purpose: Find out what effect acid rain has on plants .

Method: To find out what effect acid rain on plants, we set up the following experiment.

For experience was selected houseplant - Euphorbia ribbed.

Glass jars 1/3 filled with soil, moistened it and planted

in each of the jars on a plant with the same stem height and root length. A week later, in one of cans burned 2 g of sulfur. The gas accumulated in the jar was sprinkled with water, using this sprinkler. So we simulated acid rain. The second of the jars left to control.


· 09/12/17.

Can No.

Impact acid precipitation

Changes occurring with plants



Leaves wilted, after 3 days brownish spots appeared on them.



Plants healthy


After 2 months we compared our objects.

Can No.

Impact acid precipitation

External plant species

Height overhead part

Length root







New the leaves were light green in color

5 cm

6. 5cm





plant cool


9 cm




"sour rain" caused damage to the skin of the leaves.

ü V in acidic soil, the root system of the plant develops poorly.

l Backlog root growth leads to restraint of stem growth.

Topic №2. Signs of exposure to "acid rains" on the plants of our area .

Purpose: Find out if the plants in our area are affected by acid rain.

One of the signs of exposure to acid rainfall on plants are

blackening of leaf tips or tips leaflets turn brown, leaves may have brownish spots.


Such signs we noted in the pine. Water droplet hangs on the tips of the needles in it acid (sulfuric) causes the destruction of needle cells. Brown spots were observed on poplar leaves.

Findings: In our areas also receive acid rain, which causes the destruction of the skin leaves and dying off the tips of the needles.

Topic 3. Liming of acidic soil

Purpose : Find out if adding chalk to acidic soil affects growth and development plants.


Take 2 jars, fill them 1/3 soil. Simulated "acid rain". Made a soil solution filtered it and checked with an indicator for acidity. The test gave positive result. Chalk powder was added to the soil of the first jar. To both banks planted the same plants Euphorbia ribbed . Observations spent a week after planting and 2.5 months later.


Can No.


External plant species

Height plants













5 cm

7.5 cm




plant in a depressed state, the leaves are wrinkled on the leaves, brown spots.

Leaves fall off, the top of the stem dies off, the plant is in a very depressed state.

5 cm

4.9 cm.


grow and develop better in the soil that is limed.

Topic №4 . rainfall in our area.

Purpose: Find out if Are there such sources in our village?


Possible sources of acid rain

Availability these sources in our area

Color metallurgy




Boilers, coal fired


Landfills household waste (incineration)


Industrial enterprises



acid rain formations are road transport and fires in places household landfills.

2. Fires are caused by human beings.

Working pins:

Ø Supplied experiments once again confirm that acid rain has negative impact on the plant organism: growth is inhibited aboveground part of the plant and root system, the upper part of the stem dies off, the skin of the leaves is destroyed, the foliage falls off.

Ø For acid rain knows no bounds, it falls everywhere

Ø Cause acid rain is a man ,his activity.

Ø Burning municipal solid waste, my fellow villagers, pollute the air with substances from which form acid rain.

Results of the work in the environmental circle.

2. We participate in the action "From a clean yard to a clean planet”

garbage incineration.


We believe that it is necessary

ü continue work on this topic

ü find out do all plants respond to acid rain in the same way

ü find out if what are the protective adaptations of plants from exposure to them acid precipitation

ü conduct explanatory work on respect for nature and conservation environment.

Learn more