Abstract
The effects of acidic atmospheric inputs on forest nutrient status must be assessed within the context of natural, internal acid production by carbonic and organic acids as well as the nutrient inputs and drains by management practices such as harvesting, fire, and fertilization. In all cases the anion associated with acid inputs must be mobile in the soil if leaching is to occur; immobilization of anions can effectively prevent cation leaching. Soil acidification will occur only if the often substantial buffering capacity of the soil in question is exceeded by acid inputs and if cation weathering from primary minerals is insufficient to offset cation losses by leaching. Such circumstances are rare but certainly could occur in theory, at least, given sufficiently large acid inputs on poorly buffered soils. Soils most sensitive to change are thought to be those of moderately acid p H and low cation exchange capacity. Neither very acid soils nor neutral, highly buffered soils are sensitive to acidification by acid rain. Given extremely high acid inputs, acid rain can cause temporary increases in nitrogen mineralization and nitritication as well as Al mobilization in soils. While temporary increases in N availability can cause increased forest growth in N‐deficient forests, increased Al availability can cause toxic reactions in tree roots. Little is known about tree Al toxicity levels as yet, however. It must be emphasized that assessment of acid rain effects is a problem of quantification. Given sufficiently high inputs on sensitive sites, negative effects of acid rain must occur, as is true of inputs of any substance, including H 2 O. Acid rain inputs of sufficient magnitude to cause acute effects, such as growth increase due to N mobilization or growth decrease due to Al mobilization, are apparently very rare under ambient field conditions. Long‐term effects on forest nutrient status can be either beneficial or adverse, depending on site nutrient status, silvicultural practices, and amount of atmospheric inputs.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Anion immobilization can prevent cation leaching in forest soil.
Verbatim
e0“immobilization of anions can effectively prevent cation leaching”
t0“forest”
Claim · model-written summary
Soil acidification requires acid inputs to exceed buffering and weathering to fail to replace leached cations.
Verbatim
e0“Soil acidification will occur only if the often substantial buffering capacity of the soil in question is exceeded by acid inputs and if cation weathering from primary minerals is insufficient to offset cation losses by leaching”
t0“forest”
Claim · model-written summary
Moderately acid soils with low cation exchange capacity are considered most sensitive to change.
Verbatim
e0“Soils most sensitive to change are thought to be those of moderately acid p H and low cation exchange capacity”
t0“forest”
Claim · model-written summary
Very acid and neutral highly buffered soils are considered insensitive to acid rain acidification.
Verbatim
e0“Neither very acid soils nor neutral, highly buffered soils are sensitive to acidification by acid rain”
t0“forest”
Claim · model-written summary
At extremely high inputs, acid rain may increase nitrogen mineralization, nitrification, and soil aluminum mobilization.
Verbatim
e0“acid rain can cause temporary increases in nitrogen mineralization and nitritication as well as Al mobilization in soils”
t0“forest”
Claim · model-written summary
Increased nitrogen availability can temporarily increase growth in nitrogen deficient forests.
Verbatim
e0“temporary increases in N availability can cause increased forest growth in N‐deficient forests”
Claim · model-written summary
Increased aluminum availability can cause toxicity in tree roots.
Verbatim
e0“increased Al availability can cause toxic reactions in tree roots”
Claim · model-written summary
Acid rain inputs sufficient to cause acute forest growth responses are apparently rare under ambient field conditions.
Verbatim
e0“Acid rain inputs of sufficient magnitude to cause acute effects, such as growth increase due to N mobilization or growth decrease due to Al mobilization, are apparently very rare under ambient field conditions”
t0“forest”
Claim · model-written summary
Long term effects on forest nutrient status may be beneficial or adverse depending on site nutrients, management, and atmospheric inputs.
- Taxon
- foreste0
- Outcome
- forest nutrient statuse0
- Qualifier
- silvicultural practices, and amount of atmospheric inputse0
- Setting
- site nutrient statuse0
Not reportedDirection
Verbatim
e0“Long‐term effects on forest nutrient status can be either beneficial or adverse, depending on site nutrient status, silvicultural practices, and amount of atmospheric inputs”