Direct effect of ammonia emission can be remarked only in cold climate like in the northern part of Scandinavia or in cold winters. Damages can be remarked on the vegetation under those conditions and red or reddish brown colouring can be seen on coniferous trees. In mild climate the trees generally recover in the summertime. The indirect effects of ammonia are more widespread and serious and result on ammonium deposition on ecosystems. Acidification and nitrogen enrichment of the soil can result from nitrogen deposition on weakly buffered ecosystems. This phenomena can result in the disappearance of many plant species. Competition between slow growing and fast growing plants will be seen and changes can be observed for example from a heath- and peatlands into grasslands.
Ammonia emission should be considered seriously particularly where livestock density is high and fragile ecosystems are close by. The acidification effects have already caused problems in some areas in The Netherlands and Germany.