Abstract
In this thesis the effects of sulphur and nitrogen deposition on forests are analysed. Two different models, an ecosystem model, and a model that describes uptake of cations, were developed with the purpose of increasing the understanding of the effects of air pollutants on the long-term nutrient availability for forest growth. In addition, the limitations and consequences of the models used to analyse effects of air pollutants on forest were studied in a comparison of different models and model descriptions. The ecosystem model showed that imbalances between nutrients in the leaf biomass of trees are causally related to decreased nutrients stores in forests affected by leaching induced by acid deposition. High forest growth levels are attained by the fertilizing effect of nitrogen deposition. The uptake model showed that aluminium affect the uptake of cations negatively through changes in root surface chemistry that can be interpreted as decreasing the uptake capacity of the roots. Increased concentrations of Ca and Mg can mitigate the negative Al effects. However, Ca and Mg appeared to be antagonists by affecting each others uptake negatively. In the field, Al may, through its inhibiting effect on uptake of cations, be a contributing factor to the nutritional imbalances
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Citation Formats
Oene, Harmke van.
Modelling the impacts of sulphur and nitrogen deposition on forests.
Sweden: N. p.,
1994.
Web.
Oene, Harmke van.
Modelling the impacts of sulphur and nitrogen deposition on forests.
Sweden.
Oene, Harmke van.
1994.
"Modelling the impacts of sulphur and nitrogen deposition on forests."
Sweden.
@misc{etde_10114456,
title = {Modelling the impacts of sulphur and nitrogen deposition on forests}
author = {Oene, Harmke van}
abstractNote = {In this thesis the effects of sulphur and nitrogen deposition on forests are analysed. Two different models, an ecosystem model, and a model that describes uptake of cations, were developed with the purpose of increasing the understanding of the effects of air pollutants on the long-term nutrient availability for forest growth. In addition, the limitations and consequences of the models used to analyse effects of air pollutants on forest were studied in a comparison of different models and model descriptions. The ecosystem model showed that imbalances between nutrients in the leaf biomass of trees are causally related to decreased nutrients stores in forests affected by leaching induced by acid deposition. High forest growth levels are attained by the fertilizing effect of nitrogen deposition. The uptake model showed that aluminium affect the uptake of cations negatively through changes in root surface chemistry that can be interpreted as decreasing the uptake capacity of the roots. Increased concentrations of Ca and Mg can mitigate the negative Al effects. However, Ca and Mg appeared to be antagonists by affecting each others uptake negatively. In the field, Al may, through its inhibiting effect on uptake of cations, be a contributing factor to the nutritional imbalances observed in trees affected by air pollutants. The magnitude of this effect is also dependent on tree growth rate and supply rates of nutrients. A reduction in nitrogen deposition is required to compensate an additional scarcity of base cations induced by the recently decreased deposition of these ions. A future reduction in forest growth will occur by reduced supply rates of either base cations or nitrogen. This reduction should be viewed against the increased present-day forest growth. Attention needs therefore to be directed at the effects of air pollutants on the sustainability of forest ecosystems. 78 refs, 10 figs}
place = {Sweden}
year = {1994}
month = {Dec}
}
title = {Modelling the impacts of sulphur and nitrogen deposition on forests}
author = {Oene, Harmke van}
abstractNote = {In this thesis the effects of sulphur and nitrogen deposition on forests are analysed. Two different models, an ecosystem model, and a model that describes uptake of cations, were developed with the purpose of increasing the understanding of the effects of air pollutants on the long-term nutrient availability for forest growth. In addition, the limitations and consequences of the models used to analyse effects of air pollutants on forest were studied in a comparison of different models and model descriptions. The ecosystem model showed that imbalances between nutrients in the leaf biomass of trees are causally related to decreased nutrients stores in forests affected by leaching induced by acid deposition. High forest growth levels are attained by the fertilizing effect of nitrogen deposition. The uptake model showed that aluminium affect the uptake of cations negatively through changes in root surface chemistry that can be interpreted as decreasing the uptake capacity of the roots. Increased concentrations of Ca and Mg can mitigate the negative Al effects. However, Ca and Mg appeared to be antagonists by affecting each others uptake negatively. In the field, Al may, through its inhibiting effect on uptake of cations, be a contributing factor to the nutritional imbalances observed in trees affected by air pollutants. The magnitude of this effect is also dependent on tree growth rate and supply rates of nutrients. A reduction in nitrogen deposition is required to compensate an additional scarcity of base cations induced by the recently decreased deposition of these ions. A future reduction in forest growth will occur by reduced supply rates of either base cations or nitrogen. This reduction should be viewed against the increased present-day forest growth. Attention needs therefore to be directed at the effects of air pollutants on the sustainability of forest ecosystems. 78 refs, 10 figs}
place = {Sweden}
year = {1994}
month = {Dec}
}