The study, published in Biological Reviews, shows that changes are noticeable in the living conditions of plant and animal species. For instance, some plant species benefit from the increased availability of nitrogen and soil acidification. The vegetation structure of, for example, blackberries, nettles and taller grasses becomes taller and denser. Some animal species also benefit, but others suffer from increased nitrogen deposition and disappear. This is partly due to invisible changes in the food quality of plants, which affect the animals that eat these plants and those higher up the food chain. This has not been studied before.
To arrive at the outcomes, knowledge on key principles in food ecology was summarised to predict the effect of increased nitrogen deposition on changes in food quality. After which these changes were linked to species traits of animal species. This showed that for both plant and animal species, there is no purely negative or positive effect of increased nitrogen deposition, but on a global level it means that with chronically increased nitrogen deposition levels, there will be a net decrease in species diversity.
Decrease in species diversity
Animal species with rapid development, which require constant food quality and struggle to reach better food are expected to decline the most under increased nitrogen deposition. There is also predicted to be an increased risk of pest outbreaks of a small number of generalist species, but at the same time a decline of many specialised species.