The impact of forestry as a land use on water quality outcomes: An integrated analysis

The adoption of the EU land use, land use change and forestry (LULUCF) regulation ensures that for the first time afforestation in Europe will contribute toward the achievement of European Union (EU) climate change commitments under the Paris Agreement. However, increased afforestation in Europe could have unintended environmental trade-offs that may hamper the achievement of EU Water Framework Directive targets. While much of the previous forestry research has focused on the potential negative impacts of afforestation and harvesting processes on water quality at a single point in time, this study applies an ordered probit model to investigate the impact of afforestation and forest cover (in a predominantly agricultural setting) on water quality over a 20-year period. In addition, we present an analysis of a simulated increase in afforestation and forest cover, and a corresponding decrease in agriculture area, on water quality. The results show an increase in water quality in 2.62% of cases. Both increased forest cover and the substitution of livestock have a positive impact on water quality outcomes. Despite the negative impacts associated with the process of afforestation, the long term positives associated with forest cover over the course of a forest rotation, make it a preferable land use option in terms of water quality relative to more seasonal agricultural land uses. Given the expected increase in afforestation in line with national policy, Ireland offers a unique opportunity to observe the outcomes of a large scale afforestation programme in a rural setting