Describes the results of the Covered Catchment Project at Gardsjon in Southwest Sweden. A major project in which a large (800m2) roof has been erected under a forest canopy to shelter the soil from the acid rain that falls in that area. Also covered is the results from the project which shows reduced acidification with lower levels of sulphur in soil and water and run-off water, indicating the effects of the deposition of acidifying substances from acid rain.