Monitoring of forest ecosystems in Ireland : FOREM 9 project : final report

Abstract

Intensive monitoring has been carried out under EC Regulation 3528/86 (project number 8860 IR 001.0) at Ballyhooly, Co. Cork since 1988. In 1991, three new plots (Roundwood, Cloosh and Brackloon) were established (9060IR0030) to give a more comprehensive network of such plots in Ireland. Monitoring of these three plots continued under project numbers 9360IR0030, 9560IR0030, 9760 IR 0030 9860 IR 0030, 9960IR0030, 2000.60.IR, 2001.60.IR and the current project, focusing on atmospheric inputs and biogeochemical cycling. In 2001, a new plot, Ballinastoe was established, to replace the Roundwood plot, which was due to be clearfelled. This project, (FOREM9, 2002.60.IR) ran from January 2002 to December 2002. The monitoring is designed to improve understanding of the effects of atmospheric pollution on forest ecosystems, and is based on permanent sample plots located in important forest ecosystems in Ireland. The monitoring procedures followed those in the previous projects and closely follow the ICP Manual (UN/ECE, 1998 and updates). Measurements included: precipitation in an open-field plot; quantitative collection and chemical analysis of forest throughfall and stemflow; collection and chemical analysis of forest soil solution from zero-tension lysimeters below the forest floor, and from suction lysimeters at greater depths. The health status of the forests in Ireland is generally good. The Roundwood and Ballinastoe sites are located in the east of Ireland. As such, they are it is subject to higher levels of atmospheric pollutants than the two sites located on the west coast. If there were to be a deterioration in the health of forests in Ireland due to atmospheric deposition, it would be expected to first appear on the east coast, where deposition is highest. Thus the Roundwood and Ballinastoe sites are very valuable for the intensive monitoring programme. Atmospheric deposition in Ireland is dominated by marine ions, notably sodium and chloride. This is due to Ireland’s location on the western seaboard of continental Europe. However, the country is exposed to pollutants during periods of easterly air flows. Evidence of these is seen particularly at the Roundwood and Ballinastoe sites, in eastern Ireland. These “pollution events” merit more comprehensive treatment, to ascertain both their frequency and intensity, and to make some estimation of their potential effects on the forest ecosystem. Soil water sampling is essential to the understanding of these events. Calculation of soil water fluxes carried out in this project, improves our insight into the longer-term environmental impacts of atmospheric deposition on these forests.