It has come to something when we have to speak about sick forests and sick rivers, and this in clean, green Ireland.
Anyone with an interest in the environment knows about the malaise affecting our rivers and lakes, especially in summer, when nutrient enrichment caused by the spread of chemicals to foster growth causes many thousands of fish to go belly-up. We record it, we abhor it but it happens with sad predictability the following year.
The UCC department of zoology and animal ecology has been studying forests and their effect on adjoining river systems. The team, led by Dr John O'Halloran and Prof Paul Giller, specialists in the management of ecosystems, are involved in a European-wide project to measure the biodiversity of forests. In the Irish context, they have concluded that there are places where it would be best not to plant forests because of the greatly increased risk of acidification. The problem, according to the team, is caused by the leaching of acids collected in forests, and varies in scale from one part of Ireland to another. For instance, both Wicklow and Connemara are particularly vulnerable - Connemara due to its underlying geology and Wicklow because its east coast location is exposed to weather fronts carrying pollution from Britain and the European mainland. Munster, on the other hand, is well suited to afforestation because of the prevalence of red sandstone and the fact that 60 per cent of the winds in the region are from the south-west, a generally favourable factor from the point of view of airborne pollution. The point, says the UCC team, is that some areas may have to be ruled in and others ruled out. This finding is hardly likely to win widespread approval given the fact that, as Dr O'Halloran says, afforestation is spreading across rural Ireland "on the back of generous tax reliefs".
The researchers also found that despite a commonly held view to the contrary, conifer plantations support a significant range of animal species. On average, they found that 31 species of birds existed in the conifer plantations surveyed. In summer, that rose to 41. It also suggests that contrary to another commonly held view, the substitution of broadleaf plantations for conifers may not necessarily lead to any significant increase in wildlife.