| Research on the interaction between plantation forestry and aquatic
environments is essential to develop environmentally compatible and sustainable management
further. Given, in Ireland, the generally low levels of atmospheric pollution, its geology
and maritime climate, and the unique fauna and flora due to its island history, such
studies are important not only in the regional context, but also internationally, as they
provide an opportunity to examine the effect of forestry and forest management practices
on aquatic systems per se, without the complications of acidification. Here, some
of the major findings of forestry and water research in Ireland have been reviewed and
compared with those from the UK and elsewhere. Plantation forests do not exacerbate
acidification in the south of Ireland (Munster) as a whole so that the influence of
forestry on water chemistry is far less important than in other parts of the country (such
as Wicklow and Mayo). The main forestry influence on streams in Munster is more likely
through physical factors, but their nature is unclear. In a few catchments some negative
effects are evident, but in many others apparently positive forest effects occur. In this
context, smaller scale catchment-level effects appear to be more important in explaining
the various relationships between plantation forests and stream ecology than larger scale
regional factors. The management of riparian zones, particularly in forested catchments,
is of major importance for the structure and functioning of aquatic communities and
further work is needed on best management practices. It is suggested that it is
unreasonable to base forest management on national Forest-Fisheries guidelines since
regions vary too much and the signal from local conditions is too strong. The approach
for environmentally benign, scientifically sound forestry management has to be at the
catchment scale. Trees in the right places may be beneficial ecologically but further
work is needed to identify these locations. The introduction of new forest management
practices such as adoption of new species mixes and continuous forest cover are at an
early stage in Ireland and their influence on aquatic systems is unknown.
Keywords: forest-stream interactions, Irish plantation forestry, hydrochemistry,
macroinvertebrates, salmonids, forest management |