Mark Wilson,Tom Gittings, Josephine Pithon, John O’Halloran, Tom C. Kelly, Paul Giller Bird Assemblages of Irish Plantation Forestry: Effects of Growth Stage and Tree Species Correspondence address: BIOFOREST Project, Dept. ZEPS, UCC, Cork.

Researchers based in: University College Cork Trinity College Dublin PROJECT RESEARCHERS

Three sub-projects: 1. Afforestation of open habitats 2. Contribution of open space within plantations 3. Effect of tree species and stage of forest cycle PROJECT STRUCTURE

 Pre-thicket Pure sprucePure ashSpruce/ Ash mix 2 species: Sitka spruce Picea sitchensis ash Fraxinus exelsior 4 ages: pre-thicket (<9 years) thicket (9-17 years) mid-rotation (23-30 years) mature (>35 years)   Mature  Mid-rotation  Thicket

4-9 points located in each site 1-3 visits, 2001 and 2002 distance and identity of all birds < 50m habitat variables: canopy height % cover of canopy, shrub and ground vegetation POINT COUNT METHODOLOGY tree spacing

DATA PREPARATION densities estimated using Distance v.4 computer package site species richness calculated for: all bird species detected (total species richness) amber and red listed birds birds typical of forests, open habitats, and generalists

DATA ANALYSES ordination of sites by bird species composition and densities correlation of species richness values with environmental variables cluster analysis and ordination of sites by habitat variables, to derive forest structural types indicator analysis, to identify species typical of different forest structural types

STRUCTURAL HABITAT GROUPS Variation represented by ordination axes: tree height tree spacing canopy cover ground vegetation cover

ORDINATION BY BIRD ASSEMBLAGES Variation represented by ordination axes: occurrence and abundance of 47 species of birds within each site SPRUCE ASH MIXED

TYPICAL BIRD SPECIES OF EACH STRUCTURAL GROUP Intermediate sites Dunnock, Wren, Robin, Blackbird, Chiffchaff Mature sites Chaffinch, Coal Tit, Goldcrest, Treecreeper, Sparrowhawk Young sites Stonechat, Whitethroat, Linnet, Meadow Pipit, Reed Bunting, Redpoll

BIRD SPECIES RICHNESS negatively correlated with growth stage-related variables and distance from forest edge positively correlated with densities of Dunnocks, Blackbirds and Wrens no significant difference between pure spruce, pure ash, or spruce/ash mixed sites positively correlated with shrub cover ESPECIALLY FOR OPEN HABITAT AND AMBER/RED SPECIES

CONCLUSIONS AND RECOMMENDATIONS 1. This study found no difference in species richness between tree species Other studies found broadleaved semi-natural forests in Ireland better for birds Only one species of broadleaf in this study Broadleaved plantation not the same as semi- natural woodland

CONCLUSIONS AND RECOMMENDATIONS 2. Species richness decreases with distance from the forest edge, increases with shrub layer Species richness positively correlated with densities of Dunnocks, Blackbirds and Wrens Encourage development of understorey by preventing canopy closure, and by management of open space within and around forests

CONCLUSIONS AND RECOMMENDATIONS 3. Bird species richness, especially of bird species of conservation concern was negatively correlated with growth stage-related variables Elements of scrub shaded out as forests mature Open habitat species, including nearly all Amber/Red species, are lost as canopy closes Avoid planting habitats with bird assemblages that are intolerant of afforestation

State body for promoting forestry research Environmental Protection Agency National Development Plan PROJECT FUNDING

ACKNOWLEDGEMENTS Thanks to Coillte for allowing us to work on their land. Thanks to Dr. Stuart Newson and Dr. David Noble of the BTO in Thetford, England, for advice on data analysis. Thankyou for listening.