380 likes | 639 Views
Biodiversity across the forest cycle in ash and Sitka spruce plantations:. Stand structure and vegetation change. Laura French, George Smith, Saoirse O’Donoghue, Anne-Marie McKee, Sue Iremonger, Daniel Kelly, Fraser Mitchell Department of Botany, Trinity College Dublin.
E N D
Biodiversity across the forest cycle in ash and Sitka spruce plantations: Stand structure and vegetation change Laura French, George Smith, Saoirse O’Donoghue, Anne-Marie McKee, Sue Iremonger, Daniel Kelly, Fraser Mitchell Department of Botany, Trinity College Dublin
University College, Cork University of Dublin, Trinity College Coillte Teoranta
Forestry and biodiversity • Forestry an increasing land use in Ireland
Forestry and biodiversity • Forestry an increasing land use in Ireland • Can represent a threat to existing biodiversity
Forestry and biodiversity • Forestry an increasing land use in Ireland • Can represent a threat to existing biodiversity • Can be an opportunity to enhance biodiversity at local and landscape scales
Forestry and biodiversity • What is the biodiversity of commercial forestry plantations?
Objectives • How does stand structure develop in plantations?
Objectives • How does stand structure develop in plantations? • How does species richness change over the forest cycle?
Objectives • How does stand structure develop in plantations? • How does species richness change over the forest cycle? • How does tree species influence vegetation species richness?
Objectives • How does stand structure develop in plantations? • How does species richness change over the forest cycle? • How does tree species influence vegetation species richness? • How does species richness of typical woodland plants change?
Sitka spruce ash Study sites • 20 Sitka spruce • 12 ash • 12 spruce-ash mix • Spruce 5 - 46 yr old • Ash 5 - 80 yr old • 3 100m2 plots per site / species combination
Sitka spruce structural types PCA Ordination Axis 2 (Var Expl = 21%) Prethicket 30% Canopy Cover Axis 1 (Var Expl = 73%)
Sitka spruce structural types PCA Ordination Axis 2 (Var Expl = 21%) Thicket 80% Canopy Cover Axis 1 (Var Expl = 73%)
Sitka spruce structural types PCA Ordination Axis 2 (Var Expl = 21%) Closed-maturing 87% Canopy Cover Axis 1 (Var Expl = 73%)
Sitka spruce structural types PCA Ordination Axis 2 (Var Expl = 21%) Reopening 71% Canopy Cover Axis 1 (Var Expl = 73%)
Sitka spruce structural types PCA Ordination Axis 2 (Var Expl = 21%) Mature 55% Canopy Cover Axis 1 (Var Expl = 73%)
A A C BC B BC B BC A C Vascular plants Bryophytes Species richness over the Sitka spruce forest cycle Mean species richness per plot
45 y = -0.6162x + 63.062 40 R2 = 0.71 35 30 25 Mean total species richness per plot 20 15 10 5 0 30 50 70 90 Canopy cover (% cover per 100 m2 quadrat) Canopy cover and species richness
A AB AB B B Vascular plants Bryophytes Species richness over the ash forest cycle Mean species richness per plot B B B A A
Ash Sitka spruce Ash compared with Sitka spruce A A A Mean species richness per plot B B A
Ash Sitka spruce Woodland species over the forest cycle D C CD Mean species richness per plot BC B AB A AB A A
Conclusions • Species richness changes significantly over the forest cycle
Conclusions • Species richness changes significantly over the forest cycle • Ash forests have higher species richness of vascular plants
Conclusions • Species richness changes significantly over the forest cycle • Ash forests have higher species richness of vascular plants • Sitka spruce forests have higher species richness of bryophytes
Conclusions • Species richness changes significantly over the forest cycle • Ash forests have higher species richness of vascular plants • Sitka spruce forests have higher species richness of bryophytes • Species richness of woodland vascular plants increases along forest cycle
Conclusions • Plantations of ash and Sitka spruce are not necessarily “ecological deserts”
Conclusions • Plantations of ash and Sitka spruce are not necessarily “ecological deserts” • Not “oases of biodiversity” either
The BIOFOREST project is funded by the National Development Plan through the EPA and COFORD as part of the Environmental RTDI Programme 2000-2006 Project Website: http://bioforest.ucc.ie