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Physiological ecology of understorey trees in alternative managementsystemsSophie BertinMaurizio Mencuccini1, John Grace1, Mike Perks2, Nigel Straw2 & Bill Mason21 University of Edinburgh & 2 Forest ResearchPhD project Co-Sponsored from the Forest Research Innovation Fund & the Torrance Bequest for Plant Ecology GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Continuous Cover Forestry & Sitka Spruce • CCF : increasingly common alternative management system for British forests • Sitka spruce : dominant commercial tree species in the UK Limited knowledge of desirable conditions for seedling regeneration and growth under CCF GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Green Spruce Aphid & Climate Change (I) • Main defoliator of Sitka spruce • Sap feeding insect Prediction: climate change is likely to enhance aphid population growth and therefore declines in Sitka spruce productivity (Straw, 1995). GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Green Spruce Aphid & Climate Change (II) • Life cycle of the green spruce aphid GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Aphid attack Low light conditions Research Question How are Sitka spruceseedling growth and survival affected by the interactions between & ? GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006 GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
General Aim and Hypothesis • General aim Understanding seedling tree ecophysiology within CCF systems • Hypothesis Low light level & aphid attack = poorer Sitka spruce seedling growth and survival GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Methods (I) • 2006: Exploratory experiments • Short-term pot-plant shade/aphid experiment, NRS nursery, Roslin • Transect investigations of natural regeneration and treated trees in CCF sites, Borders • 2007-08: Detailed experiments • Full field shade/aphid experiment, Roslin • Large scale field manipulation experiment, Wales NRS Borders Wales GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Methods (II) • Layout of short-term pot-plant experiment 2006 GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Aphid population size (Straw and Green, 2001) Plant allometry (architecture) and needle densities Assessment Protocols (I) GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Assessment Protocols (II) • Plant Physiological measurements • Photosynthesis • Chlorophyll fluorescence kinetics GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Research Outcomes • Guidelines for natural regeneration under CCF management systems • Implications for the impact of green spruce aphids on Sitka spruce • Development of chlorophyll fluorometer techniques to assist CCF stand manipulation GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006
Acknowledgments • Mike Perks (NRS) • Maurizio Mencuccini (UoE) • Forest Research staff • University of Edinburgh GLOBAL CHANGE SYMPOSIUM 15 MARCH 2006