Mixed-aged radiata?

Andrew McCullagh, UCD, Ireland COST FP0603 - Short Term Scientific Mission

Objective

To investigate whether Pinus radiata could grow successfully in a mixed-aged setting

Why?

Method - Pinus radiata

• Main timber crop in NZ • Motive for project• Fire ecology

Burdon 2007 in Ecosystems of the World Vol 19

Method - data

Consists of 2 cohorts• Stocking• Age-gap• Four sites

Slide from Scion PSP Department

DBH

Height

Survival

ITGMShula 1997 – Projecting Inventory Data (FRI)

Method - model

Assumptions

Survival

Method - model

Logistic Equation

-Stand Density Index-Relative Density-Change in potential diameter

Results

Results

1. Cohorts tend towards low probability of survival – older cohort does better

2. High stocking reduces level of survival

Results

1. Cohorts tend towards low probability of survival – older cohort does better

2. High stocking reduces level of survival3. Large age-gap – small reduction

Re-Run

Simulation run again up to 40 years

Conclusions

Mixed-aged Pinus radiata unlikely to succeed

Stocking is a factor

Recommendations

Modify project to include a process such as light interception to strengthen results

Other species 3rd cohort

Acknowledgements

• Supervisor – Dr Jennifer Grace• Staff at Scion• Cost