1. Swedish University of Agricultural Sciences Department of Forest Products Run-off quality from sprinkled debarked logs and logs with bark from Picea abies and Pinus contorta PhD Maria Jonsson Swedish University of Agricultural Sciences Dept. of Forest Products maria.jonsson@sprod.slu.se

2. Swedish University of Agricultural Sciences Department of Forest Products Sprinkling (wet storage) of roundwood Necessary for wood protection during storage at industries Used by 84% of the larger Swedish sawmills during May to September Large problems with great volumes of polluted run-off (TOC, P, phenols, low pH) affecting surrounding ground and watercourses Traditionally logs with bark Pollutants probably origins from the bark, could debarked logs be the solution? In addition, measuring and grading of debarked logs are easier and more effective compared to logs with bark

3. Swedish University of Agricultural Sciences Department of Forest Products Aim of the study To investigate differences in run-off quality from sprinkled storage of Norway spruce (Picea abies) and Lodgepole pine (Pinus contorta) saw logs with and without bark.

4. Swedish University of Agricultural Sciences Department of Forest Products Location of experiments

5. Swedish University of Agricultural Sciences Department of Forest Products Materials and methods Two experimental sites in central Sweden Pilot scale and full scale Newly felled trees of Norway spruce and Lodgepole pine Half of the logs were debarked in a sawmill barker

6. Swedish University of Agricultural Sciences Department of Forest Products Materials and methods Sprinkled storage for 10 to 12 weeks Sprinkling intensity of 100 to 200 mm/day Run-off water was collected under the piles with two different methods, see below Run-off was analysed for total organic carbon (TOC), phosphorus, phenols, and pH

7. Swedish University of Agricultural Sciences Department of Forest Products Results Clearly rised concentrations of pollutants compared to the sprinkling water Similar results from both sites Differences between run- off from logs with bark and debarked logs were in most cases larger for Norway spruce than Lodgepole pine Run-off from debarked logs has significantly higher pH

8. Swedish University of Agricultural Sciences Department of Forest Products Results Run-off from debarked logs has significantly lower concentrations of phenols Phenols can be toxic to living organisms Surprising peak in the middle of the period

9. Swedish University of Agricultural Sciences Department of Forest Products Results Run-off from debarked logs has lower concen- trations of total organic carbon (TOC) Organic carbon is important for oxygen consumption Phosphorus? Higher concentrations in run-off from debarked logs and bigger difference for Lodgepole pine Effect on eutrophication uncertain or negative?

10. Swedish University of Agricultural Sciences Department of Forest Products Results High, but rapidly decreasing initial concentrations The first three weeks most important at log yards Could be used when planning storage at a log yard – keep piles sprinkled for longer periods while new wood is processed Preliminary results show that wood quality is preserved when storing debarked logs

11. Swedish University of Agricultural Sciences Department of Forest Products Conclusions Run-off from debarked logs contains less pollutants compared to run-off from logs with bark Storing debarked logs is a good alternative to storing logs with bark Wood processing industries should consider the method much more than they do today. Tradition must sometimes be questioned!

12. Swedish University of Agricultural Sciences Department of Forest Products Thank you for your attention! The study was financed by Ångpanneföreningens Foundation for Research and Development, SCA Timber, and the Skogsägarna Norrskogs Research Foundation.