Environmental Control of Wood and Tracheid Properties in Norway Spruce (Picea abies (L.) Karst.) Tuula Jyske Harri Mäkinen Pekka Saranpää

Pekka Saranpää 28/10/07 Within annual rings: earlywood, latewoodWithin annual rings: earlywood, latewood VARIATION OF WOOD PROPERTIES Between sites: fertilityBetween sites: fertility Between stems: genetic variation, effect of environmentBetween stems: genetic variation, effect of environment Within stems: juvenile (core)wood, sapwood, heartwoodWithin stems: juvenile (core)wood, sapwood, heartwood

Pekka Saranpää 28/10/07 Juvenile woodEarlywood Latewood Compression wood _________ 0,1 mm

Pekka Saranpää 28/10/07 Tracheid length of Norway spruce from the pith to the bark

Pekka Saranpää 28/10/07  The variation of wood properties from the pith to the bark and from the base to the tree top  The effect of long-term fertilisation and thinning on: » diameter growth, » wood density » tracheid dimensions?

Pekka Saranpää 28/10/07 Finland – Europe's most densely forested country Suonenjoki Parikkala 62°45'N, 27°00'E Suonenjoki Parikkala Suonenjoki Parikkala 61°36'N, 29°22'E

Pekka Saranpää 28/10/07 Thinning experiments

Pekka Saranpää 28/10/07 Growth ring width

Pekka Saranpää 28/10/07 Thinning and fertilisation Parikkala & Suonenjoki delayed first thinning normal first thinning intensive first thinning control 150 kg N ha -1 / 5 v. 300 kg N ha -1 / 5 v.

Pekka Saranpää 28/10/07 Basal area of study trees (cm 2 ) Fertilised control fertilised 1 fertilised 2 delayed normal high thinningintensity Thinned

Pekka Saranpää 28/10/07 Thinning experiments Heinola & Punkaharju  over 50 % increase of growth rate in normally thinned stands compared to low thinning intensity (based on basal area of study trees)  ca. 70 % increase of growth rate in normally thinned stands compared to low thinning intensity  latewood proportion decreased by 8 % – 20 % in normal and intensively thinned trees compared to low thinning intensity  weight density decreased only 1 % – 4 % in normal and intensively thinned trees compared to low thinning intensity

Pekka Saranpää 28/10/07  intensively thinned trees showed 4 – 9 % shorter tracheids compared to low thinning intensity  intensive thinning resulted 3 – 12 % thinner cell walls compared to low thinning intensity  only slight change in tracheid diameter (1 – 3%) Thinning experiments Heinola & Punkaharju

Pekka Saranpää 28/10/07 Thinning - fertilisation experiments Parikkala & Suonenjoki  normal fertilisation level increased ca. 40 % growth rate compared to unfertilised stand  intensive fertilisation level increased growth rate ca. 40 % compared to an unfertilised stand  normal thinning resulted an 8 % increase of growth compared to delayed thinning

Pekka Saranpää 28/10/07  intensive first thinning resulted an 30 % increase of growth compared to delayed thinning  differences in latewood proportion only 2 % – 9 %  weight density decreased only 2 % – 7 % by increasing thinning intensivity Thinning - fertilisation experiments Parikkala & Suonenjoki

Pekka Saranpää 28/10/07  only slight differences in tracheid length ( 1 % – 2 %)  cell wall thickness decreased 1 % – 7 %  minor effect on lumen diameter (0 % – 2 %)

Pekka Saranpää 28/10/07 Models to predict wood properties Models to predict the effect of growth rate on wood properties - from stem base to the tree top - from the pith to the bark Fibre properties - latewood proportion - wood density - fibre length - fibre diameter - cell wall thickness Multivariate multilevel models, GLMM

Pekka Saranpää 28/10/07 Material  Thinning intensity from below in Central and Eastern Finland (Heinola ja Punkaharju, PURO)  Timing of first thinning, intensity of nitrogen fertilisation in Eastern Finland (Parikkala ja Suonenjoki, PURO)  Effect of nitrogen fertilisation in Southern and Northern Finland (Heinola ja Kemijärvi, IMWO)  Nutrient optimisation experiments in Southern and Northern Sweden (Asa and Flakaliden (ENWO)  Fast growing Norway spruce clones in Southern Finland (Nurmijärvi and Ruotsinkylä)

Pekka Saranpää 28/10/07 Models to predict wood properties Multivariate multilevel models, GLMM Mäkinen et al For Ecol Manag 241 Latewood proportion Weight density gm -3 Fibre length, mm Fibre diameter, umCell wall proportion

Pekka Saranpää 28/10/07 Weight density Tracheid length

Pekka Saranpää 28/10/07 Conclusions Prevailing thinning intensities increase significantly growth rate of Norway spruce However, thinning and fertilisation had a minor effect on wood properties like density and fibre dimensions Within-tree and between-tree variation is the major source of variation Limited material (altogether 109 stems from various experiments) and fibre measurements only at breast height

Pekka Saranpää 28/10/07 Thank you! Foundation for Research of Natural Resources in Finland Tuula Jyske Harri Mäkinen