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Henrik Hartmann

Ph.D. candidat

Processes and mecanisms of sugar maple
mortality following partial harvest
Université du Québec à Montréal

Supervisor: Christian Messier
Cosupervisor: Marilou Beaudet

Education

• Postoc, Max-Planck Institut for Biogeochemistry, Jena, Germany, 2009 -
• Ph.D., UQAM, 2005 - 2008
• M.Sc., UQAM, 2003 - 2004 (direct switch to Ph.D.)
• B.Sc.F., Université de Moncton (2003)

Other positions

• Board member of the NCE (Network of Centres of Excellence) trainee association (NCETA)
• Representative of students and highly qualified personnel (HQP) of the Sustainable Forest Management Network (SFMN)

Ph.D. project

In Quebec, most of the uneven-aged deciduous forest is managed under the selection system. This partial cut aims at improving residual stand quality and vigor through a rotational removal of low-quality and low-vigor trees. By doing so, the selective system should yield higher residual growth rates and lower residual mortality rates. However, a study investigating stands under industrial management found that realized higher growth rates are counterbalanced by higher mortality rates.

My Ph.D. project investigates the factors that may be responsable for the post-harvest mortality of residual sugar maple trees. I studied sugar maple stands in Temiscaming (south-western Quebec) that had undergone a selection harvest in 1993 or 1994.

My working hypothesis is that some trees die as a consequence of water stress. This stress may be caused by soil compaction and/or damages to tree root systems from machinery traffic as well as from sudden exposure to high solar radiation from canopy opening.

I test these hypotheses with an indirect approach using radial growth rates as a proxy for tree vigor. The thesis has four chapters:

1. Methodological issues in survival probability estimations as a proxy for tree vigor.
2. Radial growth of residual trees as a function of harvest disturbance.
3. Survival probabilities of residual trees as a function of harvest disturbance.
4. Isotopic (¹³C /¹²C) signature dynamics of residual trees (live and dead) following partial harvest.

These investigations will allow me to answer the following questions:

• Is water stress the causal link to residual tree mortality in the selection system?
• Do harvest disturbances of the selection system (machinery traffic, canopy removal) have significant impacts on growth and survival probabilities of residual trees?
• Can these disturbances cause severe enough vigor declines to trigger tree death in some trees?

Publications

Scientific journals

1. Hartmann, H., Beaudet, M., Mazerolle, M. and Messier, C. (accepted) Sugar maple (Acer saccharum Marsh.) growth is influenced by close conspecifics and skid trail proximity following selection harvest. Forest Ecology and Management 258: 823-831. DOI:10.1016/j.foreco.2009.05.028
2. Hartmann, H. and Messier, C. (in preparation) Natural and anthropogenic disturbance alter competitive interactions in sugar maple.
3. Hartmann, H., Wirth, C., Messier, C. and Berninger, F. (2008) Effects of above and below ground partial harvest disturbance on residual sugar maple growth and water stress. Tree Physiology 28: 1851–1862. Paper 
4. Hartmann, H. and Messier, C. (2008) The role of forest tent caterpillar defoliations and partial harvest in the decline and death of sugar maple. Annals of Botany 102: 377-387. Paper  ContentSelect 
5. Hartmann, H., Messier, C. and Beaudet, M. (2008) Using longitudinal survival probabilities to test field vigour estimates in sugar maple (Acer saccharum Marsh.). Forest Ecology and Management 256: 1771–1779. Paper 
6. Hartmann, H., Messier, C. and Beaudet, M. (2007) Improving tree mortality models by accounting for environmental influences. Canadian Journal of Forest Research 37(11): 2106-2114. Paper 
7. Nolet, P., Hartmann, H., Bouffard, D. and Doyon, F. (2007) Predicted and observed sugar maple mortality in relation to site quality indicators. Northern Journal of Applied Forestry 24(4): 258-264. Paper 

Dissertation

Hartmann, H. (2008) Identifying stress factors in sugar maple decline and mortality following partial harvest: analyzing tree growth, vigour and water status. Université du Québec à Montreal. 156p.

Thèse 

Other publications

1. Hartmann, H., Beaulieu, J., Daoust, G. (2002) La diversité biologique et la foresterie de plantations. Literature revue. Canadian Forest Service, Laurentian Forestry Centre. 119p. 372ref.
2. Hartmann, H., Daoust, G. (2002) Mesurage et évaluation, 31 ans après plantation, du test de provenance E277 d’épinette de Norvège établi à la Station forestière de Valcartier, Qc. Technical report. Canadian Forest Service, Laurentian Forestry Centre. 46p. 32ref.

Peer reviews

1. Canadian Journal of Forest Research (08-145, 2008)
2. Canadian Journal of Forest Research (08-373, 2008)
3. Ecology (08-1152, 2008)
4. Journal of Applied Ecology (2009-00383, 2009)

Presentations and posters

Presentations

1. Hartmann, H., Messier, C. and Beaudet, M. (2008) Role of natural and anthropogenic stresses in tree decline and death. ESA annual meeting, Milwaukee, USA, August 2008.
2. Hartmann, H., Messier, C. and Beaudet, M. (2007) Does the visual assessment of tree vigor in the selection system reflect actual tree survival probabilities? North American Forest Ecology Workshop, Vancouver, BC, Canada, June 2007.
3. Hartmann, H., Messier, C. and Beaudet, M. (2006) Truncating live growth series for mortality probability estimations. 7th International Conference on Dendrochronology, Beijing, China, Juin 2006 and Eastern CANUSA conference, Quebec, Canada, October 2006.
4. Hartmann, H., Messier, C. and Beaudet, M. (2005) Mortality of mature Sugar maple following selection harvest in the northern hardwoods of Quebec, Canada. ESA-Intelcol Joint Meeting, Montreal, Quebec, August 2005.
5. Hartmann, H., Messier, C. and Beaudet, M. (2005) Growth response of mature Sugar maple and yellow birch following selection harvest in the northern hardwoods of Québec, Canada. North American Forest Ecology Workshop, Aylmer, Quebec, Canada, June 2005.
6. Hartmann, H., Beaudet, M. , Kneeshaw, D., Béland, M., Messier, C., Kobe, R. (2003) Croissance et mortalité juvénile du bouleau jaune (Betula alleghaniensis Britton) en fonction de la disponibilité de lumière. Scientific competition (ACFAS-Acadie), winner in the undergraduate category Natural sciences and Engineering. March 2003.

Posters

1. Hartmann, H., Messier, C. and Beaudet, M. (2007) Does the visual assessment of tree vigor in the selection system reflect actual tree survival probabilities? Annual conference of the Centre of Forest Research, Montreal, Quebec, Canada, March 2007.