Christian Kuehne

Research Scientist

(+47) 485 06 725
christian.kuehne@nibio.no

Place
Ås H8

Visiting address
Høgskoleveien 8, 1433 Ås

Biography

Education

  • Dr. forest. Göttingen University, Germany (2004)
  • M.Sc. Göttingen University, Germany (2002)
  • B.Sc. Göttingen University, Germany (2000)

Professional Experience

Prior to NIBIO I worked as Postdoctoral Research Associate at Oregon State University, USA (2005-2006) and Göttingen University, Germany (2007), as Lecturer at Freiburg University, Germany (2007-2013), and as Research Associate at the University of Maine, USA (2013-2020).
 
My research activities have covered the silvicultural manipulation of regeneration and growth dynamics of mixed species forests, limitations of the close-to-nature forest management paradigm in Central Europe, the ecology and silviculture of oak forests, as well as modeling the influence of forest management practices on stand dynamics and forest structure.

Selected publications

Kuehne C, Zimmer K, Smith A. 2024. The relationship between branch scar attributes and knot features in birch (Betula pendula and B. pubescens). Wood Sci Technol https://doi.org/10.1007/s00226-024-01554-1.
 
Kuehne C, Weiskittel AR, Kershaw Jr. JA. 2022. Development and evaluation of refined annualized individual tree diameter and height increment equations for the Acadian Variant of the Forest Vegetation Simulator: Implication for forest carbon estimates. Math Comput For Nat-Res Sci 14(2): 9-31.
 
Kuehne C, Weiskittel AR, Granhus A. 2022. Examining approaches for modeling individual tree growth response to thinning in Norway spruce. For Ecosyst 9: 100060
 
Maleki K, Rasmus A, Kuehne C, McLean JP, Antón-Fernández C. 2022. Stand-level growth models for long-term projections of the main species groups in Norway. Scan J For Res 37(2): 130-143.
 
Kuehne C, McLean P, Maleki K, Antón-Fernández C, Rasmus A. 2022. A stand-level growth and yield model for thinned and unthinned even-aged Scots pine forests in Norway. Silva Fenn 56(1): 1062.
 
Annighöfer P, Mund M, Seidel D, Ammer C, Ameztegui A, Balandier P, Bebre I, Coll L, Collet C, Hamm T, Huth F, Schneider H, Kuehne C, Löf M, Petritan A, Petritan C, Schall P, Bauhus J. 2022. Examination of aboveground attributes to predict belowground biomass of young trees. For Ecol Manage 505: 119942.
 
Nosko P, Moreau K, Kuehne C, Major KC, Bauhus J. 2022. Does a shift in shade tolerance as suggested by seedling morphology explain differences in regeneration success of northern red oak in native and introduced ranges? J For Res 33(3): 949-962.
 
Kern CC, Kenefic LS, Kuehne C, Weiskittel AR, Kaschmitter SJ, D’Amato AW, Dey DC, Kabrick JM, Palik BJ, Schuler TM. 2021. Relative influence of stand and site factors on aboveground live-tree carbon sequestration and mortality in managed and unmanaged forests. For Ecol Manage 492: 119266.
 
Mäkinen H, Henttonen HM, Kohnle U, Kuehne C, Nöjd P, Yue C, Klädtke J, Siipilehto J. 2021. Site carrying capacity of Norway spruce and Scots pine stands has increased in Germany and northern Europe. For Ecol Manage 492: 119214.
 
Kohler M, Pyttel P, Kuehne C, Modrow T, Bauhus J. 2020. On the knowns and unknowns of natural regeneration of silviculturally managed sessile oak (Quercus petraea (Matt.) Liebl.) forests – a literature review. Ann For Sci 77: 101.
 
Kuehne C, Pyttel P, Modrow T, Kohnle U, Bauhus J. 2020. Seedling development and regeneration success after ten years following group selection harvesting in a sessile oak (Quercus petraea (Matt.) Liebl.) stand. Ann For Sci 77: 71.
 
Modrow T, Kuehne C, Saha S, Bauhus J, Pyttel PL. 2020. Photosynthetic performance, height growth, and dominance of naturally regenerated sessile oak (Quercus petraea [Mattuschka] Liebl.) seedlings in small-scale canopy openings of varying sizes. Eur J For Res 139: 41–52.
 
Kuehne C, Russell MB, Weiskittel AR, Kershaw Jr. JA. 2020. Comparing strategies for representing individual-tree secondary growth in mixed-species stands in the Acadian Forest region. For Ecol Manage 459: 117823.
 
Weiskittel AR, Kuehne C. 2019. Evaluating and modeling variation in site-level maximum carrying capacity of mixed-species forest stands in the Acadian Region of northeastern North America. For Chron 95(3): 171-182.
 
Kuehne C, Weiskittel AR, Legaard KR, Simons-Legaard EM. 2019. Development and comparison of various stand- and tree-level modeling approaches to predict harvest occurrence and intensity across the mixed forests in Maine, northeastern US. Scan J For Res 34(8): 739-750.
 
Puhlick JJ, Kuehne C, Kenefic LS. 2019. Crop tree growth response and quality after silvicultural rehabilitation of cutover stands. Can J For Res 49(6): 670-679.
 
Kuehne C, Weiskittel AR, Waskiewicz J. 2019. Comparing performance of contrasting distance-independent and distance-dependent competition metrics in predicting individual tree diameter increment and survival within structurally-heterogeneous, mixed-species forests of Northeastern United States. For Ecol Manage 433: 205–216.
 
Kuehne C, Puhlick J, Weiskittel A, Cutko A, Cameron D, Sferra N, Schlawin J. 2018. Metrics for comparing stand structure and dynamics between Ecological Reserves and managed forest of Maine, USA. Ecology 99: 2876.
 
Kuehne C, Weiskittel AR, Pommerening A, Wagner RG. 2018. Evaluation of 10-year temporal and spatial variability in structure and growth across contrasting commercial thinning treatments in spruce-fir forests of northern Maine, USA. Ann For Sci 75: 20.
 
Bose AK, Weiskittel AR, Kuehne C, Wagner RG, Turnblom E, Burkhart HE. 2018. Tree-level growth and survival following commercial thinning of four major softwood species in North America. For Ecol Manage 427: 355-364.
 
Bose AK Weiskittel AR, Kuehne C, Wagner RG, Turnblom E, Burkhart HE. 2018. Does commercial thinning improve stand-level growth of the three most commercially important softwood forest types of North America? For Ecol Manage 409: 683-693.
 
Drössler L, Fahlvik N,  Wysocka NK, Hjelm K, Kuehne C. 2017. Natural regeneration in a multi-layered Pinus sylvestris-Picea abies forest after target diameter harvest and soil scarification. Forests 8: 35.
 
Saha S, Kuehne C, Bauhus J. 2017. Lessons learned from oak cluster planting trials in central Europe. Can J For Res 47: 139-148.
 
Bose A, Weiskittel AR, Wagner RG, Kuehne C. 2016. Assessing the factors influencing natural regeneration patterns in the diverse, multi-cohort, and managed forests of Maine, USA. J Veg Sci 27: 1040-1050.
 
Weiskittel A, Kuehne C, McTague JP, Oppenheimer M. 2016. Development and evaluation of an individual tree growth and yield model for the mixed species forest of the Adirondacks Region of New York, USA. For Ecosyst 3: 26.
 
Kuehne C, Weiskittel AR, Wagner RG, Roth BE. 2016. Development and evaluation of individual tree- and stand-level approaches for predicting spruce-fir response to commercial thinning in Maine, USA. For Ecol Manage 376: 84-95.
 
Annighöfer P, Ameztegui A, Ammer C, Balandier P, Bartsch N, Bolte A, Coll L, Collet C, Ewald J, Frischbier N, Gebereyesus T, Haase J, Hamm T, Hirschfelder B, Huth F, Kändler G, Kahl A, Kawaletz H, Kuehne C, Lacointe A, Lin N, Löf M, Malagoli P, Marquier A, Müller S., Promberger S, Provendier D, Röhle H, Sathornkich J, Schall P, Scherer-Lorenzen M, Schröder J, Seele C, Weidig J, Wirth C, Wolf H, Wollmerstädt J, Mund M. 2016. Species-specific and generic biomass equations for seedlings and saplings of European tree species. Eur J For Res 135: 313-329.
 
Kuehne C, Karrie C, Forrester DI, Kohnle U, Bauhus J. 2015. Root system development in naturally regenerated Douglas-fir saplings as influenced by canopy closure and crowding. J For Sci 61: 406-415.
 
Kuehne C, Weiskittel AR, Fraver S, Puettman KJ. 2015. Effects of thinning induced changes in structural heterogeneity on growth, ingrowth, and mortality in secondary coastal Douglas-fir forests. Can J For Res 45: 1448-1461.
 
Kühne C, Jacob A, Gräf M. 2014. The practice of establishing and tending oak (Qercus petraea [Matt.] Liebl., Q. robur L.) stands – An interview-based study in the eastern Upper Rhine Plain, Germany. Forstarchiv 85: 179-187. In German
 
Saha S, Kuehne C, Bauhus J. 2014. Intra- and interspecific competition differently influence growth and stem quality of young oaks (Quercus robur L. and Q. petraea (Mattuschka) Liebl.). Ann For Sci 71: 381-393
 
Kuehne C, Nosko P, Horwath T, Bauhus J. 2014. A comparative study of physiological and morphological seedling traits associated with shade tolerance in introduced red oak (Quercus rubra L.) and native hardwood tree species in southwestern Germany. Tree Physiol 34: 184-193
 
Saha S, Kuehne C, Bauhus J. 2013. Tree species richness and stand productivity in low-density cluster plantings with oaks (Quercus robur and Q. petraea). Forests 4: 650-655
 
Kuehne C, Kublin E, Pyttel P, Bauhus J. 2013. Growth and form of Quercus robur and Fraxinus excelsior respond distinctly different to initial growing space: results from 24-year-old Nelder experiments. J For Res 24: 1-14
 
Major KC, Nosko P, Kuehne C, Campbell D, Bauhus J. 2013. Regeneration dynamics of non-native northern red oak (Quercus rubra L.) populations as influenced by environmental factors: a case study in managed hardwood forests of south-western Germany. For Ecol Manage 291: 144-153
 
Bauhus J, Puettmann KJ, Kühne C. 2013. Is close-to-nature forest management in Europe compatible with managing forests as complex ecosystems? In Messier C., Puettmann K., and Coates K.D. (eds.) Managing forests as complex adaptive systems. Building resilience to the challenge of global change. Routledge Abingdon, pp. 187-213
 
Briggs N, Kuehne C, Kohnle U, Bauhus J. 2012. Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal. Can J For Res 42: 1858-1864
 
Saha S, Kuehne C, Kohnle U, Brang P, Ehring A, Geisel J, Leder B, Muth M, Petersen R, Peter J, Ruhm W, Bauhus J. 2012. Growth and quality of young oaks (Quercus robur and Q. petraea) grown in cluster plantings in Central Europe: a weighted meta-analysis. For Ecol Manage 283: 106-118
 
Kühne C, Bauhus J, Hörnig T, Oh S. 2011. Effects of canopy closure, crowding and plant size on root system development in Douglas-fir saplings. Forstarchiv 82: 184-194. In German
 
Kuehne C, Donath C, Müller-Using SI, Bartsch N. 2008. Nutrient fluxes via leaching from coarse woody debris in a Fagus sylvatica forest in the Solling Mts., Germany. Can J For Res 38: 2405-2413
 
Kuehne C, Puettmann KJ. 2008. Natural regeneration in thinned Douglas-fir stands in western Oregon. J Sust For 27: 246-274
 
Kühne C, Bartsch N. 2007. Germination of acorns and development of oak seedlings (Quercus robur L.) following flooding. J For Sci 53: 391-399
 
Kühne C, Puettmann KJ. 2006. Large scale management experiments – new approaches to silvicultural research. Forstarchiv 77: 102-109. In German
 
Kühne C, Bartsch N, Röhrig E. 2005. Silvicultural management of floodplain forests of the Upper Rhine Valley in special consideration of Quercus robur L. Schriften aus der Forstlichen Fakultät der Universität Göttingen und der Niedersächsichen Forstlichen Versuchsanstalt 140. J.D. Sauerländer’s Verlag Frankfurt am Main. 139 p. In German
 
Kühne C, Bartsch N. 2005. Fructification and seedling development of pedunculate oak (Quercus robur) in floodplain forests of the Upper Rhine Valley. Forstarchiv 76: 16-23. In German
 
Kühne C, Bartsch N. 2004. On the natural regeneration of mixed stands of European beech (Fagus sylvatica) and Norway spruce (Picea abies) in the Solling Mts., Germany. Forst u. Holz 58: 3-7. In German
 
 

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Abstract

There is currently no quality sorting of harvested hardwood timber in Norway on a national scale. Medium- and high-quality logs including those from birch (Betula pubescens Ehrh., B. pendula Roth) are thus not utilized according to their potential monetary value. Increased domestic utilization of quality birch timber requires that the quality of harvested logs be properly assessed for potential end uses. A preferred sorting procedure would use visually detectable external log defects to grade roundwood timber. Knots are an important feature of inner log quality. Thus, the aim of this study was to evaluate whether correlations between branch scar size and knot features could be found in Norwegian birch. Using 168 knots from seven unpruned birch trees, external bark attributes often showed strong correlations with internal wood quality. Both length of the mustache and length of the seal performed well as predictors of stem radius at the time of knot occlusion. The presence of a broken off branch stub as part of an occluded knot significantly increased the knot-effected stem radius, proving that the practice of removing branches and branch stubs along the lower trunk is a crucial measure if quality timber production is the primary management goal.

Abstract

Management of Scots pine (Pinus sylvestris L.) in Norway requires a forest growth and yield model suitable for describing stand dynamics of even-aged forests under contemporary climatic conditions with and without the effects of silvicultural thinning. A system of equations forming such a stand-level growth and yield model fitted to long-term experimental data is presented here. The growth and yield model consists of component equations for (i) dominant height, (ii) stem density (number of stems per hectare), (iii) total basal area, (iv) and total stem volume fitted simultaneously using seemingly unrelated regression. The component equations for stem density, basal area, and volume include a thinning modifier to forecast stand dynamics in thinned stands. It was shown that thinning significantly increased basal area and volume growth while reducing competition related mortality. No significant effect of thinning was found on dominant height. Model examination by means of various fit statistics indicated no obvious bias and improvement in prediction accuracy in comparison to existing models in general. An application of the developed stand-level model comparing different management scenarios exhibited plausible long-term behavior and we propose this is therefore suitable for national deployment.

To document

Abstract

Tree diameter increment (ΔDBH) and total tree height increment (ΔHT) are key components of a forest growth and yield model. A problem in complex, multi-species forests is that individual tree attributes such as ΔDBH and ΔHT need to be characterized for a large number of distinct woody species of highly varying levels of occurrence. Based on more than 2.5 million ΔDBH observations and over 1 million ΔHT records from up to 60 tree species and genera, respectively, this study aimed to improve existing ΔDBH and ΔHT equations of the Acadian Variant of the Forest Vegetation Simulator (FVS-ACD) using a revised method that utilize tree species as a random effect. Our study clearly highlighted the efficiency and flexibility of this method for predicting ΔDBH and ΔHT. However, results also highlighted shortcomings of this approach, e.g., reversal of plausible parameter signs as a result of combining fixed and random effects parameter estimates after extending the random effect structure by incorporating North American ecoregions. Despite these potential shortcomings, the newly developed ΔDBH and ΔHT equations outperformed the ones currently used in FVS-ACD by reducing prediction bias quantified as mean absolute bias and root mean square error by at least 11% for an independent dataset and up to 41% for the model development dataset. Using the revised ΔDBH and ΔHT estimates, greater prediction accuracy in individual tree aboveground live carbon mass estimation was also found in general but performance varied with dataset and accuracy metric examined. Overall, this analysis highlights the importance and challenges of developing robust ΔDBH and ΔHT equations across broad regions dominated by mixed-species, managed forests.