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Review article - Peer-reviewed, 2019

Maintenance of long-term experiments for unique insights into forest growth dynamics and trends: review and perspectives

Pretzsch, Hans; del Rio, Miren; Biber, Peter; Arcangeli, Catia; Bielak, Kamil; Brang, Peter; Dudzinska, Malgorzata; Forrester, David Ian; Klaedtke, Joachim; Kohnle, Ulrich; Ledermann, Thomas; Matthews, Robert; Nagel, Juergen; Nagel, Ralf; Nilsson, Urban; Ningre, Francois; Nord-Larsen, Thomas; Wernsdorfer, Holger; Sycheva, Ekaterina

Abstract

In this review, the unique features and facts of long-term experiments are presented. Long-term experimental plots provide information of forest stand dynamics which cannot be derived from forest inventories or small temporary plots. Most comprise unthinned plots which represent the site specific maximum stand density as an unambiguous reference. By measuring the remaining as well as the removed stand, the survey of long-term experiments provides the total production at a given site, which is most relevant for examining the relationship between site conditions and stand productivity on the one hand and between stand density and productivity on the other. Thus, long-term experiments can reveal the site-specific effect of thinning and species mixing on stand structure, production and carbon sequestration. If they cover an entire rotation or even the previous and following generation on a given site, they reveal a species' long-term behaviour and any growth trends caused by environmental changes. Second, we exploit the unique data of European long-term experiments, some of which have been surveyed since 1848. We show the long-term effect of different density regimes on stand dynamics and an essential trade-off between total stand volume production and mean tree size. Long-term experiments reveal that tree species mixing can significantly increase stand density and productivity compared with monospecific stands. Thanks to surveys spanning decades or even a century, we can show the changing long-term-performance of different provenances and acceleration of stand production caused by environmental change, as well as better understand the growth dynamics of natural forests. Without long-term experiments forest science and practice would be not in a position to obtain such findings which are of the utmost relevance for science and practice. Third, we draw conclusions and show perspectives regarding the maintenance and further development of long-term experiments. It would require another 150years to build up a comparable wealth of scientific information, practical knowledge, and teaching and training model examples. Although tempting, long-term experiments should not be sacrificed for cost-cutting measures. Given the global environmental change and the resulting challenges for sustainable management, the network of long-term experiments should rather be extended regarding experimental factors, recorded variables and inter- and transdisciplinary use for science and practice.

Keywords

Unthinned stands; Total stand volume production; Maximum stand density; Density-growth relationship; Mixing effects; Growth trends; Biomonitoring; Silvicultural guidelines

Published in

European Journal of Forest Research
2019, volume: 138, number: 1, pages: 165-185
Publisher: SPRINGER

Authors' information

Pretzsch, Hans
Tech Univ Munich
del Rio, Miren
Univ Valladolid
Biber, Peter
Tech Univ Munich
Arcangeli, Catia
Forest Mensurat Modelling and Forecasting Ctr Susta
Bielak, Kamil
Warsaw Univ Life Sci
Brang, Peter
Swiss Fed Res Inst WSL
Dudzinska, Malgorzata
Forest Res Inst
Forrester, David Ian
Swiss Fed Res Inst WSL
Klaedtke, Joachim
Forest Res Stn Baden Wurttemberg
Kohnle, Ulrich
Forest Res Stn Baden Wurttemberg
Ledermann, Thomas
Fed Res and Training Ctr Forests Nat Hazards and Land
Matthews, Robert
Forest Mensurat Modelling and Forecasting Ctr Susta
Nagel, Juergen
Northwest German Forest Res Stn
Nagel, Ralf
Northwest German Forest Res Stn
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre
Ningre, Francois
Univ Lorraine
Nord-Larsen, Thomas
Univ Copenhagen
Wernsdorfer, Holger
Univ Lorraine
Sycheva, Ekaterina
Tech Univ Munich

UKÄ Subject classification

Forest Science

Publication Identifiers

DOI: https://doi.org/10.1007/s10342-018-1151-y

URI (permanent link to this page)

https://res.slu.se/id/publ/105956