Published Date 1 February 2017, Vol.385:1–9, doi:10.1016/j.foreco.2016.11.015
Author
Thomas Van de Peer a,b,
Kris Verheyen b,
Vincent Kint a,
Elisa Van Cleemput a,
Bart Muys a,,
aDivision of Forest, Nature and Landscape, Department of Earth & Environmental Sciences, KU Leuven, Celestijnenlaan 200 E, Box 2411, BE-3001 Leuven, Belgium
bForest & Nature Lab, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode, Belgium
Received 10 August 2016. Revised 8 November 2016. Accepted 9 November 2016. Available online 17 November 2016.
Highlights
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Tree architecture before and during canopy closure is analyzed.
Diversity and identity of neighbors are not yet important determinants.
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Regulating inter-tree competition might facilitate tree quality shaping.
Abstract It is acknowledged that trees behave remarkably plastic in response to environmental conditions. Even so, knowledge of how tree architecture in pure and mixed stands compare is largely underexplored. Such information is relevant from a fundamental ecological and an applied silvicultural perspective, given the increased attention for mixed species silviculture and the close linkages between tree architecture and high-quality timber production. The main objective of this work was to test the effects of competition, diversity and species identity of neighboring trees on the architecture of five important European tree species (Quercus robur, Betula pendula, Fagus sylvatica, Pinus sylvestris and Tilia cordata) in a temperate plantation before and during canopy closure. Data were collected in FORBIO-Zedelgem, a five-year old tree diversity experiment in Belgium. For 396 trees we measured architectural properties including branchiness, tree height-to-diameter (HD) ratio, branch diameter and branch insertion angle, and we investigated how these properties were shaped in different competitive neighborhoods using mixed regression models. Species showed contrasting architectural responses to neighborhood competition, in line with species life-history strategies. In more competitive environments, trees of Q. robur (slow growing and light-demanding) increased HD ratio and branch insertion angle to optimize light foraging in the upper canopy; trees of B. pendula (fast growing and light-demanding) increased HD ratio and decreased branching following the branch autonomy principle; trees of F. sylvatica (slow growing and shade tolerant) increased branching to improve light uptake under shading and finally, trees of P. sylvestris (fast growing and light-demanding) and T. cordata (slow growing and shade tolerant) were not shaped in response to competition. Diversity and identity of species in a trees’ neighborhood did not contribute to the architectural plasticity, although competitive differences between pure and mixed stands underpinned such effects for B. pendula, with lower branching in the highly competitive monocultures. We conclude that competition between trees, but not diversity, influences the architecture of young plantation trees before and during canopy closure in mixtures. To guide tree architectural development towards high-quality timber, management may have to pay considerable attention to competitive processes already in the juvenile forest stages. Keywords
Published Date 1 February 2017, Vol.385:140–149,doi:10.1016/j.foreco.2016.11.031 Author
Timo Kuuluvainen a,,
Annika Hofgaard b
Tuomas Aakala a
Bengt Gunnar Jonsson c
aDept. of Forest Sciences, University of Helsinki, Finland
bDept. of Terrestrial Ecology, Norwegian Institute for Nature Research, Norway
cDept. of Natural Sciences, Mid Sweden University, Sweden
Received 2 May 2016. Revised 18 November 2016. Accepted 21 November 2016. Available online 2 December 2016.
Highlights
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North Fennoscandian mountain forests are relatively little affected by human utilization.
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They are very important for biodiversity conservation and for their sociocultural values.
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Fine scale processes are essential features of mountain forests and their dynamics.
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Rapid change in climate is predicted to profoundly affect forest ecology and dynamics.
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Some of the changes are gradual but also drastic disturbances will become more likely.
Abstract North Fennoscandian mountain forests are distributed along the Scandes Mountains between Sweden and Norway, and the low-mountain regions of northern Norway, Sweden and Finland, and the adjacent northwestern Russia. Regionally, these forests are differentiated into spruce, pine or birch dominance due to climatic differences. Variation in tree species dominance within these regions is generally caused by a combination of historical and prevailing disturbance regimes, including both chronic and episodic disturbances, their magnitude and frequency, as well as differences in edaphic conditions and topography. Because of their remoteness, slow growth and restrictions of use, these mountain forests are generally less affected by human utilization than more productive and easily utilizable forests at lower elevations and/or latitudes. As a consequence, these northern forests of Europe are often referred to as “Europe’s last wilderness”, even if human influence of varying intensity has been ubiquitous through historical time. Because of their naturalness, the North Fennoscandian mountain forests are of paramount importance for biodiversity conservation, monitoring of ecosystem change and for their sociocultural values. As such, they also provide unique reference areas for basic and applied research, and for developing methods of forest conservation, restoration and ecosystem-based management for the entire Fennoscandia. However, the current rapid change in climate is predicted to profoundly affect the ecology and dynamics of these forests in the future. Graphical abstract
R B Tabakaev1, P S Gergelizhiu, A V Kazakov and A S Zavorin
Published under licence by IOP Publishing Ltd IOP Conference Series: Materials Science and Engineering, Volume 66, conference 1
Abstract
Relevance is determined by necessity of utilizing of local low-grade fuels by energy equpment. Most widespread Tomsk oblast (Russian Federation region) low-grade fuels are described and listed. Capability of utilizing is analysed. Mass balances of heat-technology conversion materials and derived products are described. As a result, recycling capability of low-grade fuels in briquette fuel is appraised.
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
References
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Popel O S Reutov B F and Antropov A P 2010 Thermal engineering11909–918
[2]
Zavorin A S Kazakov A V Makeev A A and Podorov S V 2012 Thermal engineering1 77–82
[3]
Zavorin A S Kazakov A V and Tabakaev R B 2012 Bulletin Tomsk Polytechnic University4 18–22
The effectiveness of the small-tonnage solid composite fuel production from biomass R B Tabakaev et al 2015 IOP Conference Series: Materials Science and Engineering 93 012017
