A growth model for mixed forest stands

2000 ◽  
Vol 134 (1-3) ◽  
pp. 29-43 ◽  
Author(s):  
H.H Bartelink
Author(s):  
Kirsten Höwler ◽  
Torsten Vor ◽  
Peter Schall ◽  
Peter Annighöfer ◽  
Dominik Seidel ◽  
...  

AbstractResearch on mixed forests has mostly focused on tree growth and productivity, or resistance and resilience in changing climate conditions, but only rarely on the effects of tree species mixing on timber quality. In particular, it is still unclear whether the numerous positive effects of mixed forests on productivity and stability come at the expense of timber quality. In this study, we used photographs of sawn boards from 90 European beech (Fagus sylvatica L.) trees of mixed and pure forest stands to analyze internal timber quality through the quality indicator knot surface that was quantitatively assessed using the software Datinf® Measure. We observed a decrease in knot surface with increasing distance from the pith as well as smaller values in the lower log sections. Regarding the influence of neighborhood species identity, we found only minor effects meaning that timber qualities in mixed stands of beech and Norway spruce (Picea abies (L.) H. Karst.) tended to be slightly worse compared to pure beech stands.


2013 ◽  
Vol 21 (2) ◽  
pp. 71-84 ◽  
Author(s):  
Guy R. Larocque ◽  
Nancy Luckai ◽  
Shailendra N. Adhikary ◽  
Arthur Groot ◽  
F. Wayne Bell ◽  
...  

Competition in forest stands has long been of interest to researchers. However, much of the knowledge originates from empirical studies that examined the effects of competition. For instance, many studies were focused on the effects of the presence of herbaceous species on the development of tree seedlings or the decrease in individual tree growth with increases in stand density. Several models that incorporate competitive effects have been developed to predict tree and stand growth, but with simplified representations of competitive interactions. While these studies provided guidance useful for forest management, they contributed only partially to furthering our understanding of competitive mechanisms. Also, most competition studies were conducted in single-species stands. As competitive interactions occurring in mixed stands are characterized by a higher degree of complexity than those in single-species stands, a better understanding of these mechanisms can contribute to developing optimal management scenarios. The dynamics of forest stands with at least two species may be affected not only by competition, but also by facilitation or complementarity mechanisms. Thus, knowledge of the mechanisms may provide insight into the relative importance of intra- versus inter-specific competition and whether competition is symmetric or asymmetric. Special attention to the implementation of field experimental designs is warranted for mixed stands. While traditional spacing trials are appropriate for single-species stands, the examination of competitive interactions in mixed stands requires more complex experimental designs to examine the relative importance of species combinations. Forest productivity models allow resource managers to test different management scenarios, but again most of these models were developed for single-species stands. As competitive interactions are more complex in mixed stands, models developed to predict their dynamics will need to include more mechanistic representations of competition.


2012 ◽  
Vol 49 (No. 11) ◽  
pp. 502-514 ◽  
Author(s):  
P. Kantor ◽  
V. Hurt

The study is already the 5<sup>th </sup>account on the production potential and stability of mixed forest stands in uplands. A spruce/beech stand established in the mid-30s of the 20<sup>th</sup>century is assessed. The stand is situated at an altitude of 470 m and since 1960, it is left to its spontaneous development. At that time, the stand was characterized as a silviculturally neglected dense spruce young growth to a small pole-stage stand with an admixture of beech (spruce 71%, beech 13%). In the course of 41 years, spruce proportion in the stand without intentional thinning measures decreased from 71 to 56% and, vice versa, beech proportion increased from 13 to 31%. Present dominant and co-dominant position of spruce in the stand, its health condition and development in recent years indicate that the ecosystem under evaluation is stabilized fulfilling all functions on the given site at an age of 65 years. The stand is permanently fully stocked and its initial standing volume of 109 m<sup>3</sup>/ha at an age of 24 years in 1960 increased to 560 m<sup>3</sup>/ha at an age of 65 years in 2001.


2018 ◽  
Vol 64 (No. 9) ◽  
pp. 387-393 ◽  
Author(s):  
Runova Elena M ◽  
Garus Ivan A ◽  
Serkov Denis V

Researches and generalizations of information on basic patterns of formation, growth, and structure of Irkutsk region forest stands and plantations enabled to study dynamics of formation and productivity of mixed pine forests, being naturally developed under various economic impacts. Such parameters as diameter-, height-, and volume-wise pine and larch increment in mixed forest stands were studied. The obtained results were accurate due to a wealth of experimental material, statistical and mathematical processing using MS Excel application software, graphic methods of processing the materials. The following conclusions can be made based on the materials collected: areas and yields of larch in Irkutsk region have been sharply reduced, since there are processes of intense deforestation and weak natural regeneration of larch here. Mixed forest plantations of pine and larch grow rather successfully, however, such areas are few, since there is no commercial procurement of larch seeds in Irkutsk region, no larch seedlings are cultivated in nursery forests; larch saplings occupy a much smaller area than Scots pine saplings do; basic taxation parameters and structure of mixed pine-larch forest plantations are formed at the young age; saplings have mean productivity, equivalent to the 3rd yield class; mixed forest stands are of high practical and industrial value that depends on conditions of domestic and foreign market.


2009 ◽  
Vol 51 (3) ◽  
pp. 522-539 ◽  
Author(s):  
Stefanie Eckel ◽  
Frank Fleischer ◽  
Pavel Grabarnik ◽  
Marian Kazda ◽  
Aila Särkkä ◽  
...  

2011 ◽  
Vol 162 (3) ◽  
pp. 51-58
Author(s):  
Pascal Junod

Finely mixed forest stands form the hub of the ever-increasing benefits provided by the forest ecosystem. They may be considered as catalysts for diversity, stability, richness of structure, sustainability, prosperity, conviviality … That being the case, it seems necessary to increase our knowledge of them, particularly on the plateau, where they represent an often unsuspected potential. This article reviews the advantages of such stands together with their requirements and, based on concrete examples, presents the high degree of variety and mixture. The origins, values and management of these forests are discussed, with the intention of encouraging a creative and adaptable silviculture which has no qualms in mixing species or accepting the complexity of the resulting structures: An inventive silviculture where research into the function of each tree is desirable. In a climate of incertitude the finely mixed forest is both a fundamental postulate and an asset to be actively encouraged.


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