Influence of temporal aggregation on strategic forest management under risk of wind damage

2011 ◽  
Vol 219 (1) ◽  
pp. 397-414 ◽  
Author(s):  
Nicklas Forsell ◽  
Ljusk Ola Eriksson
2019 ◽  
Vol 92 (4) ◽  
pp. 375-380 ◽  
Author(s):  
Barry Gardiner ◽  
Alexis Achim ◽  
Bruce Nicoll ◽  
Jean-Claude Ruel

Abstract This paper discusses the advance in our understanding of the interaction between wind and trees over the last 25 years. It does this by comparing papers in this special issue of Forestry and a companion volume in Agricultural and Forest Meteorology, based on work presented at the 8th IUFRO Wind and Trees Conference in 2017, with papers published in book format after the 1st IUFRO Wind and Trees Conference in 1993. The analysis is divided into sections on ‘airflow and tree mechanics’, ‘forest management and ecology’, ‘tree adaptation and acclimation’ and ‘modelling and statistical techniques’. It is clear that in the last 25 years large advances have been made in our understanding of airflow and turbulence within and above forest canopies and the wind flow and wind loading around and on individual trees. There have also been important developments in the mechanistic and statistical modelling of wind damage risk to forests. Much of the progress has been aided by the enormous advances in measurement systems, computer power and modelling techniques. Furthermore, this knowledge is beginning to influence the approach to temperate and boreal forest management and the development of systems to mitigate the risk of wind damage. At the same time there has been a growing awareness of the ecological impact of wind in many forests around the world, including tropical forests. However, other areas of the effect of wind on trees have progressed much less in the last 25 years. This includes the process of fatiguing in the root-soil system, both during individual storms and over longer periods, and which is known to be a critical factor in the process of windthrow. In addition the exact nature of damage propagation within forests during a storm, and then in subsequent storms, has received relatively little attention although new studies using advanced computational methods are making advances. Of particular relevance, and despite the known critical importance of tree acclimation to the wind, there have been very few studies in the last 25 years on wind acclimation in full-size trees. This is an area of enormous importance in understanding how resistance to the wind varies for different species and between areas with different wind climates. In summary, overall much has been learnt since the 1st Wind and Trees conference but there remain many intriguing and exciting challenges ahead for this multi-disciplinary subject.


2014 ◽  
Vol 15 (8) ◽  
pp. 1489-1500 ◽  
Author(s):  
Mikael Andersson ◽  
Seppo Kellomäki ◽  
Barry Gardiner ◽  
Kristina Blennow

2007 ◽  
Vol 22 (4) ◽  
pp. 285-296 ◽  
Author(s):  
Scott D. Roberts ◽  
Constance A. Harrington ◽  
Karl R. Buermeyer

Abstract Silvicultural treatments designed to enhance stand structural diversity may result in increased wind damage. The ability to avoid conditions that might lead to excessive wind damage would benefit forest managers. We analyzed wind damage following implementation of a variable-density thinning at four sites on the Olympic National Forest in northwest Washington. The prescription created small canopy gaps and retained unthinned patches within a uniformly thinned matrix, thus creating substantial amounts of internal edge. Our objective was to determine whether variable-density thinning resulted in elevated wind damage and whether the damage was spatially related to elements of the treatment, i.e., canopy gaps and uncut patches. Wind damage on the thinned plots averaged slightly more than 8.0 trees/ha. Although precise determinations of residual stem densities were not available, we estimate that total wind damage amounted to 1.3% of total stems remaining following treatment. Approximately 80% of the wind damage was blowdown, the remaining damage being stem breakage, leaning, or bowing. Nearly 54% of the damaged stems were less than 20 cm dbh. The maximum amount of damage observed was 51 trees/ha, but only 3 of 13 thinned plots had wind damage exceeding 7 trees/ha. The overall level of wind damage across all thinned plots after two growing seasons was not statistically greater than on unthinned control plots. Internal edges created by gaps, skid trails, and unthinned patches did not inherently increase wind damage risk; however, where gaps were located in topographically vulnerable positions, greater wind damage did occur. Overall wind damage was not excessive on any of the plots, and after 2 years, all residual stands remained intact and in a manageable condition. Our preliminary results suggest that variable-density thinning that includes creation of small canopy gaps does not necessarily predispose stands to greater risk of wind damage than uniform thinning. However, care must be taken in locating gaps and skid trails away from topographically vulnerable positions.


2009 ◽  
Vol 258 (7) ◽  
pp. 1567-1577 ◽  
Author(s):  
T. Heinonen ◽  
T. Pukkala ◽  
V.-P. Ikonen ◽  
H. Peltola ◽  
A. Venäläinen ◽  
...  

2006 ◽  
Vol 36 (9) ◽  
pp. 2247-2258 ◽  
Author(s):  
Hongcheng Zeng ◽  
Heli Peltola ◽  
Ari Talkkari ◽  
Harri Strandman ◽  
Ari Venäläinen ◽  
...  

The aim of this study was to integrate component models for tree growth, wind damage, and airflow to assess the consequences of alternative forest-management options on the long-term risk of wind damage on a regional scale. This work could help forest managers to identify possible vulnerable edges and determine the probability of risk for alternative management plans. This new, integrated system was applied to assessing the risk of wind damage over a 20-year period on three alternative management choices. The risk was compared for the current forest edges without creating new edges (case study I) and situations where new edges were created through different clear-cut options (case studies II and III). Case study II represented more intensive cuttings compared with case study III (over four times more timber was cut). It was found that despite intensive cuttings in case study II, only 15% and 7% fewer vulnerable edges were found on average (risk probability class ≥0.1%) in case studies I and III, respectively. Therefore, forest managers must consider the possible risk of wind damage when harvesting timber.


2020 ◽  
Vol 50 (9) ◽  
pp. 946-952 ◽  
Author(s):  
K. David Coates ◽  
Erica B. Lilles ◽  
Amalesh Dhar ◽  
Erin C. Hall

In many regions, forestry practices are shifting to partial harvesting approaches that seek to maintain species and structural diversity in managed forests. We monitored windthrow for 21 years following partial cutting treatments with 0%, 30%, and 60% removal in a large, replicated experiment located in mixed-species mature and old-growth forests of fire origin. There was no evidence that wind damage to merchantable trees (≥17.5 cm) varied among the three removal treatments. We found no evidence of a short-term spike in susceptibility to windthrow after partial cutting during the initial years following treatment. Over 21 years, a total basal area of 2.4 m2·ha–1 was damaged, which was 5.9% of the original standing basal area at the start of the experiment. We found clear differences in susceptibility to windthrow among the different tree species. The percentage of original standing trees that were windthrown varied from 0% to 23.7%. Eight of nine species had ≤10% damage over the monitoring period. Foresters should be aware of differences among tree species in risk of wind damage but should not use a general concern about susceptibility to windthrow as a reason to avoid partial cutting systems (that can achieve a diversity of management objectives) in structurally diverse, multispecies forests.


2009 ◽  
Vol 190 (1) ◽  
pp. 57-74 ◽  
Author(s):  
Nicklas Forsell ◽  
Peder Wikström ◽  
Frédérick Garcia ◽  
Régis Sabbadin ◽  
Kristina Blennow ◽  
...  

2000 ◽  
Vol 135 (1-3) ◽  
pp. 303-313 ◽  
Author(s):  
Ari Talkkari ◽  
Heli Peltola ◽  
Seppo Kellomäki ◽  
Harri Strandman

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