Assessment of Effective Wind Loads on Individual Plantation-Grown Forest Trees

Round 1

Reviewer 1 Report

Abstract: It remains unclear from the abstract, what the hypothesis and results or the paper are;

Introduction: Relevant literature on wind is cited, I miss hypothesis at the end of the introduction and an overall aim of the paper

Data and method:

The sample size of trees with detailed measurements (n=5) is low for international publication; The multitude of different measurements on different sub-samples makes it hard to keep track of which measurements were actually taken on the same trees; The number of abbreviations introduced in the data and method section makes the paper hard to read.

Was TLS merely used to derive crown parameters? Crown paramters were not used in the further analysis, so maybe this section can be omitted.

Results: Fig 5: It remains unclear, which of the 3 plotted models was chosen and why

Fig 7: It is not clear to me, which 2-phase linear model was used to determine the change point

Discussion: A discussion of methods and results is entirely missing

Author Response

We thank the Editor and the reviewer for their valuable comments and suggestions on the submitted manuscript. We think that the comments and suggestions greatly helped to improve the manuscript’s quality. The responses of the authors are in red.

Author Response File: Author Response.docx

Reviewer 2 Report

Wind has a significant effect on the development of forest ecosystems, and it is one of the factors determining the formation of trees, landscapes, and forest sites (Mitchell 2012). It modifies characteristics of forest stands, significantly affects their composition and structure, and somewhat determines growth conditions (Jansosn et al. 2014). To a considerable extent, the susceptibility of trees and whole stands to wind damage depends on individual morphological traits of trees; in forest communities, it also depends on their structure. Many sources have described the effect of wind on forest ecosystems, including problems connected with the effect of wind on stem morphology and mechanics (England et al. 2000; Spatz et al. 2000; Peltola et al. 2006).

1. Mitchell, S. J. (2012). “Wind as a natural disturbance agent in forests- An integrative overview,” Forestry 86, 147-157. DOI: 10.1093/forestry/cps058
2. Jansons, A., Matisons, R., Krisans, O., Puriņa, L., Dzēriņa, B., and Neimane, U. (2014). “Height of the mass point and some properties of crown of 26 year old Scots pine and Lodgepole pine as potential parameters for wind damage in Zvirgzde, Latvia,” Baltic Forestry 20(1), 48-57
3. England, A. H., Baker, C. J., and Saunderson, S. E. T. (2000). “A dynamic analysis of windthrow of trees,” Forestry 73(3), 225-238. DOI: 10.1093/forestry/73.3.225
4. Spatz, H.-C., and Bruechert, F. (2000). “Basic biomechanics of selfsupporting plants: wind loads and gravitational loads on a Norway spruce tree,” Forest Ecology Management 135, 33-44. DOI:10.1016/S0378-1127(00)00296-6
5. Peltola, H. (2006). “Mechanical stability of trees under static loads,” American Journal of Botany 93(10), 1501-1511. DOI: 10.3732/ajb.93.10.1501

The article presented for review is fascinating, but needs some clarifications, corrections, and corrections.

Line 44 - Storms and Organs. Strong winds on the European continent are usually called orcans.

Lines 64-77 - The interactions between trees and the mechanical functioning of trees should also be mentioned. Mechanical loads that effect the development, morphology, and structural traits of woody plants are the foundation for the concept of adaptation growth of trees.

Studies conducted on stability of trees and stands indicate that to a considerable degree it is dependent on the volume of external load and stand structure, in which a particularly important role is played by the species composition, tree height, and diameter at breast height, crown area, root depth and spread, stocking, and soil type (Peltola et al. 2000; Hale et al. 2004; Scott and Mitchell 2005; Jonson et al. 2014). James et al. (2006) stated that the stability of a single tree exposed to a dynamic load is influenced by its size, shape, and structure. Along with the biometrics of trees changing in time (with age) and an increased risk of wind damage, the ultrastructure and properties of xylem are naturally modified at all levels of its structure. As a result, the xylem in the trunk of a single tree is highly heterogeneous and exhibits variability both in the radial and axial planes of the trunk (Jelonek et. al 2019). In terms of mechanics, these changes may be a major determinant of wind resistance in trees.  (Which the authors did not mention)

 

1. Peltola, H., Kellomaki, S., Hassinen, A., and Granander, M. (2000). “Mechanical stability of Scots pine, Norway spruce, and birch- An analysis of tree pulling experiments in Finland,” Forest Ecology and Management 135, 143-153. DOI: 10.1016/S0378-1127(00)00306-6Lines 115 – 134 –
2. Hale, S. E., Levy, P. E., and Gardiner, B. A. (2004). “Trade-offs between seedling growth, thinning and stand stability in Sitka spruce stands: A modelling analysis,” Forest Ecology and Management 187, 105-115. DOI: 10.1016/S0378-1127(03)00313-X
3. Scott, R. E., and Mitchell, S. J. (2005). “Empirical modeling of windthrow risk in partially harvested stands using tree, neighborhood, and stand attributes,” Forest Ecology and Management 218, 193-209. DOI: 10.1016/j.foreco.2005.07.012
4. Jansons, A., Matisons, R., Krisans, O., Puriņa, L., Dzēriņa, B., and Neimane, U. (2014). “Height of the mass point and some properties of crown of 26 year old Scots pine and Lodgepole pine as potential parameters for wind damage in Zvirgzde, Latvia,” Baltic Forestry 20(1), 48-57.
5. James, K., Haritos, N., and Ades, P. K. (2006). “Mechanical stability of trees under dynamic loads,” American Journal Botany 93(10), 1522-1530. DOI: 10.3732/ajb.93.10.1522
6. Jelonek, T. Tomczak, A., Karaszewski, Z., Jakubowski, M., Arasimowicz-Jelonek, M., Grzywiński, W., Kopaczyk, J., Klimek, K. (2019). The biomechanical formation of trees. Drewno. 62. 10.12841/wood.1644-3985.318.05.

 

Lines 141-143 - Why was this sensor placement adopted (2, 9, 18, and 21 m)? Wouldn't it be better to take relative heights for the whole stand (1/3,1/2, 2/3 H of trees)?

Lines 156 – 163 - Were the groups of trees compared similar in terms of biometric characteristics. What model/principle was used to select these groups? This should be described.

Lines 178-181 - Why were measurements at 1 m, 2 m, and 3 m heights used?

Lines 267-271 - The authors performed a regression analysis but did not provide the key parameters of such analysis. It is not known if the correlations were statistically significant, and it is not known if the studied features had a normal distribution.

Lines 277-278 - This conclusion is rather obvious. Stem deviation will increase with height.

Line 350 - The authors should mention the SIM (Static Integrated Measuring) or Elasto - inclino method for measuring stem fracture strength. However, the force generated in the test is basically no more than 4% of the force acting on the tree during Hurricane Winds.

Figure 4 - In the figure, the authors introduced the description B1 to B5 and in the figure title B1 to B35?

1) Did the study pines have symmetrical trunk cross sections?

2) In what geographical direction were the sensors placed?

3. The paper lacks basic data on the structure of the tree tissue, which is heterogeneous in the trunk. It changes in the trunk both in radial and axial direction. It would be advisable to supplement the study with data containing the average width of annual rings (at least at the height of DBH) or density of the wood tissue. As already mentioned, the elasticity of trunks largely depends on the characteristics and properties of wood, which is characterized by very high variability. This should not be forgotten.

4 The paper is too extensive and contains a lot of unnecessary descriptions. The authors could consider either shortening the manuscript or dividing the results into two less extensive papers.

5. there is virtually no discussion of the results obtained, which is a weakness of this manuscript. There is extensive literature describing the biomechanical functioning of trees in response to wind loads. There are also quite a few articles describing the techniques used for trees in urban areas. A "discussion" section should be considered, or the "Results and discussion" section should be expanded to include a somewhat more extensive discussion of the results obtained.

Author Response

We thank the Editor and the reviewer for their valuable comments and suggestions on the submitted manuscript. We think that the comments and suggestions greatly helped to improve the manuscript’s quality. The responses of the authors are in red.

Author Response File: Author Response.docx