Contribution to the automation of the calculations involving the forest inventory with the aid of an office computer

1970 ◽  
Vol 20 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Tree Species ◽  
Forest Inventory ◽  
Basal Area ◽  
Annual Increment ◽  
Mixed Stands ◽  
Mean Values ◽  
Standing Trees ◽  
General Program ◽  
Magnetic Card ◽  
The Right

Contribution to the automation of the calculations involving  the forest inventory with the aid of an office computer - In this contribution an attempt was made to perform the  calculations involving the forest inventory by means of an office computer  Olivetti P203.     The general program (flowchart 1), identical for all tree species except  for the values of the different parameters, occupies the tracks A and B of a  magnetic card used with this computer. For each tree species one magnetic  card is required, while some supplementary cards are used for the  subroutines. The first subroutine (flowchart 1) enables us to preserve  temporarily the subtotals between two tree species (mixed stands) and so  called special or stand cards (SC). After the last tree species the totals  per ha are calculated and printed on the former, the average trees occuring  on the line below. Appendix 1 gives an example of a similar form resulting  from calculations involving a sampling in a mixed stand consisting of Oak  (code 11), Red oak (code 12), Japanese larch (code 24) and Beech (code 13).  On this form we find from the left to the right: the diameter class (m), the  number of trees per ha, the basal area (m2/ha), the current annual increment  of the basal area (m2/year/ha), current annual volume increment (m3/year/ha),  the volume (m3/ha) and the money value of the standing trees (Bfr/ha). On the  line before the last, the totals of the quantities mentioned above and of all  the tree species together are to be found. The last line gives a survey of  the average values dg, g, ig, ig, v and w.     Besides this form each stand or plot has a so-called 'stand card SC' on  wich the totals cited above as well as the area of the stand or the plot and  its code are stored. Similar 'stand card' may replace in many cases  completely the classical index cards; moreover they have the advantage that  the data can be entered directly into the computer so that further  calculations, classifications or tabling can be carried out by means of an  appropriate program or subroutine. The subroutine 2 (flowchart 2) illustrates  the use of similar cards for a series of stands or eventually a complete  forest, the real values of the different quantities above are calculated and  tabled (taking into account the area). At the same time the general totals  and the general mean values per ha, as well as the average trees are  calculated and printed. Appendix 2 represents a form resulting from such  calculations by means of subroutine 2.

Wind damage over 21 years across different levels of tree removal in natural-origin mixed forests of northwestern British Columbia

2020 ◽  
Vol 50 (9) ◽  
pp. 946-952 ◽  
Author(s):  
K. David Coates ◽  
Erica B. Lilles ◽  
Amalesh Dhar ◽  
Erin C. Hall
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Structural Diversity ◽  
Wind Damage ◽  
Managed Forests ◽  
Partial Cutting ◽  
Forestry Practices ◽  
Management Objectives ◽  
Standing Trees ◽  
Risk Of Wind Damage

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.

scholarly journals Strong positive biodiversity–productivity relationships in a subtropical forest experiment

2017 ◽  
Author(s):  
Yuanyuan Huang ◽  
Yuxin Chen ◽  
Nadia Castro-Izaguirre ◽  
Martin Baruffol ◽  
Matteo Brezzi ◽  
...  
Keyword(s):  
Species Richness ◽  
Basal Area ◽  
Selection Effects ◽  
Annual Increment ◽  
Mixed Stands ◽  
Climate Regulation ◽  
Biodiversity Restoration ◽  
Complementarity Effects ◽  
The Relationship ◽  
Novel Design

Forest ecosystems contribute substantially to global terrestrial primary productivity and climate regulation, but, in contrast to grasslands, experimental evidence for a positive biodiversity-productivity relationship in highly diverse forests is still lacking1. Here, we provide such evidence from a large forest biodiversity experiment with a novel design2 in subtropical China. Productivity (stand-level tree basal area, aboveground volume and carbon and their annual increment) increased linearly with the logarithm of tree species richness. Additive partitioning3 showed that increasing positive complementarity effects combined with weakening negative selection effects caused a strengthening of the relationship over time. In 2-species mixed stands, complementary effects increased with functional distance and selection effects with vertical crown dissimilarity between species. Understorey shrubs reduced stand-level tree productivity, but this effect of competition was attenuated by shrub species richness, indicating that a diverse understorey may facilitate overall ecosystem functioning. Identical biodiversity-productivity relationships were found in plots of different size, suggesting that extrapolation to larger scales is possible. Our results highlight the potential of multi-species afforestation strategies to simultaneously contribute to mitigation of climate change and biodiversity restoration.

scholarly journals Habitat selection of secondary hole-nesting birds in riverine forests along Drava river in Croatia

2020 ◽  
Vol 144 (11-12) ◽  
pp. 558-558
Author(s):  
Mario Slatki ◽  
Jelena Kralj
Keyword(s):  
Tree Species ◽  
Structural Characteristics ◽  
Bird Species ◽  
Rank Correlation ◽  
Basal Area ◽  
Principal Component ◽  
Relative Number ◽  
Bird Community ◽  
Habitat Characteristics ◽  
Mixed Stands

The correlation between secondary hole-nesters community characteristics and floristic and structural characteristics of their habitat was studied in riverine forest stands near river Drava in Croatia. Standard point count method was used for bird community sampling and circular plot method for habitat sampling. Sampling was carried out on 66 points. PCA analysis that included 28 independent habitat variables was used, followed by Spearman rank correlation between principal component scores and bird community variables (number of species and number of pairs). Tree basal area was used as an indication of stand maturity and to classify studied points into four forest types (ash, poplar, alder and mixed). Eight secondary hole-nesting species and 14 tree species were recorded. The average forest age was 59.8 ± 20.5 years, with ash and mixed stands being on average older than alder and poplar stands. Shannon-Wiener index of secondary hole-nesters diversity was highest in stands with dominant ash and was increasing with stand maturity. A significant positive correlation was found between number of bird species as well as number of pairs and older stands with lower number of tree species and lower relative number of poplar and alder. It can be concluded that diversity of secondary hole-nesting bird species as well as their abundance is correlated with structural habitat characteristics and that older stands show greater bird biodiversity and abundance.

scholarly journals To the methods for actualization of main stands parameters of hardwood tree species of Ukraine

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
О. P. Bala
Keyword(s):  
Tree Species ◽  
Forest Inventory ◽  
Site Index ◽  
Coefficient Of Determination ◽  
Average Height ◽  
Mixed Stands ◽  
Continuous Forest ◽  
Growth Prognosis ◽  
Hardwood Tree ◽  
Continuous Forest Inventory

Continuous forest inventory, as one of the methods of forest management of the country, in contrast to the basic inventory, has a number of advantages, which primarily provide the opportunity to obtain the most complete and reliable information about the current state of the forest, as it provides annual updates of main stands parameters of forest found on Ukraine. Hardwood tree species (oak, ash, beech, hornbeam, etc.) occupy a special place among all that grow in Ukraine and occupy almost 44 % of the forest area covered with forest vegetation. According to the latest state forest inventory as of 01.01.2011, hardwood tree species are dominated by oak stands - 62.6 % of the area of all hardwood tree species, forest beech - 20.2 %, hornbeam - 3.2 % and ash ordinary, forming mainly mixed stands with oak. A systematic approach to the effective solution of the problem of continuous forest inventory requires the development of objective methods and mathematical models for updating the main stands parameters of forests. In Ukraine, for actualization main stands parameters, two methods have been developed to forecast their growth. The first is based on modeling the percentage of current increment by average height and wood stock, the second - on the developed dynamic site index curves and yield tables for modal stands. The aim of the work is to improve the methodological approaches to modeling the growth prognosis of the main stands parameters by the second method. To achieve these goals used the method of nonlinear regression using IBM SPSS Statistics. As a result of the conducted researches it was offered to model a new unified ratio of the stands parameter a year ahead to the same stands parameter now multiplied by the age of the stand to model the growth prognosis for all stands parameters. This made it possible during the simulation to describe the changes in growth by the main stands parameters with almost absolute accuracy (the coefficient of determination of the obtained models is 1.0). The equation obtained for growth prognosis has the same form for stands of all tree species, of different origin, composition and site index classes.

INFLUENCE OF TREE SPECIES MIXTURE TO REDUCE WIND DAMAGES IN BIRCH STANDS

2020 ◽  
Author(s):  
Baiba Jansone ◽  
Edgars Dubrovskis ◽  
Linards Sisenis
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Age Groups ◽  
Basal Area ◽  
Adaptation To Climate Change ◽  
Mixed Stands ◽  
Birch Trees ◽  
Species Mixture ◽  
Overstory Trees ◽  
Historical Management

Climate change is linked to increase in frequency and/or severity of different damages in forest stands. Birch (Betula spp.) stands can be significantly affected by wind and snow (freezing rain). Aim of our study was to assess, if admixture of other tree species reduces the proportion of damaged trees in birch stands. Data from total of 836 sample plots (size 500m2) in birch stands at the age of up to 81 year were analysed. Among the mixed sands (MS) and pure stands (PS >80% of single tree species), the mean proportion (± confidence interval) of damage was assessed from the total number (TN) and basal area (BA) of overstory (first layer) trees. MS were further assessed in two groups – one or more species in admixture (MS+1 and MS+2). The proportion of mixed birch stands was increasing with age: from average of 21% at the age of up to 20 years to 64% at the age of 61-70 years, most likely do to difference in historical management. In period between the 1950th and 1990th, birch was considered as undesirable species and the older stands formed mainly due to low survival of coniferous trees and natural ingrowth of birch, whereas starting from the 1990th birch was more widely recognized and used as target species. Proportion of undamaged birch trees (both, when assessed as TN or BA) was not significantly different between MS and PS. Also presence of second layer trees did not affect the proportion of damaged overstory trees significantly. There were significant differences among the groups of mixed stands: more wind or snow damaged trees were found in certain age groups in stands with more than one admixture species present. Creating a mixed birch stands in comparison to pure stands of the same tree species may not result in lower frequency of damaged trees, thus this approach cannot be automatically recommended as a tool for adaptation to climate change

Floristic Variation of Tree Communities and Their Association with Soil Properties in Pulau Jerejak, Penang, Peninsular Malaysia

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi
Keyword(s):  
Tree Species ◽  
Diversity Index ◽  
Basal Area ◽  
Peninsular Malaysia ◽  
Importance Value ◽  
Conservation Action ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Tree Communities ◽  
Floristic Variation

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

Live tree species basal area of the contiguous United States (2000-2009)

2013 ◽  
Author(s):  
Barry T. Wilson ◽  
Andrew J. Lister ◽  
Rachel I. Riemann ◽  
Douglas M. Griffith
Keyword(s):  
United States ◽  
Tree Species ◽  
Basal Area ◽  
Live Tree

scholarly journals An approximate point-based alternative for the estimation of variance under big BAF sampling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Thomas B. Lynch ◽  
Jeffrey H. Gove ◽  
Timothy G. Gregoire ◽  
Mark J. Ducey
Keyword(s):  
Forest Inventory ◽  
Variance Estimation ◽  
Basal Area ◽  
Volume Estimation ◽  
Delta Method ◽  
Sampling Point ◽  
Variance Estimator ◽  
Computer Simulation Studies ◽  
New Formula ◽  
Estimation Of Variance

Abstract Background A new variance estimator is derived and tested for big BAF (Basal Area Factor) sampling which is a forest inventory system that utilizes Bitterlich sampling (point sampling) with two BAF sizes, a small BAF for tree counts and a larger BAF on which tree measurements are made usually including DBHs and heights needed for volume estimation. Methods The new estimator is derived using the Delta method from an existing formulation of the big BAF estimator as consisting of three sample means. The new formula is compared to existing big BAF estimators including a popular estimator based on Bruce’s formula. Results Several computer simulation studies were conducted comparing the new variance estimator to all known variance estimators for big BAF currently in the forest inventory literature. In simulations the new estimator performed well and comparably to existing variance formulas. Conclusions A possible advantage of the new estimator is that it does not require the assumption of negligible correlation between basal area counts on the small BAF factor and volume-basal area ratios based on the large BAF factor selection trees, an assumption required by all previous big BAF variance estimation formulas. Although this correlation was negligible on the simulation stands used in this study, it is conceivable that the correlation could be significant in some forest types, such as those in which the DBH-height relationship can be affected substantially by density perhaps through competition. We derived a formula that can be used to estimate the covariance between estimates of mean basal area and the ratio of estimates of mean volume and mean basal area. We also mathematically derived expressions for bias in the big BAF estimator that can be used to show the bias approaches zero in large samples on the order of $\frac {1}{n}$ 1 n where n is the number of sample points.

scholarly journals Comparison of Forest Inventory Methods at Plot-Level between a Backpack Personal Laser Scanning (BPLS) and Conventional Equipment in Jeju Island, South Korea

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 308
Author(s):  
Chiung Ko ◽  
Seunghyun Lee ◽  
Jongsu Yim ◽  
Donggeun Kim ◽  
Jintaek Kang
Keyword(s):  
South Korea ◽  
Forest Inventory ◽  
Laser Scanning ◽  
Jeju Island ◽  
Time Data ◽  
Non Invasive ◽  
Coniferous Plantation ◽  
Standing Trees ◽  
Time Required ◽  
Inventory Method

In recent years, light detection and ranging (LiDAR) has been increasingly utilized to estimate forest resources. This study was conducted to identify the applicability of a LiDAR sensor for such estimations by comparing data on a tree’s position, height, and diameter at breast height (DBH) obtained using the sensor with those by existing forest inventory methods for a Cryptomeria japonica forest in Jeju Island, South Korea. For this purpose, a backpack personal laser scanning device (BPLS, Greenvalley International, Model D50) was employed in a protected forest, where cutting is not allowed, as a non-invasive means, simultaneously assessing the device’s field applicability. The data collected by the sensor were divided into seven different pathway variations, or “patterns” to consider the density of the sample plots and enhance the efficiency. The accuracy of estimating the variables of each tree was then assessed. The time spent acquiring and processing real-time data was also analyzed for each method, as well as total time and the time required for each measurement. The findings showed that the rate of detection of standing trees by LiDAR was 100%. Additionally, a high statistical accuracy was observed in pattern 5 (DBH: RMSE 1.22 cm, bias—0.90 cm, Height: RMSE 1.66 m, bias—1.18 m) and pattern 7 (DBH: RMSE 1.22 cm, bias—0.92 cm, Height: RMSE 1.48 m, bias—1.23 m) compared to the results from the typical inventory method. A range of 115–162.5 min/ha was required to process the data using the LiDAR, while 322.5–567.5 min was required for the typical inventory method. Thus, the application of a backpack personal LiDAR can lead to higher efficiency when conducting a forest resource inventory in a coniferous plantation with understory vegetation. Further research in various stands is necessary to confirm the efficiency of using backpack personal laser scanning.

Impact of Deer Browsing on Regeneration in Mixed Stands in Southern New England

1995 ◽  
Vol 12 (3) ◽  
pp. 115-120 ◽  
Author(s):  
David B. Kittredge ◽  
P. Mark S. Ashton
Keyword(s):  
New England ◽  
Tree Species ◽  
Sugar Maple ◽  
Red Maple ◽  
White Pine ◽  
Mixed Stands ◽  
Tree Species Composition ◽  
Southern New England ◽  
Pine Seedlings ◽  
Species Specific

Abstract Browsing preferences by white-tailed deer were evaluated for 6 tree species in northeastern Connecticut. Deer density averaged 23/mile². Deer exhibited no species-specific preferences for seedlings greater than 19 in. For seedlings less than 19 in., hemlock and black birch were preferred. Red maple, sugar maple, and white pine seedlings were avoided. Red oak seedlings were neither preferred nor avoided. A much higher proportion of seedlings greater than 19.7 in. in height was browsed, regardless of species. Browsing preferences for species in the smaller seedling class, combined with a lack of preference for species in the larger class may result in future stands with less diverse tree species composition. Deer densities in excess of 23/mile² may be incompatible with regeneration of diverse forests in southern New England. North. J. Appl. For. 12(3):115-120.

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