Predicting the mortality of Pinus sylvestris attacked by Gremmeniella abietina and occurrence of Tomicus piniperda colonization

2005 ◽  
Vol 35 (4) ◽  
pp. 860-867 ◽  
Author(s):  
Ulf Sikström ◽  
Gunnar Jansson ◽  
Jan Weslien

The fungus Gremmeniella abietina (Lagerb.) Morelet is widely distributed in the northern hemisphere and causes scleroderris canker in several coniferous species. In Sweden, large areas, mainly with 30- to 40-year-old Scots pine (Pinus sylvestris L.) forests, were attacked by the fungus in 2000. The main aim of this study was to investigate the relationship between tree crown transparency (CT) induced by G. abietina and P. sylvestris tree mortality. Furthermore, regeneration–colonization by Tomicus piniperda (L.) was monitored in the investigated stands. Thirty-five permanent sample plots were established in five P. sylvestris stands (38–46 years old) infected by G. abietina and located in the central part of Sweden. During the 2 years following the attack, the total tree mortality accounted for 380 trees·ha–1 and 6.2 m2·ha–1 on average in the five stands, corresponding to 35% of the trees and 27% of the basal area at the time of the attack. Galleries with broods of T. piniperda occurred in trees with a CT value higher than 97%. A model was derived for predicting the probability of P. sylvestris tree mortality. The mortality of individual trees was found to be related to CT, position of needle loss within the crown (CTPOS), and tree diameter at breast height. Furthermore, there was an interaction between CT and CTPOS and a tendency for CT and site to interact. For a P. sylvestris tree with a 0.16-m diameter at breast height and a CT value of 90% spread throughout the crown, the model indicated a mortality probability of 0.03. Above this CT value, the probability of mortality increased substantially. For coniferous species, irrespective of the cause of damage, a CT value of 90%–95% appears to be a critical range; any values greater than this indicate a high probability of mortality.

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1502
Author(s):  
Cezary Beker ◽  
Mieczysław Turski ◽  
Katarzyna Kaźmierczak ◽  
Tomasz Najgrakowski ◽  
Roman Jaszczak ◽  
...  

Studies were carried for 200 trees coming from eight pure pine stands aged 25–95 years, growing in a fresh mixed coniferous forest habitat, in the Murowana Goślina Forest Experimental Station (52°34′ N, 17°00′ E) in western Poland. The aim of the study was to determine the size of the assimilatory apparatus of single pines (Pinus sylvestris L.): weight of leaved twigs (ugc), needle weight (ic), the volume of leaved twigs (ugo) and needle volume (io) and its relationship with selected dendrometric and increment traits of trees. The basic dendrometric traits were determined (height—h and diameter at breast height—d1.3) together with selected increments (heights—Ih5 and Ih10, diameter at breast height—Id5 and Id10, basal area at breast height—Ig5 and Ig10, volume—Iv5 and Iv10). A statistically significant linear correlation and a multiple linear correlation were shown between analysed traits, which confirms a strong relationship of the size of the assimilatory apparatus with tree increment. In this context, the strong correlation with the increment in basal area at breast height (correlation coefficient 0.8731 ÷ 0.9836) and with the increment in diameter at breast height (correlation coefficient 0.7835 ÷ 0.9581), after determining the increment in diameter at breast height requires only simple mathematical transformations to determine the increment in basal area at breast height. For the above-mentioned reasons, the increment in basal area at breast height is predisposed to be commonly used in the determination of the efficiency of the assimilatory apparatus of trees.


Author(s):  
Н.Н. Дубенок ◽  
В.В. Кузьмичев ◽  
А.В. Лебедев

Основными исходными данными для определения запаса служат результаты обмеров диаметров и высот деревьев. Но обмеры диаметров деревьев на высоте груди выполнить намного проще, чем обмеры высот, поэтому ограничиваются замерами высот 15–25 деревьев. Цель исследования – по материалам измерения модельных деревьев в сосновых древостоях выбрать наиболее адекватную простую модель, которая передает зависимость между высотой деревьев и диаметром на высоте груди. Объектом исследования послужили сосновые древостои искусственного происхождения на постоянных пробных площадях в Лесной опытной даче Российского государственного агарного университета – МСХА имени К.А. Тимирязева. В работе используются данные обмеров деревьев на 17 постоянных пробных площадях с 1934 по 2005 гг. Возраст древостоев на момент проведения измерений от 50 до 125 лет. По итогам проведения 77 перечетов массив данных составил 1157 наблюдений. И модель фиксированных эффектов, и модель смешанных эффектов адекватно описали зависимость между высотами и диаметрами деревьев в культурах сосны. Но, как и ожидалось, первая модель имеет худшие значения метрик качества по сравнению со второй. Модель со смешанными эффектами более точно предсказывает значения высот по сравнению с моделью фиксированных эффектов. Недостающие значения высот большого количества деревьев на участке можно вычислить более точно с помощью модели смешанных эффектов, а не применения модели фиксированных эффектов или использования только фиксированной части (средний отклик) модели смешанных эффектов. Применение разработанной модели должно ограничиваться только в тех условиях, к которым относятся экспериментальные материалы The main data for the stock of research results is the diameter of measurements and heights of trees. But measurements of the diameter at breast height are much easier to perform than measurements of heights, therefore, they are limited to measuring the heights of 15–25 trees. The aim of the study is to select the most adequate simple model based on the measurements of model trees in pine antiquities, which conveys the relationship between the height of trees and the diameter at breast height. The object of the study was pine stands of artificial origin on permanent test plots in the Forest Experimental Station Russian State Agararian University – Moscow Timiriazev Agricultural Academy. The work uses data from tree measurements on 17 permanent sample plots from 1934 to 2005. The age of the stands at the time of measurements was from 50 to 125 years. As a result of 77 enumerations, the data array amounted to 1157 observations. Both the fixed effects model and the mixed effects model adequately describe the relationship between heights and diameters of trees in pine stumps. But, as expected, the first model has worse quality metrics than the second. The mixed effects model more accurately predicts heights from the fixed effects model. The missing heights of a large number of trees on a site can be calculated accurately using mixed effects models, rather than using fixed effects models or using only a fixed portion (mean response) of the mixed effects model. The application of the developed model should be limited only in those conditions to which the experimental materials are applied.


2013 ◽  
Vol 6 (3) ◽  
pp. 196-204

Associations between bivariate variables relative to the unexplained relationships of height-Dbh (diameter at breast height) models were investigated. Seven permanent sample plots measuring 40m by 250m at Omo Forest Reserve were used to assess the relationships between height and diameter at breast height of three tree species as affected by the variables of neighbouring trees. The result showed differences in the coefficient of determination of the bivariate models and multivariate models. The models arrived at for each of the species and for the bivariate models are: Scottelia coriaceae: Ht = 2.59 + 0.473D+ 0.0012D2 for 5cm ≤ D ≤100cm (R2 = 0.70) Sterculia rhinopetala: Ht = 5.96 + 0.467D+ 0.00296D2 for 5cm ≤ D ≤100cm (R2 = 0.77) Strombosia pustulata: Ht = 2.02 + 0.722D+ 0.00581D2 for 5cm ≤ D ≤ 60cm (R2 = 0.81) Where both Ht and D are height and Diameter at breast height. While on the other hand the multivariate models that considered the effect of neighbouring trees are: Scottelia coriaceae: 2 1 2 3 4 Ht = 3.74 + 0.41x −1.14x + 0.205x +1.278x (R = 0.723) Sterculia rhnopetala: 2 1 2 3 4 Ht = 6.18 + 0.2601x +1.163x + 0.438x − 0.442x (R = 0.608) Strombosia pustalata: 2 1 2 3 4 Ht = 6.84 + 0.399x − 0.318x − 0.138x − 0.838x (R = 0.650) x1 = diameter at breast height, x2 = Mean neighbouring tree distance, x3 = Frequency of the neighbouring tree and x4 = Position of the crown.


Author(s):  
S.E. Bassey ◽  
S. Ajayi

This research estimated aboveground tree stand level Biomass in Erukot Forest of Oban Division, Cross River National Park. A total of 872 individual trees were identified and measured for diameter at breast height and total height (dbh ≥ 5cm). The 872 individual trees spread across 51 species belonging to 25 different tree families. Simple random sampling was used with sampling intensity of 0.3% to lay 15 nested plots (7m x 7m, 25m x 25m and 35m x 35m). Diameter at breast height, total height and specific density of each wood species were used to determine aboveground biomass for each tree. Conversion factors were applied to estimate stand level green and dry biomass, sequestered carbon and carbon dioxide (CO2) emission in the study area. Simple linear regression models were fitted into the stand level growth data for the forest (basal area and volume). The mean diameter at breast height and mean total height were 38.5cm and 18.5m respectively. Mean basal area of 39.8 m2 ha-1 was obtained with a mean volume of 177.3 m3 ha-1 . Average green biomass, dry biomass, carbon stock and carbon-dioxide emission of 521.8113 ton ha-1 , 341.5880 ton ha-1 , 183.196 ton ha-1 and 694.2067 ton ha-1 respectively were obtained in the study area. Stand level biomass model developed for the forest showed that common logarithm of volume per hectare is significantly related to common logarithm of stand biomass (R2 = 58%). The actual and predicted biomasses were not significantly different (Paired T-test at p ˂ 0.05). Estimated bias of 0.10% for the stand biomass model means that the developed model can be used to predict the aboveground biomass of the study area without any adjustment. The research has provided easy to use regression model for determining aboveground biomass at stand level. This is very useful for carbon trade and assessment of carbon-dioxide emissions through deforestation in the study area. The model is also a tool for assessing the wood productivity of the study area and for better management of the park. Keyword: Sequestered carbon, aboveground biomass, dry biomass, conversion factor


2005 ◽  
Vol 35 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell

The probability that an individual tree will remain in even-aged Norway spruce (Picea abies (L.) Karst.) stands subjected to different thinning programmes was modelled, using data from a thinning experiment established in 25 localities in southern Sweden. A logistic regression approach was used to predict the probability and the Hosmer–Lemeshow goodness-of-fit test to evaluate the fit. Diameter at breast height (DBH), quadratic mean DBH, thinning intensity, thinning quotient, basal area, number of stems per hectare, stand age, number of thinnings, and site index were used as explanatory variables. Separate analyses for stands thinned from below, stands thinned from above, and unthinned stands were performed. The modelled probability graphs for trees not being removed, plotted against their diameter at breast height, had clear S-shapes for both unthinned stands and stands thinned from below. The graph for stands thinned from above was bell-shaped.


2004 ◽  
Vol 18 (4) ◽  
pp. 839-846 ◽  
Author(s):  
Geraldo Alves Damasceno-Junior ◽  
João Semir ◽  
Flavio Antonio Maës dos Santos ◽  
Hermógenes de Freitas Leitão-Filho

A study was conducted in a riparian forest (Rio Paraguai, Brazil) to verify the vegetation mortality after an exceptional flooding in 1995. Individuals with diameter at breast height > 5 cm were sampled in 108 (10×10m) plots in 1994, and re-sampled in 1996. The total mortality rate was 4.1% per year. The mortality increased with the increasing of topographic positions, at community level, suggesting that places where the flooding is less frequent are more affected by extreme floods.


2009 ◽  
Vol 85 (3) ◽  
pp. 446-452 ◽  
Author(s):  
François Guillemette ◽  
Marie-Claude Lambert

Four methods of estimating diameter at breast height (DBH) were used on 558 northern hardwood stems, located in 6, 0.25-ha plots, to compare their effects. The first method was a diameter tape reading and the second was a systematic reading, along a predefined axis, taken with a calliper. The last 2 methods were both obtained from the arithmetic mean of 2 different pairs of calliper readings taken at right angles. The first pair was directed along the major bole axis and the other pair along the minor axis. The 4 methods were compared in terms of mean tree diameter, plot basal area and plot volume. There were significant differences (p < 0.05) in parameter estimates among methods, and the differences varied according to species (Acer saccharum Marsh. and Betula alleghaniensis Britt.) and tree size class. Differences among methods were more evident for larger DBH classes, which contribute most to the significant differences observed for both the plot and stand basal area and volume. Overall, tree DBH, plot basal area and plot volume provided by these 4 methods ranked in this ascending order: mean calliper reading directed along the minor axis, systematic calliper reading, mean calliper reading directed along the major axis, and diameter tape. The difference in stand basal area or volume between the estimates obtained with a systematic calliper reading and a diameter tape was 1.1 m2/ha with a mean basal area of about 21 m2/ha, or 10.5 m3/ha with a mean stand volume of 169 m3/ha. Because of the magnitude of these differences, it is recommended the method of DBH estimation be specified in studies, to be careful when crossing databases or models using different methods of DBH estimation, and to always maintain the same method of DBH estimation when remeasuring a plot. Key words: northern hardwoods, dendrometer, diameter tape, calliper, caliper, DBH measurement, basal area, volume


1992 ◽  
Vol 22 (3) ◽  
pp. 341-347 ◽  
Author(s):  
W.R. Smith ◽  
R.M. Farrar Jr. ◽  
P.A. Murphy ◽  
J.L. Yeiser ◽  
R.S. Meldahl ◽  
...  

Data were collected on open-grown loblolly pine (Pinustaeda L.), longleaf pine (Pinuspalustris Mill.), and shortleaf pine (Pinusechinata Mill.) and analyzed to provide predictive equations of crown width and maximum potential basal area growth for crown competition and growth and yield models. The measurements were taken on 115 open-grown loblolly pine trees and 76 shortleaf pines in southeastern Arkansas. The longleaf pine data consisted of 81 open-grown trees from southern Alabama, Georgia, and Florida. A circle and an ellipse were tested as geometric models of the vertically projected crown. No significant differences between the tree shapes were found based on analyses of length and azimuth of the largest crown diameter, and the circle was chosen as an appropriate model. This indicated that only the distance between trees, not their orientation to one another, need be included in models of crown competition based on crown contact. Predictive equations of mean crown width based on diameter at breast height were fitted for each species for use in models of crown competition. A Chapman–Richards growth rate function with an intercept term was fit to periodic annual inside-bark basal area growth based on initial inside-bark basal area to provide empirical estimates of maximum basal area growth rates for growth and yield modeling of the given species. Additionally, equations to predict double bark thickness as a function of diameter at breast height were fit for each species to facilitate the use of the equations with outside-bark measurements of diameter.


1990 ◽  
Vol 20 (5) ◽  
pp. 496-502 ◽  
Author(s):  
T. G. Gregoire ◽  
S. M. Zedaker ◽  
N. S. Nicholas

The computed estimate of basal area was the focus of this investigation into the accuracy of tree diameter measurements. Diameter at breast height was measured on 101 trees, the breast height disc was removed from the stem, and each disc outline was then digitized to determine its actual area. Actual areas were compared with the basal areas computed with the field measurements of diameter by expressing the deviations as a proportion of the actual areas. These relative errors averaged 3.1% when basal area was computed with a taped diameter at breast height, and they averaged −2.5% when the mean of two calipered, perpendicular diameter at breast height measurements were used. Noncircularity accounted for about 2.6% of the bias, on average, in basal areas from taped diameters. Root mean square error of relative basal area errors ranged from 7.3 to 7.9% among these methods. The difference between basal areas computed with a taped diameter at breast height and with calipered diameter at breast height was computed and expressed as a proportion of the actual basal area. On average, a difference of 5% was observed. Interval estimates for these differences are presented.


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