scholarly journals Growth Relationships in Silver Fir Stands at Their Lower-Altitude Limit in Romania

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 439
Author(s):  
Gheorghe-Marian Tudoran ◽  
Avram Cicșa ◽  
Albert Ciceu ◽  
Alexandru-Claudiu Dobre

This study presents the biometric relationships among various increments that is useful in both scientific and practical terms for the silvicultural of silver fir. The increments recorded in the biometric characteristics of trees are a faithful indicator of the effect of silvicultural work measures and of environmental conditions. Knowing these increments, and the relationships among them, can contribute to adaptations in silvicultural work on these stands with the purpose of reducing risks generated by environmental factors. We carried an inventory based on tree increment cores. The sample size was determined based on both radial increment and height increment variability of the trees. The sample trees were selected in proportion to their basal area on diameter categories. Current annual height increment (CAIh) was measured on felled trees from mean tree category. For CAIh we generated models based on the mean tree height. Percentages of the basal area increment and of form-height increment were used to compute the current annual volume increment percentage (PCAIv). For the mean tree, the CAIh estimated through the used models had a root-mean-square error (RMSE) of 0.8749 and for the current annual volume increment (CAIv) the RMSE value was 0.1295. In even-aged stands, the mean current volume increment tree is a hypothetical tree that may have the mean basal area of all the trees and the form-height of the stand. Conclusions: The diameter, height, and volume increments of trees are influenced by structural conditions and natural factors. The structures comprising several generations of fir mixed with beech and other deciduous trees, which have been obtained by the natural regeneration of local provenances, are stable and must become management targets. Stable structures are a condition for the sustainable management of stands.

1991 ◽  
Vol 56 ◽  
Author(s):  
B. Meuleman

After  its introduction at the start of this century, the Corsican pine has become  an important forest tree in Flanders (Belgium). The total area covered by  Corsican pine is about 11.000 ha. Due to climatological factors it is  virtually absent from the Walloon part of Belgium. Despite the crisis in 1984  - 1986, practical experiences with its vitality and disease resistance are  generally positive. Compared to Scots pine which is native to Belgium, its  productivity and insensitivity for insect pests is large.     To quantify the productivity of Corsican pine, a growth table was  constructed using a method developed by PALM and DAGNELIE. It was based on  data from 321 temporarily and 80 permanent plots distributed over Flanders.  Five yield classes were distinguished according to dominant height at 50  years. For each yield class, a series of tables as a function of treatment  was constructed. Treatments were characterized by the mean annual  circumference increment.     These tables allow to predict the growth of Corsican pines. Such  predictions for the whole range of species are necessary for the development  of a good forestry policy and for timber industries. The tables also provide  information for any given Corsican pine stand that is helpful in practice:  expected productivity, stand density, determination of the felling quantum.      The data show that the productivity of Corsican pine is very high. The very  early culmination of the current annual volume increment and the rather  constant level of the mean annual volume increment after culmination are  interesting new findings. It is also shown that it is possible to work with  long rotation periods. This offers good opportunities for the production of  high quality wood and is also important for the social and ecological role of  the forest.     Productivity is lowest on very dry and sandy soils. A high productivity on  moderately dry sand and loamy sand soils and loamy soils make the Corsican  pine one of the most valuable tree species for the Kempen in Flanders.  Although productivity is very high on well drained sandy loam and loam soils,  plantation of Corsican pine on these locations is not advised.


2021 ◽  
Vol 11 (3) ◽  
pp. 3700-3713

The present study was carried out in the Oued Laou watershed belonging to the Moroccan Rif. It aims at the elaboration of mathematical tariffs for cubing Aleppo pine, the morphometric and increments study. The data analyzed for this purpose were collected after a preliminary stratification of the forest based on the plantation age. The study of the region’s climate shows that the western sector of the watershed is part of the temperate humid bioclimate, and the eastern sector belongs to the warm variant subhumid. The analysis of the stand-study structure shows that the distribution of the number of stems as a function of the circumference is a distribution close to normal. Cubic rates have been constructed to estimate the volume of trees. The mean annual volume increment of Aleppo pine varies between 3.10 and 4.83 m3/ha/year from one plot to another; this small fluctuation largely reflects the homogeneity of the study area. Aleppo pine has a wide ecological and spatial plasticity: colonization of all substrates, bioclimates ranging from semi-arid to temperate humid. It’s a species that exhibits uniform behavior despite topographic and edaphic variations.


2004 ◽  
pp. 63-75
Author(s):  
Martin Bobinac

The effects of selection thinning were analyzed at a permanent sample plot in the artificially established spruce stand aged 32 years, on the site of mountain beech. The state in the 32-year-old stand was as follows: 3911 trees per ha, basal area 57.5 m2ha-1 and volume 378.3 m3ha-1. Selection thinning removed 1378 tree per ha (35.2%) and 110 m3ha-1 (29.2%), and in the period between the ages of 32 and 40 years, predominantly because of mortality, another 550 trees per ha and 21.8 m3ha-1. On the remaining trees during the period between the ages of 32 and 40 years, basal area increased by 33%, and volume by 67%. Current volume increment was 20.7 m3ha-1 and it was concentrated on the future trees (28% of the total number of trees produces 52% of volume increment). The disproportion in the intensity of diameter and height increment after the thinning resulted in the increase of form quotient.


2019 ◽  
Vol 49 (11) ◽  
pp. 1412-1424 ◽  
Author(s):  
Huilin Gao ◽  
Dongsheng Chen ◽  
Xiaomei Sun ◽  
Shougong Zhang

Using the branch data from 90 sample trees, we developed novel models of outer- and inner-crown profiles for the northern, eastern, southern, and western sides of planted Larix kaempferi (Lam.) Carrière trees in northeastern China via the integration of competition indices (CIs) based on nonlinear marginal regression (NMR). We also used nonparametric boundary regression (NBR) to model the crown-profile boundary. The largest crown radius and inflection points of sample trees were calculated using NBR and NMR. We determined that the CIs of the ratio of the diameter of the subject tree to the quadratic mean diameter (CI3) and ratio of the basal area of the subject tree to the mean basal area of the stand (CI5) were the best distance-independent CIs for incorporation into the models of outer- and inner-crown profiles, respectively. The CIs showed a significant effect on the outer-crown profile in all four directions for dominant, intermediate, and suppressed trees but did not show a significant effect on inner-crown profile. The outer-crown radius increased and inner-crown radius decreased with increasing CI3 and CI5, respectively. The crown profile on the northern side was the largest, which conformed to the regularity in the mean current increment of the sampled branches.


1992 ◽  
Vol 8 (01) ◽  
pp. 87-96 ◽  
Author(s):  
Angelina Martinez-Yrizar ◽  
Jose Sarukhan ◽  
Alfredo Perez-Jimenez ◽  
Emmanuel Rincon ◽  
Jose Manuel Maass ◽  
...  

ABSTRACTPhytomass was determined for a tropical deciduous forest in Chamela, Jalisco, México. The mean canopy height was 6.9 m, and the total basal area was 25.6 m2ha−1(dbh > 3.0 cm). The estimated phytomass for this forest (85 Mg ha−1) is among the highest values for tropical dry forests with similar seasonal climates. A stepwise multiple regression analysis showed that phytomass can be predicted firstly by basal area (R2= 0.88), then by wood specific gravity (R2= 0.91), and finally by the inclusion of tree height in the regression (R2= 0.92). Each new independent variable explained significant variance in the phytomass estimation.


2003 ◽  
Vol 33 (10) ◽  
pp. 1962-1973 ◽  
Author(s):  
Philip G Comeau ◽  
Jian R Wang ◽  
Tony Letchford

Five years after spacing a young, 11 m tall paper birch (Betula papyrifera Marsh.) stand, we examine relationships between growth of understory white spruce (Picea glauca (Moench) Voss), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), and level of birch retention. Our objectives were to evaluate the effectiveness of selected measures of competition for estimating the effects of the residual birch and to evaluate the influence of residual birch densities on growth responses of naturally regenerated subalpine fir and white spruce. Basal area of Scouler willow (Salix scouler iana Barratt) and birch were found to effectively predict light transmittance (diffuse noninterceptance). The best models for predicting 4-year volume growth of subalpine fir and white spruce incorporate initial crown volume of the subject trees and transmittance as independent variables. Lorimer's index and Hegyi's index gave similar results to those obtained using basal area and transmittance, suggesting that there is little benefit in including measurements of proximity in a competition index. For both species, the correlation between basal area increment and light was substantially stronger than observed for volume increment. However, height increment of both subalpine fir and spruce was only weakly correlated with measured light levels. The ratio of height increment to volume increment decreased with both increasing initial height and transmittance for subalpine fir and white spruce.


2018 ◽  
Vol 11 (1) ◽  
pp. 59 ◽  
Author(s):  
Henrique Luis Godinho Cassol ◽  
João Manuel de Brito Carreiras ◽  
Elisabete Caria Moraes ◽  
Luiz Eduardo Oliveira e Cruz de Aragão ◽  
Camila Valéria de Jesus Silva ◽  
...  

Secondary forests (SF) are important carbon sinks, removing CO2 from the atmosphere through the photosynthesis process and storing photosynthates in their aboveground live biomass (AGB). This process occurring at large-scales partially counteracts C emissions from land-use change, playing, hence, an important role in the global carbon cycle. The absorption rates of carbon in these forests depend on forest physiology, controlled by environmental and climatic conditions, as well as on the past land use, which is rarely considered for retrieving AGB from remotely sensed data. In this context, the main goal of this study is to evaluate the potential of polarimetric (quad-pol) ALOS-2 PALSAR-2 data for estimating AGB in a SF area. Land-use was assessed through Landsat time-series to extract the SF age, period of active land-use (PALU), and frequency of clear cuts (FC) to randomly select the SF plots. A chronosequence of 42 SF plots ranging 3–28 years (20 ha) near the Tapajós National Forest in Pará state was surveyed to quantifying AGB growth. The quad-pol data was explored by testing two regression methods, including non-linear (NL) and multiple linear regression models (MLR). We also evaluated the influence of the past land-use in the retrieving AGB through correlation analysis. The results showed that the biophysical variables were positively correlated with the volumetric scattering, meaning that SF areas presented greater volumetric scattering contribution with increasing forest age. Mean diameter, mean tree height, basal area, species density, and AGB were significant and had the highest Pearson coefficients with the Cloude decomposition (λ3), which in turn, refers to the volumetric contribution backscattering from cross-polarization (HV) (ρ = 0.57–0.66, p-value < 0.001). On the other hand, the historical use (PALU and FC) showed the highest correlation with angular decompositions, being the Touzi target phase angle the highest correlation (Φs) (ρ = 0.37 and ρ = 0.38, respectively). The combination of multiple prediction variables with MLR improved the AGB estimation by 70% comparing to the NL model (R2 adj. = 0.51; RMSE = 38.7 Mg ha−1) bias = 2.1 ± 37.9 Mg ha−1 by incorporate the angular decompositions, related to historical use, and the contribution volumetric scattering, related to forest structure, in the model. The MLR uses six variables, whose selected polarimetric attributes were strongly related with different structural parameters such as the mean forest diameter, basal area, and the mean forest tree height, and not with the AGB as was expected. The uncertainty was estimated to be 18.6% considered all methodological steps of the MLR model. This approach helped us to better understand the relationship between parameters derived from SAR data and the forest structure and its relation to the growth of the secondary forest after deforestation events.


1990 ◽  
Vol 20 (9) ◽  
pp. 1399-1407 ◽  
Author(s):  
David C. LeBlanc

This paper describes relationships between tree growth indices based on ring width measurements at 1.4 m aboveground and indices derived from whole-stem analysis for red spruce (Picearubens Sarg.) in a high-elevation spruce-fir forest on Whiteface Mountain, New York. Coefficients of determination for linear regressions between mean, standardized chronologies for breast-height ring width versus whole-stem ring width and basal area increment versus annual volume increment are 0.89 and 0.93, respectively. However, substantial variability is apparent in breast-height versus whole-stem relationships for individual trees, particularly for unstandardized growth indices. Also, relationships between unstandardized growth indices exhibit temporal instability associated with individual tree maturation and stand dynamics. Nonetheless, strong relationships between mean standardized chronologies of breast-height and whole-stem growth indices validate the use of breast-height growth indices to represent year-to-year variation in mean growth performance of red spruce. A volume-equation-based procedure is described that provides better dendrochronological estimates of annual volume increment than estimates based on basal area increment alone.


1969 ◽  
Vol 81 (3-4) ◽  
pp. 125-131
Author(s):  
John K. Francis

Unthinned spacing of Honduras pine (Pinus caribaea var. hondurensis Morelet) ranging in age from 23.3 to 25 years, was evaluated at four installations in Puerto Rico on the basis of survival, growth, and yield. Results showed that marked significant differences existed in means of survival, diameters, and heights of trees in spacings ranging from 1.5 x 1.5 m to 4.3 x 4.3 m. However, because of decreasing diameter and height growth and increasing mortality in the narrower spacings (1.5 m, 2.1 m), and continued rapid diameter growth in the wider spacings (3.0 m, 4.3 m), there were no significant differences in basal area, total inside bark volume, and mean annual volume increment among spacings. Wide spacings are recommended where early thinnings are not possible.


2021 ◽  
Vol 126 ◽  
pp. 23-39
Author(s):  
Janez Golob ◽  
Tom Levanič ◽  
David Hladnik

Based on previous measurements from 1962 to 2017 on forest research plots located on former slash-and-burn farming areas in the cadastral municipality of Koprivna, the diameter and height increment as well as volume increments of the two main tree species - spruce and larch - were calculated. These set-aside natural research plots have a smaller mean basal area diameter, but the number of trees is higher than in comparable managed forests. Due to the high-density of tree stands over the past thirty years, radial increment of spruce and larch has declined. To determine the influence of environmental factors on radial growth of spruce and larch, a dendrochronological analysis was conducted. According to the dendrochronological analysis of radial increment of trees, the number of years with a negative response has been higher since 1984.


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