THE EFFECT OF ALTITUDE ON THE STRUCTURE OF ALEPPO PINE TREES IN THE CHETTABA FOREST (ALGERIA)

Author(s):  
Haddad Amar ◽  
Rached-Kanouni Malika

Knowledge of vegetation characteristics is necessary for the management of disturbed areas. The aim of this study was to investigate the effect of elevation on tree structure in Aleppo pine spatial systems in the Chettaba forest, located in northeastern Algeria. An inventory of trees of P. halepensis forest formations was conducted based on dendometric parameters (tree diameter and height) which were measured on 4 plots (30 m × 30 m). The results obtained showed that the average height varies from 7.79 cm to 9.71 cm, while the average diameter appears from 24.39 cm to 30.61 cm, respectively. The height-diameter relationship of the trees varies with the altitude horizons (774 m to 1023 m). The Weibull theoretical distribution was used to characterize stand structure, due to its flexibility and the wide variability of distribution shapes it produces. Management measures, such as full protection of forest relics, will have to be implemented.

2016 ◽  
Vol 58 (4) ◽  
pp. 240-245
Author(s):  
Łukasz Tyburski ◽  
Paweł Przybylski

Abstract In 2015 in Kampinos National Park (KNP), monitoring of tree crown condition was conducted in specimens of the Scots pine, which is the dominant tree species in the park (73.3%). The monitoring was aimed at providing information about the health of pine trees in the national park area. The monitoring was conducted on 26 plots throughout the park. The stands where the pine is not a dominant species were omitted. On each plot, 20 trees were subjected to assessment. In total, 520 pine trees were examined. The monitoring was conducted by the assessment of tree crowns based on the adapted forest monitoring methodology conducted as part of National Environmental Monitoring. On the basis of the monitoring, it was found that 75.4% of the trees are characterised by slight defoliation and 94.4% of the specimens were not found to have discoloration of the assimilation apparatus. No differences were found between areas situated closer and further from the administrative borders of Warsaw. On the basis of the monitoring, it was found that the pine trees in KNP are in a good health condition. Dendrometric measurements show that the average diameter at breast height (DBH) of the analysed trees is 26.6 cm. The average height of the trees is 20.4 m. The average age of the examined tree stands is 84. The monitoring will be continued in subsequent years in order to record the changes taking place in tree crowns.


Author(s):  
A. I. Lobanov ◽  
V. V Mulyava ◽  
N. A. Konovalova

xModern forest shelter belts do not fully protect arable land and most often have a different life state. In theseconditions, the preservation of forest belts, their performance of protective functions in the system of agroforestry andother complex measures remains an urgent task. The studies were carried out in a field-protective forest belt located in thevicinity of the Oktyabrsky village of the Krasnoturansky district of the Krasnoyarsk Territory, where a temporary test plotwas laid using generally accepted methods. The aim of the research was to study the current state of this forest belt by identifying the sanitary state and preservation of the stand and growth rates of Scots pine. Analysis of the current state of thestand showed that the average category of the state of trees is 1.3 points. The stand safety is 44.9%. Pine trees at the age of 28after planting have reached an average height of 11.6 m with an average diameter of 19.1 cm. The forest belt has an optimalopenwork-blown design and is capable of self-renewal naturally. To prevent further degradation of arable leached chernozems in treeless areas of the steppe zone of the Krasnoyarsk Territory, it is advisable to create pine forest shelter belts.


2021 ◽  
Vol 67 (No. 1) ◽  
pp. 21-35
Author(s):  
Aleksey Ilintsev ◽  
Darya Soldatova ◽  
Alexander Bogdanov ◽  
Sergey Koptev ◽  
Sergey Tretyakov

The purpose of the research is to analyse the successful creation of an artificial pine forest by seeding and develop recommendations for the guaranteed reproduction of pine stands in Northern European Russia. In recent decades, there has been a steady decline in the share of pine stands and their replacement with low-value and low-yielding tree species. We surveyed 12 permanent sample plots that were laid out in various variants of forest crops. The taxation parameters were obtained by a standard analysis of the experimental data. The evaluation parameters of the stands vary within the following limits: the average diameter of the pine trees varied from 21.9 to 30.9 cm; the total basal area of the pine varied from 19.1 to 38.8 m2∙ha–1; the average height of the pine varied from 20.1 to 26.8 m; the number of growing trees varied from 754 to 1 952 ha–1; the pines varied from 382 to 762 ha–1; the growing stocks of stands varied from 416 to 608 m3∙ha–1. The distribution of pine trees by thickness steps showed that all the studied samples were close to the normal distribution curve. The results of the correlation and multidimensional analyses showed that the creation method of the forest crops had a significant impact on the value of the taxation parameters. It was found that the best options for growing pure pine stands that can be recommended for practical production are plots with a large share of soil cultivation and the size of the seedbed.


2020 ◽  
pp. 33-43
Author(s):  
Olga N. Ratnicava ◽  
Irina P. Lisitsyna ◽  
Inna V. Аgeichik

Based on studies of geomorphology, stratigraphy, hydrology, various maps of Polesie, zones of influence of amelioration canals, vegetation maps, modern satellite images, as well as field studies of peatlands of Pripyat Polesie, two independent drainage systems have been identified, with a network of amelioration canals that intensively discharge water into the rivers Stwiga and Ybort`. Maps of key points were built In GIS-format, on which five sites were laid in the field within the Mezhch and Neresnya peat deposits for further long-term monitoring of GWL parameters. The locations of the sensors installation are based on the relationship of bog phytocenoses with the average annual GWL values and the amplitude of their fluctuations. Analysis of the GWL parameters before and after environmental rehabilitation measures will allow assessing the effectiveness of planned measures in disturbed areas and obtaining new data on areas of peat deposits in their natural state.


2021 ◽  
Author(s):  
Haddad Amar ◽  
Beldjazia Amina ◽  
Kadi Zahia ◽  
Redjaimia Lilia ◽  
Rached-Kanouni Malika

Mediterranean ecosystems are considered particularly sensitive to climate change. Any change in climatic factors affects the structure and functioning of these ecosystems and has an influence on plant productivity. The main objective of this work is to characterize one of the Mediterranean ecosystems; the Chettaba forest massif (located in the North-East of Algeria) from a vegetation point of view and their link with monthly variations using Landsat 8 satellite images from five different dates (June 25, 2017, July 27, 2017, August 28, 2017, October 15, 2017). The comparison of NDVI values in Aleppo pine trees was performed using analysis of variance and the use of Friedman's non-parametric test. The Mann-Kendall statistical method was applied to the monthly distribution of NDVI values to detect any trends in the data over the study period. The statistical results of NDVI of Aleppo pine trees indicate that the maximum value is recorded in the month of June, while the lowest values are observed in the month of August where the species studied is exposed to periods of thermal stress.


2010 ◽  
Vol 52 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Mait Lang

Metsa katvuse ja liituse hindamine lennukilt laserskanneriga Tests were carried out in mature Scots pine, Norway spruce and Silver birch stands at Järvselja, Estonia, to estimate canopy cover (K) and crown cover (L) from airborne lidar data. Independent estimates Kc and Lc for K and L were calculated from the Cajanus tube readings made on the ground at 1.3 m height. Lidar data based cover estimates depended on the inclusion of different order returns significantly. In all the stands first order return based estimate K1 was biased positively (3-10%) at the reference height of 1.3 m compared to ground measurements. All lidar based estimates decreased with increasing the reference height. Single return (Ky) and all return (Kk) based canopy cover estimates depended more on the sand structure compared to K1. The ratio of all return count to the first return count D behaved like crown cover estimate in all stands. However, in spruce stand D understimated Lc significantly. In the Scots pine stand K1(1.3) = 0.7431 was most similar canopy cover estimate relative to the ground estimate Kc = 0,7362 whereas Ky(1.3) and Kk(1.3) gave significant underestimates (>15%) of K. Caused by the simple structure of Scots pine stand - only one layer pine trees, the Cajanus tube based canopy cover (Kc), crown cover (Lc) and lidar data based canopy density D(1.3) values were rather similar. In the Norway spruce stand and in the Silver birch stand second layer and regeneration trees were present. In the Silver birch stand Kk(1.3) and Ky(1.3) estimated Kc rather well. In the Norway spruce stand Ky(1.3) and K1(1.3) were the best estimators of Kc whereas Kk(1.3) underestimated canopy cover. Lidar data were found to be usable for canopy cover and crown cover assessment but the selection of the estimator is not trivial and depends on the stand structure.


1998 ◽  
Vol 22 (4) ◽  
pp. 241-244 ◽  
Author(s):  
Young-Jin Lee ◽  
J. David Lenhart

Abstract The response of diameter and height of unthinned planted stands loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm.) pine in East Texas to different classes of planting densities were analyzed. After tracking the development of diameter and height for 15 yr on a set of permanent plots representing a broad range of plantation parameters, average diameter and average height trends were observed. For both species, average diameter values were significantly larger with lower planting densities. In contrast, average height growth is insensitive to planting density at younger age classes for loblolly and at older age classes for slash pine plantations. South. J. Appl. For. 22(4):241-244.


2003 ◽  
Vol 93 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Vivienne Chuter ◽  
Craig Payne ◽  
Kathryn Miller

Neutral-position casting of the foot is used for the manufacture of functional foot orthoses, and an accurate cast is widely assumed to be a prerequisite for a good orthotic device. The primary aim of this study was to determine the variability of casting between inexperienced and experienced clinicians and the variability of one experienced clinician taking multiple casts. Ten inexperienced and ten experienced clinicians took a cast of the right foot of a single subject, and a single experienced clinician took ten casts of the same foot. The frontal plane forefoot-to-rearfoot relationship of each cast was determined, and no difference was found in the mean and variances among the three groups. The range of the forefoot-to-rearfoot relationship across all groups was from 10.0° everted to 6.5° inverted, indicating that there is a wide range in neutral-position casting of the foot. As outcome studies have reported the successful outcomes of functional foot orthoses, this wide variability may not necessarily be a problem. (J Am Podiatr Med Assoc 93(1): 1-5, 2003)


2014 ◽  
Vol 47 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Mao Sui ◽  
Ming-Yu Li ◽  
Eun-Soo Kim ◽  
Jihoon Lee

In this article, the effect of deposition amount on self-assembled Au droplets fabricated on GaAs(111)B and (110) is presented. The investigation is systematically performed by the variation of the Au deposition amount from 2 to 20 nm while fixing the other growth parameters such as annealing temperature and duration to clearly observe the effect. Under identical growth conditions, the self-assembled Au droplets show significantly different size and density depending on the amount of Au deposition:i.e.the average height varies by 436% from 21.8 to 95.5 nm and the average diameter swings by 827% from 52 to 430 nm, showing that the size increase is dominated by the lateral expansion. Meanwhile the average density varies by over two orders of magnitude from 1.24 × 108to 4.48 × 1010 cm−2on GaAs(111)B. With relatively low Au deposition amounts, below 3 nm, round dome-shaped mini Au droplets with high packing density can be fabricated, while super large Au droplets result with higher deposition amounts, above 10 nm, with a density two orders of magnitude lower. It is also found that the surface index has a minor effect on the fabrication of self-assembled Au droplets with the variation of deposition amount. The results are systematically analyzed and discussed in terms of atomic force microscopy and scanning electron microscopy images, line profiles, power spectrums, r.m.s. surface roughness, and size and density plots.


2014 ◽  
Vol 90 (04) ◽  
pp. 489-497 ◽  
Author(s):  
William C. Parker

The relationship of stand structural features with understory light levels, estimated by gap light index (GLI), was investigated in 22 second-growth eastern white (Pinus strobus L.) and red pine (Pinus resinosa Ait.)-dominated stands in central Ontario that encompassed a broad range in density and basal area. Simple, empirical light models were developed to quantify the influence of several stand structural variables on canopy transmittance as estimated by GLI. Models were also derived to facilitate the operational identification of residual basal area, density, and percent canopy closure associated with target understory light levels that optimize the growth of white pine regeneration and its protection from weevil and blister rust when using the uniform shelterwood silvicultural system. Regression models indicated significant negative, nonlinear relationships of GLI with density, basal area, a stand density index, total crown area, and foliar biomass, while GLI was linearly related to percent canopy closure. Application of these models to identify density, basal area, and canopy closure values associated with target light levels for the regeneration and removal cuts of uniform shelterwoods demonstrates the use of this information to help guide management of white pine–red pine forests.


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