scholarly journals A comparative analysis of directed and spontaneous development of mixed forests of fir, spruce and beech on Mt. Tara

2017 ◽  
pp. 141-170
Author(s):  
Snezana Obradovic ◽  
Damjan Pantic ◽  
Milan Medarevic ◽  
Biljana Sljukic

The data of periodic complete measurements of permanent sample plots and compartments in which they were located in the period 1955/60-2005/2010 served as the basis for this research. Two sets of data from a 50-year time span enabled a comparative analysis of a number of structural and numerical elements of regularly managed selection forests of fir, spruce and beech that more or less spontaneously developed in the sample plots. The number of trees in low-diameter categories decreased in the regularly managed compartments, but it was partly compensated by regeneration and ingrowth, which amounted to 7.9 trees per year. In forests with spontaneous development, the ingrowth is either missing or minimal, and it amounts to 2.7 trees per year. From the aspect of preserving the natural composition of these forests and thus their biological stability, a significant decline in the number of beech trees is worrying, above all in the lowest-diameter categories. The accumulation of large-dimension trees is more pronounced in the sample plots in relation on the compartments with regular management. This trend resulted in high basal area values (max. was observed in compartment 131 and at the end of the analyzed period, it amounted to 37.8 m2?ha-1, and in SP-2 to 55.7 m2?ha-1) and volume (max. 605.4 m3?ha-1 was achieved in compartment 66, with a 79% share of fir, i.e. 898 m3?ha-1 in SP-2 in which the share of fir is 71%). Increase of volume in diameter catagories above 50 cm amounts to on average 120% in compartments, and in stands with spontaneous development to as much as 230%. Current volume increment is high and at the end of the period it amounted to on average 12.9 m3?ha-1 in the compartments, and 14.9 m3?ha-1 in the sample plots. In both these values the share of fir is 80%. However, increment percentage, as a more reliable indicator of vitality and good living and stand conditions decreased from 2.54% to 2.32% in the observed compartments and from 2.31% to 1.91% in the sample plots, under the conditions of spontaneous development. On the basis of the above, certain disturbances and negative trends can be identified, both in regularly managed forests and stands with spontaneous development, while they are significantly more pronounced in the latter case. This is reflected in the unfavorable spatial relationships and light regime, and consequently difficult regeneration and ingrowth (especially of beech) as well as the slowing dynamics of these forests, which finally disrupts their structure and functional value. In regularly managed forests, the reason for that is the rigid understanding of the felling ripeness diamater and lower intensity cutting of large-dimension inventory, which slowed down the dynamics and made regeneration and ingrowth difficult. More intensive operations in this part of the inventory would provide a better spatial distribution of trees (horizontal and vertical) and a a better light regime, while the development of these forests would be accelerated. This is confirmed by the fact that forests with self-regulation processes (spontaneous development) become gradually depleted in low and medium storey trees and turn into a one-layer structure with a horizontal canopy which was observed in the investigated sample plots.

2010 ◽  
Vol 40 (8) ◽  
pp. 1680-1685 ◽  
Author(s):  
Mark C. Vanderwel ◽  
Hilary C. Thorpe ◽  
John P. Caspersen

Harvest slash can represent a major source of downed woody debris (DWD) in selection-managed forests. In this study, we analyze the volume, cover, size distribution, and decay-class distribution of DWD input by selection harvesting in central Ontario, Canada. Selection harvesting input 23.9 m3 DWD·ha–1 (0.013 m2 DWD·m–2), with cut basal area explaining 46% and 30% of the respective within-stand variation in cover and volume, respectively. The size distribution of the slash was similar to that of DWD in permanent sample plots (including old-growth stands and stands that have not been recently harvested), countering a common assumption that harvesting inputs only small-sized material. Harvest-origin DWD was bimodally distributed across decay classes, with the first peak (decay class 1) associated with fresh harvest slash and a second smaller peak (decay class 3) likely representing dead trees and branches that were felled or broken during harvest operations. A matrix projection model showed that slash can maintain DWD levels in managed, uneven-aged stands comparable with those in unmanaged stands, but the mean decay class increases steadily over a 20-year period after harvest. Our results underline the importance of harvest inputs for maintaining DWD pools in selection-managed forests and provide baseline information against which to compare forests managed with higher utilization standards.


1970 ◽  
Vol 16 (2) ◽  
pp. 3-11 ◽  
Author(s):  
H Meilby ◽  
L Puri ◽  
M Christensen ◽  
S Rayamajhi

To monitor the development of four community-managed forests, networks of permanent sample plots were established in 2005 at sites in Chitwan, Kaski and Mustang Districts, Nepal. This research note documents the procedures used when preparing for establishment of the plot networks, evaluates the applied stratification of the forest on the basis of data gathered in pilot surveys conducted in the early 2005, and provides a discussion on the implications of the choices made. Key words: Community-managed forests; permanent sample plots; stratification; allocation; estimates Banko Janakari Vol.16(2) 2006 pp.3-11


1982 ◽  
Vol 12 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Chhun-Huor Ung ◽  
Jean Beaulieu ◽  
Daniel Demers

This paper describes a prediction model adopted by the Department of Energy and Resources of Quebec to (i) update temporary sample plots and (ii) project into the future the state of permanent sample plots in Quebec forests. Predicting the growth of a forest species means predicting the state of this species in time. Three basic characteristics mark the state of a species in a given year: number of trees, their total basal area, and their total volume. To date, in Quebec, normal or empirical yield tables have been used to predict the state of some species in ideal or real growth conditions, but these yield tables apply only to pure or almost pure even-aged stands. The prediction model for hardwood and softwood species presented in this paper serves the same purpose as the yield tables; however, it differs from the yield tables in that it can predict the state of each hardwood or softwood species found in pure or mixed, even- or uneven-aged stands. The prediction model was validated for 19 species found in a pilot territory located in the Basse-Gatincau (southwestern Quebec). The paper terminates with a discussion on the limitation of the prediction model and the conditions for its use.


2009 ◽  
Vol 39 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet

Recently, sugar maple ( Acer saccharum Marsh.) decline in northeastern North America has been regarded as a major factor structuring hardwood forests by favouring American beech ( Fagus grandifolia Ehrh.) in the understory of maple-dominated stands. To determine whether soil fertility differences associated with sugar maple decline may have promoted the expansion of American beech, we explored the relationships between the soil base status and the sapling and tree strata density and composition, using data from 426 permanent sample plots distributed throughout Quebec. Our results indicate that American beech is currently expanding in the sugar maple range of Quebec. The abundance and proportion of American beech in the sapling stratum are mainly associated with the proportion of American beech in the tree stratum, the relative basal area of dead sugar maple trees, and the base status of soils. In accordance with the many studies reporting on the high sensitivity of sugar maple to the acid–base status of soils and the decline of the sugar maple population, this study supports the hypothesis that soil base cation depletion, caused in part by atmospheric acid deposition, is among the main factors involved in the present-day expansion of American beech over a large area in Quebec.


2011 ◽  
pp. 97-108 ◽  
Author(s):  
Milan Knezevic ◽  
Violeta Babic ◽  
Zoran Galic ◽  
Olivera Kosanin

The soils formed on sandstones in sessile oak forests (Quercetum montanum typicum Cer. et Jov. 1953) were researched in the area of Fruska Gora. On permanent sample plots established in management units ?Cortanovacka Forest-Hopovo-Velika Remeta? and ?Beocin-Manastir-Katanske Livade-Osovlje?, in the are of NP ?Fruska Gora?, aiming at the monitoring of the effect of light regime on the development of sessile oak progeny in the given environmental conditions, based on the morphogenetic characteristics of the soil and analytic values of the soil properties, and based on the soil classification by Skoric et al. (1985), the following two soil types were defined: acid brown soil (dystric cambisol), and illimerised soil (luvisol). Acid brown soil belongs to the form of medium deep soils, and illimerised soil is classified as deep soil.


2020 ◽  
Vol 26 ◽  
pp. 00032
Author(s):  
Alexey Nikolaev ◽  
Natalia Shlat ◽  
Irina Kolbasova ◽  
Julia Timofeeva

The article considers the arguments about the need to rethink the concept of athletes’ psychological training for the competition. The idea of the article is the shift to the teaching the means of individual psychological training of athletes for the competition. The accuracy of this concept is grounded on the empirical data. The article presents the data of the comparative analysis of employing by athletes the means of psychological training for the competition and opinion of coaches about it. The authors explain the reasons why coaches do not prepare football players psychologically in the process of physical, technical, and tactical training. 5 reasons to explain it are considered in the article. In the process of coaches’ training they are taught to regulate the psychological condition and behavior of athletes, but they are not taught how to train the athletes to do that themselves. The necessity of training football players in the means of self-regulation of their psychological condition for the matches has been proved.


1998 ◽  
Vol 74 (4) ◽  
pp. 606-616 ◽  
Author(s):  
Darwin Burgess ◽  
Craig Robinson

Two of the oldest permanent sample plots (PSPs) in Canada were set up at Petawawa, Ontario (45° 57′ N, 77° 34′ W) to examine the effect of thinning on the development of natural white (Pinus strobus L.) and red pine (Pinus resinosa Ait). Field data were collected periodically, starting in 1918 when the stand was 40 years old and continuing for 71 years. Six thinning treatments were completed, beginning in 1918, and then in 1933, 1941, 1959, 1969 and 1989. The intensity of thinning varied through time with 14, 27, 38, 8, 30, and 7% of the basal area removed. The sawlog volume mean annual increment for the thinned plot remained stable at about five m3 ha−1 yr−1, but the sawlog volume periodic annual increment for the control declined markedly during the last 10-year measurement period to less than 2 m3 ha−1 yr−1. The residual volume was higher in the control; but, if the harvested sawlog volume (264.5 m3 ha−1) was added to the residual sawlog volume (301.3 m3 ha−1) for PSP one, then the sawlog production on the thinned plot has been about the same and its residual volume concentrated on fewer, larger and more valuable trees. The level of natural mortality in the control plot (129.7 m3 ha−1 of sawlog volume) was greater than 10 times that in the thinned plot, thereby adding more coarse woody debris to improve wildlife habitat. These two approaches had a major influence on stand development. The approach used will depend on specific stand-level management objectives. Key words: white pine, red pine, natural stand management, shelterwood system, permanent sample plots.


2021 ◽  
pp. 20-21
Author(s):  

The results of experimental studies of the effect of concentrated dynamic loads on a three-layer structure with glass fiber filler are presented. A comparative analysis of the obtained results with theoretical data is carried out. Keywords: three-layer structure, striker, bearing layer, fiberglass, impact loading. [email protected]


Author(s):  
Peter O’Connor

The Web provides unprecedented opportunities for Web site operators to implicitly and explicitly gather highly detailed personal data about site visitors, resulting in a real and pressing threat to privacy. Approaches to protecting such personal data differ greatly throughout the world. To generalize greatly, most countries follow one of two diametrically opposed philosophies—the self-regulation approach epitomized by the United States, or the comprehensive omnibus legislative approach mandated by the European Union. In practice, of course, the situation is not so black and white as most countries utilize elements of both approaches. This chapter explains the background and importance of protecting the privacy of personal data, contrasts the two major philosophical approaches to protection mentioned above, performs a comparative analysis of the current situation throughout the world, and highlights how the legislative approach is being adopted as the de facto standard throughout the world. The use of trust marks as an alternative to the self-regulation or legislative approach is also discussed, while the effectiveness of each of these efforts is also examined.


FLORESTA ◽  
2013 ◽  
Vol 43 (3) ◽  
pp. 395 ◽  
Author(s):  
Leonardo Pequeno Reis ◽  
José Natalino Macedo Silva ◽  
Pamella Carolline Marques Dos Reis ◽  
João Olegário Pereira de Carvalho ◽  
Waldenei Travassos de Queiroz ◽  
...  

Avaliou-se o efeito da exploração de madeira, realizada em 1997, na estrutura e dinâmica de algumas espécies de Sapotaceae em uma Floresta Ombrófila Densa, no município de Moju, Pará (02º12’26”S e 48º48’14”W). De uma área de floresta de 1.050 ha, foram selecionados 200 hapara exploração seletiva de intensidade de 23 m3.ha-1. Nessa área, foram alocadas 22 parcelas permanentes de 0,5 ha, totalizando 11 ha amostrais, onde foram medidas todas as árvores com DAP ≥10 cm, nos anos de 1995 (antes da exploração), 1998 e 2010 (após exploração). Os parâmetros avaliados foram densidade (Da) e área basal (m2.ha-1). No período de 1995 a 2010, Sapotaceae apresentou uma redução significativa de 7,7% na densidade (p = 0,0147) e aumento na dominância em 1,4% (p = 0,7851). Nesse mesmo período, observou-se redução da densidade e dominância para Pouteria laurifolia (Gomes) Radlk. (66,7 e 50,6%), Pouteria macrocarpa (Mart.) D. Dietr. (25 e 29,4%), Micropholis acutangula (Ducke) Eyma (20 e 11%), Manilkara huberi (Ducke) A. Chev. (16,4 e 17,7%) e Manilkara paraensis (Huber) Standl. (12,5 e 31,4%). A espécie com maior valor comercial, M. huberi, não mostrou recuperação nesse parâmetro, porém houve ingresso de três novas espécies na população de Sapotaceae estudada.AbstractEffect of reduced impact logging in some sapotaceae species in the eastern amazon. Effect of logging, held in 1997, on structure and dynamics of some Sapotaceae species were evaluated in a dense tropical rain forest located in the municipality of Moju, Pará (02º 12’ 26” S e 48º 48’ 14” W). Two hundred ha out of 1,050 ha forest area were selectively logged for timber (23 m3ha-1 logging intensity) in 1997.Twenty-two 0.5 ha permanent sample plots (11 ha sample) were established and all trees with dbh ≥ 10 cm were identified and measured for dbh in 1995 (before logging), 1998 and 2010 (after logging). Parameters evaluated were Density (De) and Basal area (G-m2 ha-1). Sapotaceae presented a significant reduction of 7.7% on tree density (p=0.0147), and an dominance increase of 1.4% (p=0.7851). In the same period, decreases in density and basal area were observed to Pouteria laurifolia (Gomes) Radlk. (66.7 and 50.6%), Pouteria macrocarpa (Mart.) D. Dietr. (25 and 29.4%), Micropholis acutangula (Ducke) Eyma (20 and 11%), Manilkara huberi (Ducke) A. Chev. (16.4 and 17.7%) and Manilkara paraensis (Huber) Standl. (12.5 and 31.4%). The main commercial species M. Huberi did not recover its original density. On the other hand, three new species of the family were recorded in the focused period.Keywords: Forest management; Pouteria; Manilkara; Amazonian Forest.


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