scholarly journals Change of stand structure in upper tree line caused by disturbances

Beskydy ◽  
2013 ◽  
Vol 6 (1) ◽  
pp. 75-86
Author(s):  
K. Gubka ◽  
J. Pittner
Keyword(s):  
Bark Beetle ◽  
Stand Structure ◽  
Negative Impact ◽  
Forest Stand ◽  
Repeated Measurements ◽  
Wind Disturbance ◽  
Tree Line ◽  
Number Of Stems ◽  
Individual Trees ◽  
Different Altitudes

In 2002, the series of 4 permanent research plots of different altitudes (difference 100 m) was established in forest stand that is the part of upper tree line. In the plots we registered the quantitative and qualitative biometric characteristics of individual trees. The results showed that the stand is relatively statically stable (sufficient parameters of crown ratio and slenderness). The studied stand had adequate density and the number of stems was increasing with the decreasing altitude (from 1,460 to 1,260 m a.s.l.). The stand was comparable with the model one (yield tables) regarding the quantitative as well as qualitative parameters.After the wind disturbance in 2004, two studied plots in higher altitudes were totally destroyed. In the time of repeated measurements (in 2010) the negative impact of the bark-beetle outbreak began to be visible. It was reflected in increased mortality of spruce also in the research plots situated in lower altitudes of studied stand. We confirmed that the neglect of forest hygiene and adequate silvicultural treatment leads to decline of stand condition and functionality in the upper tree line forests.

scholarly journals Tree mortality in the dynamics and management of uneven-aged Norway spruce stands in southern Finland

2020 ◽  
Vol 139 (6) ◽  
pp. 989-998
Author(s):  
Sauli Valkonen ◽  
Lucie Aulus Giacosa ◽  
Juha Heikkinen
Keyword(s):  
Tree Mortality ◽  
Stand Structure ◽  
Basal Area ◽  
Repeated Measurements ◽  
Common Causes ◽  
Single Tree Selection ◽  
Spruce Stands ◽  
Causes Of Mortality ◽  
Number Of Stems ◽  
Adverse Influence

Abstract This study focused on tree mortality in spruce-dominated stands managed using the single-tree selection method in southern Finland. Together with regeneration and tree growth, mortality is one of the basic elements of the stand structure and dynamics in selection stands. The study was based on data acquired from a set of 20 permanent experimental plots monitored with repeated measurements for 20 years. The average mortality in the number of stems (N) was 4.45 trees ha−1a−1, in basal area (G) 0.07 m2 ha−1a−1, and in stemwood volume (V) 0.56 m3 ha−1a−1. In relative terms it was 0.50% of N, 0.30% of G and 0.27% of V, respectively. Wind and snow were the most common causes of mortality, while deaths by biotic causes (mammals, insects, pathogens) were extremely rare. Some 6–10% of the total loss in the number of stems and volume was attributable to the loss or removal of trees that sustained serious damage in harvesting. Most of the mortality occurred in the smallest diameter classes of up to 20 cm. Such a high mortality among small trees can have an adverse influence on the sustainability of selection structures if not successfully checked in harvesting and management.

scholarly journals Potential Analysis of Forest Stand Inventory in Production Forest Management Unit (KPHP) Nunukan IV, Nunukan Regency-North Kalimantan

AGRIFOR ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 19
Author(s):  
Andi Almarief
Keyword(s):  
Growth Rate ◽  
Stand Structure ◽  
Species Group ◽  
Forest Stand ◽  
Forest Governance ◽  
Average Volume ◽  
Diameter Class ◽  
Potential Analysis ◽  
Forest Inventories ◽  
Number Of Stems

This research aims at (1) to determined the potential, the structure and speciescomposition of forest stands in KPHP Nunukan IV for the basis of forest governance andmanagement of the plan.This research uses data from forest inventories KPHP that implementedin July 2017. Tally sheet data from the field was classified by the growth rate, diameter class and species group and then was calculated for number of stems and volume. The results of this research are 1) from 50 plots retrieved 79 species. 2) Species compotition is dominated by Shorea with average volume 175,31 m3/ha. 3) Stand structure,  the total number of trees 137 stems/ha and volume 245,01 m3/ha. Shorea dominate 90 stems/ha and volume175,31 m3/ha.4) for seedlings obtained INP At the highest level is meranti by 45,93%, Kapur by 14,14 % and Keruing by 14,14%. The highest INP of saplings on the type of Meranti at 66,79%, Guava 30,18 % and 19,84 % Medang. At the highest level of pole INP obtained on the type of Meranti at 94,7 % , Mendarahan 24,01% and Jambu-Jambu 21,09%. At the level of the tree has the largest INP Meranti 88,51%, Medang 30,64% dan Keruing 24,49%.

scholarly journals Forest stand structure and coarse woody debris determine the biodiversity of beetle communities in Mediterranean mountain beech forests

2021 ◽  
pp. e01637
Author(s):  
Francesco Parisi ◽  
Michele Innangi ◽  
Roberto Tognetti ◽  
Fabio Lombardi ◽  
Gherardo Chirici ◽  
...  
Keyword(s):  
Coarse Woody Debris ◽  
Stand Structure ◽  
Woody Debris ◽  
Forest Stand ◽  
Beech Forests ◽  
Forest Stand Structure

scholarly journals How Bark Beetle Attack Changes the Tensile and Compressive Strength of Spruce Wood (Picea abies (L.) H. Karst.)

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 87
Author(s):  
Radim Löwe ◽  
Miroslav Sedlecký ◽  
Adam Sikora ◽  
Anna Prokůpková ◽  
Roman Modlinger ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Picea Abies ◽  
Bark Beetle ◽  
Reference Group ◽  
Ct Scanning ◽  
The Czech Republic ◽  
Central European ◽  
Spruce Wood ◽  
Mechanical And Physical Properties ◽  
Individual Trees

Since 2014, forestry in the Czech Republic has been significantly affected by a bark beetle outbreak. The volume of infested trees has exceeded processing capacity and dead standing spruce (Picea abies) remain in the forest stands, even for several years. What should be done with this bark beetle wood? Is it necessary to harvest it in order to preserve the basic mechanical and physical properties? Is it possible to store it under standard conditions, or what happens to it when it is “stored” upright in the forest? These are issues that interested forest owners when wood prices were falling to a minimum (i.e., in 2018–2019) but also today, when the prices of quality wood in Central European conditions are rising sharply. To answer these questions, we found out how some of the mechanical properties of wood change in dead, bark beetle-infested trees. Five groups of spruce wood were harvested. Each of these groups was left upright in the forest for a specified period of time after bark beetle infestation, and one group was classified as a reference group (uninfested trees). Subsequently, we discovered what changes occurred in tensile and compressive strength depending on the time left in the stand and the distance from the center of the trunk. When selecting samples, we eliminated differences between individual trees using a CT scanning technique, which allowed us to separate samples, especially with different widths of annual rings and other variations that were not caused by bark beetle. The results showed the effect of log age and radial position in the trunk on tensile and compressive strength. The values for tensile strength in 3-year infested trees decreased compared to uninfested trees by 14% (from 93.815 MPa to 80.709 MPa); the values for compressive strength then decreased between the same samples by up to 25.6% (from 46.144 MPa to 34.318 MPa). A significant decrease in values for compressive strength was observed in the edges of the trunks, with 44.332 MPa measured in uninfested trees and only 29.750 MPa in 3-year infested trees (a decrease of 32.9%). The results suggest that the use of central timber from bark beetle-infested trees without the presence of moulds and fungi should not be problematic for construction purposes.

scholarly journals Natural and Anthropogenic Variation of Stand Structure and Aboveground Biomass in Niger Delta Mangrove Forests

2021 ◽  
Vol 4 ◽  
Author(s):  
Chukwuebuka J. Nwobi ◽  
Mathew Williams
Keyword(s):  
Aboveground Biomass ◽  
Niger Delta ◽  
Stand Structure ◽  
Oil Pollution ◽  
Negative Impact ◽  
Forest Degradation ◽  
Total Biomass ◽  
Mangrove Forests ◽  
Area Index ◽  
Nipa Palm

Mangrove forests are important coastal wetlands because of the ecosystem services they provide especially their carbon potential. Mangrove forests productivity in the Niger Delta are poorly quantified and at risk of loss from oil pollution, deforestation, and invasive species. Here, we report the most extensive stem girth survey yet of mangrove plots for stand and canopy structure in the Niger Delta, across tidal and disturbance gradients. We established twenty-five geo-referenced 0.25-ha plots across two estuarine basins. We estimated aboveground biomass (AGB) from established allometric equations based on stem surveys. Leaf area index (LAI) was recorded using hemispherical photos. We estimated a mean AGB of 83.7 Mg ha–1 with an order of magnitude range, from 11 to 241 Mg ha–1. We found significantly higher plot biomass in close proximity to a protected site and tidal channels, and the lowest in the sites where urbanization and wood exploitation was actively taking place. The mean LAI was 1.45 and ranged fivefold from 0.46 to 2.41 and there was a significant positive correlation between AGB and LAI (R2 = 0.31). We divided the plots into two disturbance regimes and three nipa palm (Nypa fruticans) invasion levels. Lower stem diameter (5–15 cm) accounted for 70% of the total biomass in disturbed plots, while undisturbed regimes had a more even (∼25%) contribution of different diameter at breast height (DBH) size classes to AGB. Nipa palm invasion also showed a significant link to larger variations in LAI and the proportion of basal area removed from plots. We conclude that mangrove forest degradation and exploitation is removing larger stems (>15 cm DBH), preferentially from these mangroves forests and creates an avenue for nipa palm colonization. This research identifies opportunities to manage the utilization of mangrove resources and reduce any negative impact. Our data can be used with remote sensing to estimate biomass in the Niger Delta and the inclusion of soil, leaf properties and demographic rates can analyze mangrove-nipa competition in the region.

Spray Deposition from Ground-based Applications of Carbaryl to Protect Individual Trees from Bark Beetle Attack

2008 ◽  
Vol 37 (3) ◽  
pp. 1170-1179 ◽  
Author(s):  
Christopher J. Fettig ◽  
A. Steven Munson ◽  
Stephen R. McKelvey ◽  
Parshall B. Bush ◽  
Robert R. Borys
Keyword(s):  
Bark Beetle ◽  
Spray Deposition ◽  
Individual Trees

scholarly journals Transformation of even-aged spruce stands at the School Forest Enterprise Kostelec nad Černými lesy: Structure and final cutting of mature stand

2012 ◽  
Vol 52 (No. 4) ◽  
pp. 158-171 ◽  
Author(s):  
J. Remeš
Keyword(s):  
Forest Stand ◽  
Growth Potential ◽  
Main Criterion ◽  
Individual Tree ◽  
Main Method ◽  
Single Tree ◽  
Mature Stand ◽  
Spruce Stands ◽  
Individual Trees ◽  
Very High

This paper deals with the transformation of pure even-aged forest stands to mixed and more uneven-aged stands on an example of selected even-aged Norway spruce stands in the School Forest Enterprise (SFE) in Kostelec nad Černými lesy. A forest stand where individual tree felling was used as the main method of forest stand regeneration was chosen as a conversion example. The main criterion of tree maturity is the culmination of mean volume increment of a single tree. The analyses confirmed a very high variability in the growth potential of individual trees. The potential and actual increment was strongly influenced by the stand position of tree and by crown release. These results show a high potential level of tree growth even at the age of 120 years. From 30% to 9% of all trees on particular experimental plots achieved felling maturity.

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