scholarly journals Kuivenduse mõju rabamänniku arengule Järvselja Õppe- ja Katsemetskonna kuivendatud puistu näitel / Effect of drainage on the development of an oligotrophic bog Scots pine (P. sylvestris L.) stand in Järvselja

2013 ◽  
Vol 58 (1) ◽  
pp. 12-25
Author(s):  
Silver Sisask
Keyword(s):  
Scots Pine ◽  
Stand Structure ◽  
Measurement Data ◽  
Basal Area ◽  
Growth Conditions ◽  
Site Class ◽  
Growing Stock ◽  
Actual Change ◽  
Forest Drainage ◽  
Stand Characteristics

Abstract The effect of drainage in peatland forests has been studied in Estonia but research on bog pine (Pinus sylvestris L.) stands is lacking and mixed opinions on the expediency of amelioration in this site type are found. In order to obtain more information on the post drainage effects, measurements were conducted in a drained oligotrophic bog Scots pine stand (with a relatively thin peat layer) in Järvselja. Relationship between stand characteristics and distance from the drainage ditch was described and measurement data was compared with data that had been collected 59 years earlier in the same stand. Over time the stand structure and productivity had changed. Due to lengthy drainage, increase in several stand characteristics became evident: mean height 84% (8.60 ± 0.39 m), mean DBH 48% (6.55 ± 0.59 cm), basal area 59% (10.6 ± 3.4 m2 ha-1) and growing stock 179% (169 ± 32 m3 ha-1). Growth conditions had improved (site class improvement 1.8 units) and since earlier comparison data was from an already drained stand, actual change in stand characteristics and productivity compared to pre-drained state, has to be even greater. The studied stand is a good example of successful forest drainage in a bog pine forest and these results contribute to a better understanding of post drainage developments in these types of forests

scholarly journals Thinning Response and Potential Basal Area in a Mixed Sub-humid Low-elevation Oak-Hornbeam Forest

2021 ◽  
Author(s):  
Mathias Neumann ◽  
Hubert Hasenauer
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Climatic Conditions ◽  
Diameter Distribution ◽  
Stem Density ◽  
Growing Stock ◽  
A Site ◽  
Water Nutrients ◽  
Related Mortality

Abstract Competition for resources (light, water, nutrients, etc.) limits the size and abundance of alive trees a site can support. This carrying capacity determines the potential carbon sequestration in alive trees as well as the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as case study. We expected lower increment for heavy thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, whereas two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. The heavy thinned stand had over ten years similar increment as the moderate thinned and unthinned stands. Basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands lead to much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.

scholarly journals Estimation of above-ground biomass in forest stands from regression on their basal area and height

2016 ◽  
Vol 64 (1) ◽  
pp. 70-92 ◽  
Author(s):  
Mait Lang ◽  
Ando Lilleleht ◽  
Mathias Neumann ◽  
Karol Bronisz ◽  
Samir G. Rolim ◽  
...  
Keyword(s):  
Regression Models ◽  
Measurement Data ◽  
Basal Area ◽  
Growth Conditions ◽  
Repeated Measurements ◽  
Carbon Accounting ◽  
Published Data ◽  
Above Ground Biomass ◽  
Forest Stands ◽  
Ground Biomass

Abstract A generic regression model for above-ground biomass of forest stands was constructed based on published data (R2 = 0.88, RSE = 32.8 t/ha). The model was used 1) to verify two allometric regression models of trees from Scandinavia applied to repeated measurements of 275 sample plots from database of Estonian Network of Forest Research (FGN) in Estonia, 2) to analyse impact of between-tree competition on biomass, and 3) compare biomass estimates made with different European biomass models applied on standardized forest structures. The model was verified with biomass measurements from hemiboreal and tropical forests. The analysis of two Scandinavian models showed that older allometric regression models may give biased estimates due to changed growth conditions. More biomass can be stored in forest stands where competition between trees is stronger. The tree biomass calculation methods used in different countries have also substantial influence on the estimates at stand-level. A common database of forest biomass measurements from Europe in similar to pan-tropical tree measurement data may be helpful to harmonise carbon accounting methods.

scholarly journals Influence of thinning intensity and canopy type on Scots pine stand and growth dynamics in a mixed managed forest

2016 ◽  
Vol 25 (2) ◽  
pp. e057 ◽  
Author(s):  
Irantzu Primicia ◽  
Rubén Artázcoz ◽  
Juan-Bosco Imbert ◽  
Fernando Puertas ◽  
María-del-Carmen Traver ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Growth Rates ◽  
Stand Structure ◽  
Growth Dynamics ◽  
Basal Area ◽  
Beech Forest ◽  
Annual Increment ◽  
Thinning Intensity ◽  
Canopy Type

Aim of the study: We analysed the effects of thinning intensity and canopy type on Scots pine growth and stand dynamics in a mixed Scots pine-beech forest. Area of the study: Western Pyrenees. Material and methods: Three thinning intensities were applied in 1999 (0, 20 and 30% basal area removed) and 2009 (0, 20 and 40%) on 9 plots. Within each plot, pure pine and mixed pine-beech patches are distinguished. All pine trees were inventoried in 1999, 2009 and 2014. The effects of treatments on the tree and stand structure variables (density, basal area, stand and tree volume), on the periodic annual increment in basal area and stand and tree volume, and on mortality rates, were analysed using linear mixed effects models. Main Results: The enhancement of tree growth was mainly noticeable after the second thinning. Growth rates following thinning were similar or higher in the moderate than in the severe thinning. Periodic stand volume annual increments were higher in the thinned than in the unthinned plots, but no differences were observed between the thinned treatments. We observed an increase in the differences of the Tree volume annual increment between canopy types (mixed < pure) over time in the unthinned plots, as beech crowns developed. Research highlights: Moderate thinning is suggested as an appropriate forest practice at early pine age in these mixed forests, since it produced higher tree growth rates than the severe thinning and it counteracted the negative effect of beech on pine growth observed in the unthinned plots.Keywords: competition; Fagus sylvatica L.; Pinus sylvestris L.; forest management; mortality; Mediterranean forest.

Optimizing the Management of Uneven-aged Forest Stands

1974 ◽  
Vol 4 (3) ◽  
pp. 274-287 ◽  
Author(s):  
Darius M. Adams ◽  
Alan R. Ek
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Objective Functions ◽  
Target Structure ◽  
Diameter Class ◽  
Northern Hardwood ◽  
Growing Stock ◽  
Present Worth ◽  
Programming Techniques

Two perennial problems in the management of uneven-aged forests are considered: (i) determination of the optimal sustainable distribution of trees by diameter class, i.e. stand structure, for a given initial stocking level, and (ii) the optimal cutting schedule for the conversion of an irregular stand to a target structure. It is shown, using examples for northern hardwood stands in Wisconsin, that both problems can be solved via mathematical programming techniques. The programming approaches utilize a set of nonlinear equation models for stand table projections which consider the interdependence of size classes within the stand. To illustrate procedures, optimal stand structures are found for a case where initial stand basal area is constrained to specified levels and the objective is to maximize value growth over the cutting cycle. A conversion cutting schedule is then determined for a case in which the objective is maximization of present worth. It is emphasized that both the optimal distribution and conversion problems can be generalized to consider a broad range of objective functions, lengths of cutting cycle, and constraints on the growing stock.

scholarly journals Evaluating tree-to-tree competition during stand development in a relict Scots pine forest: how much does climate matter?

Trees ◽  
2021 ◽  
Author(s):  
Laura Marqués ◽  
J. Julio Camarero ◽  
Miguel A. Zavala ◽  
Markus Stoffel ◽  
Juan A. Ballesteros-Cánovas ◽  
...  
Keyword(s):  
Scots Pine ◽  
Stand Structure ◽  
Climatic Variability ◽  
Basal Area ◽  
Climatic Conditions ◽  
Climate Impacts ◽  
Stand Development ◽  
Relict Population ◽  
Competition Effects ◽  
Over Time

Abstract Key message Competitive interactions change over time and their influence on tree growth is intensified during drought events in marginal Scots pine populations. Abstract Competition is a key factor driving forest dynamics and stand structure during the course of stand development. Although the role of neighbourhood competition on stand dynamics has received increasing attention, the response of competition to environmental fluctuations and stand development remains poorly explored. We evaluated changes in competition during stand development in a dry-edge Scots pine relict population located in Central Spain. Typically, tree-to-tree interactions have been investigated through static competition measurements, which usually lack the temporal variation associated to natural forest development and environmental conditions. Here, we assessed how individual and neighbourhood components of competition evolved along a 35-year period, and we related competition dynamics to population structure and drought levels. On six plots, 508 trees were mapped and diameters at breast height (DBH) were measured. Two increment cores were taken from target trees to derive basal area increment (BAI), and neighbourhood was reconstructed back to 1980. Results provide insights into inter-annual variability in competition effects and their role on tree radial growth depending on climatic conditions. From the year 2005 onwards, both individual and neighbourhood components of competition showed a decoupled pattern over time. This effect was particularly pronounced during the extreme drought in 2012, in which the individual component decreased, whereas the neighbourhood component increased. In addition, climatic variability modulated the competition effects during stand development. This approach of evaluating competition dynamics proves to be promising for studying forest stand development and the influence of climate impacts on tree populations subjected to xeric conditions.

scholarly journals A study of the relationship between heights and diameters at breast height in tree stands of Scots pine in the Training and Experimental Forestry of the Leningrad region

2021 ◽  
Author(s):  
М.О. Гурьянов ◽  
Д.Э. Раупова
Keyword(s):  
Mathematical Models ◽  
Scots Pine ◽  
Stand Structure ◽  
Leningrad Region ◽  
Habitat Conditions ◽  
Growing Stock ◽  
Breast Height ◽  
Stand Height ◽  
The Individual ◽  
The Relationship

Взаимосвязи между высотами деревьев и диаметрами на высоте груди широко применяются при определении запасов и сортиментной структуры древостоев. Для их описания применяются многочисленные математические модели. Сравнительный анализ точности шести моделей на примере древостоев сосны обыкновенной Учебно-опытного лесничества Ленинградской области показал близкую точность каждой из них. При этом для разных пробных площадей наибольшую точность показывали разные модели. Это обуславливает необходимость дальнейших исследований по данной тематике с целью выявления наиболее применимых для различных древесных пород, возрастов и условий местопроизрастаний математических моделей. В практической деятельности часто используются таблицы, составленные с учетом соотношений высот и диаметров на высоте груди в древостоях, основными из которых являются таблицы объемов стволов по разрядам высот и сортиментные таблицы. В рамках исследования было установлено, что фактические зависимости высот деревьев от диаметров на высоте груди отличаются от приведенных в таблицах, что обусловлено индивидуальными особенностями структуры и условий местопроизрастания древостоев. По этой причине разряды высот, определенные для отдельных ступеней толщины, зачастую отличаются от найденных по средним для древостоя высоте и диаметру на высоте груди. Это приводит к расхождениям в найденных с учетом данных двух подходов запасах древостоев, а также выхода и стоимости сортиментов в них. Несмотря на незначительность различий, их наличие свидетельствует о необходимости дальнейших исследований с целью повышения точности определения таксационных показателей древостоев. The relationships between heights and diameters at breast height of trees are widely used in determining of growing stock and assortment structure of stands. Numerous mathematical models are used to describe them. A comparative analysis of the accuracy of six models on the example of tree stands of Scots pine in the Training and Experimental Forestry of the Leningrad region showed the close accuracy of each of them. For different sample plots, however, the highest accuracy was showed by different models. This necessitates further research on this topic in order to identify the most applicable mathematical models for different tree species, ages and habitat conditions. In practice are often used the tables, compiled taking into account the ratios of heights and diameters at breast height in tree stands, the main of which are tables of volumes of trees by height ranks and assortment tables. Within the framework of the study, it was found that the actual relationships between tree heights and diameters at breast height differ from those given in the tables, which is due to the individual features of the stand structure and habitat conditions. For this reason, the height ranks, determined for individual diameter classes often differ from those found for the average tree stand height and diameter at breast height. This leads to discrepancies in the growing stocks of tree stands, found taking into account these two approaches, as well as the yield and cost of assortments in them. Although the differences are insignificant, they highlight the need for further research in order to improve the accuracy of determining the inventory parameters of tree stands

scholarly journals Thinning Response and Potential Basal Area—A Case Study in a Mixed Sub-Humid Low-Elevation Oak-Hornbeam Forest

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1354
Author(s):  
Mathias Neumann ◽  
Hubert Hasenauer
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Climatic Conditions ◽  
Diameter Distribution ◽  
Stem Density ◽  
Growing Stock ◽  
A Site ◽  
Water Nutrients ◽  
Related Mortality

Competition for resources (light, water, nutrients, etc.) limits the size and abundance of live trees a site can support. This carrying capacity determines the potential carbon sequestration in live trees and the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment, and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as a case study. We expected lower increment for heavily thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, in which two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. Over ten years, the heavily thinned stand had a similar increment as that of the moderately thinned and unthinned stands. The basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning, suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands led to a much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.

scholarly journals The structure analysis of the Norway spruce stands after schematic thinning in the 1st protected zone of water-supply storage

Beskydy ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 99-108
Author(s):  
M. Bátor ◽  
L. Danková
Keyword(s):  
Water Supply ◽  
Norway Spruce ◽  
Stand Structure ◽  
Slenderness Ratio ◽  
Basal Area ◽  
Forest Edge ◽  
Static Stability ◽  
Growing Stock ◽  
Spruce Stands ◽  
Protected Zone

The water-supply storages are important resources of drinking water in some regions of Slovakia, especially in surrounding of Banská Bystrica. Málinec is one of the three storages in this region. In protected zone of this storage are planted Norway spruce (hereinafter „spruce“) stands monocultures because of ensuring required water quality in storage. There are 24 years old spruce stands without admixture of deciduous trees in the upper layer. Understory is formed by blackthorn (PRP 1). On this locality was carried out geometric (schematic) thinning what is not recommended in protected zones because of worse influencing of soil permeability, humus decomposition and open forest edge creating. There was identified one older permanent research plot (PRP) and established one new PRP where was performed own measurements. Into the PRPs there are transekts and remaining area. Acreage of PRP is 0,234 and 0,315 ha. On the whole area were measured tree diameter and assessed tree classes (5 degrees–Polanský 1955). Moreover, on transekts were measured tree and also crown height. Based of measured variables were calculated stand characteristics like slenderness ratio, crown ratio, growing stock and basal area. If it is possible, these were compared with older results. The aim of this work is evaluation of spruce stands structure and their stability after schematic thinning. This kind of silvicultural treatment is absolutely unfit in stands with specific (water-protested) function (Slodičák et al. 2010). These stands are from the perspective of static stability too unfit–basal area and abundance of trees is nearly as in yield tables (Kolektív 1992) but growing stock is much higher and a lot of trees is too slim. The slenderness ratio is from 75 to 90 %. But the crown lenght is quite good with crown ratio 52–64 %. In these ages of stands are crowns reduced too much. Suitable individual thinning has been in these stands neglected (growing stock is higher than normal). There is assumed reduced stand lifetime after schematic thinning. Current stand structure is due to the young age inappropriate.

scholarly journals Comparing the characteristics of boom-corridor and selectively thinned stands of Scots pine and birch

Silva Fennica ◽  
2021 ◽  
Vol 55 (3) ◽  
Author(s):  
Yrjö Nuutinen ◽  
Jari Miina ◽  
Timo Saksa ◽  
Dan Bergström ◽  
Johanna Routa
Keyword(s):  
Scots Pine ◽  
Stand Structure ◽  
Raw Material ◽  
Stem Volume ◽  
Stand Development ◽  
Work Time ◽  
Growing Stock ◽  
Biomass Removal ◽  
Downy Birch ◽  
To Receive

Young, dense forest in Finland and Sweden urgently need to receive first thinning. In such stands, conventional selective thinning methods make the harvester work time consuming and, thus, costly. To make small-sized trees economically competitive as raw material for bioenergy and biorefining, new harvesting technologies and/or thinning methods need to be developed. A potential solution is boom-corridor thinning (BCT), rendering effective cutting work. The aim of this study was to describe and compare the stand structure of two Scots pine stands ( L.) and one birch-dominated ( Roth with natural downy birch, Ehrh.) stand after BCT and selective thinning at the first thinning phase. Furthermore, simulations were conducted to predict the future stand development after the first thinning treatments. The density of the growing stock was 16–46% higher after BCT treatment than after selective thinning because BCT stands included more small and supressed trees with a dbh < 100 mm. However, the numbers of future crop trees with a dbh > 140 mm per hectare were at the same level in both treatments. The stem volume removal per hectare did not differ between treatments. However, simulation of stand development and intermediate thinning and clearcutting revealed that the total removal volume was 10–18% higher in BCT stands compared to selectively thinned ones. The saw log volumes harvested did, however, not differ between treatments. This study shows that BCT generates stands with higher biodiversity compared to conventional thinning as higher levels of biomass removal can be reached throughout stand rotations.Pinus sylvestrisBetula pendulaB. pubescens

scholarly journals Regression kriging to improve basal area and growing stock volume estimation based on remotely sensed data, terrain indices and forest inventory of black pine forests

2020 ◽  
Vol 50 ◽  
Author(s):  
Ferhat Bolat ◽  
Sinan Bulut ◽  
Alkan Günlü ◽  
İlker Ercanlı ◽  
Muammer Şenyurt
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Volume Estimation ◽  
Landsat 8 ◽  
Regression Kriging ◽  
Remotely Sensed Data ◽  
Growing Stock ◽  
Stock Volume ◽  
Mean Square Errors ◽  
Sentinel 2

Background: The use of satellite imagery to quantify forest metrics has become popular because of the high costs associated with the collection of data in the field.Methods: Multiple linear regression (MLR) and regression kriging (RK) techniques were used for the spatial interpolation of basal area (G) and growing stock volume (GSV) based on Landsat 8 and Sentinel-2. The performance of the models was tested using the repeated k-fold cross-validation method.Results: The prediction accuracy of G and GSV was strongly related to forest vegetation structure and spatial dependency. The nugget value of semivariograms suggested a moderately spatial dependence for both variables (nugget/sill ratio approx. 70%). Landsat 8 and Sentinel-2 based RK explained approximately 52% of the total variance in G and GSV. Root-mean-square errors were 7.84 m2 ha-1 and 49.68 m3 ha-1 for G and GSV, respectively.Conclusions: The diversity of stand structure particularly at the poorer sites was considered the principal factor decreasing the prediction quality of G and GSV by RK.

Sign in / Sign up

Export Citation Format

Share Document