scholarly journals A Crown Width-Diameter Model for Natural Even-Aged Black Pine Forest Management

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 610 ◽  
Author(s):  
Dimitrios Raptis ◽  
Vassiliki Kazana ◽  
Angelos Kazaklis ◽  
Christos Stamatiou
Keyword(s):  
Forest Management ◽  
Nonlinear Models ◽  
Management Practice ◽  
Basal Area ◽  
Field Measurements ◽  
Pinus Nigra ◽  
Least Square ◽  
Black Pine ◽  
Mixed Effect ◽  
Crown Width

Crown size estimations are of vital importance in forest management practice. This paper presents nonlinear models that were developed for crown width prediction of Black pine (Pinus nigra Arn.) natural, pure, even-aged stands in Olympus Mountain, central Greece. Using a number of measured characteristics at tree and plot level from 66 sample plots as independent variables, an attempt was made to predict crown width accurately, initially based on Least Square Analysis. At the second stage, nonlinear mixed effect modeling was performed in order to increase the fitting ability of the proposed models and to deal with the lack of between observations independence error assumption. Based on the same form, a generalized crown width model was developed by including six main regressors, such as the diameter at breast height, the total height, the canopy base height, the basal area, the relative spacing index and the diameter to quadratic mean diameter ratio, while at the final stage, the same model was expanded to mixed-effect. The proposed models were evaluated against independent crown width sample observations that were also obtained from the study area. The results showed that the two types of mixed-effect models performed equally well and, therefore, we propose those for use in forestry practice. Furthermore, the exact contribution of each inherent variable in crown width allometry was evaluated, thus providing a framework to facilitate field measurements for forest management predictions.

scholarly journals Assessing Tree Drought Resistance and Climate-Growth Relationships under Different Tree Age Classes in a Pinus nigra Arn. ssp. salzmannii Forest

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1161
Author(s):  
Manuel Esteban Lucas-Borja ◽  
Arun K. Bose ◽  
Enrique Andivia ◽  
David Candel-Pérez ◽  
Pedro A. Plaza-Álvarez ◽  
...  
Keyword(s):  
Water Balance ◽  
Drought Resistance ◽  
Basal Area ◽  
Pinus Nigra ◽  
Tree Age ◽  
Black Pine ◽  
Growth Reduction ◽  
Age Classes ◽  
Commercial Thinning ◽  
Large Trees

The magnitude of drought impact in forest ecosystems depends on which group of trees are more severely affected; greater mortality of smaller trees can modulate the trajectories of succession, while the mortality of larger trees can disproportionately offset the ecosystem’s carbon balance. Several studies have documented a greater vulnerability of large trees to extreme droughts while some other studies reported a greater growth reduction in smaller trees during droughts. We tested these hypotheses by comparing tree basal area increment (BAI), drought resistance (i.e., magnitude of growth decline during drought), and resilience (i.e., magnitude of growth recovery after drought) across five different age-classes in black pine (Pinus nigra Arn. Ssp salzmannii) forests in Spain. Our results showed that the BAI patterns, drought resistance, and resilience were strongly influenced by tree age-classes. In addition, the effect of climatic water balance (precipitation minus potential evapotranspiration) on BAI significantly varied among age-classes. The effect of water balance on BAI was lower for younger age-classes (1–39 years of age) compared to older age-classes. We observed a greater growth reduction (i.e., lower resistance) in older trees (>40 years of age) during droughts compared to younger trees (<40 years of age). However, all trees, irrespective of their ages, were able to recover the growth rates after the drought. In general, younger trees showed a greater capacity in recovering the growth rate (i.e., more resilient) than older trees. We detected no significant effects of stand basal area and stand density on BAI, drought resistance, and resilience. Overall, our results indicated that growth of older trees was more negatively affected during drought. Therefore, these older/larger trees can be selected for commercial thinning, or can be released from competition, which can minimize the potential impacts of future droughts in black pine forests in Spain.

scholarly journals Onset of canopy closure for black pine, Turkish red pine and Scots pine forests

2018 ◽  
Vol 64 (No. 5) ◽  
pp. 224-229 ◽  
Author(s):  
Kara Ferhat ◽  
Topaçoğlu Osman
Keyword(s):  
Scots Pine ◽  
Basal Area ◽  
Stand Density ◽  
Pinus Nigra ◽  
Red Pine ◽  
Pine Forests ◽  
Canopy Closure ◽  
Black Pine ◽  
Scots Pine Forests ◽  
Turkish Red Pine

Canopy closure plays an important role in regeneration and management activities in forestry. Thus, determining the density at which canopy closure occurs is important for the success of silvicultural treatments. Turkish red pine (Pinus brutia Tenore), black pine (Pinus nigra J.F. Arnold) and Scots pine (Pinus sylvestris Linnaeus) forests are usually managed at a density that is near or below the canopy closure. Residual stand density during the management of these species is commonly described by stand basal area – BA (m<sup>2</sup>·ha<sup>–1</sup>), however, the BA levels for the canopy closure have not been clearly indicated for these species. The minimum density for the onset of canopy closure (D<sub>OCC</sub>) was determined for Turkish red pine, black pine and Scots pine forests in this study. D<sub>OCC</sub> values were compared across the species. For the D<sub>OCC</sub>, the maximum tree area that a tree can occupy under open-grown conditions was used. The D<sub>OCC</sub> curves of black pine and Scots pine seem to be similar, but the canopy closure in Turkish red pine forests occurs with fewer trees per hectare for a given mean tree diameter. According to the D<sub>OCC</sub> curves, regeneration and tending activities will be more practical and effective in these forests.

scholarly journals Height Allometry of Pinus nigra Arn. in Troodos National Forest Park, Cyprus

2021 ◽  
Vol 13 (11) ◽  
pp. 5998
Author(s):  
Dimitrios I. Raptis ◽  
Vassiliki Kazana ◽  
Nikolaos Onisiforou ◽  
Christos Stamatiou ◽  
Angelos Kazaklis
Keyword(s):  
Forest Management ◽  
Mathematical Formulation ◽  
Tree Height ◽  
Large Degree ◽  
Pinus Nigra ◽  
Mixed Effects ◽  
Parameter Estimates ◽  
Black Pine ◽  
Biological Processes ◽  
Total Height

Total height is one of the basic morphometric tree variables included in all forest management inventories, because it is connected with several forest processes and functions related to the estimation of the woody tree volume and sustainable forest yield. The current research, based on a total sample of 1059 measured Black pine (Pinus nigra Arn.) trees from Cyprus, is an attempt to explore the biological processes related to the tree height allometry of this species and develop a generalized mixed-effects model for tree height prediction. The proposed model, with three additional basic covariates and two random parameters, explained almost 96% of the height variance. The model results showed that although competition and site-connected variables affected the total height, it was the crown base height that explained, to a large degree, the height expression. Through the mixed-effects modeling approach it was possible to explore the complex biological processes related to the tree allometry of Black pine and depict those within a mathematical formulation. The proposed generalized model decreased the error significantly, and therefore it can be used for operational forest management purposes. However, for marginal predictions, use of only the fixed part of the basic model could suffice, since this also provided unbiased parameter estimates.

Estimation de la hauteur des peuplements forestiers par diffusiomètre radar

2000 ◽  
Vol 30 (12) ◽  
pp. 1983-1991 ◽  
Author(s):  
J M Martinez ◽  
A Beaudoin ◽  
P Durand ◽  
T Le Toan ◽  
N Stach
Keyword(s):  
Forest Management ◽  
Basal Area ◽  
Tree Height ◽  
Pinus Nigra ◽  
Site Index ◽  
Sensor Data ◽  
Stem Volume ◽  
Backscatter Coefficient ◽  
Scatter Coefficient ◽  
Local Site

This paper presents the results of an analysis of radar airborne scatterometer data obtained over an Austrian black pine (Pinus nigra Arnold ssp. nigricans Host.) forest in Lozère, France. This system provides vertical sounding inside canopy from which can be derived tree height estimations. The objective of this paper is to analyse the validity of these measurements and, then, to study the interest of this kind of sensors for better forest management. The mean and top height estimations give very good results with a relative error of about 6%. The radar measures the back scatter coefficient of the vegetation from which can be estimated other parameters such as stem volume or basal area. The radar backscatter coefficient is found to be sensitive to the biomass in a low to intermediate range of values (0-200 m3/ha), particularly when the canopy backscattering is separated from the ground echo. The estimation of stem volume using a regression with both tree height estimations and backscatter measurements gives satisfying results. Finally, we discuss the interest of this kind of sensor data for an improved and detailed forest management giving an example of application on the evaluation of the variability of the local site index within a stand.

Mixed-effects height–diameter models for black pine (Pinus nigra Arn.) forest management

Trees ◽  
2021 ◽  
Author(s):  
Dimitrios I. Raptis ◽  
Vassiliki Kazana ◽  
Angelos Kazaklis ◽  
Christos Stamatiou
Keyword(s):  
Forest Management ◽  
Pinus Nigra ◽  
Mixed Effects ◽  
Black Pine

An evaluation of a strategic de-stocking regime for dairying to improve nitrogen efficiency and reduce nitrate leaching from dairy farms in nitrate-sensitive areas

2000 ◽  
pp. 105-110
Author(s):  
Cecile De Klein ◽  
Jim Paton ◽  
Stewart Ledgard
Keyword(s):  
New Zealand ◽  
Nitrate Leaching ◽  
Management Practice ◽  
Field Measurements ◽  
Dairy Farms ◽  
Nitrogen Efficiency ◽  
Management Tool ◽  
Pasture Production ◽  
Leaching Losses ◽  
Sensitive Areas

Strategic de-stocking in winter is a common management practice on dairy farms in Southland, New Zealand, to protect the soil against pugging damage. This paper examines whether this practice can also be used to reduce nitrate leaching losses. Model analyses and field measurements were used to estimate nitrate leaching losses and pasture production under two strategic de-stocking regimes: 3 months off-farm or 5 months on a feed pad with effluent collected and applied back to the land. The model analyses, based on the results of a long-term farmlet study under conventional grazing and on information for an average New Zealand farm, suggested that the 3- or 5-month de-stocking could reduce nitrate leaching losses by about 20% or 35-50%, respectively compared to a conventional grazing system. Field measurements on the Taieri Plain in Otago support these findings, although the results to date are confounded by drought conditions during the 1998 and 1999 seasons. The average nitrate concentration of the drainage water of a 5-month strategic de-stocking treatment was about 60% lower than under conventional grazing. Pasture production of the 5-month strategic de-stocking regime with effluent return was estimated based on data for apparent N efficiency of excreta patches versus uniformlyspread farm dairy effluent N. The results suggested that a strategic de-stocking regime could increase pasture production by about 2 to 8%. A cost/ benefit analysis of the 5-month de-stocking system using a feed pad, comparing additional capital and operational costs with additional income from a 5% increase in DM production, show a positive return on capital for an average New Zealand dairy farm. This suggests that a strategic destocking system has good potential as a management tool to reduce nitrate leaching losses in nitrate sensitive areas whilst being economically viable, particularly on farms where an effluent application system or a feed pad are already in place. Keywords: dairying, feed pads, nitrate leaching, nitrogen efficiency, productivity, strategic de-stocking

Zwischenevaluation des Wald-Wild-Management-Instruments (WWMI) im Pilotprogramm effor2 «Wald und Wild» | Preliminary evaluation of the Game-Forest-Management-Tool (GFMT) in the effor2 pilot programme «Game and Forest»

2003 ◽  
Vol 154 (8) ◽  
pp. 305-313 ◽  
Author(s):  
Roman Eyholzer ◽  
Martin Baumann ◽  
Rolf Manser
Keyword(s):  
Forest Management ◽  
Management Practice ◽  
Management Tool ◽  
Preliminary Evaluation ◽  
Optimal Contract ◽  
Technical Tool ◽  
Entire Study ◽  
Pilot Programme ◽  
Complex Problems ◽  
Entire Study Area

Faced with the challenging task of balancing forest interests and wildlife, the Swiss Forest Agency initiated the pilot programme«Game and Forest», which is committed to a philosophy of goal-oriented management practice and a redesign of forestry subsidizing. Within this programme the diverse goals of forestry and hunting have been amalgamated to a superimposed goal and set out in a corresponding contract. The Game-Forest-Management-Tool (GFMT) has been divised to simulate the effect of various strategies to deal with the complex problems of forest-wildlife. Optimal contract-fulfilling procedures can be simulated on a PC using this technical tool. The efficiency of the measures suggested by simulations that were carried out are being tested in a study area within the pilot programme, «Game and Forest». Half way through this trial, after two years, we can say that there has been no significant increase of non-browsed areas. In 2004, after the collection of data for the entire study area, we will be able to tell whether applying this computer simulated strategy truly leads to an augmentation of non-browsed area and a decrease in bark-peeled forests in the pilot area.

Effect of traffic-induced air pollution on seed germination of Arizona Cypress (Cupressus arizonica Green) and Black Pine (Pinus nigra Arnold)

2020 ◽  
Vol 55 ◽  
pp. 126841
Author(s):  
Zahra Babapour Aliyar ◽  
Abbas Banj Shafiei ◽  
Nasrin Seyedi ◽  
Salar Rezapour ◽  
Saeed Musavi Moghanjugi
Keyword(s):  
Air Pollution ◽  
Seed Germination ◽  
Pinus Nigra ◽  
Black Pine ◽  
Cupressus Arizonica

scholarly journals Largest-Crown-Width Prediction Models for 53 Species in the Western United States

2004 ◽  
Vol 19 (4) ◽  
pp. 245-251 ◽  
Author(s):  
William A. Bechtold
Keyword(s):  
United States ◽  
Prediction Models ◽  
Basal Area ◽  
Stem Diameter ◽  
Western United States ◽  
Quadratic Term ◽  
Crown Width ◽  
Coefficients Of Variation ◽  
Bioclimatic Index ◽  
Minor Improvement

Abstract The mean crown diameters of stand-grown trees 5.0-in. dbh and larger were modeled as a function of stem diameter, live-crown ratio, stand-level basal area, latitude, longitude, elevation, and Hopkins bioclimatic index for 53 tree species in the western United States. Stem diameter was statistically significant in all models, and a quadratic term for stem diameter was required for some species. Crown ratio and/or Hopkins index also improved the models for most species. A term for stand-level basal area was not generally needed but did yield some minor improvement for a few species. Coefficients of variation from the regression solutions ranged from 17 to 33%, and model R2 ranged from 0.15 to 0.85. Simpler models, based solely on stem diameter, are also presented. West. J. Appl. For. 19(4):245–251.

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