Single tree crown shape and volume models for Pinus nigra planted forests in Italy to support forest management strategies in artificial stands

Abstract Background Tree crown can be considered the engine of trees whose size is a key variable to understand the most important ecological and physiological processes that occur in forest ecosystem. The shape and dimension of single-tree crown are affected by a combination of multiple factors such as lateral competition, fertility as well as forest management practices. Anyway, few models are provided in literature to derive their shape and volume from sampled data except the light transmittance or light measurements under canopy closure (Photosynthetic Active Radiation or Leaf Area Index). The main goal of the study is to present a simple and effective method to predict crown shape and crown volume in artificial black pine plantations in Italy from simple field data. Two key parameters involved in crown volume calculation in literature were here modelled. Such parameters were the distance from the top where the crown expresses its the maximum radius (L 0 ) and the radius at crown base height (r cb ). The analysis of crown profile and volume is based on available knowledge we found in literature (Pretzsch 2009) and where the considered species was not included. Results The nonlinear equation results the most adequate for the fitting and able to characterise the ecological processes more properly. Even if just slightly different, the mean absolute error was lower and statistically significant and around 84 cm for L 0 and 36 cm for r cb . Then the use of a modelling procedure also allowed the calculation of confidence intervals and was more powerful than a single multiplier, which is the most common method available in literature. Once compared with field data collected during thinning harvesting, the calculated volumes were correlated with thinning intensities and able to characterise the number of trees removed in each treatment and the increased amount of PAR on the ground. Conclusions The proposed model results useful to evaluate the spatial structure of forest stand without sophisticated and time-consuming surveys and could be an additional tool to support the practical management of artificial black pine stands.

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Single-tree crown shape and crown volume models for Pinus nigra J. F. Arnold in central Italy

Annals of Forest Science ◽

10.1007/s13595-021-01099-4 ◽

2021 ◽

Vol 78 (3) ◽

Author(s):

Umberto Di Salvatore ◽

Maurizio Marchi ◽

Paolo Cantiani

Keyword(s):

Central Italy ◽

Pinus Nigra ◽

Tree Crown ◽

Single Tree ◽

Crown Volume ◽

Crown Shape ◽

Volume Models

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Simulation of Ku-Band Profile Radar Waveform by Extending Radiosity Applicable to Porous Individual Objects (RAPID2) Model

Remote Sensing ◽

10.3390/rs12040684 ◽

2020 ◽

Vol 12 (4) ◽

pp. 684 ◽

Cited By ~ 2

Author(s):

Kai Du ◽

Huaguo Huang ◽

Yuyi Zhu ◽

Ziyi Feng ◽

Teemu Hakala ◽

...

Keyword(s):

Penetration Depth ◽

Forest Canopy ◽

Stem Density ◽

Forest Stands ◽

Area Index ◽

Single Tree ◽

Crown Shape ◽

Band Profile ◽

Ku Band ◽

Individual Objects

Similar to light detection and ranging (lidar), profile radar can detect forest vertical structure directly. Recently, the first Ku-band profile radar system designed for forest applications, called Tomoradar, has been developed and evaluated in boreal forest. However, the physical relationships between the waveform and forest structure parameters such as height, leaf area index (LAI), and aboveground biomass are still unclear, which limits later forestry applications. Therefore, it is necessary to develop a theoretical model to simulate the relationship and interpret the mechanism behind. In this study, we extend the Radiosity Applicable to Porous IndiviDual objects (RAPID2) model to simulate the profile radar waveform of forest stands. The basic assumption is that the scattering functions of major components within forest canopy are similar between profile radar and the side-looking radar implemented in RAPID2, except several modifications. These modifications of RAPID2 mainly include: (a) changing the observation angle from side-looking to nadir-looking; (b) enhancing the ground specular scattering in normal direction using Fresnel coefficient; (c) increasing the timing resolution and recording waveform. The simulated waveforms were evaluated using two plots of Tomoradar waveforms at co- and cross- polarizations, which are collected in thin and dense forest stands respectively. There is a good agreement (R2 ≥ 0.80) between the model results and experimental waveforms in HH and HV polarization modes and two forest scenes. After validation, the extended RAPID2 model was used to explore the sensitivity of the stem density, single tree LAI, crown shape, and twig density on the penetration depth in the Ku-band. Results indicate that the backscattering of the profile radar penetrates deeper than previous studies of synthetic aperture radar (SAR), and the penetration depth tends to be several meters in Ku-band. With the increasing of the needle and twig density in the microwave propagation path, the penetration depth decreases gradually. It is worth noting that variation of stem density seems to have the least effect on the penetration depth, when there is no overlapping between the single tree crowns.

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Fifty years of partial harvesting in a mixed mesophytic forest: composition and productivity

Canadian Journal of Forest Research ◽

10.1139/x03-262 ◽

2004 ◽

Vol 34 (5) ◽

pp. 985-997 ◽

Cited By ~ 82

Author(s):

Thomas M Schuler

Keyword(s):

Forest Management ◽

Sugar Maple ◽

Acer Rubrum ◽

Timber Harvesting ◽

Red Oak ◽

Northern Red Oak ◽

Single Tree ◽

Periodic Growth ◽

Mesophytic Forest ◽

Single Tree Selection

Long-term silvicultural trials contribute to sustainable forest management by providing a better scientific understanding of how forest ecosystems respond to periodic timber harvesting. In this study, species composition, diversity, and net periodic growth of tree species in a mixed mesophytic forest in the central Appalachians were evaluated after about a half century of management. Three partial cutting practices on 18 research compartments and on 3 unmanaged reference compartments were evaluated (19512001) on 280 ha. Single-tree selection, diameter-limit harvesting, and timber harvesting in 0.162-ha patches were assessed on three northern red oak site index50 (SI) classes: 24, 21, and 18. ShannonWeiner's diversity index (H′) declined from the first (19511959) to last (19872001) measurements and was related to both SI (P = 0.004) and treatment (P = 0.009). Sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) were the two most abundant species in recent years (19872001); in contrast, in initial inventories (19511959), northern red oak (Quercus rubra L.) and chestnut oak (Quercus prinus L.) were most abundant. Net periodic annual increment (PAI) of merchantable trees (DBH ≥12.7 cm) was related to both SI (P = 0.004) and treatment (P = 0.003). Mean PAI ranged from 4.6 m3·ha1·year1 for single-tree selection to 2.5 m3·ha1·year1 for unmanaged reference areas across all SI classes. The decline of oak species suggests that only intensive and specific forest management focused on maintaining oak species can obtain historical levels of diversity.

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Analytical approaches for modeling tree crown volume in black wattle (Acacia mearnsii De Wild.) stands

African Journal of Agricultural Research ◽

10.5897/ajar2016.11747 ◽

2016 ◽

Vol 11 (49) ◽

pp. 4979-4989

Author(s):

C. Cadori Guilherme ◽

R. Sanquetta Carlos ◽

Pellico Netto Sylvio ◽

Behling Alexandre ◽

Costa Junior Sergio ◽

...

Keyword(s):

Tree Crown ◽

Acacia Mearnsii ◽

Crown Volume ◽

Black Wattle ◽

Analytical Approaches

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Forest summer albedo is sensitive to species and thinning: how should we account for this in Earth system models?

Biogeosciences ◽

10.5194/bg-11-2411-2014 ◽

2014 ◽

Vol 11 (8) ◽

pp. 2411-2427 ◽

Cited By ~ 19

Author(s):

J. Otto ◽

D. Berveiller ◽

F.-M. Bréon ◽

N. Delpierre ◽

G. Geppert ◽

...

Keyword(s):

Forest Management ◽

Tree Species ◽

Near Infrared ◽

Model Parameters ◽

Earth System ◽

Forest Thinning ◽

Area Index ◽

System Models ◽

Maximum Change ◽

Earth System Models

Abstract. Although forest management is one of the instruments proposed to mitigate climate change, the relationship between forest management and canopy albedo has been ignored so far by climate models. Here we develop an approach that could be implemented in Earth system models. A stand-level forest gap model is combined with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest thinning on summertime canopy albedo. This approach reveals which parameter has the largest affect on summer canopy albedo: we examined the effects of three forest species (pine, beech, oak) and four thinning strategies with a constant forest floor albedo (light to intense thinning regimes) and five different solar zenith angles at five different sites (40° N 9° E–60° N 9° E). During stand establishment, summertime canopy albedo is driven by tree species. In the later stages of stand development, the effect of tree species on summertime canopy albedo decreases in favour of an increasing influence of forest thinning. These trends continue until the end of the rotation, where thinning explains up to 50% of the variance in near-infrared albedo and up to 70% of the variance in visible canopy albedo. The absolute summertime canopy albedo of all species ranges from 0.03 to 0.06 (visible) and 0.20 to 0.28 (near-infrared); thus the albedo needs to be parameterised at species level. In addition, Earth system models need to account for forest management in such a way that structural changes in the canopy are described by changes in leaf area index and crown volume (maximum change of 0.02 visible and 0.05 near-infrared albedo) and that the expression of albedo depends on the solar zenith angle (maximum change of 0.02 visible and 0.05 near-infrared albedo). Earth system models taking into account these parameters would not only be able to examine the spatial effects of forest management but also the total effects of forest management on climate.

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Investigation of stem anatomy in relation to hydraulic conductance, vegetative growth and yielding potential of ‘Summit’ cherry trees grafted on different rootstock candidates

Folia Horticulturae ◽

10.2478/fhort-2021-0019 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Tijana Narandžić ◽

Mirjana Ljubojević ◽

Jovana Ostojić ◽

Goran Barać ◽

Vladislav Ognjanov

Keyword(s):

Hydraulic Conductivity ◽

Sweet Cherry ◽

Correlation Coefficients ◽

Hydraulic Conductance ◽

Fruit Production ◽

Tree Crown ◽

Stem Anatomy ◽

Crown Volume ◽

Cultivar Selection ◽

Cherry Trees

Abstract Severe climate alterations that seriously challenge fruit production, combined with the demand for healthy, pesticide-free fruits, continuously direct rootstock/cultivar selection towards high adaptable varieties breeding. This study aimed to investigate the rootstocks’ influence on the performance of grafted ‘Summit’ cherry trees, including potentially dwarfing Prunus cerasus, Prunus fruticosa and Prunus mahaleb rootstock candidates. Anatomical properties of rootstock and scion stems were investigated to determine variation among different rootstocks and scion-rootstock combinations and to establish the link between trunk hydraulic conductivity, effective tree crown volume and yielding potential. Cross-section anatomical characteristics varied significantly both in rootstock and scion stems, indicating a clear influence of rootstock genotype on grafted sweet cherry trees. It was observed that all investigated cherry rootstock candidates belong to the low-vigorous rootstocks, based on the estimated effective crown volume of grafted trees compared to ‘Gisela 5’, with values ranging from 0.86 to 2.97 m3 in the fifth year after planting. Results showed a statistically significant positive correlation between trunk hydraulic conductivity, effective tree crown volume and yielding potential, with correlation coefficients up to 0.96. Significantly higher effective crown volume and trunk hydraulic conductance of trees grafted on P. cerasus compared to the trees on control, as well as highest yielding potential, showed better adaptation of these rootstock candidates in the trial without irrigation implemented. It was found that PC_05_04 rootstock candidate could be considered as the most appropriate choice when raising the high-density sweet cherry plantations, due to assessed parameters of vegetative and generative growth.

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Summertime canopy albedo is sensitive to forest thinning

Biogeosciences Discussions ◽

10.5194/bgd-10-15373-2013 ◽

2013 ◽

Vol 10 (9) ◽

pp. 15373-15414 ◽

Cited By ~ 1

Author(s):

J. Otto ◽

D. Berveiller ◽

F.-M. Bréon ◽

N. Delpierre ◽

G. Geppert ◽

...

Keyword(s):

Forest Management ◽

Tree Species ◽

Structural Changes ◽

Near Infrared ◽

Canopy Structure ◽

Model Parameters ◽

Transfer Model ◽

Forest Thinning ◽

Crown Volume ◽

The Difference

Abstract. Despite an emerging body of literature linking canopy albedo to forest management, understanding of the process is still fragmented. We combined a stand-level forest gap model with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest thinning, that is removing trees at a certain time during the forest rotation, on summertime canopy albedo. The effects of different forest species (pine, beech, oak) and four thinning strategies (light to intense thinning regimes) were examined. During stand establishment, summertime canopy albedo is driven by tree species. In the later stages of stand development, the effect of tree species on summertime canopy albedo decreases in favour of an increasing influence of forest thinning on summertime canopy albedo. These trends continue until the end of the rotation where thinning explains up to 50% of the variance in near-infrared canopy albedo and up to 70% of the variance in visible canopy albedo. More intense thinning lowers the summertime shortwave albedo in the canopy by as much as 0.02 compared to unthinned forest. The structural changes associated with forest thinning can be described by the change in LAI in combination with crown volume. However, forests with identical canopy structure can have different summertime albedo values due to their location: the further north a forest is situated, the more the solar zenith angle increases and thus the higher is the summertime canopy albedo, independent of the wavelength. Despite the increase of absolute summertime canopy albedo values with latitude, the difference in canopy albedo between managed and unmanaged forest decreases with increasing latitude. Forest management thus strongly altered summertime forest albedo.

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Hydrology-oriented forest management trade-offs. A modeling framework coupling field data, simulation results and Bayesian Networks

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.05.134 ◽

2018 ◽

Vol 639 ◽

pp. 725-741 ◽

Cited By ~ 9

Author(s):

Alberto Garcia-Prats ◽

María González-Sanchis ◽

Antonio D. Del Campo ◽

Cristina Lull

Keyword(s):

Forest Management ◽

Bayesian Networks ◽

Field Data ◽

Data Simulation ◽

Modeling Framework ◽

Coupling Field ◽

Trade Offs ◽

Simulation Results

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Effects of a windthrow disturbance on the carbon balance of a broadleaf deciduous forest in Hokkaido, Japan

Biogeosciences ◽

10.5194/bg-12-6837-2015 ◽

2015 ◽

Vol 12 (23) ◽

pp. 6837-6851 ◽

Cited By ~ 7

Author(s):

K. Yamanoi ◽

Y. Mizoguchi ◽

H. Utsugi

Keyword(s):

Forest Management ◽

Carbon Balance ◽

Deciduous Forest ◽

Carbon Sink ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

Co2 Flux ◽

White Birch ◽

Eddy Covariance Method ◽

Area Index

Abstract. Forests play an important role in the terrestrial carbon balance, with most being in a carbon sequestration stage. The net carbon releases that occur result from forest disturbance, and windthrow is a typical disturbance event affecting the forest carbon balance in eastern Asia. The CO2 flux has been measured using the eddy covariance method in a deciduous broadleaf forest (Japanese white birch, Japanese oak, and castor aralia) in Hokkaido, where incidental damage by the strong Typhoon Songda in 2004 occurred. We also used the biometrical method to demonstrate the CO2 flux within the forest in detail. Damaged trees amounted to 40 % of all trees, and they remained on site where they were not extracted by forest management. Gross primary production (GPP), ecosystem respiration (Re), and net ecosystem production were 1350, 975, and 375 g C m−2 yr−1 before the disturbance and 1262, 1359, and −97 g C m−2 yr−1 2 years after the disturbance, respectively. Before the disturbance, the forest was an evident carbon sink, and it subsequently transformed into a net carbon source. Because of increased light intensity at the forest floor, the leaf area index and biomass of the undergrowth (Sasa kurilensis and S. senanensis) increased by factors of 2.4 and 1.7, respectively, in 3 years subsequent to the disturbance. The photosynthesis of Sasa increased rapidly and contributed to the total GPP after the disturbance. The annual GPP only decreased by 6 % just after the disturbance. On the other hand, the annual Re increased by 39 % mainly because of the decomposition of residual coarse-wood debris. The carbon balance after the disturbance was controlled by the new growth and the decomposition of residues. The forest management, which resulted in the dead trees remaining at the study site, strongly affected the carbon balance over the years. When comparing the carbon uptake efficiency at the study site with that at others, including those with various kinds of disturbances, we emphasized the importance of forest management as well as disturbance type in the carbon balance.

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