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.

scholarly journals Practical Extension of a Lake States Tree Height Model

2008 ◽  
Vol 25 (4) ◽  
pp. 186-194 ◽  
Author(s):  
Don C. Bragg
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Site Index ◽  
Individual Response ◽  
White Pine ◽  
Eastern White Pine ◽  
Tree Model ◽  
Individual Tree ◽  
Height Model

Abstract By adapting data from national and state champion lists and the predictions of an existing height model, an exponential function was developed to improve tree height estimation. As a case study, comparisons between the original and redesigned model were made with eastern white pine (Pinus strobus L.). For example, the heights predicted by the new design varied by centimeters from the original until the pines were more than 25 cm dbh, after which the differences increased notably. On a very good site (50-year base age site index [SI50] = 27.4 m) at the upper end of the range of basal area (BA; 68.9 m2/ha) for the region, the redesigned model predicted a champion-sized eastern white pine (actual measurements: 97.0 cm dbh, 50.9 m tall) to be 51.3 m tall, compared with 38.8 m using the original formulation under the same conditions. The NORTHWDS Individual Response Model (NIRM) individual tree model further highlighted the influence of these differences with long-term simulations of eastern white pine height. On a moderate site (SI50 = 18.7 m) with intermediate (BA = 15 m2/ha) stand density, NIRM results show that the original model consistently predicts heights to be 20–30% lower for mature white pine.

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 A vertically discretised canopy description for ORCHIDEE (SVN r2290) and the modifications to the energy, water and carbon fluxes

2014 ◽  
Vol 7 (6) ◽  
pp. 8565-8647 ◽  
Author(s):  
K. Naudts ◽  
J. Ryder ◽  
M. J. McGrath ◽  
J. Otto ◽  
Y. Chen ◽  
...  
Keyword(s):  
Forest Management ◽  
Land Surface ◽  
Large Scale ◽  
Land Surface Model ◽  
Basal Area ◽  
Tree Height ◽  
Surface Model ◽  
Spatial And Temporal Variability ◽  
Validation Data ◽  
Mitigate Climate Change

Abstract. Since 70% of global forests are managed and forests impact the global carbon cycle and the energy exchange with the overlying atmosphere, forest management has the potential to mitigate climate change. Yet, none of the land surface models used in Earth system models, and therefore none of today's predictions of future climate, account for the interactions between climate and forest management. We addressed this gap in modelling capability by developing and parametrizing a version of the land surface model ORCHIDEE to simulate the biogeochemical and biophysical effects of forest management. The most significant changes between the new branch called ORCHIDEE-CAN (SVN r2290) and the trunk version of ORCHIDEE (SVN r2243) are the allometric-based allocation of carbon to leaf, root, wood, fruit and reserve pools; the transmittance, absorbance and reflectance of radiation within the canopy; and the vertical discretisation of the energy budget calculations. In addition, conceptual changes towards a~better process representation occurred for the interaction of radiation with snow, the hydraulic architecture of plants, the representation of forest management and a~numerical solution for the photosynthesis formalism of Farquhar, von Caemmerer and Berry. For consistency reasons, these changes were extensively linked throughout the code. Parametrization was revisited after introducing twelve new parameter sets that represent specific tree species or genera rather than a group of unrelated species, as is the case in widely used plant functional types. Performance of the new model was compared against the trunk and validated against independent spatially explicit data for basal area, tree height, canopy strucure, GPP, albedo and evapotranspiration over Europe. For all tested variables ORCHIDEE-CAN outperformed the trunk regarding its ability to reproduce large-scale spatial patterns as well as their inter-annual variability over Europe. Depending on the data stream, ORCHIDEE-CAN had a 67 to 92% chance to reproduce the spatial and temporal variability of the validation data.

scholarly journals A vertically discretised canopy description for ORCHIDEE (SVN r2290) and the modifications to the energy, water and carbon fluxes

2015 ◽  
Vol 8 (7) ◽  
pp. 2035-2065 ◽  
Author(s):  
K. Naudts ◽  
J. Ryder ◽  
M. J. McGrath ◽  
J. Otto ◽  
Y. Chen ◽  
...  
Keyword(s):  
Forest Management ◽  
Land Surface ◽  
Large Scale ◽  
Gross Primary Production ◽  
Canopy Structure ◽  
Basal Area ◽  
Tree Height ◽  
Surface Model ◽  
Spatial And Temporal Variability ◽  
Validation Data

Abstract. Since 70 % of global forests are managed and forests impact the global carbon cycle and the energy exchange with the overlying atmosphere, forest management has the potential to mitigate climate change. Yet, none of the land-surface models used in Earth system models, and therefore none of today's predictions of future climate, accounts for the interactions between climate and forest management. We addressed this gap in modelling capability by developing and parametrising a version of the ORCHIDEE land-surface model to simulate the biogeochemical and biophysical effects of forest management. The most significant changes between the new branch called ORCHIDEE-CAN (SVN r2290) and the trunk version of ORCHIDEE (SVN r2243) are the allometric-based allocation of carbon to leaf, root, wood, fruit and reserve pools; the transmittance, absorbance and reflectance of radiation within the canopy; and the vertical discretisation of the energy budget calculations. In addition, conceptual changes were introduced towards a better process representation for the interaction of radiation with snow, the hydraulic architecture of plants, the representation of forest management and a numerical solution for the photosynthesis formalism of Farquhar, von Caemmerer and Berry. For consistency reasons, these changes were extensively linked throughout the code. Parametrisation was revisited after introducing 12 new parameter sets that represent specific tree species or genera rather than a group of often distantly related or even unrelated species, as is the case in widely used plant functional types. Performance of the new model was compared against the trunk and validated against independent spatially explicit data for basal area, tree height, canopy structure, gross primary production (GPP), albedo and evapotranspiration over Europe. For all tested variables, ORCHIDEE-CAN outperformed the trunk regarding its ability to reproduce large-scale spatial patterns as well as their inter-annual variability over Europe. Depending on the data stream, ORCHIDEE-CAN had a 67 to 92 % chance to reproduce the spatial and temporal variability of the validation data.

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.

scholarly journals Comparison of interferometric and stereo-radargrammetric 3D metrics in mapping of forest resources

2015 ◽  
Vol XL-7/W3 ◽  
pp. 425-431
Author(s):  
K. Karila ◽  
M. Karjalainen ◽  
X. Yu ◽  
M. Vastaranta ◽  
M. Holopainen ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Forest Canopy ◽  
Basal Area ◽  
Tree Height ◽  
Forest Resources ◽  
Canopy Height ◽  
Stem Diameter ◽  
Stem Volume ◽  
Test Plot ◽  
3D Data

Accurate forest resources maps are needed in diverse applications ranging from the local forest management to the global climate change research. In particular, it is important to have tools to map changes in forest resources, which helps us to understand the significance of the forest biomass changes in the global carbon cycle. In the task of mapping changes in forest resources for wide areas, Earth Observing satellites could play the key role. In 2013, an EU/FP7-Space funded project “Advanced_SAR” was started with the main objective to develop novel forest resources mapping methods based on the fusion of satellite based 3D measurements and in-situ field measurements of forests. During the summer 2014, an extensive field surveying campaign was carried out in the Evo test site, Southern Finland. Forest inventory attributes of mean tree height, basal area, mean stem diameter, stem volume, and biomass, were determined for 91 test plots having the size of 32 by 32 meters (1024 m<sup>2</sup>). Simultaneously, a comprehensive set of satellite and airborne data was collected. Satellite data also included a set of TanDEM-X (TDX) and TerraSAR-X (TSX) X-band synthetic aperture radar (SAR) images, suitable for interferometric and stereo-radargrammetric processing to extract 3D elevation data representing the forest canopy. In the present study, we compared the accuracy of TDX InSAR and TSX stereo-radargrammetric derived 3D metrics in forest inventory attribute prediction. First, 3D data were extracted from TDX and TSX images. Then, 3D data were processed as elevations above the ground surface (forest canopy height values) using an accurate Digital Terrain Model (DTM) based on airborne laser scanning survey. Finally, 3D metrics were calculated from the canopy height values for each test plot and the 3D metrics were compared with the field reference data. The Random Forest method was used in the forest inventory attributes prediction. Based on the results InSAR showed slightly better performance in forest attribute (i.e. mean tree height, basal area, mean stem diameter, stem volume, and biomass) prediction than stereo-radargrammetry. The results were 20.1% and 28.6% in relative root mean square error (RMSE) for biomass prediction, for TDX and TSX respectively.

Determining Site Index and Estimating Timber Volumes Without Measuring Heights

1994 ◽  
Vol 18 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Robert L. Bailey ◽  
John R. Brooks
Keyword(s):  
Tree Height ◽  
Pinus Elliottii ◽  
Site Index ◽  
Slash Pine ◽  
Diameter Distribution ◽  
Stem Volume ◽  
Average Height ◽  
Time Saving ◽  
Individual Tree ◽  
Dominant Height

Abstract We present a time-saving method for predicting average dominant height, and thus site index, and predicting yield of a slash pine (Pinus elliottii Engelm.) plantation without measuring any tree heights. We identify a segment in the upper end of the diameter distribution where the average height of all trees is equal to average dominant height. The arithmetic mean diameter of these trees, called dominant height diameter (DHD), is used in a regression to predict average dominant height. With individual tree height prediction equations that use average dominant height and tree volume or weight equations that use tree height and dbh, plot volumes or weights can then be predicted. For 922 plots in slash pine plantations, total-stem volume per acre was predicted with an R2 of 0.978 with this method. South. J. Appl. For. 18(1):15-18.

Time trends in inheritance and projected efficiencies of early selection in a large 17-year-old progeny test of Pinusradiata

1991 ◽  
Vol 21 (8) ◽  
pp. 1200-1207 ◽  
Author(s):  
J. N. King ◽  
R. D. Burdon
Keyword(s):  
Selection Criterion ◽  
Basal Area ◽  
Tree Height ◽  
Stem Diameter ◽  
Stem Volume ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Needle Penetration ◽  
Expected Gain ◽  
Partial Correlations

In an open-pollinated progeny trial of Pinusradiata D. Don, stem diameter assessments were cross-referenced for 410 families for ages 5, 10, and 17 years from planting. Also cross-referenced were Cyclaneusma needle cast (CYCLA) and wood density (PILO) measured by Pilodyn needle penetration. Estimated narrow-sense heritability for stem diameter declined mildly from 0.34 at age 5 to 0.25 at age 17. Estimated heritability of family means, however, only declined from 0.59 to 0.55. CYCLA and PILO gave, respectively, narrow-sense heritability estimates of 0.32 and 0.40, with repeatabilities of family means of 0.57 and 0.67. The genetic age-age correlations for stem diameter were all positive and somewhat higher than phenotypic (family-mean) age–age correlations. Such correlations indicated comparable or slightly slower rank changes among progeny families than had been reported previously for diameter, basal area, or stem volume in P. radiata and Pinustaeda L., but faster rank changes than the literature reports for tree height. A considerable contribution of CYCLA to rank changes in stem diameter was evident from path coefficients and partial correlations. PILO made no evident contribution to rank changes. Predicted gains for stem diameter at age 17 were almost maximal using year-10 data, while using CYCLA as an auxiliary selection criterion enhanced expected gain, particularly with selection at year 5. Predicted gains for stem diameter, with age–age correlations extrapolated according to the Lambeth relationship, indicated maximal gains per annum with selection at 7–8 years for rotations of 25–30 years.

Preliminary DRIS norms for coastal Douglas-fir soils in Washington and Oregon

1995 ◽  
Vol 25 (2) ◽  
pp. 208-214 ◽  
Author(s):  
J.S. Shumway ◽  
H.N. Chappell
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Integrated System ◽  
N Fertilizer ◽  
Soil Test ◽  
Fertilizer Response ◽  
Response Data ◽  
Limiting Nutrient ◽  
Diagnostic Work

The Diagnosis and Recommendation Integrated System (DRIS) has been used successfully in agricultural crops and holds promise for use in forest stands. This study used soil tests to develop DRIS norms and evaluate their effectiveness in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) forests. DRIS norms for nitrogen, phosphorus, potassium, and calcium were developed using soil test and site index data from 72 soil series that commonly support Douglas-fir in western Washington. The norms were tested using soil test and stand basal area growth response data from 20 thinned and 30 unthinned N fertilizer test sites in coastal Washington and Oregon. Response to urea fertilizer in thinned stands averaged 34% and 43% for 224 and 448 kg N•ha−1, respectively, when N was identified as the most limiting nutrient. When N was not the most limiting nutrient, N response averaged 8% and 10% for 224 and 448 kg N•ha−1, respectively. Results were similar in unthinned stands and thinned stands, although response to fertilizer appeared to be slightly less in unthinned stands when N was the most limiting nutrient. DRIS correctly classified 25 of the 33 sites (76%) where N fertilizer increased growth by more than 15%. More importantly, 13 of the 17 (76%) sites that responded by less than 15% were correctly identified by DRIS. The results clearly indicate that N fertilizer response is dependent on the interactions (balance) between soil nutrients at a given site. Future soil diagnostic work needs to focus on techniques, like DRIS, that provide an assessment of these interactions.

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