Search

Effective forest management and conservation are increasingly critical in addressing the challenges posed by climate change. Advances in remote sensing technologies, such as terrestrial laser scanning, offer promising tools for more accurate assessments in forestry research. This study explores the application of TLS in biomass estimation by conducting a bibliometric analysis of scientific articles indexed in Scopus and the Web of Science. By examining the literature from 2010 to 2024, the study identifies key trends, knowledge gaps, and emerging research opportunities, as well as practical applications in forest management and conservation. The analysis reveals a significant rise in scientific output on TLS, with an average annual growth rate of 8.16%. The most cited works address biomass estimation at the individual tree level using laser scanning data. China and the United States lead in the publication volume with 11 articles. The collaboration network highlights research disparities among regions such as Latin America. Overall, TLS has proven effective for the non-destructive measurement of forest variables and biomass.

Effective forest management and conservation are increasingly critical in addressing the challenges posed by climate change. Advances in remote sensing technologies, such as terrestrial laser scanning, offer promising tools for more accurate assessments in forestry research. This study explores the application of TLS in biomass estimation by conducting a bibliometric analysis of scientific articles indexed in Scopus and the Web of Science. By examining the literature from 2010 to 2024, the study identifies key trends, knowledge gaps, and emerging research opportunities, as well as practical applications in forest management and conservation. The analysis reveals a significant rise in scientific output on TLS, with an average annual growth rate of 8.16%. The most cited works address biomass estimation at the individual tree level using laser scanning data. China and the United States lead in the publication volume with 11 articles. The collaboration network highlights research disparities among regions such as Latin America. Overall, TLS has proven effective for the non-destructive measurement of forest variables and biomass. [ABSTRACT FROM AUTHOR]

The article thoroughly investigates the relationships between terrain features and tree measurements derived from aerial laser scanning (ALS) data and field surveys in a 1067-hectare forested area. A digital elevation model (DEM) was generated from ALS data, which was then used to derive additional layers such as slope, aspect, topographic position index (TPI), and landforms. The authors developed a mathematical procedure to determine the radii for the topographic position index. The canopy height model was created, and individual trees were segmented using a novel voxel aggregation method, allowing for the calculation of tree height and crown size. Accuracy assessments were conducted between ALS-derived data and field-collected data. Terrain variability within each forest unit was evaluated using characteristics such as standard deviation, entropy, and frequency. The relationships between tree height and the derived topographic features within forest subcompartments, as well as the correlation between the height yield map for the entire area and the TPI layer, were analysed. The authors found strong correlation between the topographic position index and tree heights in both cases. The presented remote-sensing-based methodology and the results can be effectively used in digital forest site mapping, complemented by field sampling and laboratory soil analyses, and, as final goal, in carbon stock assessment. [ABSTRACT FROM AUTHOR]

The continuous and reliable assessment of crop water status through water indicators enables the sustainable management of water resources, especially in arid or semi-arid climate scenarios exacerbated by climate change. Therefore, the main objective of this study is to determine and compare the sensitivity of indices derived from trunk diameter fluctuations for the accurate and automatic detection of changes in the water status of cherry trees. The water stress indicators examined are maximum daily trunk shrinkage (MDS), trunk growth rate (TGR), early daily trunk shrinkage (EDS), and late daily trunk shrinkage (LDS). During two growing seasons, 'Lapins' sweet cherry trees were subjected to different water stress levels: (i) a control treatment irrigated at 115% of crop evapotranspiration demand to ensure non-limiting water conditions, and (ii) a deficit irrigation treatment, with two irrigation withholding cycles. Vegetative growth was affected by water stress. Trunk daily growth rate and late daily trunk shrinkage exhibited a high variability and did not clearly show differences in plant water status. Both EDS and MDS showed a third-degree polynomial relationship with Ψstem. MDS had a lineal relationship with Ψstem of up to −1.4 MPa; however, further decreases in Ψstem did not necessarily lead to increased MDS. In contrast, EDS became non-linear at −1.8 MPa, making it a more useful plant water indicator than MDS for 'Lapins' sweet cherry trees when detecting severe water stress conditions. The frequencies of both MDS and EDS decreased from 85% to 35% when water stress increased. Therefore, the information provided by MDS and EDS frequencies, along with their daily values, could be useful as irrigation management tools for sweet cherry trees. [ABSTRACT FROM AUTHOR]

ABSTRACT The aim of this study was to evaluate development in the following tree species: Acacia mangium Willd, Anadenanthera colubrina var. cebil (Griseb.) Altschu, Casuarina equisetifolia L. ex J. R. Forst. & G. Forst, Handroanthus impetiginosus (Mart. Ex DC.) Mattos, and Colubrina glandulosa subsp. reitzii (M.C.Johnst.) Borhidi under two water regimes in the Irrigated Perimeter of Baixo Acaraú, in the state of Ceará. The experiment was conducted over seven years, with the factors represented by water regimes, species and periods in an arrangement of split-split plots in a completely randomised design repeated over time with four replications of two plants each. The response variables were total height, diameter at breast height, volume, absolute growth rate in height and diameter, and current and average annual increase in volume. After seven years, the species Acacia mangium, Casuarina equisetifolia, Handroanthus impetiginosus, Anadenanthera colubrina and Colubrina glandulosa presented the following respective mean volumes: 0.62, 0.47, 0.45, 0.31 and 0.29 m3 irrespective of the water regime. Despite a reduction in the growth rates of the species during each period, they remained positive, and growth did not stop. The mean values for volume confirm that the species showed similar growth for the water regimes under study. An irrigated regime of up to one year is therefore suggested for cultivating these species in the Irrigated Perimeter of Baixo Acaraú, Ceará.

The primary climatic characteristic of olive cultivation in Peru is the coastal desert environment with moderate temperatures, minimal precipitation, and high atmospheric water content during the winter season. This report presents a comprehensive study on water and carbon fluxes in a drip-irrigated olive orchard in Pisco Province, Peru, addressing the current lack of information on olive physiology and water management under these environmental conditions. The eddy covariance system installed in September 2019 showed an average ET of 2.18 ± 0.38 mm d−1, with seasonal variation. Drip irrigation was set at 60 m3 ha−1 d−1 during the growing season and reduced to half that amount in the winter. The study suggests that using deficit irrigation based on affordable dendrometry sensors could reduce water use by close to 30% while potentially preserving biomass gain and fruit yields. This could help improve water management in olive cultivation in coastal Peru.

Azadirachta indica (indian neem) is an exotic species that presents high adaptability to different edaphoclimatic conditions, being employed for several uses, mainly wood for energy purposes. use of its wood for energy purposes. In this context, the aim of this research was to evaluate the physicochemical and energetic characteristics of charcoal from wood in two diametric classes: class 1 (8,59 – 10,50 cm) and class 2 (4,78 – 6,07 cm). 10 trees from the indian neem species were randomly sampled (Azadirachta indica), five individuals for each diametric class, with different ages and taken cutting disk to 0 (basis) 25, 50, 75 and 100% from the commercial level, of which the volume of wood with bark, without bark, the percentage volume of bark and dry mass of wood were calculated. Diametrically opposed wedges were used to determine the basic density of the wooden disks. The remaining wedges of the disks were applied for carbonization, evaluation of yields and physical and energetic characteristics of the produced charcoal. The test of Test t of Students (p ≤ 0,05) was employee in the analysis and assessment of the results. Diametric class 1 showed a higher mean basic density (0,57 g cm-3 ) than the mean value of class 2 (0,47 g cm-3 ). Diametric class 2 had the highest levels of bark (20,94%). The charcoal yield was higher in class 1 (35.36%). The Azadirachta indica Showed good potential for the production of charcoal, which could reduce the anthropic pressure on the native species intended for this purpose. [ABSTRACT FROM AUTHOR]

There is a great need to identify interactions among silvopastoral systems and microclimatic indicators that describe the effect of trees compared to conventional pasture systems without trees. The objective of this study was to evaluate thermal conditions in a silvopastoral system and a pasture area exposed to full sunlight in the eastern Amazon, Brazil. The silvopastoral system was composed of the forest tree species Bertholletia excelsa H.B.K., Dipteryx odorata (Aubl.) Willd, and Khaya grandifoliola C.DC.. During the monitoring period, a forest inventory was carried out that included 30 trees from each species for which thermal profiles were created using a high-precision thermographic camera. Near-infrared thermography showed a positive and direct correlation with dendrometric variables. Silvopastoral systems with K. grandifoliola reduced the heat profile the most compared to conditions in a pasture fully exposed to sunlight, which demonstrates the ecosystem service provided by trees for thermal regulation in these systems. The microclimatic conditions explain the greater presence of bovines in the silvopastoral system as they were most likely in search of the thermal comfort provided by the trees during the period of the highest daytime temperatures. The silvopastoral system benefits the caloric balance and thermal comfort of pasture animals. [ABSTRACT FROM AUTHOR]

The complexity in the management of field tools for recording dasometric information has led to the use of allometric equations that save time, work, and costs allowing the estimation of variables that are difficult to record, such as total height (TH). The objective of this research was to develop an allometric equation for the species Alnus acuminata in order to calculate TH from the diameter at breast height (DBH). At the Obonuco-AGROSAVIA Research Center in Pasto (Nariño), dasometric information was recorded for 75 months for 200 even-aged trees. Four models were evaluated: linear, polynomial, Mixed linear (random effect per tree age), and Mixed linear (random effect per tree). For the selection of the best model, the criteria were used with the lowest values ​​of Akaike (AIC) and Bayesian (BIC). The information was analyzed using the "Nonlinear Mixed-Effects Models" package, R software. The results revealed that A. acuminata had an 81% survival; the TH average was 7.4 ± 1.3 m; and the average DBH was 9.51 ± 2.23cm. The average annual increase of DBH was 1.5 cm year-1, and the TH was 1.18 m∙ per year-1. The mixed linear model confirmed the assumptions of normality, independence, and homogeneity of variances in addition of having good criteria in its predictive performance and efficiency through the equation TH=2.07+0.35*DBH+0.95*Age. This research contributes to the management of native species of the high tropics by designing an equation for the first vegetative growth phases of A. acuminata in high mountain agroecological zones.

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Ciencias Agricolas is the property of University of Narino, Faculty of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Various edaphoclimatic factors influence mango productivity (dendrometry, flowering and fruiting). The objective of the study was to analyze the edaphoclimatic factors that influence the productivity of 3 mango varieties (Keitt, Ataúlfo and Manila) in the Papaloapan Basin in Veracruz, Mexico. Dendrometric measurements were carried out on trees of 3 mango varieties in 15 orchards (n = 5 orchards per variety) and the values of 33 edaphoclimatic variables were acquired using geographic information systems; a comparison analysis was carried out with the dendrometric and edaphoclimatic variables. The Manila variety stood out in dendrometric terms as a response to ideal edaphoclimatic conditions for its physiological development. However, the 3 varieties are developed under unique edaphoclimatic values to which they are already adapted, with Keitt and Manila having the highest productivity. [ABSTRACT FROM AUTHOR]

We present a data set resulting from the first round of a national monitoring program of forest reserves. It contains 9538 permanent plots, distributed across 111 study sites in mainland France (including Corsica). Notably focusing on dead wood measurement, this protocol has primarily been applied in strict forest reserves and special nature reserves (sensu Bollmann & Braunisch 2013), with 68% (6494) of the plots being currently located in strict forest reserves (unmanaged) and 24.7% (2363 plots) in forests unmanaged for at least 50 years. Sites cover a large variety of ecological conditions, from lowland to subalpine forests, but with an underrepresentation of Mediterranean forests (Table 1). The protocol assesses all the stages of a tree's life cycle, from seedling to decomposed lying dead wood. On each plot, a combination of three sampling techniques was used: (1) fixed‐area inventory for regeneration, standing dead trees, living trees, and coarse woody debris (CWD) with diameter over 30 cm; (2) transect lines for CWD with diameter <30 cm; and (3) fixed‐angle plot method for living trees with diameter at breast height (DBH) >30 cm (using a relascopic angle of 3%). Measurements include exact tree location (azimuth, distance), species, diameter(s), tree‐related microhabitats, decay stage and bark cover, and seedling cover. With ongoing climate change, the program network can also provide important information to monitor changes in forest ecosystems. It can also be used as forest management monitoring or conservation status assessment. These data are freely available for noncommercial scientific use (Creative Commons Attribution 4.0 CC BY SA 4.0) with attribution, and this paper must be cited if this material is reused. [ABSTRACT FROM AUTHOR]

The present study aims to show the effects of dendrometric and orographic factors on the natural regeneration of Aleppo pine (Pinus halepensis Mill.) in the Saharan Atlas, particularly the Senalba Chergui massif (Eastern Senalba mountain range) in Algeria, for its important forest area occupied by Aleppo pine in semi-aridregions. The sampling adopted is stratified and subjective; stratified sampling makes it possible to obtain representative stations for the various existing ecological situations, we divided our study area into 04 homogeneous stations according to the appearance of vegetation, the slope exposure and the type of the soil; and for every station, temporary observation plots are installed through subjective sampling, this method is used to study heterogeneous ecological environments; we installed in our study stations seventy (70) temporary plots, and the plot is a circular sampling unit that covers an area of 400 m2 . In each plot, dendrometric variables were measured: diameter at breast height, total tree height, dominant height, average density per hectare, basal area per hectare, the age of stands, and cumulative surface of crown cover; and a phytoecological survey was carried out to determine the environmental parameters, such as altitude, slope, exposure and lithology. We used the principal component analysis (PCA) to identify the homogeneous sample plots (compared to the regeneration), descriptive statistics, and the Analysis of variance (ANOVA). The number of seedlings per square meter varies between 0 and 0.23, and there are several factors affecting these results,mainly: Crown cover, density, basal area, age of stands and slope exposure. [ABSTRACT FROM AUTHOR]

Simple Summary: Black-tufted marmosets (Callithrix penicillata) regularly exploit exudates by gouging the bark from trees with their specialized teeth. Determining preferred tree species to exploit exudates is important for forest management aimed at maintaining urban populations of marmosets. We investigated the trees used by black-tufted marmosets to obtain exudates in urban forest fragments in the Brazilian Cerrado, with a view to better understanding the relationship between marmosets and obtaining exudates. We characterized the tree species, the dendrometry, and the characteristics of the holes made by the marmosets. Based on these data, we proposed a gouging effort index (ChiSI). We found 108 individuals that were exploited by black-tufted marmosets belonged to 16 species of 10 tree families. Eleven new tree species used by black-tufted marmosets for exudates were identified. Exudate exploration was predominantly of medium intensity, with round holes concentrated in the canopy. The species Tapirira guianensis and Croton urucarana were preferred. Therefore, T. guianensis and C. urucarana should be considered the most important tree species for black-tufted marmosets that live in urban forests in the Cerrado. Knowledge of the pattern of exploitation of trees can help us understand the relationship between marmosets and plants, especially in declining forests, such as those in the Brazilian Cerrado. Black-tufted marmosets (Callithrix penicillata) regularly exploit exudates by gouging the bark of trees with their specialized teeth. Determining preferred tree species to exploit exudates is important for forest management aimed at maintaining an essential food source for urban marmosets. We characterized the tree species, dendrometry, and the characteristics of the holes made by marmosets to obtain exudates. Based on these data, we proposed a gouging effort index (Chiseling Suitability Index for Marmosets, ChiSI). We identified 16 species belonging to 10 families of trees with gouging marks made by marmosets. Eleven new tree species used by black-tufted marmosets for exudates were identified in urban forests in the Cerrado. Exudate exploration was predominantly of medium intensity, with round holes concentrated in the canopy. The species Tapirira guianensis and Croton urucarana were preferred. The ChiSI was characterized by a narrow range for both T. guianensis and C. urucarana. Despite the flexibility of obtaining exudates, the black-tufted marmosets concentrate their exploitation to only a few tree species. The T. guianensis and C. urucarana tree species should be considered the most important species for management plans and the preservation of black-tufted marmosets that live in urban forests in the Cerrado. [ABSTRACT FROM AUTHOR]

Landslides represent an important and possibly very dangerous natural hazard. Dendrogeomorphic methods can provide unique data on the behaviour of landslides in the past by studying the tree-ring series of disturbed trees. Knowledge about past landslide activity in the flysch part of the Outer Western Carpathians is generally very scarce or missing. The past activity of selected landslides (possibly endangering neighbouring settlements) was studied using data from 106 increment cores from 53 disturbed individuals of Picea abies (L.) H. Karst. to assess its past spatiotemporal activity. In total, six certain event years and 13 probable events were detected during the period between 1927 and 2017. Certain events always occurred in groups of the two following events, suggesting the inertia of landslide movements after the initial triggering. The spatiotemporal reconstruction revealed a distinctly increased activity of movements in the zone of the main scarp and particularly in the landslide front, which could possibly endanger human infrastructure during its significant reactivation. However, the reconstruction performed suggests general landslide inactivity since 1997, when the last high-magnitude reactivation occurred.

This work focused on the evaluation of four essential aspects of biomass based on peach trees grown in the Andean region of Ecuador. In one case, mathematical models have been developed allowing the amount of lignocellulosic material to be quantified from easily measurable parameters such as crown diameter, stem diameter and plant height. Performing quick surveys, these equations led to obtain the amount of biomass contained in a plot. In a second case, elemental analysis of biomass was performed in order to determine the amount of CO2 captured from the atmosphere through photosynthesis during its growth, and thus to assess the contribution of these plots in mitigating climate change. Afterwards, residual biomass from pruning was quantified and a proximal analysis was carried out. This allowed us to assess the suitability of these materials as solid biofuels. The models obtained to determine the volume of the branches gave determination coefficients of 0.98. Models to quantify the biomass of the whole plant had r2 of 70%. The density of the dried material was 0.92 g/cm3, obtaining an average dry wood weight of 44.8 kg per plant. This represents a content of 1682 moles of captured CO2 of a developed plant crop (3 years). The average ash on dry wood was 3%, fixed carbon content on dry wood was 7%, and volatile content dry wood was 78%. The moisture content of waste materials after pruning was 45.96%. The drying time in store for humidity below 10%, suitable for burning boiler, was 15 days. The higher heating value of peach wood was 18.92MJ/kg.

Abstract Commercial height of the tree is a key variable for estimating the wood stock in tropical forests managed for timber production purposes. Most available measurement devices suffer limitations in this type of forest, promoting low precision measurements with high variation errors. The laser meter device appears as a viable alternative, as in addition to using trigonometric principles, it is not necessary that the device is close to the eyes of the meter to carry out the measurement. The device can be used to measure commercial height of trees on flat or sloping terrain, at different distances from the tree. However, there are no studies evaluating the precision of this device. The objective of this study was to determine the precision of the laser meter method for estimating the commercial height of trees, as compared to the actual measurement in a tropical forest in the Brazilian Amazon. Measurements were made on 300 trees with commercial height between 7 and 14 m. Actual commercial heights were measured with graduated ruler. Applied tests were paired t test, graphical analysis of residuals and calculations of bias statistics, mean absolute deviation, standard deviation of differences, and coefficient of determination (R2). Paired t test indicated that the mean of the heights measured by the laser meter is statistically equal to that of the graduated ruler. Measurements with laser meter did not show bias and had mean error of 0.0745. The standard deviation of the differences indicated dispersion of errors of 0.97, equal to that shown in the graduated rule. Laser meter presents an alternative method for estimating the commercial height of trees in tropical forest in the Brazilian Amazon. There was no tendency to underestimate or overestimate the commercial heights of trees. Use of the laser meter is potentially of use for measuring the commercial height of trees in tropical forests.

Landslides represent an important and possibly very dangerous natural hazard. Dendrogeomorphic methods can provide unique data on the behaviour of landslides in the past by studying the tree-ring series of disturbed trees. Knowledge about past landslide activity in the flysch part of the Outer Western Carpathians is generally very scarce or missing. The past activity of selected landslides (possibly endangering neighbouring settlements) was studied using data from 106 increment cores from 53 disturbed individuals of Picea abies (L.) H. Karst. to assess their past spatiotemporal activity. In total, six certain event years and 13 probable events were detected during the period between 1927 and 2017. Certain events always occurred in groups of the two following events, suggesting the inertia of landslide movements after the initial triggering. The spatiotemporal reconstruction revealed a distinctly increased activity of movements in the zone of the main scarp and particularly in the landslide front, which could possibly endanger human infrastructure during its significant reactivation. However, the reconstruction performed suggests general landslide inactivity since 1997, when the last high-magnitude reactivation occurred. [ABSTRACT FROM AUTHOR]

ABSTRACT Allometric models defining the relationship between stem diameter and total tree height in the Amazon basin are important because they refine the estimates of tree carbon stocks and flow in the region. This study tests different allometric models to estimate the total tree height from the stem diameter in an ecotone zone between ombrophilous and seasonal forests in the Brazilian state of Roraima, in northern Amazonia. Stem diameter and total height were measured directly in 65 recently fallen trees (live or dead). Linear and nonlinear regressions were tested to represent the D:H relation in this specific ecotone zone. Criteria for model selection were the standard error of the estimate (Syx) and the adjusted coefficient of determination (R²adj), complemented by the Akaike Information Criterion (AIC). Analysis of residuals of the most parsimonious nonlinear models showed a tendency to overestimate the total tree height for trees in the 20-40 cm diameter range. Application of our best fitted model (Michaelis-Menten) indicated that previously published general equations for the tropics that use diameter as the independent variable can either overestimate tree height in the study area by 10-29% (Weibull models) or underestimate it by 8% (climate-based models). We concluded that our site-specific model can be used in the ecotone forests studied in Roraima because it realistically reflects the local biometric relationships between stem diameter and total tree height. Studies need to be expanded in peripheral areas of northern Amazonia in order to reduce uncertainties in biomass and carbon estimates that use the tree height as a variable in general models.

Copyright of Ecologia Mediterranea is the property of Ecologia Mediterranea and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of new tools based on remote sensing data in agriculture contributes to cost reduction, increased production, and greater profitability. Airborne LiDAR (Light Detection and Ranging) data show a significant potential for geometrically characterizing tree plantations. This study aims to develop a methodology to extract walnut (Juglans regia L.) crowns under leafless conditions using airborne LiDAR data. An original approach based on the alpha-shape algorithm, identification of local maxima, and k-means algorithms is developed to extract the crowns of walnut trees in a plot located in Viver (Eastern Spain) with 192 trees. In addition, stem diameter and volume, crown diameter, total height, and crown height were estimated from cloud metrics and other 2D parameters such as crown area, and diameter derived from LiDAR data. A correct identification was made of 178 trees (92.7%). For structure parameters, the most accurate results were obtained for crown diameter, stem diameter, and stem volume with coefficient of determination values (R2) equal to 0.95, 0.87 and 0.83; and RMSE values of 0.43 m (5.70%), 0.02 m (9.35%) and 0.016 m3 (21.55%), respectively. The models that gave the lowest R2 values were 0.69 for total height and 0.70 for crown height, with RMSE values of 0.84 m (12.4%) and 0.83 m (14.5%), respectively. A suitable definition of the central and lower parts of tree canopies was observed. Results of this study generate valuable information, which can be applied for improving the management of walnut plantations.

Commercial height of the tree is a key variable for estimating the wood stock in tropical forests managed for timber production purposes. Most available measurement devices suffer limitations in this type of forest, promoting low precision measurements with high variation errors. The laser meter device appears as a viable alternative, as in addition to using trigonometric principles, it is not necessary that the device is close to the eyes of the meter to carry out the measurement. The device can be used to measure commercial height of trees on flat or sloping terrain, at different distances from the tree. However, there are no studies evaluating the precision of this device. The objective of this study was to determine the precision of the laser meter method for estimating the commercial height of trees, as compared to the actual measurement in a tropical forest in the Brazilian Amazon. Measurements were made on 300 trees with commercial height between 7 and 14 m. Actual commercial heights were measured with graduated ruler. Applied tests were paired t test, graphical analysis of residuals and calculations of bias statistics, mean absolute deviation, standard deviation of differences, and coefficient of determination (R2). Paired t test indicated that the mean of the heights measured by the laser meter is statistically equal to that of the graduated ruler. Measurements with laser meter did not show bias and had mean error of 0.0745. The standard deviation of the differences indicated dispersion of errors of 0.97, equal to that shown in the graduated rule. Laser meter presents an alternative method for estimating the commercial height of trees in tropical forest in the Brazilian Amazon. There was no tendency to underestimate or overestimate the commercial heights of trees. Use of the laser meter is potentially of use for measuring the commercial height of trees in tropical forests. [ABSTRACT FROM AUTHOR]

We combined measurements of tree growth and carbon dioxide exchange to investigate the effects of selective logging on the Aboveground Live Biomass (AGLB) of a tropical rain forest in the Amazon. Most of the measurements began at least 10 months before logging and continued at least 36 months after logging. The logging removed ∼15% of the trees with Diameter at Breast Height (DBH) greater than 35 cm, which resulted in an instantaneous 10% reduction in AGLB. Both wood production and mortality increased following logging, while Gross Primary Production (GPP) was unchanged. The ratio of wood production to GPP (the wood Carbon Use Efficiency or wood CUE) more than doubled following logging. Small trees (10 cm < DBH < 35 cm) accounted for most of the enhanced wood production. Medium trees (35 cm < DBH < 55 cm) that were within 30 m of canopy gaps created by the logging also showed increased growth. The patterns of enhanced growth are most consistent with logging-induced increases in light availability. The AGLB continued to decline over the study, as mortality outpaced wood production. Wood CUE and mortality remained elevated throughout the 3 years of postlogging measurements. The future trajectory of AGLB and the forest's carbon balance are uncertain, and will depend on how long it takes for heterotrophic respiration, mortality, and CUE to return to prelogging levels.

Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of annual mean) in Santarém, though this variability showed no significant relation with precipitation among years. Initial estimates of the C balance of live wood including recruitment and mortality as well as growth suggests that live wood biomass is at near steady-state in Manaus, but accumulating at about 1.5 Mg C ha(-1) at the other two sites. The causes of C imbalance in living wood pools in Santarém and Rio Branco sites are unknown, but may be related to previous disturbance at these sites. Based on size distribution and growth rate differences in the three sites, we predict that trees in the Manaus forest have greater mean age (approximately 240 years) than those of the other two forests (approximately 140 years).

Diameter fluctuations of branches, shoots, or fruits are related to plant transpiration and water potential. In the past, several models have related dendrometric variables and evapotranspiration on a daily scale. However, trunk–branch shrinkage occurs only between dawn and midday, while evapotranspiration occurs most of the day from sunrise to sunset. Previous models have failed to incorporate this key fact. The objective of the present study was to assess the relationship of hourly daily shrinkage (HDS) between dawn and the next 4 h to the hourly reference evapotranspiration (EToh) of the same period in walnut trees and pomegranate plants under different irrigation regimes. Our data show that the relationship between EToh and HDS is much better than several previous models that included maximum daily shrinkage (MDS) and reference evapotranspiration (ETo). The novel slope analysis of the relationship between HDS versus time used here corresponds to the velocity at which the HDS occurs, which depends on the ETo intensity at that moment. This new method of analyzing this type of data calls for a revision of these models and sets a new baseline for future analysis.

The new method for evaluation of tree populations presented here is based on a correlation analysis within a set of dendrometric variables. The correlation analysis is carried out for each population separately. The method evaluates differences between resulting correlation matrices. These distances can be used by hierarchical cluster analysis (unweighted pair-group average) or by ordination analysis (non-metric multidimensional scaling - NMS). Test data were obtained in 10 research plots in the area of Medvědí Mt., Šumava National Park. Plots are located in Norway spruce [Picea abies (Linnaeus) H. Karsten] climax forests. The results enable ecological interpretation of both classification and NMS. The populations (subpopulations) differ in their origin (spontaneous succession or partial planting) and environmental conditions (extreme environment near the mountain summit versus water-logged soils). These differences were reflected in results of the classification and ordination of the spruce (sub)populations.

The objective of this work was to evaluate the adjustment of taper models with and without bark for clone GG100 in a commercial plantation located in the southern state of Tocantins. Twenty-five trees were cubed in which data were fitted five taper models, three of which were the most used in Brazil and two representing the poorly tested models in the country. In the evaluation of the taper models, the following statistical criteria were adopted: standard error of the estimate, adjusted coefficient of determination, mean deviation, sum of squares of the relative residue, percentage residue, and analysis of the distribution of residues. It was concluded by an exponent-shape type model to describe the trunk profile with and without bark of individual clones of clone GG100. [ABSTRACT FROM AUTHOR]

Global warming has become international concern, culminating with the ratification of the Kyoto Protocol which includes definitions and objectives of the sustainable development mechanisms and features that make it easier for the industrialized countries to jointly compensate for their polluting greenhouse gas emissions. São Paulo is a state known for its industrial development and distortion of the green areas in ecosystems associated with the Atlantic Forest biome. In the middle of this chaotic scenery lies the Billings reservoir in São Bernardo do Campo-SP, its forest ecosystem is the provider of numerous environmental services. Quantification of biomass (Bwood) of stems resulted in estimates of 113.73.ha-1, which corresponded to 56.87 tC.ha-1. The estimates obtained for the forest ecosystem of the reservoir can be used as a reference for the establishment of forest restoration projects under the under the sustainable development mechanism established the Kyoto Protocol. [ABSTRACT FROM AUTHOR]

The sustainable agriculture of forest plantations demands the permanent monitoring of the quantity of processed wood, thus becoming difficult to monitor large planted areas by using only manual procedures. Therefore, in this research artificial neural networks (RNA) of multilayer perceptrons, were modeled to estimate the spatial of wood volume in a Eucalyptus-sp plantation located in the state of Mato Grosso del Sur in the Central-West region of Brazil. As input variables in the RNA spectral bands, the textures of the bands obtained with Gray Level Co-occurrence Matrices and vegetation index were used, which were derived from digital satellite image Spot 6. The resulting RNA with the best performance presented accuracy of 93.32% and coefficient of determination of 0.9761. However, this network presented a mean square error of 16.32% (RMSE de 7.85 m³ha-1), but with a unbiased distribution of the residuals. So, the model showed to be suitable to monitor the amount of wood in large areas without overestimating or underestimating the prediction. Compared with different machine learning methods using the same variables, the built network seems to have a higher precision and accuracy. Even in the neuronal models using only spectral bands and vegetation indexes, a better performance was evidenced, showing that the textures contribute in the improvement of predictions. [ABSTRACT FROM AUTHOR]

ABSTRACT Buttresses and other natural structures modify the shape of stems in Amazonia and change the diameter at breast height (DBH) measured at 1.3 m at ground level. The lack of adequate measurement techniques affects negatively forest dynamics analyses and biomass estimating. The study evaluated an indirect method of measuring diameters in trees with DBH > 40 cm using principles of digital photogrammetry. The results obtained with two cameras (smartphone and Sony) were compared with direct measurements using diametric tape and a ladder. The technique is adequate to measure the diameters of trees with measurement point above 2 m of ground, with a confidence interval of ±1cm. The use of photogrammetry as a supplementary tool to the diametric tape (IC ± 0.24 cm) is recommended, helping to measure trees with diameter above the reach of the technician in forest inventories.

Abstract A dendrometric and energetic characterisation of Tamarix africana L. was carried out in this study. This is an indigenous plant species in the Mediterranean area, and it can survive in semi-arid areas with saline soils and occasional floods. Owing to these characteristics, this species is a good candidate for its use in the restoration of several environments, such as the marshes. This opens up the possibility of improving the management of biomass, which can be used for obtaining economic benefits from its energetic use. For the stems, biomass volume functions were determined from their diameter and length with r2 of 0.96. For the whole plant, biomass volume functions were determined from the diameter of the projected area in the soil and the height of the plant with r2 of 0.95. For energetic characterisation, the density, higher heat value, and the composition of this wood were measured in terms of following elements: carbon, nitrogen, hydrogen, sulphur and chlorine, volatiles and ash. The determination of its composition in C allows us to evaluate the CO 2 fixed by the plant during its growth. The average catchment was estimated to be 2.58 kg/plant. Highlights • Dendrometric analysis has been carried out of Tamarix africana. • It has become the elemental, proximate and structural analysis. • Models for predicting higher calorific have been evaluated. [ABSTRACT FROM AUTHOR]

The objective of this work was to perform a complete evaluation of using biomass from pruning residues of ficus trees ( Ficus benjamina ), widely grown as ornamental plants in cities in Ecuador. Due to their great capacity for propagation and fast growth, these trees need frequent pruning and so generate a large amount of ligneous residues. A dendrometric analysis of the plant was performed to calculate the quantity of residues generated from easily measurable variables, such as crown diameter and plant height. The models obtained gave a coefficient of determination of R 2 = 0.75. Pruning residues included mixtures of wood and leaves. The percentages of leaf and woody biomass were measured and a calorific analysis, elemental analysis, proximal analysis and structural analysis of the different mix proportions were carried out. Nitrogen content was acceptable for use as biofuel. Ash content in the wood is 5%, but the inclusion of leaves in the sample increases the ash content up to 11% when the leaf percentage is greater than 50%. About 10 kg of material, on average, was obtained from each tree. The mean calorific value of these residues was 19 MJ kg −1 and was influenced by the volatile content and lignin. [ABSTRACT FROM AUTHOR]

The new method for evaluation of tree populations presented here is based on a correlation analysis within a set of dendrometric variables. The correlation analysis is carried out for each population separately. The method evaluates differences between resulting correlation matrices. These distances can be used by hierarchical cluster analysis (unweighted pair-group average) or by ordination analysis (non-metric multidimensional scaling - NMS). Test data were obtained in 10 research plots in the area of Medvědí Mt., Šumava National Park. Plots are located in Norway spruce [Picea abies (Linnaeus) H. Karsten] climax forests. The results enable ecological interpretation of both classification and NMS. The populations (subpopulations) differ in their origin (spontaneous succession or partial planting) and environmental conditions (extreme environment near the mountain summit versus water-logged soils). These differences were reflected in results of the classification and ordination of the spruce (sub)populations. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to assess the accuracy of different hypsometers: Blume Leiss [BL], Suunto [ST], Relascope [RL], Vertex [VX], Haga [HG] and TruPulse [TP] for height measuring. Data were collected from telescopic poles (A, B and C with 4.45, 10.75 and 7.8 m, respectively) using thirteen different observers. The height was analyzed by analysis of variance in randomized block and tested by Tukey test. The t test (99% significance) was also used to compare equality between real total height of each telescopic pole and heights measured with hypsometers. The results showed that only the RL was different from other hypsometers when all were analyzed together. The hypsometers VX, HG and BL showed the best results in all analyzes, presenting a high semblance to the real height. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare geometric parameters of olive trees (tree height, crown base height, crown diameters, crown area), using LiDAR data of different densities: 0.5, 3.5 and 9 points m-2. Two strategies were proposed and verified with a focus on raster and raw data analysis. Statistical tests have shown, that for the tree height and crown base height estimation, the choice of strategy was irrelevant, but denser LiDAR data provided more accurate results. The raster analysis strategy applied for sparse and dense LiDAR datasets allowed crown shape to be determined with a similar accuracy which means raster data are useful for estimating other indirect tree parameters. The quality of results was independent from the tree size. [ABSTRACT FROM AUTHOR]

Slope movements are a common natural hazard. That is why considerable funds are spent annually to limit their effects or to research their prevention. This study evaluates dendrometric approaches as a fast and low-cost alternative to classical methods of slope movement mechanism analysis. A total of 1688 trees growing on the Mazák landslide in the Moravskoslezské Beskydy Mts. and 100 reference trees growing out of the landslide area were analysed. The Mazák landslide is approximately 400 m in length and presents varied morphological features (scarps, rotated blocks, scree slopes, shallow landslide areas, etc.). The slope and direction of stem inclination was recorded for each tree. The results were categorized into four distinct landforms (scarp with outcrops of bedrock, scree slope, front of partial landslide block, plateau of partial landslide block) and were then compared with parameters for the reference trees. The general model of tree tilting for the landslide area was verified and partially confirmed. Trees growing on the plateau of rotated blocks are predominantly oriented upslope; trees growing on scree slopes of shallow movement and creep are predominantly oriented downslope. Trees growing on rocky scars do not differ significantly from the reference trees. Trees growing from fronts of rotated blocks are oriented both upslope and downslope. From these results, several recommendations regarding dendrometric evidence of slope movement mechanisms are presented: (i) all trees growing on the landslide are to be analysed; (ii) old trees maintain stem tilt intensities and directions for long periods, but young trees are more sensitive to ground movements; (iii) tree root depth influences root sensitivity to movements of various depths; (iv) the general shape of a stem can denote specific mechanisms of slope movement and (v) comparisons with reference trees should always be conducted to exclude potential non-geomorphic effects on tree stem tilt. [ABSTRACT FROM AUTHOR]

The use of residual biomass from fruit tree pruning requires the creation of logistic schedules based on the knowledge of the amount of residues available in each plot. Remote sensing is shown as an important tool to quantify these resources. The objective of this research was to estimate the amount of pruned materials from olive trees ( Olea europea L.) using dendrometric parameters obtained from field measurements and airborne LiDAR (Light Detection and Ranging) data. Pruning, mean crown diameter, stem diameter, total height and crown height were measured in the field for a set of 25 trees in Viver, Central East Spain. Airborne discrete LiDAR data were acquired and used to extract the crown area of the trees and metrics based on the height distribution of the LiDAR points. Two types of regression models to predict the amount of pruned material were computed, firstly using dendrometic measurements obtained in the field, and then based on tree metrics derived from LiDAR data. The dendrometric variables obtained from field measurements were also compared with the metrics obtained from LiDAR data. High values of R 2 were obtained for the models, ranging from 0.86 to 0.89. The regression models derived from LiDAR data used the area as an explanatory variable. The results of this study show the potential of airborne LiDAR data to predict pruning residues in olive trees. [ABSTRACT FROM AUTHOR]

The methodologies which are considered the most promising for irrigation management are those based on the analysis of the water status of the plants themselves. This justifies the study and improvement of indicators based on automatic and continuous measures to enable real-time monitoring data, as indices from sap flow, dendrometry and leaf turgor pressure techniques. The aim of this paper is to analyze such methodologies in order to demonstrate their principles, advantages and challenges. In conclusion, the methodologies analyzed still have many technological advances and challenges before being presented to the final user. The future research should work these tools for elaboration of technical indexes that allow their simplification, on the instrumental point of view, and the interpretation of their results. [ABSTRACT FROM AUTHOR]