Allometry for estimating aboveground tree biomass in tropical and subtropical eucalypt woodlands: towards general predictive equations

2005 ◽  
Vol 53 (7) ◽  
pp. 607 ◽  
Author(s):  
Richard J. Williams ◽  
Ayalsew Zerihun ◽  
Kelvin D. Montagu ◽  
Madonna Hoffman ◽  
Lindsay B. Hutley ◽  
...  
Keyword(s):  
General Equation ◽  
Tree Height ◽  
Information Criterion ◽  
Single Species ◽  
Carbon Accounting ◽  
Cross Sectional ◽  
Predictive Equations ◽  
Site Specific ◽  
Individual Trees ◽  
Leave One Out

A fundamental tool in carbon accounting is tree-based allometry, whereby easily measured variables can be used to estimate aboveground biomass (AGB). To explore the potential of general allometry we combined raw datasets from 14 different woodland species, mainly eucalypts, from 11 sites across the Northern Territory, Queensland and New South Wales. Access to the raw data allowed two predictor variables, tree diameter (at 1.3-m height; D) and tree height (H), to be used singly or in various combinations to produce eight candidate models. Following natural log (ln) transformation, the data, consisting of 220 individual trees, were re-analysed in two steps: first as 20 species–site-specific AGB equations and, second, as a single general AGB equation. For each of the eight models, a comparison of the species–site-specific with the general equations was made with the Akaike information criterion (AIC). Further model evaluation was undertaken by a leave-one-out cross-validation technique. For each of the model forms, the species–site-specific equations performed better than the general equation. However, the best performing general equation, ln(AGB) = –2.0596 + 2.1561 ln(D) + 0.1362 (ln(H))2, was only marginally inferior to the species–site-specific equations. For the best general equation, back-transformed predicted v. observed values (on a linear scale) were highly concordant, with a slope of 0.99. The only major deviation from this relationship was due to seven large, hollow trees (more than 35% loss of cross-sectional stem area at 1.3 m) at a single species–site combination. Our best-performing general model exhibited remarkable stability across species and sites, when compared with the species–site equations. We conclude that there is encouraging evidence that general predictive equations can be developed across sites and species for Australia’s woodlands. This simplifies the conversion of long-term inventory measurements into AGB estimates and allows more resources to be focused on the extension of such inventories.

Estimation of crown form for six conifer species of northern California

1990 ◽  
Vol 20 (8) ◽  
pp. 1137-1142 ◽  
Author(s):  
Greg S. Biging ◽  
Lee C. Wensel
Keyword(s):  
Sierra Nevada ◽  
Tree Height ◽  
Wildlife Habitat ◽  
Conifer Species ◽  
Damage Potential ◽  
Cross Sectional ◽  
Individual Tree ◽  
Crown Volume ◽  
Using Data ◽  
Individual Trees

Geometric models are presented for the prediction of crown volume and width at any height in the crown of six conifer species in the Sierra Nevada. Crown volume is defined as the geometric space occupied by the crown and is allometrically related to the diameter, height, and crown ratio of individual trees. Crown diameter is derived from crown volume, tree height, and crown ratio. The crown volumes and associated measures can be used to compute indices of individual tree competition such as those used in the CACTOS (California Conifer Timber Output Simulator) system or to compute other measures such as wildlife habitat suitability or insect damage potential. Estimation equations are developed by regression using data collected on crowns of 593 felled trees. The equations use dbh, total height, and crown ratio to estimate total crown volume, crown volume above a specified height, and cumulative crown cross sectional area at a specified height.

Site-Specific Low Angle Plasma FIB Milling for Cross-Sectional Electrical Characterization

2019 ◽  
Author(s):  
Chuan Zhang ◽  
Jane Y. Li ◽  
John Aguada ◽  
Howard Marks
Keyword(s):  
Cross Section ◽  
Focused Ion Beam ◽  
Electrical Characteristic ◽  
Preparation Method ◽  
Ion Beam ◽  
Grazing Angle ◽  
Electrical Characterization ◽  
Sample Preparation Method ◽  
Cross Sectional ◽  
Site Specific

Abstract This paper introduces a novel sample preparation method using plasma focused ion-beam (pFIB) milling at low grazing angle. Efficient and high precision preparation of site-specific cross-sectional samples with minimal alternation of device parameters can be achieved with this method. It offers the capability of acquiring a range of electrical characteristic signals from specific sites on the cross-section of devices, including imaging of junctions, Fins in the FinFETs and electrical probing of interconnect metal traces.

scholarly journals Evaluating the Impacts of Speed Limit Increases on Rural Two-Lane Highways Using Quantile Regression

2021 ◽  
pp. 036119812110197
Author(s):  
Md Shakir Mahmud ◽  
Nischal Gupta ◽  
Babak Safaei ◽  
Hisham Jashami ◽  
Timothy J. Gates ◽  
...  
Keyword(s):  
Quantile Regression ◽  
Spillover Effects ◽  
Speed Limit ◽  
Passenger Cars ◽  
Cross Sectional ◽  
Speed Limits ◽  
Site Specific ◽  
Rural Highways ◽  
Speed Selection ◽  
Numerous Site

Understanding speed selection behavior of drivers following speed limit increases is critically important. To date, the literature has largely focused on freeways and the effects of speed limit changes on two-lane highways remains under researched. Prior research has generally focused on changes to mean speeds, although the speeds of both the highest and lowest drivers are also of great interest. This study investigates trends in free-flow travel speeds following 2017 legislation that increased the posted speed limit from 55 to 65 mph on 943 mi of rural highways in Michigan. Speed data were collected for over 46,000 drivers at 67 increase segments where speed limit increased and 28 control segments where speed limits remained unchanged, before and during each of the two successive years following the speed limit increases. Site-specific traffic, geometric, and cross-sectional information was also collected. Impacts of the speed limit increases on the 15th, 50th, and 85th percentile speeds were evaluated using quantile regression. Separate analyses were conducted for passenger cars and heavy vehicles. Locations where the speed limits were raised experienced increases in travel speeds ranging from 2.8 to 4.8 mph. The control sites experienced marginal changes in speeds, which suggests that any spillover effects of the higher speed limits have been limited. Significant differences were observed across the quantiles with respect to the effects of the speed limit increases, as well as numerous site-specific variables of interest. The results provide important insights about the nature of driver speed selection and the impacts of speed limit increases.

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

TRIPLOID APPLE VARIETIES OF SUMMER RIPENING SELECTION VNIISPK ON CLONAL ROOTSTOCK 54-118

1970 ◽  
pp. 34-36
Author(s):  
А. M. Galasheva ◽  
Е. N. Sedov
Keyword(s):  
Tree Height ◽  
Projection Area ◽  
Cross Sectional ◽  
Crown Width ◽  
Crown Volume ◽  
The World ◽  
Apple Cultivars ◽  
Crown Projection Area ◽  
Academy Of Sciences ◽  
First Time

For the first time in the world and in Russia, Academician of the Russian Academy of Sciences, breeder Evgeny Nikolaevich Sedov created a series of triploid apple cultivars from intervalent crosses 2х × 4х. Triploid apple cultivars bear fruit more regularly, have higher self-fruitfulness and have fruits of high marketability. The article presents data on the study of triploid apple cultivars of the summer ripening period of the VNIISPK breeding - Augusta, Daryona, Maslovskoye, Osipovskoye, Zhilinskoye, Spasskoye and Yablochny Spas as well as the control Canadian cultivar Melba on a semi-dwarf clone rootstock 54-118. Maslovskoye, Zhilinskoye, Spasskoye and Yablochny Spas have immunity to scab. The orchard was planted in 2014, the garden planting scheme was 5 x 2 m. The indicators of the growth force (tree height, crown width and stem diameter) and the yield of trees were studied. At the age of six, the trees of triploid cultivars reached a height of 2.2 m (Maslovskoye) to 3.0 m (Yablochny Spas) on a semi-dwarf rootstock 54-118. The highest indicators of crown volume (3.3-5.3 m3), crown projection area (4.2-5.3 m2) and the cross-sectional area of the stem (46.5-52.8 cm2) were in Osipovskoye, Yablochny Spas, Zhilinskoye and Spasskoye. The highest yield in an average of three years was given by triploid scab-immune apple cultivars on a semi-dwarf rootstock 54-118: Maslovskoye, Zhilinskoye, Spasskoye and Yablochny Spas.

scholarly journals Nonlinear modeling growth body weight of Mangalarga Marchador horses

2017 ◽  
Vol 47 (4) ◽  
Author(s):  
Felipe Amorim Caetano Souza ◽  
Tales Jesus Fernandes ◽  
Raquel Silva de Moura ◽  
Sarah Laguna Conceição Meirelles ◽  
Rafaela Aparecida Ribeiro ◽  
...  
Keyword(s):  
Body Weight ◽  
Linear Models ◽  
Nonlinear Modeling ◽  
Growth Curves ◽  
Live Weight ◽  
Information Criterion ◽  
Coefficient Of Determination ◽  
Cross Sectional ◽  
Adult Body Weight ◽  
The Cross

ABSTRACT: The analysis of the growth and development of various species has been done using the growth curves of the specific animal based on non-linear models. The objective of the current study was to evaluate the fit of the Brody, Gompertz, Logistic and von Bertalanffy models to the cross-sectional data of the live weight of the MangalargaMarchador horses to identify the best model and make accurate predictions regarding the growth and maturity in the males and females of this breed. The study involved recording the weight of 214 horses, of which 94 were males and 120 were non-pregnant females, between 6 and 153 months of age. The parameters of the model were estimated by employing the method of least squares, using the iteratively regularized Gauss-Newton method and the R software package. Comparison of the models was done based on the following criteria: coefficient of determination (R²); Residual Standard Deviation (RSD); corrected Akaike Information Criterion (AICc). The estimated weight of the adult horses by the models ranged between 431kg and 439kg for males and between 416kg and 420kg for females. The growth curves were studied using the cross-sectional data collection method. For males the von Bertalanffymodel was found to be the most effective in expressing growth, while in females the Brody model was more suitable. The MangalargaMarchador females achieve adult body weight earlier than the males.

scholarly journals HEIGHT-DIAMETER MODELS FOR THREE SUBTROPICAL FOREST TYPES IN SOUTHERN BRAZIL

2015 ◽  
Vol 39 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Alexander Christian Vibrans ◽  
Paolo Moser ◽  
Laio Zimermann Oliveira ◽  
João Paulo de Maçaneiro
Keyword(s):  
Deciduous Forest ◽  
Tree Height ◽  
Information Criterion ◽  
Confidence Bands ◽  
Natural Forests ◽  
Forest Types ◽  
Model Quality ◽  
Statistical Parameters ◽  
Santa Catarina ◽  
Ombrophilous Forest

Total tree height (h) is often difficult to measure in natural forests. Regression models based on easily accessed variables like DBH (d) can be an alternative, since their assumptions are validated. The aims of this study are to: (i) calibrate specific and generic h-d models for three forest types (Seasonal Deciduous Forest, DEC; Mixed Ombrophilous Forest, MIX; and Dense Rainforest, DEN) in Santa Catarina state testing the regression assumptions and evaluating model quality; (ii) verify different h-d relationship between forest types. The dataset (1,766 measured tree h and 3,150 estimated h) was collected by Santa Catarina Forest and Floristic Inventory (IFFSC) in 418 systematically located sample plots. Models were calibrated for two datasets, one containing hypsometer measurements, the other h estimations made by field crews. Specific models were calibrated for species with at least 30 sampled trees. Residual normality, randomness and heteroskedasticity were evaluated by analytical methods. Confidence bands were generated by the Working-Hotelling method; z test for means was applied to compare models based on the two databases. The statistical parameters such as corrected Akaike Information Criterion provided evidences that logarithmic models were better adjusted to the data. Both datasets were statistically different for DEN and MIX. Differences in h-d relationships were found between forest types. The use of calibrated h-d models is an alternative for studying the relationships between these variables and to assess vertical structure patterns of forest communities, when h measurements are not feasible, although, for situations that more accurate h values are needed, they will not always provide reliable predictions.

scholarly journals Aboveground Biomass Stockpile of Trees in Vallanadu Blackbuck Sanctuary, Peninsular India

2021 ◽  
Vol 16 (3) ◽  
pp. 755-763
Author(s):  
M. Nagaraj M. Nagaraj ◽  
M. Udayakumar
Keyword(s):  
Aboveground Biomass ◽  
Tamil Nadu ◽  
Basal Area ◽  
Single Species ◽  
Forest Tree ◽  
Annual Rainfall ◽  
Dry Forests ◽  
Peninsular India ◽  
Tree Inventory ◽  
Individual Trees

A forest tree inventory study was conducted in Vallanadu Black buck sanctuary, Tuticorin. The current study was conducted to assess tree density, species richness, basal area (BA) and aboveground biomass (AGB) stockpile. The study area has been classified as Southern Thorn Forest (SFT). One hundred square plots (total area 1 ha), each 10m × 10m (100 m2 each) laid randomly across study area. All live trees with ≥5 cm diameter at breast height (DBH) measured at 137 cm above the ground. As the whole, 1335 individual trees ≥5cm DBH recorded. A total number of 18 species recorded from 14 genera and 11 families in study area. The family Mimosaceae has maximum number of species (7 species) followed by Rhamnaceae (2 species), while 9 families had just single species’ each. The total basal area recorded was 22.046 m2 ha-1, while, the mean wood density (WD) of trees estimated as 0.70±0.093 g cm-3. Total amount of 50.065 Mg ha-1 present in STF. The contribution of different species in terms of total AGB varied significantly. Commiphora berryi stocked 45.13% (22.588 Mg ha-1) of AGB followed by A. planifrons (23.31%, 11.669 Mg ha-1), A. mellifera (7.233%, 3.621 Mg ha-1), whereas remaining 15 species collectively stocked 24.327% (12.187 Mg ha-1) AGB. The STF had a large number of trees compared to some dry forests within Tamil Nadu. Southern Thorn Forest endowed with a moderate number of trees species. Aboveground biomass stockpile of trees is comparable with the range recorded from Indian dry forests. The study area experiences lesser mean annual rainfall and >6 months dry season. Further, endowed with short-bole and smaller leaved trees, hence stocked a relatively lesser AGB in trees.

scholarly journals Distribution of the initial site of infection in diabetic foot and associated initiating etiologies

2021 ◽  
Vol 8 (11) ◽  
pp. 3320
Author(s):  
Joe Mathew ◽  
Rajeev S.
Keyword(s):  
Diabetic Foot ◽  
The Other ◽  
Common Condition ◽  
Cross Sectional ◽  
Site Specific ◽  
Loss Of Life ◽  
Factors Influencing ◽  
Male Patients ◽  
Nail Infection

Background: Diabetic foot is a very common condition responsible for a major bulk of surgical admissions and out-patient visits. Lack of awareness of many factors influencing the incidence of this disease complex has led to loss of life, limb and quality of life. The site-specific incidence of initial site and initiating factor has not been studied in diabetic foot.Methods: A study has been done over a period of one and a half years which looked into the distribution of initial site of infection in diabetic foot and associated initiating etiologies. The study was cross sectional. History, general inspection of foot, dermatological, neuropathic and vascular assessments were done, in addition to making careful notes about the site and cause of infection.Results:60.7% of patients were >60 years old, 55.3% were male patients. 63.3% of patients had diabetes for more than 10 years. In 29.3% the initial site of infection was the big toe, 22% in the ball of foot, 18% in the other 4 toes together, 14.7% in the interdigital spaces, 10.7% in the heel and 5.3% in the mid foot. In most of the cases the etiology is multifactorial, trauma in 56%, musculoskeletal deformities in 47.3%, callosities in 41.3%, cracks and fissures in 16.7%, fungal infection in 7.3%, nail infection in 6%, no initiating introduction of infection identified in 10.7%.Conclusions: Awareness of and thus particular stress being place on identification of specific site and cause of infection should help in care of the foot in diabetics.

scholarly journals Cross-sectional study using primary care and cancer registration data to investigate patients with cancer presenting with non-specific symptoms

BMJ Open ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. e033008 ◽  
Author(s):  
Clare Pearson ◽  
Veronique Poirier ◽  
Karen Fitzgerald ◽  
Greg Rubin ◽  
Willie Hamilton
Keyword(s):  
Primary Care ◽  
Cancer Diagnosis ◽  
Cross Sectional Study ◽  
Cancer Registration ◽  
Sectional Study ◽  
Cross Sectional ◽  
Site Specific ◽  
Registration Data ◽  
Referral Criteria ◽  
Specific Symptoms

IntroductionPatients presenting to primary care with site-specific alarm symptoms can be referred onto urgent suspected cancer pathways, whereas those with non-specific symptoms currently have no dedicated referral routes leading to delays in cancer diagnosis and poorer outcomes. Pilot Multidisciplinary Diagnostic Centres (MDCs) provide a referral route for such patients in England.ObjectivesThis work aimed to use linked primary care and cancer registration data to describe diagnostic pathways for patients similar to those being referred into MDCs and compare them to patients presenting with more specific symptoms.MethodsThis cross-sectional study linked primary care data from the National Cancer Diagnosis Audit (NCDA) to national cancer registration and Route to Diagnosis records. Patient symptoms recorded in the NCDA were used to allocate patients to one of two groups - those presenting with symptoms mirroring referral criteria of MDCs (non-specific but concerning symptoms (NSCS)) and those with at least one site-specific alarm symptom (non-NSCS). Descriptive analyses compared the two groups and regression analysis by group investigated associations with long primary care intervals (PCIs).ResultsPatients with NSCS were more likely to be diagnosed at later stage (32% stage 4, compared with 21% in non-NSCS) and via an emergency presentation (34% vs 16%). These patients also had more multiple pre-referral general practitioner consultations (59% vs 43%) and primary care-led diagnostics (blood tests: 57% vs 35%). Patients with NSCS had higher odds of having longer PCIs (adjusted OR: 1.24 (1.11 to 1.36)). Patients with lung and urological cancers also had higher odds of longer PCIs overall and in both groups.ConclusionsDifferences in the diagnostic pathway show that patients with symptoms mirroring the MDC referral criteria could benefit from a new referral pathway.

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