Adjusting for the effect of missing or dominated plants in progeny and clonal trials of Eucalyptus

2020 ◽  
Vol 50 (4) ◽  
pp. 438-443
Author(s):  
Getúlio Caixeta Ferreira ◽  
Aurélio Mendes Aguiar ◽  
Bruno Marco de Lima ◽  
José Luis Lima ◽  
Gabriel Dehon Sampaio Peçanha Rezende ◽  
...  
Keyword(s):  
Plant Performance ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Progeny Trial ◽  
Clonal Trial ◽  
Selection Of

The objective of this paper was to estimate the effect of either missing or dominated plants (those that developed poorly) in experiments evaluating progenies or clones of Eucalyptus. Additionally, it was to investigate whether the use of the area available per plant is a suitable strategy to mitigate the effect of missing plants. Lastly, it was to evaluate whether missing or dominated plants in the experiments affected the association between plant performance in a progeny trial (PT) and their respective clones in a clonal trial (CT). Five 5-year-old PTs and four 3-year-old CTs were used. The recorded trait was diameter at breast height (DBH). The area available per plant was used to carry out the adjustment, taking into consideration the absence of neighboring plants as well as dominated plants. It was found that with the level of missing plants below 20% in experiments, the adjustment using the area available per plant did not improve the efficiency of the selection of either PTs or CTs. The strategy of considering not only missing plants but also dominated plants is not beneficial for the adjustment.

scholarly journals Estimation of Genetic Parameters and Wood Yield Selection Index in a Clonal Trial of Korean Pine (Pinus koraiensis) in Northeastern China

2021 ◽  
Vol 13 (8) ◽  
pp. 4167
Author(s):  
David Kombi Kaviriri ◽  
Huan-Zhen Liu ◽  
Xi-Yang Zhao
Keyword(s):  
Selection Index ◽  
Tree Height ◽  
Stem Volume ◽  
Korean Pine ◽  
Branch Number ◽  
Basal Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stem Straightness ◽  
Clonal Trial

In order to determine suitable traits for selecting high-wood-yield Korean pine materials, eleven morphological characteristics (tree height, basal diameter, diameter at breast height, diameter at 3 meter height, stem straightness degree, crown breadth, crown height, branch angle, branch number per node, bark thickness, and stem volume) were investigated in a 38-year-old Korean pine clonal trial at Naozhi orchard. A statistical approach combining variance and regression analysis was used to extract appropriate traits for selecting elite clones. Results of variance analysis showed significant difference in variance sources in most of the traits, except for the stem straightness degree, which had a p-value of 0.94. Moderate to high coefficients of variation and clonal repeatability ranged from 10.73% to 35.45% and from 0.06% to 0.78%, respectively. Strong significant correlations on the phenotypic and genotypic levels were observed between the straightness traits and tree volume, but crown breadth was weakly correlated to the volume. Four principal components retaining up to 80% of the total variation were extracted, and stem volume, basal diameter, diameter at breast height, diameter at 3 meter height, tree height, and crown height displayed high correlation to these components (r ranged from 0.76 to 0.98). Based on the Type III sum of squares, tree height, diameter at breast height, and branch number showed significant information to explain the clonal variability based on stem volume. Using the extracted characteristics as the selection index, six clones (PK105, PK59, PK104, PK36, PK28, and K101) displayed the highest Qi values, with a selection rate of 5% corresponding to the genetic gain of 42.96% in stem volume. This study provides beneficial information for the selection of multiple traits for genetically improved genotypes of Korean pine.

scholarly journals Nesting habitat selection of Mediterranean raptors in managed pinewoods: searching for common patterns to derive conservation recommendations

2013 ◽  
Vol 24 (2) ◽  
pp. 138-151 ◽  
Author(s):  
RAFAEL BARRIENTOS ◽  
BERNARDO ARROYO
Keyword(s):  
Habitat Selection ◽  
Tree Cover ◽  
Nesting Habitat ◽  
Random Factor ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Heterogeneous Habitats ◽  
Large Trees ◽  
Generalised Linear Mixed Model ◽  
Selection Of

SummaryInvestigating habitat selection is a key step in improving the population conservation of forest species in areas managed for different purposes, from timber harvesting to hunting or recreation. Because economic resources allocated to conservation are limited, studies that assess cost-effective strategies are necessary, especially when concerning non-threatened species. We studied nest-site habitat selection of two raptor communities (totalling 245 nests from the five most common species: Short-Toed Eagle Circaetus gallicus, Goshawk Accipiter gentilis, Sparrowhawk A. nisus, Common Buzzard Buteo buteo and Booted Eagle Aquila pennata) in two pinewoods in central Spain separated by 200 km. Using a Generalised Linear Mixed Model for each species and with locality as a random factor, we obtained five models of habitat selection. We highlighted the common nesting patterns in order to facilitate an integrated management of forestry in relation to raptor nesting habitat selection. The most important variable for all species, with the exception of the Sparrowhawk was the nest-tree diameter at breast height, with raptors preferentially selecting nesting trees of large width. Tall trees and a high amount of tree cover around the nesting tree were also important habitat features for several species. Our results suggest that pinewoods should retain unharvested patches with moderate tree coverage (30–70%) containing not only several large trees (diameter at breast height > 40 cm) but also small ones. At the landscape level, open forests and heterogeneous habitats are preferred. These forest patches should be dispersed throughout the landscape.

scholarly journals Development of a height estimation method based on the diameter at breast height of Prosopis alba Grisebach selected populations from a progeny trial in Santiago del Estero, Argentina

Agriscientia ◽  
2019 ◽  
Vol 36 (2) ◽  
pp. 89-95
Author(s):  
Javier Eduardo Frassoni ◽  
Marisa Jacqueline Joseau
Keyword(s):  
Estimation Method ◽  
Estimation Model ◽  
Height Estimation ◽  
Diameter At Breast Height ◽  
Prosopis Alba ◽  
Breast Height ◽  
Progeny Trial ◽  
Reduced Height ◽  
Field Activity ◽  
Linear Regressions

The main objective of this work was to develop a height estimation method of Prosopis alba based on the diameter at breast height (DBH) of populations with superior characteristics selected through a progeny trial located in the INTA Experimental Agricultural Station, Province of Santiago del Estero, Argentina. The progeny trial was established in 2008 and consists of 3,671 individuals (202 families). The registered variables were DBH and total height (TH) of 123 individuals, taken at random from the three blocks that make up the trial. Linear regressions were performed to develop the model that best fits height estimation with all the sampled individuals (AI model) and, also using the data of 7 individuals - the three trees of greater diameter, the three of smaller diameter and an individual of intermediate diameter-, called the reduced height estimation model (RHEM model). AI model and RHEM model were satisfactory to estimate height of the trees based on their DBH in the trial of progenies in Santiago del Estero. However, the RHEM model offers an important saving of time and effort, simplifying the field activity.

scholarly journals Seemingly Unrelated Mixed-Effects Biomass Models for Black Locust in West Poland

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 380
Author(s):  
Karol Bronisz ◽  
Szymon Bijak ◽  
Rafał Wojtan ◽  
Robert Tomusiak ◽  
Agnieszka Bronisz ◽  
...  
Keyword(s):  
Black Locust ◽  
Random Effect ◽  
Tree Height ◽  
Cross Model ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dependent Variables ◽  
Dry Biomass ◽  
Biomass Components ◽  
Independent Variable

Information about tree biomass is important not only in the assessment of wood resources but also in the process of preparing forest management plans, as well as for estimating carbon stocks and their flow in forest ecosystems. The study aimed to develop empirical models for determining the dry mass of the aboveground parts of black locust trees and their components (stem, branches, and leaves). The research was carried out based on data collected in 13 stands (a total of 38 sample trees) of black locust located in western Poland. The model system was developed based on multivariate mixed-effect models using two approaches. In the first approach, biomass components and tree height were defined as dependent variables, while diameter at breast height was used as an independent variable. In the second approach, biomass components and diameter at breast height were dependent variables and tree height was defined as the independent variable. Both approaches enable the fixed-effect and cross-model random-effect prediction of aboveground dry biomass components of black locust. Cross-model random-effect prediction was obtained using additional measurements of two extreme trees, defined as trees characterized by the smallest and largest diameter at breast height in sample plot. This type of prediction is more precise (root mean square error for stem dry biomass for both approaches equals 77.603 and 188.139, respectively) than that of fixed-effects prediction (root mean square error for stem dry biomass for both approaches equals 238.716 and 206.933, respectively). The use of height as an independent variable increases the possibility of the practical application of the proposed solutions using remote data sources.

Calotropis procera (apple of sodom).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Sand Dunes ◽  
Fibre Production ◽  
Calotropis Procera ◽  
Desert Grassland ◽  
Evergreen Shrub ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Shifting Sand ◽  
Pale Green

Abstract C. procera is a fleshy evergreen shrub about 1.8-5.5 m tall, with a diameter at breast height of 15-20 cm (von Maydell, 1986). The flowers are pale green to white, with purple tips. A fibre obtained from the bark is used to make lines, bow-strings and twine; it can also be spun with cotton, or used to stuff mattresses and pillows. The fibre is strengthened by soaking in water for 1-2 days, but extensive soaking may reduce durability. The wood is of small dimensions and is too light for most uses. C. procera produces a distinctive white latex, which contains cardiotoxins and hydrocarbons with many medicinal and pesticidal properties. C. procera has been widely planted for fibre production and has become naturalized on the American and Australian continents. It is often abundant on degraded areas and is an indicator of overgrazing. C. procera is a widespread pioneer in semi-desert grassland and bushland (e.g. in Africa), and it also colonizes shifting sand-dunes such as in Rajasthan, India. However, due to its properties as a pioneer, there is a risk that this species may become a weed. More research is needed on C. procera to maximize production and marketing of its many potential products.

Yield and diametric structure of Dimorphandra mollis Benth

2021 ◽  
Vol 51 ◽  
Author(s):  
Karoline Paulino Costa ◽  
Messulan Rodrigues Meira ◽  
Silma Leite Rocha ◽  
Thaíse Ohana Moura Fernandes ◽  
Ernane Ronie Martins
Keyword(s):  
Environmental Protection ◽  
Social Economic ◽  
Average Diameter ◽  
Brazilian Savanna ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Minas Gerais State ◽  
Environmental Protection Area ◽  
Protection Area ◽  
Environmental Importance

ABSTRACT Dimorphandra mollis is native to the Brazilian Savanna and has social, economic and environmental importance. This study aimed to evaluate the yield and diametric distribution of Dimorphandra mollis Benth. in the Pandeiros River Environmental Protection Area, in Bonito de Minas, Minas Gerais state, Brazil. Five areas were assessed, totaling five hectares (50 plots of 1,000 m2). The total number of plants, yield per plant (2018, 2019 and 2020) and diameter at breast height were recorded, considering all trees from the plots in diametric classes. The average diameter at breast height of all plants was 6.05 ± 3.07 cm, and that of the plants that produced in at least one of the evaluated years was 7.46 ± 3.15 cm. The diametric distribution showed classes with no individuals, indicating imbalance, as well as a trend to inverted “J” shape. The maximum annual yield was 8.08 kg ha-1 of dry fruits (2019), the minimum 0.42 kg ha-1 (2018), and the average 2.74 kg ha-1, with biennial characteristic.

scholarly journals PRESERVATION OF PRIMARY FOREST CHARACTERISTICS DESPITE FRAGMENTATION AND ISOLATION IN A FOREST REMNANT FROM VIÇOSA, MG, BRAZIL1

2015 ◽  
Vol 39 (6) ◽  
pp. 985-994 ◽  
Author(s):  
Markus Gastauer ◽  
Marcos Eduardo Guerra Sobral ◽  
João Augusto Alves Meira-Neto
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Tree Species ◽  
Primary Forest ◽  
Forest Patch ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Forest Remnant ◽  
Primary Forests ◽  
Biotic Resources

According to its owners, the Forest of Seu Nico (FSN) from the Viçosa municipality, Minas Gerais, Brazil, never has been logged and is therefore considered a primary forest. Nevertheless, the forest patch suffered impacts due to selective wood and non-timber extraction, fragmentation and isolation. Aim of this study was to test if the FSN, despite impacts, preserved characteristics of primary forests, which are elevated percentages of non-pioneer (>90%), animal-dispersed (>80 %), understory (>50%) and endemic species (~40%). For that, all trees with diameter at breast height equal or major than 3.2 cm within a plot of 100 x 100 m were identified. With 218 tree species found within this hectare, the FSN's species richness is outstanding for the region. The percentages of non-pioneer (92 %), animal-dispersed (85 %), understory (55 %) and endemic species (39.2 %) from the FSN fulfill the criteria proposed for primary forest. Therefore, we conclude that the FSN maintained its characteristics as a primary forest which highlights its importance for the conservation of biotic resources in the region, where similar fragments are lacking or not described yet.

scholarly journals Genetic diversity in Australian Cedar genotypes selected by mixed models

2012 ◽  
Vol 36 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Rulfe Tavares ◽  
Alexandre Pio Viana ◽  
Deborah Guerra Barroso ◽  
Antonio Teixeira do Amaral Júnior
Keyword(s):  
Genetic Diversity ◽  
Mixed Models ◽  
Forest Products ◽  
Raw Material ◽  
Morphological Data ◽  
Technical Improvement ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Toona Ciliata ◽  
Increasing Demand

The increasing demand for raw material for multiple uses of forest products and by-products has attracted the interest for fast growing species, such as the Australian Cedar (Toona ciliata), which presents high productive and economic potential. The present work aimed at estimating genetic diversity by DNA markers and morphological traits supported for the mixed models. The following traits were measured and genotypes were sampled randomly in different areas: diameter at breast height, height, cylindrical volume, diameter, distance between nodes and crown diameter. Twelve RAPD primers were used and generated a total of 91 marks, 82 of which were polymorphic. The high percentage of polymorphic markers, 90.10%, demonstrated that discrimination in this species is efficient, but it yet little studied, for this case we can find the extent of the genetic basis for the application of technical improvement. The assessment of genetic diversity by the UPGMA method using the binary and morphological data provided the expression of genetic dissimilarities among the accessions evaluated, optimizing the perception of this divergence. The use of mixed models was efficient to assess combined genetic diversity to optimize the selection of genotypes with divergent genetic values for diameter at breast height.

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