scholarly journals Relationship risk-return of native species sawn wood in the state of Pará, Brazil 2003-2007

CERNE ◽  
2010 ◽  
Vol 16 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Rommel Noce ◽  
Márcio Lopes da Silva ◽  
Lourival Marin Mendes ◽  
Agostinho Lopes de Souza ◽  
José Luiz Pereira de Rezende ◽  
...  
Keyword(s):  
Growth Rate ◽  
Native Species ◽  
The Other ◽  
Native Forest ◽  
Forest Species ◽  
Risk Return ◽  
Graphic Analysis ◽  
Relationship Of ◽  
Coherent Relationship ◽  
Geometric Growth

This study characterized the risk-return relationship of sawn wood of different native forest species of the Amazonian area. Specifically, it was determined the risk-return relationship of Ipê, Jatobá, Maçaranduba, Angelim Pedra, Angelim Vermelho and Cumaru boards, in 2003-2007 period. The Geometric Growth Rate of prices of the m³ of boards of each species was admitted as return estimative and the variation coefficient as indicative of risk; the estimated values were plotted in dispersion graphics allowing graphic analysis. It was noticed that their prices float, relatively, in the same way and that Jatobá stands out in attractiveness terms, considering the whole period while the other species presented a coherent relationship among themselves i.e., higher returns associated with high risks. Angelim Vermelho and Maçaranduba stood out for the attractiveness, in an annual perspective.

scholarly journals Performance of Five Native Atlantic Forest Species Planted in Containers of Different Size for Restoring Degraded Areas in Minas Gerais

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 937
Author(s):  
Vicente Toledo Machado de Morais Junior ◽  
Laércio Antônio Gonçalves Jacovine ◽  
Klisman Oliveira ◽  
Thaynara Pereira Albuquerque ◽  
Isabella Salgado Faustino ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Native Species ◽  
Forest Restoration ◽  
Species Level ◽  
Forest Recovery ◽  
Plant Performance ◽  
Native Forest ◽  
Forest Species ◽  
Hymenaea Courbaril ◽  
Plastic Bags

Forest restoration in Brazil has gained relevance in the country’s environmental agenda, due to the need for forest recovery of large liabilities of existing forests and participation in several international vegetation restoration agreements. However, forest restoration management faces challenges, it being necessary to create a database of species-level performances to increase the success of these projects. The objective was to evaluate the survival and growth of five Atlantic Forest native species (Anadenanthera macrocarpa; Ceiba speciosa; Cytharexyllum myrianthum; Hymenaea courbaril; and Peltophorum dubium) in plastic bags (1177 cm3) and tubes (180 cm3). Ninety seedlings (18 of each species) were planted per container. Plant performance in the field consisted of evaluating the increase in the diameter and height of seedlings of the native forest species. Diameter at soil level (DSL) and plant height (H) were measured at 42 months after transplanting, and the monthly periodic increments (MPI) of the DSL and H were calculated. Plant survival (SV) of seedlings was affected by the type of container, registering the highest SV rates in those planted in plastic bags. Cytharexyllum myrianthum and H. courbaril presented high SV rates in tubes. The growth rate of the species at 42 months differed according to the containers tested. Cytharexyllum myrianthum presented the lowest SV rates (16.7–27.8%), regardless of the container used in this experiment. Ceiba speciosa was sensitive to the reduction in size of the container, showing low SV in tubes (27%) compared with plastic bags (61%); i.e., this species did not tolerate conditions with root growth restriction. Anadenathera macrocarpa and H. courbaril showed no differences in SV, regardless of the container used. The results assist the production of native species of the Atlantic Forest, reinforcing the need to understand performances in the field at the species level.

scholarly journals Population Relationship of Three Forestry Species, Aegiphila ferruginea, Oreopanax ecuadorensis, Vallea stipularis; in the Leonan de Llucud Forest, Chambo Canton, Chimborazo Province

2021 ◽  
Author(s):  
O. Guadalupe Arias ◽  
K. Chávez Inca ◽  
J. Rodríguez Guerra
Keyword(s):  
Similarity Index ◽  
Evergreen Forest ◽  
Native Forest ◽  
Forest Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Palabras Clave ◽  
Close Relationship ◽  
Relationship Of ◽  
Near Threatened

The present investigation aims to relate the population of three native forest species of the Andean region of Ecuador: Oreopanax ecuadorensis Seem, Aegiphila ferruginea, and Vallea stipularis in the Leonan de Llucud high montane evergreen forest located in the Chambo canton. Through the inventory and observation of the distribution of these three species in three altitudinal floors, establishing ten plots within which circular subplots of five meters radius were placed, taking the species under study as the center, all individuals with diameter at breast height greater than or equal to 7 cm were selected. For each altitudinal floor, the Importance Value Index, the Simpson and Shannon-Weaver Biodiversity Indices, and the Sorensen Similarity Index were calculated. The results presented below are the result of the data obtained in the field and its interpretation. V. stipularis and O. ecuadorensis Seem show a close relationship, while A. ferruginea has a low population due to the exploitation it is subjected to in this forest, thus asserting the presence of this species in the red book at a near-threatened level. Keywords: evergreen forest, native forest species, altitudinal floors. Resumen La presente investigación pretende relacionar la población de tres especies forestales nativas de la región andina del Ecuador Oreopanax ecuadorensis Seem, Aegiphila ferruginea y Vallea stipularis en el bosque siempre verde montano alto Leonan de Llucud ubicado en el cantón Chambo; mediante la inventariación y observación de la distribución de estas tres especies en tres pisos altitudinales, estableciendo diez parcelas dentro de las cuales se colocaron subparcelas circulares de cinco metros de radio tomando como centro a las especies en estudio, se seleccionaron todos los individuos con Diámetro a la Altura del Pecho, mayor o igual a 7 cm. Para cada piso altitudinal se calculó el Índice de Valor de Importancia, los Índices de biodiversidad de Simpson y Shannon – Weaver y el Índice de similitud de Sorensen. Los resultados que a continuación presentamos son resultado de los datos obtenidos en campo y su interpretación. Teniendo que V. stipularis y O. ecuadorensis Seem presentan gran afinidad; en tanto que A. ferruginea presenta una baja poblacional debido a la explotación a la cual es sometida en este bosque, aseverándose así la presencia de esta especie en el libro rojo en nivel de casi amenazado. Palabras clave: bosque siempre verde, especies forestales nativas, pisos altitudinales.

scholarly journals Establishment and Competition of Native Forest Species in Araucaria angustifolia Stands with Different Coverage Degrees in Misiones, Argentina

2020 ◽  
Vol 3 (1) ◽  
pp. 67
Author(s):  
Flavia Y. Olguin ◽  
Ana P. Moretti ◽  
Martín A. Pinazo ◽  
Fermín Gortari ◽  
Marcelo Gauna ◽  
...  
Keyword(s):  
Native Species ◽  
Native Forest ◽  
Araucaria Angustifolia ◽  
Forest Species ◽  
Wood Production ◽  
Mixed Plantations

Mixed plantations with native species are a viable tool to meet current wood production [...]

scholarly journals Zootechnical performance and interaction between Penaeus schmitti Burkenroad, 1936 and Penaeus vannamei Boone, 1931 reared under laboratory conditions

2020 ◽  
Vol 48 (3) ◽  
pp. 342-356
Author(s):  
Rafael Fernandez de Alaiza Garcia Madrigal ◽  
Ubiratã de Assis Teixeira da Silva ◽  
Eduardo Luis Cupertino Ballester
Keyword(s):  
Growth Rate ◽  
Natural Environment ◽  
Native Species ◽  
The Other ◽  
Natural Food ◽  
Penaeus Vannamei ◽  
Mixed Treatment ◽  
Final Weight ◽  
Negative Effect ◽  
The Mean

To compare the zootechnical performance of the Brazilian native shrimp Penaeus schmitti and the exotic shrimp Penaeus vannamei, juveniles were grown under controlled conditions. Both species were simultaneously cultivated (monoculture) in separate 70 L plastic tanks at two different densities: 30 and 50 ind m-2. Also, in the other two treatments, both species were cultivated together (mixed), with and without feeding, at 30 ind m-2. During the experiment, P. vannamei generally showed a greater interest in food and voracity than P. schmitti. At harvest, for both stocking densities of monoculture treatments, the mean growth rate observed for P. vannamei was 1.0 g week-1, while P. schmitti achieved only 0.1 g week-1. The mean final weight was 10.4 ± 2.0 g; 10.7 ± 2.1 g for P. vannamei and 2.8 ± 0.3 g; 3.2 ± 0.3 g for P. schmitti, for respective densities of 50 and 30 ind m-2. In the mixed treatment with feeding, while P. vannamei reached 11.9 ± 1.4 g, P. schmitti reached only 2.6 ± 0.4 g in the same tank. The observed differences were 3.7 and 3.4 higher in favor of P. vannamei in the monoculture treatment, and up 4.5 times higher in the mixed treatment. Under strict fasting conditions, both species practiced predation/cannibalism among themselves. The results reflected the zootechnical advantages of P. vannamei, but also corroborated the negative effect that high densities and lack of natural food can exert over native species. The potential for P. schmitti cultivation and the possible impact of the escape of P. vannamei into the natural environment is discussed.

Growth and Performance of Agriculture Sector in India

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Naresh Singla ◽  
Mamandeep Kaur
Keyword(s):  
Growth Rate ◽  
Capital Formation ◽  
The Other ◽  
Agricultural Credit ◽  
Agricultural Growth ◽  
Indian Economy ◽  
Agriculture Sector ◽  
Food Grain ◽  
And Performance ◽  
Agricultural Labourers

The growth of agriculture and allied sectors is critical for the Indian economy as about 49 percent of the population is directly or indirectly dependent on agriculture. During the last decade and so, the agriculture sector has undergone profound changes resulting in sharp deceleration in its growth. The study has attempted to analyze growth and performance of the agriculture sector in India since 1980-81 and tries to comprehend some of the factors responsible for the deceleration in growth. The study has shown that agriculture sector has been able to show tremendous improvement in expansion of area and production of food grain and non-food grain crops. However, there are so many underlying factors responsible for slowdown of the agricultural growth. Some of the factors identified include: Increase in area under non-agriculture uses, excessive dependence on rain fed farming, increase in number of agricultural labourers, reducing size of the operation holdings, over use of agri-inputs, inequity in the distribution of agriculture credit along with sharp deceleration in public gross capital formation in agriculture etc. The study pointed in order to achieve higher growth rate, there is a need to enhance the gross capital formation in agriculture sector particularly on irrigation so that more area can be brought under assured irrigation. Bringing equity in distribution of agricultural credit coupled with judicious and need-based agricultural inputs are some of the other recommendations drawn based upon the study.

A polycentric growth model of gallium arsenide epitaxial layers from the gas phase with simultaneous diffusion, adsorption and chemical reaction

1988 ◽  
Vol 53 (12) ◽  
pp. 2995-3013
Author(s):  
Emerich Erdös ◽  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma
Keyword(s):  
Growth Rate ◽  
Gallium Arsenide ◽  
Epitaxial Growth ◽  
Gas Phase ◽  
Surface Reaction ◽  
Quantitative Description ◽  
The Other ◽  
Rate Equations ◽  
Impact Interaction ◽  
Partial Pressures

For a quantitative description of the epitaxial growth rate of gallium arsenide, two models are proposed including two rate controlling steps, namely the diffusion of components in the gas phase and the surface reaction. In the models considered, the surface reaction involves a reaction triple - or quadruple centre. In both models three mechanisms are considered which differ one from the other by different adsorption - and impact interaction of reacting particles. In every of the six cases, the pertinent rate equations were derived, and the models have been confronted with the experimentally found dependences of the growth rate on partial pressures of components in the feed. The results are discussed with regard to the plausibility of individual mechanisms and of both models, and also with respect to their applicability and the direction of further investigations.

scholarly journals Limitation of current probe design for oligo-cross-FISH, exemplified by chromosome evolution studies in duckweeds

Chromosoma ◽  
2021 ◽  
Vol 130 (1) ◽  
pp. 15-25
Author(s):  
Phuong T. N. Hoang ◽  
Jean-Marie Rouillard ◽  
Jiří Macas ◽  
Ivona Kubalová ◽  
Veit Schubert ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chromosome Number ◽  
Chromosome Evolution ◽  
Sequence Similarity ◽  
Flowering Plants ◽  
The Other ◽  
Probe Design ◽  
Congeneric Species ◽  
Specific Design ◽  
Spirodela Polyrhiza

AbstractDuckweeds represent a small, free-floating aquatic family (Lemnaceae) of the monocot order Alismatales with the fastest growth rate among flowering plants. They comprise five genera (Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia) varying in genome size and chromosome number. Spirodela polyrhiza had the first sequenced duckweed genome. Cytogenetic maps are available for both species of the genus Spirodela (S. polyrhiza and S. intermedia). However, elucidation of chromosome homeology and evolutionary chromosome rearrangements by cross-FISH using Spirodela BAC probes to species of other duckweed genera has not been successful so far. We investigated the potential of chromosome-specific oligo-FISH probes to address these topics. We designed oligo-FISH probes specific for one S. intermedia and one S. polyrhiza chromosome (Fig. 1a). Our results show that these oligo-probes cross-hybridize with the homeologous regions of the other congeneric species, but are not suitable to uncover chromosomal homeology across duckweeds genera. This is most likely due to too low sequence similarity between the investigated genera and/or too low probe density on the target genomes. Finally, we suggest genus-specific design of oligo-probes to elucidate chromosome evolution across duckweed genera.

scholarly journals The Consequences of Budding versus Binary Fission on Adaptation and Aging in Primitive Multicellularity

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 661
Author(s):  
Hanna Isaksson ◽  
Peter L. Conlin ◽  
Ben Kerr ◽  
William C. Ratcliff ◽  
Eric Libby
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cellular Senescence ◽  
Carrying Capacity ◽  
The Other ◽  
Binary Fission ◽  
Fundamental Aspect ◽  
Accumulated Damage ◽  
Cell Age ◽  
Multicellular Organisms

Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms.

scholarly journals On Newcomb's method of investigating periodicities and its application to Brückner's weather cycle

1914 ◽  
Vol 90 (619) ◽  
pp. 349-355
Keyword(s):  
Thermal Radiation ◽  
The Other ◽  
New Method ◽  
Critical Examination ◽  
Numerical Work ◽  
Average Value ◽  
Other Hand ◽  
Relationship Of ◽  
The Relationship ◽  
Great Simplicity

During the last few years of his life Prof. Simon Newcomb was keenly interested in the problem of periodicities, and devised a new method for their investigation. This method is explained, and to some extent applied, in a paper entitled "A Search for Fluctuations in the Sun's Thermal Radiation through their Influence on Terrestrial Temperature." The importance of the question justifies a critical examination of the relationship of the older methods to that of Newcomb, and though I do not agree with his contention that his process gives us more than can be obtained from Fourier's analysis, it has the advantage of great simplicity in its numerical work, and should prove useful in a certain, though I am afraid, very limited field. Let f ( t ) represent a function of a variable which we may take to be the time, and let the average value of the function be zero. Newcomb examines the sum of the series f ( t 1 ) f ( t 1 + τ) + f ( t 2 ) f ( t 2 + τ) + f ( t 3 ) f ( t 3 + τ) + ..., where t 1 , t 2 , etc., are definite values of the variable which are taken to lie at equal distances from each other. If the function be periodic so as to repeat itself after an interval τ, the products are all squares and each term is positive. If, on the other hand, the periodic time be 2τ, each product will be negative and the sum itself therefore negative. It is easy to see that if τ be varied continuously the sum of the series passes through maxima and minima, and the maxima will indicated the periodic time, or any of its multiples.

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