scholarly journals A PAISAGEM COMO CONDICIONADORA DE BORDAS DE FRAGMENTOS FLORESTAIS

FLORESTA ◽  
2005 ◽  
Vol 35 (1) ◽  
Author(s):  
Bethania Cristiane Herrmann ◽  
Efraim Rodrigues ◽  
André De Lima
Keyword(s):  
Species Composition ◽  
Patch Size ◽  
Nearest Neighbor ◽  
Core Area ◽  
Forest Fragments ◽  
Spatial Structures ◽  
Landscape Index ◽  
Area Index ◽  
Components Analysis ◽  
The Relationship

Fragmentos florestais diferem em sua estrutura espacial afetando a composição de espécies em suas bordas. O objetivo deste trabalho foi analisar a influência dos índices da paisagem sobre as bordas de fragmentos florestais próximos à cidade de Londrina - PR. As características estruturais dos fragmentos aqui consideradas incluem área, forma, área central e índice de área central; e as características estruturais da paisagem: área da classe, tamanho médio e coeficiente de variação do tamanho dos fragmentos de floresta, distância média até o fragmento florestal mais próximo e total de bordas de floresta. A relação entre composição de espécies, fragmentos florestais e índices de paisagem foi estudada através de Análise de Correspondência Canônica. Os índices de maior importância foram: área, forma e área central dos fragmentos. Godoy, fragmento com 2371,14 ha e inclui o Parque Estadual Mata dos Godoy, apresentou maior variação na composição de espécies quando comparado com os demais. The landscape as conditioning of edges of forest fragments Abstract Forests fragments differ in their spatial structure afecting the species composition of edges. The objective of this paper was to analyze the influence of some landscape index over sapling species composition in edges of forests fragments near Londrina - PR. The spatial structures of fragments considered in this paper involved area, shape, core area and core area index; and the spatial structures of landscape: class area, mean patch size, coefficient of variation of the size of the patch (%), mean nearest neighbor distance and total edge of forest. The relationship between sapling species composition, forests fragments and landscape index were evaluated through Principal Components Analysis. Godoy, fragment with 2371,14 ha showed more variation in the species composition when compared with other fragments.

scholarly journals Semideciduous Seasonal Forest Production of Leaves and Deciduousness in Function of the Water Balance, LAI, and NDVI

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Thomaz Correa e Castro da Costa ◽  
João Herbert Moreira Viana ◽  
Juliana Leite Ribeiro
Keyword(s):  
Water Balance ◽  
Vegetation Index ◽  
Carbon Sink ◽  
Quadratic Functions ◽  
Permanent Plots ◽  
Forest Fragments ◽  
Leaf Production ◽  
Semideciduous Forest ◽  
Area Index ◽  
The Relationship

This study investigated the relationship between leaf production, litterfall, water balance, Leaf Area Index (LAI), and Normalized Difference Vegetation Index (NDVI) in semideciduous forests. The goal was to model this phenomenon to obtain the estimates of this component as an additional compartment of the ecosystem carbon sink. The tests were conducted in eight semideciduous forest fragments. Twenty-four permanent plots were monitored monthly and LAI measurements and weighing of litterfall deposited in nets were conducted for a period of thirteen months. In this period, Landsat 5 and IRS satellite images were obtained and processed for generation of NDVI. The water balance was calculated for each day. The relationship among the variables “leaf dry weight,” “LAI,” “NDVI,” and “water balance” was verified and a regression model was built and evaluated. The deciduous phenomenon can be explained by hydric balance, and LAI and NDVI are ancillary variables. The tendency of the variables in the period of 13 months was explained by quadratic functions. The varied behavior among the monitoring sites helped to know differences in the deposition of leaves. This study showed that only the leaf component of the litterfall of a semideciduous forest in tropical climate can capture 4 to 8 Mg·ha−1·yr−1of CO2and this amount can be estimated using climate, biophysics, and vegetation index variables.

Visual Evoked-Response Correlates of Speechreading Performance in Normal-Hearing Adults

1983 ◽  
Vol 26 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Vincent J. Samar ◽  
Donald G. Sims
Keyword(s):  
Multiple Correlation Coefficient ◽  
Evoked Response ◽  
Multiple Correlation ◽  
Potential Significance ◽  
Visual Evoked Response ◽  
Latency Measure ◽  
Two Measures ◽  
Components Analysis ◽  
The Relationship ◽  
Visual Evoked

The relationship between the latency of the negative peak occurring at approximately 130 msec in the visual evoked-response (VER) and speechreading scores was investigated. A significant product-moment correlation of -.58 was obtained between the two measures, which confirmed the fundamental effect but was significantly weaker than that previously reported in the literature (-.90). Principal components analysis of the visual evoked-response waveforms revealed a previously undiscovered early VER component, statistically independent of the latency measure, which in combination with two other components predicted speechreading with a multiple correlation coefficient of S4. The potential significance of this new component for the study of individual differences in speechreading ability is discussed.

scholarly journals Optimizing Grain Yield and Water Use Efficiency Based on the Relationship between Leaf Area Index and Evapotranspiration

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Leaf Area Index ◽  
Water Use ◽  
Plant Density ◽  
Maize Yield ◽  
Area Index ◽  
Irrigation Level ◽  
Use Efficiency ◽  
The Relationship

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.

scholarly journals Spatial-Temporal Analysis of the Forest Fragments Surrounding a Conservation Unit in the Southern Region of Brazil

2020 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Bianca Fernandes ◽  
Ligia Batista
Keyword(s):  
Nearest Neighbor ◽  
Temporal Analysis ◽  
Management Plan ◽  
Edge Density ◽  
Forest Fragments ◽  
Conservation Unit ◽  
Border Effect ◽  
Action Strategies ◽  
Landsat Satellite ◽  
High Degree

In recent years, anthropogenic actions have intensified forest fragmentation, causing several damages to the landscape’s natural components, propagating the loss of biodiversity. This study aims to present an analysis of the forest fragments in a conservation unit located at southern of Brazil. The evaluation was carried out for the years 1998, 2008, and 2018, by using landscape metrics and classification of remote sensing imagery of the Landsat satellite. The following metrics were analyzed: area and edge, shape, core area, and aggregation. The results indicated an increase of 16.88% in the total area of vegetation, and the percentage of fragments increased from 16.16% to 18.89%. The number of fragments decreased, resulting in an increase of the mean area in 5.4 ha. The percentage of vegetation under border effect changed from 40.2% to 37.1%. In 1998, the average nearest neighbor distance was 155.4 m, and in 2018, 149.7 m. However, this distance is still classified as a high degree of isolation, which hinders the movement of organisms and the dispersion of species. Thus, all the analyzed metrics indicated a decrease in the fragmentation, except for the edge density metric, in which its increase of 1.86 pointed to a lower degree of conservation during the analyzed period. A study of this nature is important as it provides subsidies for future researches and can contribute to action strategies to be adopted in the management plan of the area.

On the relationship of NDVI with leaf area index in a deciduous forest site

2005 ◽  
Vol 94 (2) ◽  
pp. 244-255 ◽  
Author(s):  
Quan Wang ◽  
Samuel Adiku ◽  
John Tenhunen ◽  
André Granier
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Deciduous Forest ◽  
Forest Site ◽  
Area Index ◽  
Relationship Of ◽  
The Relationship

scholarly journals Species composition and diversity of small Afromontane forest fragments in northern Ethiopia

Plant Ecology ◽  
2006 ◽  
Vol 187 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Raf Aerts ◽  
Koen Van Overtveld ◽  
Mitiku Haile ◽  
Martin Hermy ◽  
Jozef Deckers ◽  
...  
Keyword(s):  
Species Composition ◽  
Northern Ethiopia ◽  
Forest Fragments ◽  
Afromontane Forest

Social identity, rationality, creativity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anna-Maria Kanzola ◽  
Konstantina Papaioannou ◽  
Panagiotis E. Petrakis
Keyword(s):  
Social Identity ◽  
Social Identity Theory ◽  
Identity Theory ◽  
Content Type ◽  
The Social ◽  
Social Theories ◽  
Seeking Behavior ◽  
Life Improvement ◽  
Components Analysis ◽  
The Relationship

PurposeThis study examines the relationship between rationality and creativity by means of social identity theory for the Greek society (2019–2020).Design/methodology/approachThe outline of the social identity was given through self-categorization via a distributed questionnaire. The types of behavior (rational, nonrational and loss-averse) were determined by using questions based on the Allais paradox. Principal components analysis (PCA) is used to extract the causal relationships.FindingsThe study findings demonstrate that rational individuals are more prompt to creative personality than nonrational individuals. Rational individuals are motivated to pursue creativity through life-improvement goals. Loss-averse individuals are driven through the contradictive incentive of adventure-seeking behavior without, however, being willing to easily give up their established assets.Originality/valueThis article contributes by explaining creativity among rational, nonrational and loss-averse individuals as a product of social identity theory. This contributes to the literature, by proposing that the application of social theories in economics could constitute a different foundation for economics. This refers to the notion of the social microfoundations of the political economy and macroeconomics.

Face Recognition Algorithm Based on Kernel Collaborative Representation

2013 ◽  
Vol 756-759 ◽  
pp. 3590-3595
Author(s):  
Liang Zhang ◽  
Ji Wen Dong
Keyword(s):  
Face Recognition ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Recognition Algorithm ◽  
Experimental Results ◽  
Collaborative Representation ◽  
Nonlinear Structures ◽  
Components Analysis ◽  
Kernel Principal Components Analysis ◽  
The Relationship

Aiming at solving the problems of occlusion and illumination in face recognition, a new method of face recognition based on Kernel Principal Components Analysis (KPCA) and Collaborative Representation Classifier (CRC) is developed. The KPCA can obtain effective discriminative information and reduce the feature dimensions by extracting faces nonlinear structures features, the decisive factor. Considering the collaboration among the samples, the CRC which synthetically consider the relationship among samples is used. Experimental results demonstrate that the algorithm obtains good recognition rates and also improves the efficiency. The KCRC algorithm can effectively solve the problem of illumination and occlusion in face recognition.

scholarly journals Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

1988 ◽  
Vol 18 (3-4) ◽  
pp. 309-315 ◽  
Author(s):  
Heraldo Luís de Vasconcelos
Keyword(s):  
Species Composition ◽  
Rain Forest ◽  
Abundant Species ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Terra Firme ◽  
Atta Sexdens ◽  
Conservation Areas ◽  
Continuous Forest ◽  
Leaf Cutting

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

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