scholarly journals Dominant height projection model with the addition of environmental variables

CERNE ◽  
2011 ◽  
Vol 17 (3) ◽  
pp. 427-433 ◽  
Author(s):  
Antonio Carlos Ferraz Filho ◽  
José Roberto Soares Scolforo ◽  
Maria Zélia Ferreira ◽  
Romualdo Maestri ◽  
Adriana Leandra de Assis ◽  
...  
Keyword(s):  
Climatic Variables ◽  
Monthly Precipitation ◽  
Inventory Data ◽  
Conventional Model ◽  
Projection Model ◽  
Richards Model ◽  
Dominant Height ◽  
Southern Bahia ◽  
Climatic History ◽  
Height Model

This study investigated the behavior of climatic variables inserted as inclination modifiers of the Chapman-Richards model for estimating dominant height. Thus, 1507 data pairs from a Continuous Forestry Inventory of clonal eucalyptus stands were used. The stands are located in the States of Espírito Santo and southern Bahia. The climatic variables were inserted in the dominant height model because the model is a key variable in the whole prognosis system. The models were adjusted using 1360 data pairs, where the rest of the data was reserved for model validation. The climatic variables were selected by using the Backward model construction method. The climatic variables indicated by the Backward method and inserted in the model were: mean monthly precipitation and solar radiation. The inclusion of climatic variables in the model resulted in a precision gain of 19.8% for dominant height projection values when compared with the conventional model. The advantage of the method used in this study is the actualization of inventory data contemplating climatic history and productivity estimates in areas without prior plantation.

scholarly journals Dominant Height Model for Site Classification ofEucalyptus grandisIncorporating Climatic Variables

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
José Roberto Soares Scolforo ◽  
Romualdo Maestri ◽  
Antonio Carlos Ferraz Filho ◽  
José Márcio de Mello ◽  
Antônio Donizette de Oliveira ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Eucalyptus Grandis ◽  
Site Index ◽  
Climatic Variables ◽  
Site Classification ◽  
Monthly Precipitation ◽  
Annual Increment ◽  
Dominant Height ◽  
Mean Annual Increment ◽  
Height Model

This study tested the effects of inserting climatic variables inEucalyptus grandisas covariables of a dominant height model, which for site index classification is usually related to age alone. Dominant height values ranging from 1 to 12 years of age located in the Southeast region of Brazil were used, as well as data from 19 automatic meteorological stations from the area. The Chapman-Richards model was chosen to represent dominant height as a function of age. To include the environmental variables a modifier was included in the asymptote of the model. The asymptote was chosen since this parameter is responsible for the maximum value which the dominant height can reach. Of the four environmental variables most responsible for database variation, the two with the highest correlation to the mean annual increment in dominant height (mean monthly precipitation and temperature) were selected to compose the asymptote modifier. Model validation showed a gain in precision of 33% (reduction of the standard error of estimate) when climatic variables were inserted in the model. Possible applications of the method include the estimation of site capacity in regions lacking any planting history, as well as updating forest inventory data based on past climate regimes.

scholarly journals Time Series Analysis of Climatic Variables in Peninsular Spain. Trends and Forecasting Models for Data between 20th and 21st Centuries

Climate ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 119
Author(s):  
Pitshu Mulomba Mukadi ◽  
Concepción González-García
Keyword(s):  
Time Series ◽  
Temperature Series ◽  
Climatic Variables ◽  
Monthly Precipitation ◽  
Agricultural Crops ◽  
Arima Models ◽  
Cover Time ◽  
Pests And Diseases ◽  
Historical Series ◽  
Preliminary Phase

Time series of mean monthly temperature and total monthly precipitation are two of the climatic variables most easily obtained from weather station records. There are many studies analyzing historical series of these variables, particularly in the Spanish territory. In this study, the series of these two variables in 47 stations of the provincial capitals of mainland Spain were analyzed. The series cover time periods from the 1940s to 2013; the studies reviewed in mainland Spain go up to 2008. ARIMA models were used to represent their variation. In the preliminary phase of description and identification of the model, a study to detect possible trends in the series was carried out in an isolated manner. Significant trends were found in 15 of the temperature series, and there were trends in precipitation in only five of them. The results obtained for the trends are discussed with reference to those of other, more detailed studies in the different regions, confirming whether the same trend was maintained over time. With the ARIMA models obtained, 12-month predictions were made by measuring errors with the observed data. More than 50% of the series of both were modeled. Predictions with these models could be useful in different aspects of seasonal job planning, such as wildfires, pests and diseases, and agricultural crops.

PHENOLOGY, REPRODUCTIVE BIOLOGY AND SPATIAL DISTRIBUTION OF Chresta scapigera (LESS.) Gardner (ASTERACEAE)

2021 ◽  
Vol 25 (03) ◽  
pp. 710-721
Author(s):  
Écio Souza Diniz ◽  
◽  
Rodolfo Oliveira Costa ◽  
Larissa Areal Carvalho Müller ◽  
Jan Thiele ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Reproductive Biology ◽  
Floral Biology ◽  
The Self ◽  
Climatic Variables ◽  
Campo Rupestre ◽  
Climatic Data ◽  
Monthly Precipitation ◽  
Leaf Emergence ◽  
Self Pollination

Chrestas capigera (Less.) Gardner is an important medicinal herb which, however, has been poorly studied for its biology and ecology. This study aimed to investigate its phenology, floral biology, reproductive biology (self-pollination tests), spatial distribution and correlations between phenophases and climatic data in two sites (Cerrado stricto sensu and Campo rupestre) in southern Minas Gerais, Brazil. From August of 2012 to August of 2013, we monitored phenophase occurrence for 70 individuals: emission of new leaves, flowering, production of immature fruits, and mature fruits. Floral anthesis occurred during daytime and remained all day until fruit formation. Peak leaf emergence was observed in April, correlating with minimum monthly temperature and mean monthly precipitation. Flowering and green fruit peaked in May and June, respectively, and correlated negatively with all climatic variables. Mature fruits peaked in June, but did not correlate significantly with any of the climatic variables. However, no difference was found between the two sites regarding the timing of phenophases. The spatial distribution pattern of individuals within sites was random. The self-pollination tests showed that the individuals pollinated and fertilized themselves. Our findings allow us to conclude that the phenology of C. scapigera has pronounced phenological seasonality with reproductive peak activities in the drier and colder season, which is congruent with the self-pollination and anemochoric dispersion strategy.

Adjustment of the age–height relationship for uneven-aged black spruce stands

2008 ◽  
Vol 38 (7) ◽  
pp. 2003-2012 ◽  
Author(s):  
Hakim Ouzennou ◽  
David Pothier ◽  
Frédéric Raulier
Keyword(s):  
Black Spruce ◽  
Information Criterion ◽  
Diversity Indices ◽  
Site Index ◽  
Diameter Distribution ◽  
Large Network ◽  
Permanent Sample Plots ◽  
Dominant Height ◽  
Spruce Stands ◽  
Height Model

Site index (SI) is commonly used in natural stands, even when their diameter distribution deviates from that of the monospecific, even-aged, fully stocked stands used to develop basic age–height relationships. Since deviations from basic age–height trajectories can be reflected in deviations of stand diameter distribution from a bell shape, we incorporated different diameter diversity indices into an age–height equation to help improve height predictions and determine which index is best related to stand dominant height. This procedure was performed using black spruce ( Picea mariana (Mill.) BSP) stands from a large network of permanent sample plots established across the province of Quebec, Canada. The age–height model that minimized the Akaike’s information criterion used the Shannon evenness index (ESh) as an equation modifier accounting for the diameter diversity variable. The model showed that for stands established on relatively poor sites (SI = 9), no substantial differences in dominant height were found between two contrasting ESh values. For SI = 15, however, the larger ESh value increased the dominant height by as much as 1 m at 80 years. These results suggest that introduction of ESh into an age–height model can improve calculation of site index, particularly in regions characterized by the presence of numerous uneven-aged stands.

scholarly journals Application of LIDAR to forest inventory for tree count in stands of Eucalyptus sp

CERNE ◽  
2012 ◽  
Vol 18 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Luciano Teixeira de Oliveira ◽  
Luis Marcelo Tavares de Carvalho ◽  
Maria Zélia Ferreira ◽  
Thomaz Chaves de Andrade Oliveira ◽  
Fausto Weimar Acerbi Junior
Keyword(s):  
Forest Inventory ◽  
Local Maximum ◽  
Point Clouds ◽  
Surface Model ◽  
Inventory Data ◽  
State Information ◽  
Quality Of Results ◽  
Southern Bahia ◽  
Processing Steps

Light Detection and Ranging, or LIDAR, has become an effective ancillary tool to extract forest inventory data and for use in other forest studies. This work was aimed at establishing an effective methodology for using LIDAR for tree count in a stand of Eucalyptus sp. located in southern Bahia state. Information provided includes in-flight gross data processing to final tree count. Intermediate processing steps are of critical importance to the quality of results and include the following stages: organizing point clouds, creating a canopy surface model (CSM) through TIN and IDW interpolation and final automated tree count with a local maximum algorithm with 5 x 5 and 3 x 3 windows. Results were checked against manual tree count using Quickbird images, for verification of accuracy. Tree count using IDW interpolation with a 5x5 window for the count algorithm was found to be accurate to 97.36%. This result demonstrates the effectiveness of the methodology and its use potential for future applications.

Regional changes of Pinus pinaster site index in Spain using a climate-based dominant height model

2010 ◽  
Vol 40 (10) ◽  
pp. 2036-2048 ◽  
Author(s):  
Andrés Bravo-Oviedo ◽  
Clemente Gallardo-Andrés ◽  
Miren del Río ◽  
Gregorio Montero
Keyword(s):  
Pinus Pinaster ◽  
Energy Use ◽  
Climate Models ◽  
Regional Climate ◽  
Circulation Model ◽  
Site Index ◽  
Global Circulation Model ◽  
Climate Conditions ◽  
Dominant Height ◽  
Height Model

This study compares two site index estimations for Mediterranean maritime pine ( Pinus pinaster Ait.) stands in the Iberian Peninsula. The first prediction was performed under the assumption of constant climate conditions, whereas the second one used foreseen climate according to an energy-use increment and high population growth (IPCC’s A2 emission scenario). We used an existing climate-based dominant height model that incorporates temperature, seasonal precipitation in winter and autumn, and drought length as driver variables for dominant height growth. Climate attributes were retrieved from eight regional climate models nested in the same atmospheric–ocean global circulation model. Forest stand data from 188 experimental plots in four natural regions were used to compare regional climate change trends. Results indicated a climate-related diminishing trend of site index values, although some regional differences were evident. In the northern stands, the negative effects were not observed, and in some cases, forest productivity increased on low site index classes. Conversely, in the southernmost stands, there is a significant decrease in the site index across all productivity classes. Western and eastern stands also showed a decreasing trend but to a lesser extent. Our results confirm the vulnerability of stands to warmer and drier climate conditions in the southern Mediterranean region in relation to wood productivity.

Cognitive Components of Ingroup Projection

2014 ◽  
Vol 45 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Maya Machunsky ◽  
Thorsten Meiser
Keyword(s):  
Mental Representation ◽  
Cognitive Representation ◽  
Social Categories ◽  
Projection Model ◽  
Minimal Group ◽  
Model Experiments ◽  
Superordinate Category ◽  
Cognitive Components ◽  
Per Se

This research investigated whether relative ingroup prototypicality (i.e., the tendency to perceive one’s own ingroup as more prototypical of a superordinate category than the outgroup) can result from a prototype-based versus exemplar-based mental representation of social categories, rather than from ingroup membership per se as previously suggested by the ingroup projection model. Experiments 1 and 2 showed that a prototype-based group was perceived as more prototypical of a superordinate category than an exemplar-based group supporting the hypothesis that an intergroup context is not necessary for biased prototypicality judgments. Experiment 3 introduced an intergroup context in a minimal-group-like paradigm. The findings demonstrated that both the kind of cognitive representation and motivational processes contribute to biased prototypicality judgments in intergroup settings.

A dual projection model of partisan attitude perceptions

2014 ◽  
Author(s):  
Jessica Keating ◽  
Leaf Van Boven ◽  
Charles Judd
Keyword(s):  
Projection Model ◽  
Dual Projection
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