scholarly journals Influence of Climate on Radial Growth of Black Pine on the Mountain Regions of Southwestern Turkey

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 276
Author(s):  
Mehmet Doğan ◽  
Nesibe Köse
Keyword(s):  
Cluster Analysis ◽  
Tree Ring ◽  
Hierarchical Cluster Analysis ◽  
Radial Growth ◽  
Function Analysis ◽  
Ring Width ◽  
Hierarchical Cluster ◽  
Climatic Conditions ◽  
Black Pine ◽  
Mountain Regions

In this study, we identified the most important climate factors affecting the radial growth of black pine at different elevations of the mountain regions of Southwestern Turkey (Sandıras Mountain, Muğla/Turkey). We used four black pine tree-ring chronologies, which represent upper and lower distribution limits of black pine forest on the South and North slopes of Sandıras Mountain. The relationships between tree-ring width and climate were identified using response function analysis. We performed hierarchical cluster analysis to classify the response functions into meaningful groups. Black pine trees in the mountain regions of Southwestern Turkey responded positively to a warmer temperature and high precipitation at the beginning of the growing season. As high summer temperatures exacerbated drought, radial growth was affected negatively. Hierarchical cluster analysis made clear that elevation differences, rather than aspect, was the main factor responsible for the formation of the clusters. Due to the mountainous terrain of the study area, the changing climatic conditions (air temperature and precipitation) affected the tree-ring widths differently depending on elevation.

Tree-ring model interprets growth decline in natural stands of loblolly pine in the southeastern United States

1989 ◽  
Vol 19 (5) ◽  
pp. 612-621 ◽  
Author(s):  
Robert Zahner ◽  
Joseph R. Saucier ◽  
Richard K. Myers
Keyword(s):  
Tree Ring ◽  
Loblolly Pine ◽  
Radial Growth ◽  
Ring Width ◽  
Stand Density ◽  
Climatic Conditions ◽  
Radial Increment ◽  
Aggregate Model ◽  
Ring Model ◽  
Pine Stands

Annual ring widths and ring areas from 131 even-aged, natural, well-stocked stands of loblolly pine (Pinustaeda L.) in the Piedmont region were analyzed to reveal possible causes of a previously reported decline in radial growth. A linear aggregate model was used to separate independent factors that are known to contribute to radial growth variation in this species. Stand, site, and climatic conditions were reconstructed for each stand for the 36-year period 1949–1984 from previous inventories and from weather records at appropriately located stations. Within each of six 5-year age-classes, the model identified declines in both ring width and ring area associated with stand density, climate changes, and the passage of time. Regional climate first ameliorated this decline as pine stands passed from droughty conditions early in the 36-year period to a favorable climate during the middle of the period, and the decline accelerated later with the return of dry conditions toward the end of the period. The tree-ring model simulates a decline in radial increment in trees in natural pine stands between the ages of 20 and 45 years in the Piedmont which has averaged 1% per year since 1950. Part of the downward trend was attributed to increased competition, part to regional drought, and a considerable part to unidentified factors, possibly regional atmospheric deposition.

Ecological interpretation of tree-ring width and intraannual density fluctuations inPinus sylvestrison dry sites in the central Alps and Siberia

2001 ◽  
Vol 31 (1) ◽  
pp. 18-31 ◽  
Author(s):  
Andreas Rigling ◽  
Philipp O Waldner ◽  
Theodor Forster ◽  
Otto U Bräker ◽  
Antti Pouttu
Keyword(s):  
Tree Ring ◽  
Radial Growth ◽  
Function Analysis ◽  
Ring Width ◽  
Growing Season ◽  
Density Fluctuations ◽  
Climatic Data ◽  
Central Alps ◽  
Tree Ring Width ◽  
Soil Substrate

The radial growth of Pinus sylvestris L. from nine sites at the semiarid lower forest border of the central Alps (Switzerland) and central Siberia (Russia) has been investigated using dendroecological methods. Tree growth differed according to soil substrate, with trees on dune sites showing lower mean ring widths, lower mean sensitivities, and higher autocorrelation. The relationships between climate and tree-ring width were studied using response function analysis. Independent of the climatic zone and the soil substrate, precipitation just before and at the beginning of the growing season is positively correlated with radial growth. The climatic response of dune sites is low, possibly because of the poor water-holding capacity and the high permeability of the sandy soils. Intraannual density fluctuations (IADFs) were observed at all the sites. Most IADFs were found in latewood. On dunes, fewer cores contain IADFs, and their frequency is lower. All stands showed significant relationships between IADF frequency and tree-ring width (positive) and ring age (negative). For Swiss sites, moist-cool conditions in the middle of the growing season are demonstrated as the triggering factor for IADFs. For the Russian sites, inadequate climatic data made it impossible to demonstrate any climate dependence of IADFs.

Extraordinary circumstances: Covid-19 – Italian Serie A scenario

2021 ◽  
pp. 175433712110192
Author(s):  
Milan Radojicic ◽  
Aleksandar Djokovic ◽  
Nikola Cvetkovic
Keyword(s):  
Cluster Analysis ◽  
Hierarchical Cluster Analysis ◽  
Hierarchical Cluster ◽  
Round Robin ◽  
The Past ◽  
Novel Approach ◽  
Round Robin Tournaments

Unpredictable and uncontrollable situations have happened throughout history. Inevitably, such situations have an impact on various spheres of life. The coronavirus disease 2019 has affected many of them, including sports. The ban on social gatherings has caused the cancellation of many sports competitions. This paper proposes a methodology based on hierarchical cluster analysis (HCA) that can be applied when a need occurs to end an interrupted tournament and the conditions for playing the remaining matches are far from ideal. The proposed methodology is based on how to conclude the season for Serie A, a top-division football league in Italy. The analysis showed that it is reasonable to play 14 instead of the 124 remaining matches of the 2019–2020 season to conclude the championship. The proposed methodology was tested on the past 10 seasons of the Serie A, and its effectiveness was confirmed. This novel approach can be used in any other sport where round-robin tournaments exist.

scholarly journals Detection of drought events in Greece using daily precipitation

2010 ◽  
Vol 41 (2) ◽  
pp. 126-133 ◽  
Author(s):  
N. Kalamaras ◽  
H. Michalopoulou ◽  
H. R. Byun
Keyword(s):  
Cluster Analysis ◽  
Hierarchical Cluster Analysis ◽  
Daily Precipitation ◽  
Hierarchical Cluster ◽  
Seasonal Distribution ◽  
Drought Severity ◽  
Severe Drought ◽  
Analysis Method ◽  
Cluster Analysis Method ◽  
Insight Into

In this study a method proposed by Byun & Wilhite, which estimates drought severity and duration using daily precipitation values, is applied to data from stations at different locations in Greece. Subsequently, a series of indices is calculated to facilitate the detection of drought events at these sites. The results provide insight into the trend of drought severity in the region. In addition, the seasonal distribution of days with moderate and severe drought is examined. Finally, the Hierarchical Cluster Analysis method is used to identify sites with similar drought features.

An investigation on conceptual understanding about cosmology

2019 ◽  
Vol 15 (S367) ◽  
pp. 397-399
Author(s):  
Arturo Colantonio ◽  
Irene Marzoli ◽  
Italo Testa ◽  
Emanuella Puddu
Keyword(s):  
High School ◽  
Cluster Analysis ◽  
High School Students ◽  
Conceptual Understanding ◽  
Hierarchical Cluster Analysis ◽  
Hierarchical Cluster ◽  
Content Area ◽  
School Students ◽  
Convenience Sample ◽  
Teaching Activities

AbstractIn this study, we identify patterns among students beliefs and ideas in cosmology, in order to frame meaningful and more effective teaching activities in this amazing content area. We involve a convenience sample of 432 high school students. We analyze students’ responses to an open-ended questionnaire with a non-hierarchical cluster analysis using the k-means algorithm.

Hierarchical Cluster Analysis Identifies Distinct Physiological States After Acute Brain Injury

2021 ◽  
Author(s):  
Swarna Rajagopalan ◽  
Wesley Baker ◽  
Elizabeth Mahanna-Gabrielli ◽  
Andrew William Kofke ◽  
Ramani Balu
Keyword(s):  
Cluster Analysis ◽  
Brain Injury ◽  
Hierarchical Cluster Analysis ◽  
Hierarchical Cluster ◽  
Acute Brain Injury
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