scholarly journals Growth dynamics of the branching system in grasses: an architecture-based methodology for quantitative evaluation applied to two genotypes of Paspalum vaginatum

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
Liliana Teresa Fabbri ◽  
Pedro Insausti ◽  
William B. Batista ◽  
Gabriel H. Rua
Keyword(s):  
Spatial Distribution ◽  
Production Rate ◽  
Environmental Conditions ◽  
Reproductive Effort ◽  
Growth Dynamics ◽  
Vegetative Cover ◽  
Branching Order ◽  
Aerial Growth ◽  
Paspalum Vaginatum ◽  
Branching System

Abstract The aerial growth dynamics of the shoots of the widespread turfgrass Paspalum vaginatum was studied. With the aim of identifying quantitative differential features between two genotypes, plants were cultivated outdoors in pots during two consecutive summers. Axes of different branching order were marked for periodical observation to quantify internode production rate, axis production rate, covering rate and reproductive effort. The genotypes differed significantly in the following quantitative features: plagiotropic vs. orthotropic axes proportion, internode production rate, flowering vs. vegetative tiller ratio, vegetative cover and spatial distribution of the canopy. Knowledge of these features may help to understand the great plasticity and adaptability of this species to multiple environmental conditions.

scholarly journals Spatial distribution of spruce trees in the nature reserve 'Jankove bare' on mt. Kopaonik

2009 ◽  
pp. 191-204
Author(s):  
Branko Stajic ◽  
Milivoj Vuckovic ◽  
Marko Smiljanic
Keyword(s):  
Spatial Distribution ◽  
Tree Growth ◽  
Environmental Conditions ◽  
National Park ◽  
Nature Reserve ◽  
Distance Methods ◽  
Study Results

The methodology and applicability of the study of spatial distribution of trees in Serbian forestry have been insufficiently reported and presented. This paper, based on mathematical?statistical principles, analyses the method of spatial distribution of spruce trees in the Nature Reserve 'Jankove Bare' in the National Park 'Kopaonik'. The following methods in the group of distance methods were applied: Kotar's method (1993), T2?method, and the index of distance dispersion (Johnson, Zimmer, 1985). The study results in a pure uneven-aged spruce stand based on all three methods showed that spruce trees are randomly distributed over the stand area. Therefore, environmental conditions in the study stand can be regarded as homogeneous and equally suitable for tree growth, and there are no significant interactions between the trees, which could cause a higher competition between the trees for nutrients, water, etc.

The ecology of sympatric scincid lizards (Ctenotus) in arid South Australia

1998 ◽  
Vol 46 (6) ◽  
pp. 617 ◽  
Author(s):  
J. L. Read
Keyword(s):  
Home Range ◽  
Environmental Conditions ◽  
Plant Material ◽  
Reproductive Effort ◽  
Arid Zone ◽  
South Australia ◽  
Early Summer ◽  
Home Ranges ◽  
Local Species ◽  
Olympic Dam

Ctenotus skinks are the most diverse and abundant diurnal reptile genus at Olympic Dam, in the South Australian arid zone. The home range, demography, reproduction and diet of five syntopic Ctenotus species was studied over a 6-year period in chenopod shrubland. Longevity frequently exceeded three years in C. regius, four years in C. schomburgkii and five years in C. leonhardii, with a 7-year-old specimen of C. leonhardii being recorded. Females of most species tended to be larger and lived longer than males. Two eggs were typically laid by each species in early summer. Annual reproductive effort, particularly in C. leonhardii, varied considerably depending upon the prevailing environmental conditions. All local species apparently occupied home ranges, with maximum recapture radii in different species of 40–60 m. Ctenotus appear to be unspecialised insectivores, although plant material and lizards are sometimes eaten by the larger species.

Cometary evolution and cryovolcanism 1This article is part of a Special issue that honours the work of Dr. Donald M. Hunten FRSC who passed away in December 2010 after a very illustrious career.

2012 ◽  
Vol 90 (8) ◽  
pp. 807-815 ◽  
Author(s):  
Michael J.S. Belton
Keyword(s):  
Spatial Distribution ◽  
Production Rate ◽  
Large Scale ◽  
Special Issue ◽  
Apparent Absence ◽  
Cometary Nuclei ◽  
Evolutionary Hypothesis ◽  
Wide Range ◽  
Show Evidence ◽  
Cometary Activity

Recent space observations of cometary nuclei show evidence of internal (cryovolcanic) activity while retaining aspects of their primitive origins. Using discoveries made during the two most recent cometary encounters: EPOXI at 103P/Hartley 2 and Stardust-NExT at 9P/Tempel 1, we test a hypothesis for their physical evolution, which, if true, could provide a unified basis for understanding the relative ages of their surfaces and the causes of a wide range of cometary activity. We show: (i) that the categorization of 103P/Hartley 2 as hyperactive is not a reflection of the extent of activity over the surface of the nucleus for which we find a normal H2O production rate; (ii) that the heterogeneous spatial distribution of CO2 and H2O in the inner comae of 9P/Tempel 1 and 103P/Hartley 2 is best explained by processes associated with cometary activity rather than the presence of primitive compositional heterogeneities in the nucleus; and (iii) that most of the quasi-circular depressions seen on the surface of 9P/Tempel are the result of outburst activity. The apparent absence of circular depressions and large scale layering on 103P/Hartley 2 present a challenge to the evolutionary hypothesis although the small size of its nucleus may ultimately provide an explanation.

Developing Automated Spectral Analysis Tools for Interstellar Features Extractionto Support Construction of the 3D ISM Map

2017 ◽  
Vol 12 (S330) ◽  
pp. 243-244
Author(s):  
L. Puspitarini ◽  
R. Lallement ◽  
A. Monreal-Ibero ◽  
H.-C. Chen ◽  
H. L. Malasan ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Spatial Distribution ◽  
Spatial Resolution ◽  
Environmental Conditions ◽  
Equivalent Width ◽  
Global Analysis ◽  
Line Of Sight ◽  
Absorption Data ◽  
Diffuse Interstellar Bands ◽  
Automated Spectral Analysis

AbstractOne of the ways to obtain a detailed 3D ISM map is by gathering interstellar (IS) absorption data toward widely distributed background target stars at known distances (line-of-sight/LOS data). The radial and angular evolution of the LOS measurements allow the inference of the ISM spatial distribution. For a better spatial resolution, one needs a large number of the LOS data. It requires building fast tools to measure IS absorption. One of the tools is a global analysis that fit two different diffuse interstellar bands (DIBs) simultaneously. We derived the equivalent width (EW) ratio of the two DIBs recorded in each spectrum of target stars. The ratio variability can be used to study IS environmental conditions or to detect DIB family.

scholarly journals Analysis of spatio-temporal fungal growth dynamics under different environmental conditions

IMA Fungus ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Liselotte De Ligne ◽  
Guillermo Vidal-Diez de Ulzurrun ◽  
Jan M. Baetens ◽  
Jan Van den Bulcke ◽  
Joris Van Acker ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Fungal Growth ◽  
Growth Dynamics ◽  
Spatio Temporal

scholarly journals Extreme climatic events in relation to global change and their impact on life histories

2011 ◽  
Vol 57 (3) ◽  
pp. 375-389 ◽  
Author(s):  
Juan Moreno ◽  
Anders Pape Møller
Keyword(s):  
Environmental Conditions ◽  
Life Histories ◽  
Reproductive Effort ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Reproductive Failure ◽  
Adult Survival ◽  
Extreme Climatic Events ◽  
Empirical Tests ◽  
Living Organisms

Abstract Extreme weather conditions occur at an increasing rate as evidenced by higher frequency of hurricanes and more extreme precipitation and temperature anomalies. Such extreme environmental conditions will have important implications for all living organisms through greater frequency of reproductive failure and reduced adult survival. We review examples of reproductive failure and reduced survival related to extreme weather conditions. Phenotypic plasticity may not be sufficient to allow adaptation to extreme weather for many animals. Theory predicts reduced reproductive effort as a response to increased stochasticity. We predict that patterns of natural selection will change towards truncation selection as environmental conditions become more extreme. Such changes in patterns of selection may facilitate adaptation to extreme events. However, effects of selection on reproductive effort are difficult to detect. We present a number of predictions for the effects of extreme weather conditions in need of empirical tests. Finally, we suggest a number of empirical reviews that could improve our ability to judge the effects of extreme environmental conditions on life history.

Patterns of growth and reproduction in a perennial tundra forb (Geum rossii): effects of clone area and neighborhood

1991 ◽  
Vol 69 (9) ◽  
pp. 1977-1983 ◽  
Author(s):  
Jeanne C. Chambers
Keyword(s):  
Spatial Distribution ◽  
Reproductive Effort ◽  
Pattern Analysis ◽  
Trade Off ◽  
Geometric Function ◽  
Site Characteristics ◽  
Mineral Soils ◽  
Clonal Species ◽  
Related Pattern ◽  
Growth And Reproduction

The relationships of clone area and neighborhood to ramet size, reproductive effort, and spatial distribution within Geum rossii clones were studied in an alpine ecosystem on the Beartooth Plateau, Montana. Clones growing on an early seral site in relative isolation were compared to clones on a late seral site within dense, heterogeneous neighborhoods. Individual clones of G. rossii required a minimum clone area of about 200 cm2 before maximum ramet size and reproductive effort were achieved. Mean ramet size and reproductive effort were fairly constant among clones larger than 200 cm2 on both the early and later seral sites. Within clones the size and reproductive effort of ramets were positively related. Pattern analysis revealed that ramets became more widely and irregularly spaced as clone area increased on the early seral site. This may have been a geometric function of an increase in the space required as clones aged and became larger. On the late seral site, clones were characterized by ramets that were widely and erratically spaced, that had low leaf numbers and mass, and that had low reproductive effort. For clones of comparable area on the early seral site, ramets were more closely and uniformly spaced, and leaf number, mass, and reproduction per ramet were higher. Conservative patterns of growth and reproduction make G. rossii well suited to dominate in dense, heterogeneous neighborhoods of late seral sites and to colonize mineral soils of early seral sites. Similar to other clonal species, site characteristics and the type of neighborhood determine the trade-off between the physical occupation of space and the allocation to ramet growth and reproduction in G. rossii. Key words: Geum rossii, alpine, reproductive effort, growth, clone area, pattern analysis, succession, neighborhood.

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