Dark Island heath (Ninety-mile Plain, South Australia). II. The effects of microtopography on climate, soils, and vegetation

1957 ◽  
Vol 5 (1) ◽  
pp. 86 ◽  
Author(s):  
P Rayson
Keyword(s):  
Sand Dunes ◽  
South Australia ◽  
Vegetation Pattern ◽  
Growth Conditions ◽  
Individual Growth ◽  
Homogeneous Groups ◽  
Vegetation Communities ◽  
Representative Species ◽  
Westerly Winds ◽  
The Individual

The topography of the experimental area at Dark Island is described as a series of crescentic sand dunes formed under the influence of westerly winds and separated by undulating sandplain. Variation in the heath vegetation of the area in relation to topography was described by means of the varying densities of 12 representative species. These densities indicated the individual growth tolerances of the vegetation components. One hundred and twenty-six quadrats sampled from different topographical positions were sorted into homogeneous groups by the method of positive interspecific correlation. The four resultant vegetation communities were located respectively on eastern dune slopes, western dune slopes, sandplain, and in scattered sites. Examination of soil texture, rainfall incidence, and average daily hours of direct sunlight in relation to topography showed that three microhabitats can be separated: namely, eastern and western dune slopes and the sandplain. Eastern dune slopes have the most favourable growth conditions, western the least favourable. Neither the vegetation communities nor the microhabitats could be sharply delimited. The gradual changes of soil and microclimate produced a varying but continuous vegetation pattern. This pattern depended on the growth tolerances of different species and probably also on interspecific competition for the more favourable growth sites.

The early stages of spontaneous forest regeneration on poor soils and continental sand dunes in northern Belgium

1983 ◽  
Vol 49 ◽  
Author(s):  
M. Van Miegroet
Keyword(s):  
Scots Pine ◽  
Age Differences ◽  
Forest Regeneration ◽  
Sand Dunes ◽  
Mixed Forest ◽  
Pedunculate Oak ◽  
White Poplar ◽  
Technical Problems ◽  
Homogeneous Groups ◽  
Invading Species

Spontaneous  natural regeneration under variable conditions on sandy soils and continental  sand dunes were analysed in 5 locations in N.E. Belgium.     The number of seedlings varies between 14.000 and 522.000/ha. The most  prominent invading species are red oak, pedunculate oak and Scots pine.    Two principal types of regeneration are recognized : homogeneous groups of  oak or pine and mixtures, predominantly composed by the same species.  Pioneers such as birch, willow, white poplar and wild black cherry do not  play an important role.    Social differentiation sets in quite early and is mainly provoked by age  differences. Therefore early silvicultural intervention is advisable. The  growth relationships between the species indicate that Scots pine is not in  danger of spontaneous elemination by other species. Because of the density  and variability of spontaneous forest regeneration, the conversion of pure  pine stands into mixed forest, using group regeneration to this end, poses no  real technical problems.

PATTERNS OF GROWTH IN HEIGHT AND WEIGHT FROM BIRTH TO EIGHTEEN YEARS OF AGE

PEDIATRICS ◽  
1959 ◽  
Vol 24 (5) ◽  
pp. 904-921
Author(s):  
Robert B. Reed ◽  
Harold C. Stuart
Keyword(s):  
Growth Curves ◽  
Growth Patterns ◽  
Individual Growth ◽  
Growth Spurt ◽  
Adolescent Growth Spurt ◽  
Wide Range ◽  
Basic Facts ◽  
The Individual ◽  
Rates Of Growth ◽  
Mature Size

In this report is displayed the range of variation observed in the growth curves of height and weight in a series of 134 children observed from birth to 18 years. For purposes of simplification the individuals have been classified on the basis of their rates of growth during three successive 6-year intervals. Even in terms of this crude classification several basic facts about individual growth patterns of height and weight are apparent. The wide range of differences between individuals applies not only to facts about size at specific ages but also to the pattern of change followed from age period to age period. The rate of growth during early childhood, i.e. before 6 years of age, is associated with, but not specifically predictive of, size at maturity and timing of the adolescent growth spurt. Individuals with rapid growth before 6 years of age tend to have large mature size and early adolescent growth spurt. It will be the objective of future reports from this research project to determine the manner in which the individual differences in growth demonstrated and classified here are related to aspects of physical development, to environmental influences such as dietary intake and to the level of health of the child.

scholarly journals Individual growth of Heleobia piscium in natural populations (Gastropoda: Cochliopidae) from the multiple use natural Reserve Isla Martin Garcia, Buenos Aires, Argentina

2008 ◽  
Vol 68 (3) ◽  
pp. 617-621 ◽  
Author(s):  
SM. Martin
Keyword(s):  
Buenos Aires ◽  
Natural Populations ◽  
Dynamic Structure ◽  
Reproductive Period ◽  
Individual Growth ◽  
Growth Equation ◽  
Multiple Use ◽  
Natural Reserve ◽  
Drainage Channels ◽  
The Individual

The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34° 11' 25" S and 58° 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied.

scholarly journals Size control models of Saccharomyces cerevisiae cell proliferation.

1982 ◽  
Vol 2 (4) ◽  
pp. 361-368 ◽  
Author(s):  
A E Wheals
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Proliferation ◽  
Critical Size ◽  
Transition Probability ◽  
Size Control ◽  
Time Lapse ◽  
Growth Conditions ◽  
Yeast Cells ◽  
Cycle Times ◽  
The Individual

By using time-lapse photomicroscopy, the individual cycle times and sizes at bud emergence were measured for a population of saccharomyces cerevisiae cells growing exponentially under balanced growth conditions in a specially constructed filming slide. There was extensive variability in both parameters for daughter and parent cells. The data on 162 pairs of siblings were analyzed for agreement with the predictions of the transition probability hypothesis and the critical-size hypothesis of yeast cell proliferation and also with a model incorporating both of these hypotheses in tandem. None of the models accounted for all of the experimental data, but two models did give good agreement to all of the data. The wobbly tandem model proposes that cells need to attain a critical size, which is very variable, enabling them to enter a start state from which they exit with first order kinetics. The sloppy size control model suggests that cells have an increasing probability per unit time of traversing start as they increase in size, reaching a high plateau value which is less than one. Both models predict that the kinetics of entry into the cell division sequence will strongly depend on variability in birth size and thus will be quite different for daughters and parents of the asymmetrically dividing yeast cells. Mechanisms underlying these models are discussed.

scholarly journals Growth potential can affect timing of maturity in a long-lived semelparous fish

2018 ◽  
Vol 14 (7) ◽  
pp. 20180269 ◽  
Author(s):  
Kazuki Yokouchi ◽  
Françoise Daverat ◽  
Michael J. Miller ◽  
Nobuto Fukuda ◽  
Ryusuke Sudo ◽  
...  
Keyword(s):  
Anguilla Anguilla ◽  
Growth Conditions ◽  
Growth Potential ◽  
Individual Growth ◽  
Growth Trajectories ◽  
Female Size ◽  
European Eel ◽  
Growth And Survival ◽  
Silver Eels ◽  
Reproduction Cost

Many diadromous fishes such as salmon and eels that move between freshwater and the ocean have evolved semelparous reproductive strategies, but both groups display considerable plasticity in characteristics. Factors such as population density and growth, predation risk or reproduction cost have been found to influence timing of maturation. We investigated the relationship between female size at maturity and individual growth trajectories of the long-lived semelparous European eel, Anguilla anguilla . A Bayesian model was applied to 338 individual growth trajectories of maturing migration-stage female silver eels from France, Ireland, the Netherlands and Hungary. The results clearly showed that when growth rates declined, the onset of maturation was triggered, and the eels left their growth habitats and migrated to the spawning area. Therefore, female eels tended to attain larger body size when the growth conditions were good enough to risk spending extra time in their growth habitats. This flexible maturation strategy is likely related to the ability to use diverse habitats with widely ranging growth and survival potentials in the catadromous life-history across its wide species range.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

LearnOnline

2013 ◽  
Vol 4 (2) ◽  
pp. 19-26 ◽  
Author(s):  
Muzammil M. Baig
Keyword(s):  
Online Teaching ◽  
Learning Experience ◽  
South Australia ◽  
Virtual Classroom ◽  
Personal Learning ◽  
Active Involvement ◽  
Learning Platform ◽  
New Learning ◽  
Rss Feeds ◽  
The Individual

Personal Learning Environments (PLEs) help the learners to take control of their learning. PLEs enable the learners to set their own leaning targets and manage their learning by communicating with others in the process of learning. As latest technological advancements have brought revolution in every field of life, so as in the PLEs. Modern PLEs are the integration of a number of latest technologies i.e. blogs, Wikis, RSS feeds, where content is shaped as per the individual needs and interests of the students. Focusing on these latest aspects of the PLEs, University of South Australia initiated a three year new learning platform project in 2010, called LearnOnline, which will replace the University's current online teaching environment UniSAnet. LearnOnline was launched with a vision to foster richer learning through promoting students' active involvement in their courses and involving the students in a deeper learning experience. LearnOnline is built on modular approach and consists of different components i.e. ePortfolio, Course Outline, Lecture Recording, Copyright Monitoring, Student Email, Assessment and Feedback, Virtual Classroom, Course and Teacher Evaluation. Each component is developed separately and is fully independent. This methodology is helping the incremental implementation of the LearnOnline. As soon as a component is completed, after testing, it becomes the part of LearnOnline. In this paper, the author explains the features and workings of LearnOnline in detail and also evaluates its design methodologies.

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