scholarly journals Quantitative comparison of flowering phenology traits among trees, perennial herbs, and annuals in a temperate plant community

2019 ◽  
Vol 106 (12) ◽  
pp. 1545-1557 ◽  
Author(s):  
Ai Nagahama ◽  
Tetsukazu Yahara
Keyword(s):  
Plant Community ◽  
Flowering Phenology ◽  
Quantitative Comparison ◽  
Perennial Herbs

Variation in Flowering Parameters Within and Among Five Species of Australian Alpine Ranunculus

1995 ◽  
Vol 43 (1) ◽  
pp. 103 ◽  
Author(s):  
CC Pickering
Keyword(s):  
Flowering Phenology ◽  
Alpine Region ◽  
Flowering Pattern ◽  
Temporal And Spatial Variation ◽  
Mean Values ◽  
Flower Production ◽  
A Value ◽  
Perennial Herbs ◽  
Temporal And Spatial ◽  
Perfect Synchrony

The flowering phenology of the perennial herbs Ranunculus muelleri, R. dissectifolius, R. granticola, R. millanii and R. niphophilus were characterised at two sites over two flowering seasons in the Kosciusko alpine region of Australia. The date a plant started flowering (mean values for species ranged from 8 November to 14 December), the duration of flowering (mean values for species ranged from 14.3 days to 35.1 days), asynchrony of flower production (mean values ranged from 1.38 to 10.4 days), asynchrony of first day of flowering (mean values ranged from 4.61 to 8.13), intraspecific synchrony (mean values ranged from 0.53 to 0.73, where a value of 1 equals perfect synchrony), and number of flowers (mean values ranged from 1.9 to 10.7) all differed between sites and flowering seasons within species, and among the five species. Thus, while temporal and spatial variation in flowering parameters within species occurred, it did not mask variation among species, with each of the five species of Ranunculus having a distinct flowering pattern.

Effects of plant community composition and flowering phenology on honeybee foraging in Mediterranean sylvo-pastoral systems

2013 ◽  
Vol 16 (4) ◽  
pp. 689-697 ◽  
Author(s):  
Simonetta Bagella ◽  
Alberto Satta ◽  
Ignazio Floris ◽  
Maria Carmela Caria ◽  
Ivo Rossetti ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Flowering Phenology ◽  
Plant Community Composition ◽  
Pastoral Systems

scholarly journals Shifts in flowering phenology reshape a subalpine plant community

2014 ◽  
Vol 111 (13) ◽  
pp. 4916-4921 ◽  
Author(s):  
Paul J. CaraDonna ◽  
Amy M. Iler ◽  
David W. Inouye
Keyword(s):  
Plant Community ◽  
Flowering Phenology

Toward an alignment of the actin molecule within the actin filament

1983 ◽  
Vol 41 ◽  
pp. 450-451
Author(s):  
P.R. Smith ◽  
W.E. Fowler ◽  
U. Aebi
Keyword(s):  
Actin Filament ◽  
Diffraction Data ◽  
Quantitative Estimate ◽  
Molecular Model ◽  
Quantitative Comparison ◽  
Regulatory Proteins ◽  
Essential Information ◽  
X Ray ◽  
Maximum Resolution ◽  
Lack Of Information

An understanding of the specific interactions of actin with regulatory proteins has been limited by the lack of information about the structure of the actin filament. Molecular actin has been studied in actin-DNase I complexes by single crystal X-ray analysis, to a resolution of about 0.6nm, and in the electron microscope where two dimensional actin sheets have been reconstructed to a maximum resolution of 1.5nm. While these studies have shown something of the structure of individual actin molecules, essential information about the orientation of actin in the filament is still unavailable.The work of Egelman & DeRosier has, however, suggested a method which could be used to provide an initial quantitative estimate of the orientation of actin within the filament. This method involves the quantitative comparison of computed diffraction data from single actin filaments with diffraction data derived from synthetic filaments constructed using the molecular model of actin as a building block. Their preliminary work was conducted using a model consisting of two juxtaposed spheres of equal size.

The quantitative comparison of experimental and simulated diffraction contrast images

1995 ◽  
Vol 53 ◽  
pp. 102-103
Author(s):  
Stuart McKernan
Keyword(s):  
Image Processing ◽  
Personal Computer ◽  
Close Agreement ◽  
Quantitative Comparison ◽  
Image Simulation ◽  
Computing Power ◽  
Diffraction Contrast ◽  
Simulated Images ◽  
Made In

For many years the concept of quantitative diffraction contrast experiments might have consisted of the determination of dislocation Burgers vectors using a g.b = 0 criterion from several different 2-beam images. Since the advent of the personal computer revolution, the available computing power for performing image-processing and image-simulation calculations is enormous and ubiquitous. Several programs now exist to perform simulations of diffraction contrast images using various approximations. The most common approximations are the use of only 2-beams or a single systematic row to calculate the image contrast, or calculating the image using a column approximation. The increasing amount of literature showing comparisons of experimental and simulated images shows that it is possible to obtain very close agreement between the two images; although the choice of parameters used, and the assumptions made, in performing the calculation must be properly dealt with. The simulation of the images of defects in materials has, in many cases, therefore become a tractable problem.

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Temporal Dynamics ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Plant Responses ◽  
Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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