scholarly journals Variation in size-dependent fitness components in a terrestrial orchid, Dactylorhiza majalis (Rchb.) Hunt et Summerh., in relation to environmental factors

2011 ◽  
Vol 80 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Lucyna Mróz ◽  
Piotr Kosiba
Keyword(s):  
Environmental Variables ◽  
Sharp Increase ◽  
Plant Size ◽  
High Altitudes ◽  
Fitness Components ◽  
Terrestrial Orchid ◽  
Threshold Size ◽  
Flower Production ◽  
Size Dependent ◽  
Flowering Probability

We investigated the flowering probability and flower production in relation to plant size in a terrestrial orchid, <em>Dactylorhiza majalis</em> at 10 meadow sites in central and southwestern Poland. These sites differed in altitude (low, high) and management (presence or absence of mowing). At all sites, concentrations of nutrients in the soil were also measured. The probability of flowering increased significantly with the size of the plant in all populations, indicating that individuals do not flower until they reach a threshold size. Populations at high altitudes and the unmown sites had significantly lower threshold sizes for reproduction and showed sharp increase in flowering probability with plant size, compared to other populations. The threshold sizes for reproduction tended to decrease at sites rich in N and Mg and poor in P and S. Flower production was also size-dependent in all populations. Considerable between-site differences were found in the slope and the intercept of the regression between plant size and flower production. Flower production at some sites, at high altitudes, increased more steeply with plant size than at other sites. However, no pattern in size-dependent flower production was found relative to the measured environmental variables. Most of the size-dependent components of flowering probability were related to each other but not with the size-dependent flower production.

scholarly journals THRESHOLD SIZE FOR FLOWERING IN DIFFERENT HABITATS: EFFECTS OF SIZE-DEPENDENT GROWTH AND SURVIVAL

Ecology ◽  
1997 ◽  
Vol 78 (7) ◽  
pp. 2118-2132 ◽  
Author(s):  
Renate A. Wesselingh ◽  
Peter G. L. Klinkhamer ◽  
Tom J. de Jong ◽  
Laurence A. Boorman
Keyword(s):  
Growth And Survival ◽  
Threshold Size ◽  
Size Dependent ◽  
Dependent Growth

scholarly journals Size-dependent allocation of biomass to ancillary versus flowers of the inflorescences of the epiphyte Tillandsia stricta Soland (Bromeliaceae)

2009 ◽  
Vol 23 (1) ◽  
pp. 130-135 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Rios Iglesias
Keyword(s):  
Leaf Area ◽  
Plant Species ◽  
Vegetative Growth ◽  
Reproductive Investment ◽  
Plant Size ◽  
Reproductive Allocation ◽  
Heterogeneous Environment ◽  
Plant Resources ◽  
Total Leaf Area ◽  
Size Dependent

The amount of resources invested in reproduction is closely correlated to plant size. However, the increase in reproductive investment is not always proportional to the increase in vegetative growth, as the proportion of plant resources allocated to reproduction can increase, decrease or be maintained along different plant sizes. Although comprising thousand of species, epiphytes are poorly studied in relation to reproductive allocation (RA). We describe the variation in the RA of the epiphytic bromeliad Tillandsia stricta Soland with increasing plant sizes. Our goal is not only to evaluate the RA of the whole inflorescence but also quantify the contribution of ancillary structures in the final RA of this plant species. With increasing sizes of T. stricta the reproductive allocation of biomass to the whole inflorescence decreased significantly along plant sizes from 37% to 12%. Reproductive allocation to ancillary and to flowers decreased respectively from 30% to 9% and 10% to 3%. As leaves are the main source of water and nutrients absorption in atmospheric Tillandsia, the total leaf area and area per leaf were used as indicators of foraging capacity, that also increased with plant size. We discuss these results with respect to the capacity of T. stricta to reproduce in the heterogeneous environment of the canopies.

scholarly journals Size-Dependent and Property-Independent Passive Microdroplet Sorting by Droplet Transfer on Dot Rails

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 513 ◽  
Author(s):  
Dong Yoon ◽  
Daiki Tanaka ◽  
Tetsushi Sekiguchi ◽  
Shuichi Shoji
Keyword(s):  
Surface Tension ◽  
Lateral Flow ◽  
High Potential ◽  
Laplace Pressure ◽  
Droplet Transfer ◽  
Sorting Method ◽  
Threshold Size ◽  
Size Dependent

A fully passive microdroplet sorting method is presented in this paper. On the rails with dot patterns, the droplets were sorted in different ways depending on their size. However, the effect of droplet properties on the threshold size of the sorting was eliminated. The droplet positions on two railways and the Laplace pressure of the droplets on the dot patterns allowed selective droplet transfer according to size. Different gaps between the rails altered the threshold size of the transfer. However, the threshold size was independent of the droplet’s surface tension and viscosity because the droplet transfer utilized only the droplet position and Laplace pressure without lateral flow to sort targets. This feature has a high potential for bio/chemical applications requiring categorization of droplet targets consisting of various mixtures as pre- or post-elements.

scholarly journals Size-Dependent Phase Transformation during Gas Atomization Process of Cu–Sn Alloy Powders

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 245 ◽  
Author(s):  
Hao Pan ◽  
Hongjun Ji ◽  
Meng Liang ◽  
Junbo Zhou ◽  
Mingyu Li
Keyword(s):  
Phase Transformation ◽  
Nucleation Theory ◽  
Gas Atomization ◽  
Atomization Process ◽  
Cu6sn5 Phase ◽  
Lotus Leaf ◽  
Threshold Size ◽  
Size Dependent ◽  
Droplet Sizes ◽  
Transient Nucleation

For binary element atomization, it is essential to investigate the phase transformation from liquid to solid as a functions of the droplet sizes, as well as the reaction competitiveness, during gas atomizing solidification of their nuclei. In the present work, a series of phase transformations of undercooled Cu (60.9 wt.%)/Sn droplets were analyzed when atomized by pressure gas. The results indicated that the microstructures of the obtained powders and their morphologies were highly relevant to the droplet size. According to the phase characteristics analyzed by the microstructural observations in combination with the transient nucleation theory, powders with sizes from 10 to 100 μm were divided into three categories, exhibiting lotus-leaf, island, and stripe morphologies. The competitive formation of Cu6Sn5 or Cu3Sn was also controlled by the droplet sizes, and a diameter of approximately 45 μm was identified as the threshold size. After heat treatment at 300 °C for 4 h, the powders consisted of a single η’ Cu6Sn5 phase. The obtained Cu6Sn5 phase powders can be used in the field of high-temperature applications as intermetallic balls for integrated chip interconnects.

Plant-size and fruit-position effects on reproductive allocation in Alliaria petiolata (Brassicaceae)

2000 ◽  
Vol 78 (11) ◽  
pp. 1398-1407 ◽  
Author(s):  
David J Susko ◽  
Lesley Lovett-Doust
Keyword(s):  
Seed Mass ◽  
Maternal Investment ◽  
Plant Size ◽  
Dry Mass ◽  
Reproductive Allocation ◽  
Alliaria Petiolata ◽  
Position Effects ◽  
Threshold Size ◽  
Linear Relationships ◽  
Total Seed

We examined the development of ovules and components of reproductive yield as they related to plant size and fruit position within plants of Alliaria petiolata (M. Bieb.) Cavara and Grande from three sites. We found that both factors affected fruit and seed production, and patterns of ovule fate. Larger plants were more fecund than their smaller counterparts, while proximally positioned flowers within an inflorescence produced more seeds. Maternal investment was regulated according to plant mass at two levels: among fruits (small plants had significantly lower fruit-set than did large plants), and within fruits (small plants had significantly fewer ovules and significantly higher proportions of aborted ovules per fruit than did large plants). All absolute measures of reproduction had positive linear relationships with plant size, but a threshold size for flowering was not found. Most proportional measures of reproduction were independent of plant size. Small plants produced the same relative proportions of total seed number and total seed mass per unit plant dry mass as large plants. Therefore, proportional reproductive allocation did not vary with plant size. However, small plants produced proportionately more flowers per unit dry mass. Small plants may be maximizing their overall fitness through increased allocation to male function (flower production).Key words: Alliaria petiolata, plant-size effects, fruit-position effects, reproductive allocation, patterns of ovule abortion, seed maturation.

scholarly journals Seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in the southern South China Sea under the influence of the East Asian monsoon

2015 ◽  
Vol 12 (22) ◽  
pp. 6809-6822 ◽  
Author(s):  
L. Zhou ◽  
Y. Tan ◽  
L. Huang ◽  
Z. Hu ◽  
Z. Ke
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Biomass ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Phytoplankton Growth ◽  
Southern South China Sea ◽  
Size Dependent ◽  
Seawater Salinity ◽  
Microzooplankton Grazing

Abstract. To examine seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in oligotrophic tropical waters under the influence of seasonal reversing monsoon, dilution experiments were conducted during the summer of 2009 (21 May to 9 June) and winter 2010 (9 to 18 November) in the southern South China Sea (SSCS). The results showed that environmental variables, phytoplankton biomass, phytoplankton growth rate (μ), microzooplankton grazing rate (m), and correlationship (coupling) between the μ and m, rather than the microzooplankton grazing impact on phytoplankton (m/μ) significantly varied between the two seasons. Higher relative preference index (RPI) for the larger-sized (> 3 μm) phytoplankton than pico-phytoplankton (< 3 μm), indicating significant size-selective grazing by microzooplankton on the larger-sized phytoplankton, were also observed. The μ and m were significantly correlated with seawater salinity and temperature, and phytoplankton biomass, which indicated that salient seasonal variations in the phytoplankton growth and microzooplankton grazing in the SSCS were closely related to the environmental variables under the influence of the East Asian monsoon. We propose that intermittent arrivals of the northeast winter monsoon could lead to the low μ and m, and the decoupling between the μ and m in the SSCS, through influencing nutrient supply to the surface water, and inducing surface seawater salinity decrease. The low m/μ (< 50 % on average) indicates low remineralization of organic matter mediated by microzooplankton and mismatch between the μ and m, and thus probably accounts for part of the high vertical biogenic particle fluxes in the prevailing periods of the monsoons in the SSCS. The size-selective grazing suggests that microzooplankton grazing partially contributes to the pico-phytoplankton dominance in the oligotrophic tropical waters such as that of the SSCS.

Differences in plant size and flower production between hermaphrodites and females of two gynodioecious Chionographis (Liliaceae)

1996 ◽  
Vol 74 (1) ◽  
pp. 150-153 ◽  
Author(s):  
Masayuki Maki
Keyword(s):  
Frequency Distribution ◽  
Reproductive Effort ◽  
Plant Size ◽  
Flowering Plants ◽  
Size Class ◽  
Minimum Size ◽  
Dioecious Species ◽  
Flower Production ◽  
Flowering Season ◽  
Secondary Sex Characters

Plant size and flower production were compared between female and hermaphroditic plants of two gynodioecious Chionographis. Frequency distribution of size and minimum size class of flowering plants were not different between two sex morphs in both Chionographis. In C. japonica ssp. hisauchiana, females produced more ovuliferous flowers than hermaphrodites, although the total number of flowers were not significantly different between two sex morphs. In contrast, hermaphrodites of C. japonica var. kurohimensis exceeded females in the total number of flowers, whereas the number of ovuliferous flowers was not significantly different between two sex morphs. Reproductive effort at flowering season is not different between females and hermaphrodites. These little differences in secondary sex characters, compared with dioecious species, are probably due to the selfing of hermaphrodites and weaknesses in gender specialization. Keywords: Chionographis, flower production, gynodioecy, plant size, secondary sex characters.

Threshold Size for Flowering in Different Habitats: Effects of Size- Dependent Growth and Survival

Ecology ◽  
1997 ◽  
Vol 78 (7) ◽  
pp. 2118 ◽  
Author(s):  
Renate A. Wesselingh ◽  
Peter G. L. Klinkhamer ◽  
Tom J. de Jong ◽  
Laurence A. Boorman
Keyword(s):  
Growth And Survival ◽  
Threshold Size ◽  
Size Dependent ◽  
Dependent Growth

scholarly journals Biomass explains the intensity of facilitative – not competitive – interactions: three intraspecific tests with annuals

Web Ecology ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. Ariza ◽  
K. Tielbörger
Keyword(s):  
Size Dependence ◽  
Resource Competition ◽  
Theoretical Models ◽  
Plant Size ◽  
Competitive Interactions ◽  
Positive Interactions ◽  
Plant Interactions ◽  
Belowground Competition ◽  
Size Dependent ◽  
Negative Effect

Abstract. Despite efforts to discern the role of plant size in resource competition, the circumstances under which size-dependent plant-plant interactions occur are still unclear. The traditional assumption is that competition intensifies with increasing neighbour size. However, recent studies suggest that the size (biomass) dependence of competitive interactions is strongest at very low biomass levels and becomes negligible after a certain threshold neighbour biomass has been reached. We searched for the generality of such patterns for three common annual plant species in Israel. We monitored target and neighbour biomass along their entire lifecycle using an even-aged, intraspecific and intrapopulation competition screenhouse experiment under water-limited conditions. For all focal species, neighbour presence had a net negative effect on vegetative biomass at harvest. However, this was not explained by increasing neighbour biomass over time, as a consistent pattern of size-dependent facilitative, rather than competitive, interactions was observed at all life stages. We explain these observations in terms of co-occurring aboveground facilitation and dominant belowground competition for water. Since our findings are the first of their kind and contradict theoretical predictions of biomass dependence of net negative interactions, we advocate further experiments addressing size dependence in interactions among plants. In particular, theoretical models addressing size dependence of positive interactions must be developed.

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