scholarly journals Inter-annual variation in seed production has increased over time (1900–2014)

2017 ◽  
Vol 284 (1868) ◽  
pp. 20171666 ◽  
Author(s):  
Ian S. Pearse ◽  
Jalene M. LaMontagne ◽  
Walter D. Koenig
Keyword(s):  
Seed Production ◽  
Seed Set ◽  
Global Climate ◽  
Mast Seeding ◽  
Plant Seed ◽  
Subtle Change ◽  
Animal Populations ◽  
Wide Range ◽  
Seed Crops ◽  
Over Time

Mast seeding, or masting, is the highly variable and spatially synchronous production of seeds by a population of plants. The production of variable seed crops is typically correlated with weather, so it is of considerable interest whether global climate change has altered the variability of masting or the size of masting events. We compiled 1086 datasets of plant seed production spanning 1900–2014 and from around the world, and then analysed whether the coefficient of variation (CV) in seed set, a measure of masting, increased over time. Over this 115-year period, seed set became more variable for plants as a whole and for the particularly well-studied taxa of conifers and oaks. The increase in CV corresponded with a decrease in the long-term mean of seed set of plant species. Seed set CV increased to a greater degree in plant taxa with a tendency towards masting. Seed set is becoming more variable among years, especially for plant taxa whose masting events are known to affect animal populations. Such subtle change in reproduction can have wide-ranging effects on ecosystems because seed crops provide critical resources for a wide range of taxa and have cascading effects throughout food webs.

What determines the number of seed produced in a flowering event? A case study of Calyptrogyne ghiesbreghtiana (Arecaceae)

2000 ◽  
Vol 48 (5) ◽  
pp. 659 ◽  
Author(s):  
Saul A. Cunningham
Keyword(s):  
Resource Allocation ◽  
Seed Production ◽  
Natural Variation ◽  
Seed Set ◽  
Plant Seed ◽  
Flower Production ◽  
Number Of Seeds ◽  
Female Flowers

Calyptrogyne ghiesbreghtiana Linden ex. H. Wendl. is an understorey palm that occurs at La Selva Biological Station, Costa Rica. In this paper I combine analysis of natural variation and results of experimental manipulations to ask (1) what limits seed production? and (2) what processes cause variation in seed production by C. ghiesbreghtiana? The number of seed produced per inflorescence ofC. ghiesbreghtiana was limited substantially by the loss of female flowers to floral herbivores. Much variation in the number of seed produced perinflorescence of C. ghiesbreghtiana was due to losses of developing fruits to predators. Together these phenomena illustrate the influential role of natural enemies in the reproductive success of this plant. Seed-set efficiency (number of seeds/number of female flowers) was highly variable in this species, and such high levels of variation appear to be common in other species. For species with highly variable seed-set efficiency, the role of resource allocation to flower production in determining differences in seed production among individual plants is likely to be relatively small.

scholarly journals The ecology and evolution of synchronized reproduction in long-lived plants

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Mario B. Pesendorfer ◽  
Davide Ascoli ◽  
Michał Bogdziewicz ◽  
Andrew Hacket-Pain ◽  
Ian S. Pearse ◽  
...  
Keyword(s):  
Seed Production ◽  
Predictive Modelling ◽  
Ecosystem Dynamics ◽  
Mast Seeding ◽  
Plant Reproductive Success ◽  
Proximate Mechanisms ◽  
Human Interactions ◽  
Molecular Approaches ◽  
Ontogenetic Trajectory ◽  
Seed Crops

Populations of many long-lived plants exhibit spatially synchronized seed production that varies extensively over time, so that seed production in some years is much higher than on average, while in others, it is much lower or absent. This phenomenon termed masting or mast seeding has important consequences for plant reproductive success, ecosystem dynamics and plant–human interactions. Inspired by recent advances in the field, this special issue presents a series of articles that advance the current understanding of the ecology and evolution of masting. To provide a broad overview, we reflect on the state-of-the-art of masting research in terms of underlying proximate mechanisms, ontogeny, adaptations, phylogeny and applications to conservation. While the mechanistic drivers and fitness consequences of masting have received most attention, the evolutionary history, ontogenetic trajectory and applications to plant–human interactions are poorly understood. With increased availability of long-term datasets across broader geographical and taxonomic scales, as well as advances in molecular approaches, we expect that many mysteries of masting will be solved soon. The increased understanding of this global phenomenon will provide the foundation for predictive modelling of seed crops, which will improve our ability to manage forests and agricultural fruit and nut crops in the Anthropocene. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

scholarly journals The interplay between ovule number, pollination and resources as determinants of seed set in a modular plant

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5384 ◽  
Author(s):  
Marina M. Strelin ◽  
Marcelo A. Aizen
Keyword(s):  
Resource Allocation ◽  
Seed Production ◽  
Seed Set ◽  
Pollen Limitation ◽  
Rubus Idaeus ◽  
Physiological Integration ◽  
Open Pollination ◽  
Plant Resources ◽  
Plant Seed ◽  
Ovule Number

BackgroundA classical dichotomous perspective proposes that either pollination or plant resources limit seed production. However, ovule number could also be limiting when pollination results in complete ovule fertilization and there are more plant resources available than needed to develop seeds. Moreover, this dichotomous view assumes that all flowers of a plant have equal access to a shared pool of resources, although these are frequently compartmentalized within plant modules, for example, inflorescences. How ovule number, pollination and resources affect seed production in physiologically-compartmentalized rather than physiologically-integrated plants has yet to be explored. We used raspberry (Rubus idaeus) to address this question.MethodsWe first assessed if ovule number affected the fraction of ovules that develop into seed (i.e., seed set) and whether this effect related to the extent of physiological integration among flowers within plants. This was achieved by statistically testing predictions on the sign and level of plant organization (i.e., among flowers within inflorescences, among inflorescences within ramets, and among ramets) of the relation between ovule number and seed set given different degrees of physiological integration. We then explored whether the relation between ovule number and seed set was affected by plant age (used here as a surrogate of resource availability) and pollination intensity (open-pollination vs. exclusion).ResultsWithin inflorescences, flowers with more ovules set a larger fraction of seeds. On the other hand, seed set at the inflorescence level was negatively related to the average number of ovules per flower. Seed set increased with ovule number and open-pollination, and decreased with ramet age. However, ovule number explained more variation in seed set than ramet age and pollination treatment. Ramet age affected the strength of the relation of seed set to ovule number, which was stronger in old than young ramets. Pollination did not alter the strength of this relation to any significant extent.DiscussionResults reveal the importance of ovule number as an overriding factor affecting seed set. Within inflorescences, resources appear to be differentially allocated to developing fruits from flowers with many ovules. This is consistent with the fact that in the raspberry a large proportion of the carbon invested in fruit development is fixed by the inflorescence subtending leaf. Differential resource allocation to flowers with many ovules is not affected by pollinator exclusion, being stronger in resource-exhausted ramets. This suggests that the effects of pollen limitation and resource allocation are compartmentalized at the inflorescence level. Consequently, modular plants can be viewed as reproductive mosaics where either ovule number, pollination or resources limit the number of seeds set by different flowers, so that improvements in any of them could increase plant seed production.

Experimental studies on seed production of tropical grasses in Kenya. 5. The effect of time of nitrogen top dressing on seed crops of Setaria sphacelata cv. Nandi.

1972 ◽  
Vol 20 (4) ◽  
pp. 225-231
Author(s):  
J.G. Boonman
Keyword(s):  
Adverse Effect ◽  
Seed Production ◽  
Rainy Season ◽  
Seed Set ◽  
Experimental Studies ◽  
Late Season ◽  
Main Adverse Effect ◽  
Setaria Sphacelata ◽  
Seed Crops ◽  
Seed Yields

Effects of date of applying top-dressings of N to early-season and late-season seed crops of Setaria sphacelata cv. Nandi were studied in 4 trials in 1967-71. Highest seed yields were obtained when N was applied as soon as possible after the onset of the rainy season; a delay of 4 weeks reduced yields of pure germinating seed by >60%. Total yields of herbage DM and number of heads were also reduced, but to a lesser extent; the main adverse effect was on seed set/head. In late-season crops, applying N 2 weeks after the earliest possible date proved beneficial in 2 out of 3 years. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Understanding mast seeding for conservation and land management

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Ian S. Pearse ◽  
Andreas P. Wion ◽  
Angela D. Gonzalez ◽  
Mario B. Pesendorfer
Keyword(s):  
Seed Production ◽  
Land Management ◽  
Time Management ◽  
Forest Products ◽  
Plant Invasions ◽  
Rare Plants ◽  
Mast Seeding ◽  
Non Timber Forest Products ◽  
Near Term ◽  
Seed Crops

Masting, the intermittent and synchronous production of large seed crops, can have profound consequences for plant populations and the food webs that are built on their seeds. For centuries, people have recorded mast crops because of their importance in managing wildlife populations. In the past 30 years, we have begun to recognize the importance of masting in conserving and managing many other aspects of the environment: promoting the regeneration of forests following fire or other disturbance, conserving rare plants, conscientiously developing the use of edible seeds as non-timber forest products, coping with the consequences of extinctions on seed dispersal, reducing the impacts of plant invasions with biological control, suppressing zoonotic diseases and preventing depredation of endemic fauna. We summarize current instances and future possibilities of a broad set of applications of masting. By exploring in detail several case studies, we develop new perspectives on how solutions to pressing conservation and land management problems may benefit by better understanding the dynamics of seed production. A lesson common to these examples is that masting can be used to time management, and often, to do this effectively, we need models that explicitly forecast masting and the dynamics of seed-eating animals into the near-term future. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

scholarly journals Seed production of sugar maple and American beech in northern hardwood forests, New Hampshire, USA

2017 ◽  
Vol 47 (7) ◽  
pp. 985-990 ◽  
Author(s):  
Natalie L. Cleavitt ◽  
Timothy J. Fahey
Keyword(s):  
Seed Production ◽  
Tree Species ◽  
Sugar Maple ◽  
Hardwood Forests ◽  
Mast Seeding ◽  
Plant Resources ◽  
American Beech ◽  
Northern Hardwood Forests ◽  
Northern Hardwood ◽  
Seed Crops

Mast seeding is the synchronous production of large seed crops in plant populations and for many tree species is known to be determined by the interaction between weather cues and internal plant resources. We use a 24-year record of seedfall for sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.) across a northern hardwood forest landscape to quantify their masting patterns and explore the relationship between mast years, resources, and weather cues, particularly the difference between summer temperatures in the two years prior to the seedfall year (ΔT). We found clear evidence of masting in these species, and mast years were often coincident in the two species; masting was best predicted by ΔT or ΔT plus previous-year seedfall. We saw no evidence for correspondence of masting in these trees to precipitation cues. A soil calcium addition modified elevation effects on seed production. Clarification of the controls on mast seeding for these important tree species will aid in predicting such resources as mast for wildlife and maple sugar production in northern hardwood forests.

scholarly journals Proximate causes and possible adaptive functions of mast seeding and barren flower shows in spinifex grasses (Triodia spp.) in arid regions of Australia

2014 ◽  
Vol 36 (3) ◽  
pp. 297 ◽  
Author(s):  
Boyd R. Wright ◽  
Alain F. Zuur ◽  
Gary C. K. Chan
Keyword(s):  
Arid Regions ◽  
Seed Set ◽  
Heavy Rain ◽  
Mast Seeding ◽  
High Yield ◽  
Seed Predator ◽  
Related Form ◽  
Proximate Causes ◽  
High Precipitation ◽  
Seed Crops

Mast seeding, the intermittent production of large synchronised seed crops among plant populations, is a phenomenon that occurs at exceptionally long intervals in spinifex grasses (Triodia spp.) from arid regions of Australia. This is despite the reliance of these fire-sensitive plants on seeds for post-fire regeneration, and that spinifex grasslands rate among Australia’s most flammable ecosystems. The proximate causes and possible adaptive functions of masting in seven species of spinifex from arid regions within the 350-mm rainfall isohyet were investigated. Specifically, the seed set percentages of 79 specimens collected between 1947 and 2012 were related to the following environmental covariates: antecedent rainfall over 6, 12 and 36 months, relative humidity, and the number of days above 40°C and below 0°C during anthesis. Given the potential importance of seeding events for post-fire regeneration, it was also investigated whether masting in Triodia could represent a fire-related form of environmentally predictive masting, by testing whether high-yield years corresponded to years of increased fire occurrence. Examination of the dataset showed that 43% of specimens contained completely aborted inflorescences (0% seed fill), while seed set ranged from 2 to 69% in the remaining specimens. High levels of insect activity were also found, with 42% of specimens showing evidence of insect occupation. Statistical analyses showed that the main environmental driver of seed set was high precipitation over the previous 12 months, and that high-yield years were strongly related to years of increased fire likelihood. The number of days over 40°C was a weakly significant driver of yield, while the remaining covariates were not significant. It is hypothesised that intermittent reproduction by Triodia is a fire-related form of environmentally predictive masting, which maximises chances of post-fire regeneration by satiating seed predators during flammable periods (i.e. after heavy rain years). Furthermore, it is suggested that non-viable flower crops after initial low rainfalls may have an adaptive function, by diluting pre-dispersal seed predator densities with ‘decoy’ ovules that do not mature and lead to the starvation of developing larvae.

Anti-corruption in History

2017 ◽  
Keyword(s):  
Financial Institutions ◽  
Global Media ◽  
Policy Makers ◽  
The Past ◽  
Human Wellbeing ◽  
Modern Period ◽  
Legitimate Power ◽  
Wide Range ◽  
Scant Attention ◽  
Over Time

Anticorruption in History is the first major collection of case studies on how past societies and polities, in and beyond Europe, defined legitimate power in terms of fighting corruption and designed specific mechanisms to pursue that agenda. It is a timely book: corruption is widely seen today as a major problem, undermining trust in government, financial institutions, economic efficiency, the principle of equality before the law and human wellbeing in general. Corruption, in short, is a major hurdle on the “path to Denmark”—a feted blueprint for stable and successful statebuilding. The resonance of this view explains why efforts to promote anticorruption policies have proliferated in recent years. But while the subjects of corruption and anticorruption have captured the attention of politicians, scholars, NGOs and the global media, scant attention has been paid to the link between corruption and the change of anticorruption policies over time and place. Such a historical approach could help explain major moments of change in the past as well as reasons for the success and failure of specific anticorruption policies and their relation to a country’s image (of itself or as construed from outside) as being more or less corrupt. It is precisely this scholarly lacuna that the present volume intends to begin to fill. A wide range of historical contexts are addressed, ranging from the ancient to the modern period, with specific insights for policy makers offered throughout.

scholarly journals Silicon Effects on the Root System of Diverse Crop Species Using Root Phenotyping Technology

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 885
Author(s):  
Pooja Tripathi ◽  
Sangita Subedi ◽  
Abdul Latif Khan ◽  
Yong-Suk Chung ◽  
Yoonha Kim
Keyword(s):  
Root System ◽  
Root Morphology ◽  
Morphological Traits ◽  
Crop Production ◽  
Spatial Configuration ◽  
Global Climate ◽  
Learning Technologies ◽  
Climate Change Scenarios ◽  
Crop Species ◽  
Wide Range

Roots play an essential function in the plant life cycle, as they utilize water and essential nutrients to promote growth and plant productivity. In particular, root morphology characteristics (such as length, diameter, hairs, and lateral growth) and the architecture of the root system (spatial configuration in soil, shape, and structure) are the key elements that ensure growth and a fine-tuned response to stressful conditions. Silicon (Si) is a ubiquitous element in soil, and it can affect a wide range of physiological processes occurring in the rhizosphere of various crop species. Studies have shown that Si significantly and positively enhances root morphological traits, including root length in rice, soybean, barley, sorghum, mustard, alfalfa, ginseng, and wheat. The analysis of these morphological traits using conventional methods is particularly challenging. Currently, image analysis methods based on advanced machine learning technologies allowed researchers to screen numerous samples at the same time considering multiple features, and to investigate root functions after the application of Si. These methods include root scanning, endoscopy, two-dimensional, and three-dimensional imaging, which can measure Si uptake, translocation and root morphological traits. Small variations in root morphology and architecture can reveal different positive impacts of Si on the root system of crops, with or without exposure to stressful environmental conditions. This review comprehensively illustrates the influences of Si on root morphology and root architecture in various crop species. Furthermore, it includes recommendations in regard to advanced methods and strategies to be employed to maintain sustainable plant growth rates and crop production in the currently predicted global climate change scenarios.

scholarly journals A Newfangled Collagenase Inhibitor Topical Formulation Based on Ethosomes with Sambucus nigra L. Extract

2021 ◽  
Vol 14 (5) ◽  
pp. 467
Author(s):  
Ana Henriques Mota ◽  
Inês Prazeres ◽  
Henrique Mestre ◽  
Andreia Bento-Silva ◽  
Maria João Rodrigues ◽  
...  
Keyword(s):  
Biological Activities ◽  
Scientific Evidence ◽  
Release Profile ◽  
Health Claims ◽  
Topical Formulation ◽  
Sambucus Nigra ◽  
Western Asia ◽  
Wide Range ◽  
The Impact ◽  
Over Time

Sambucus nigra L. (S. nigra) is a shrub widespread in Europe and western Asia, traditionally used in medicine, that has become popular in recent years as a potential source of a wide range of interesting bioactive compounds. The aim of the present work was to develop a topical S. nigra extract formulation based on ethosomes and thus to support its health claims with scientific evidence. S. nigra extract was prepared by an ultrasound-assisted method and then included in ethosomes. The ethosomes were analyzed in terms of their size, stability over time, morphology, entrapment capacity (EC), extract release profile, stability over time and several biological activities. The prepared ethosomes were indicated to be well defined, presenting sizes around 600 nm. The extract entrapment capacity in ethosomes was 73.9 ± 24.8%, with an interesting slow extract release profile over 24 h. The extract-loaded ethosomes presented collagenase inhibition activity and a very good skin compatibility after human application. This study demonstrates the potential use of S. nigra extract incorporated in ethosomes as a potential cosmeceutical ingredient and on further studies should be performed to better understand the impact of S. nigra compounds on skin care over the time.

Sign in / Sign up

Export Citation Format

Share Document