Post-dispersal seed predation and seed bank persistence

1998 ◽  
Vol 8 (4) ◽  
pp. 513-519 ◽  
Author(s):  
P. E. Hulme
Keyword(s):  
Seed Size ◽  
Seed Bank ◽  
Seed Predation ◽  
Negative Relationship ◽  
Seed Mass ◽  
Seed Banks ◽  
Seed Removal ◽  
Seed Predators ◽  
Grassland Plants ◽  
Buried Seeds

AbstractThis study examines whether post-dispersal seed predators could be an important selective force in determining the seed bank strategies of grassland plants. It tests the hypothesis that species with persistent seed banks should sustain proportionally less predation of buried seeds than species which have transient seed banks and that this should be true irrespective of seed size. Results are drawn from a field experiment examining the relative susceptibility of surface versus buried seeds for 19 herbaceous taxa exhibiting different degrees of seed bank persistence. The data were consistent with the hypothesis that seed predators (rodents) influence the seed bank characteristics of seeds. Rodents removed proportionally more large seeds than small seeds and removed a smaller proportion of seeds with persistent rather than transient seed banks, independently of seed size. On average, burial reduced seed removal by almost 50%. The decrease in rates of seed removal following burial was marked for seeds with persistent seed banks but negligible for seeds with transient seed banks. Herbaceous plants with relatively large seeds (seed mass > 1 mg) that form persistent seed banks were either completely avoided or only consumed in small quantities by rodents. In contrast, large-seeded species with transient seed banks suffer high rates of seed predation. Models of life-history evolution predict trade-offs between seed dormancy and seed mass since dormancy and seed size are correlated traits that both reduce risk in variable environments and thus will show patterns of negative covariation. This paper presents an alternative explanation for this trade-off based on experimental evidence of a negative relationship between seed bank persistence and predation risk.

scholarly journals Characterization and ecological significance of a seed bank from the Upper Pennsylvanian Wise Formation, southwest Virginia

2017 ◽  
Vol 57 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Petra S. Yehnjong ◽  
Michael S. Zavada ◽  
Chris Liu
Keyword(s):  
Seed Size ◽  
Seed Bank ◽  
Seedling Establishment ◽  
Environmental Variability ◽  
Seed Banks ◽  
Evolutionary Strategy ◽  
Predator Population ◽  
Seed Density ◽  
Soil Seed Banks ◽  
Large Seed

AbstractSoil seed banks are important to the maintenance and restoration of floras. Extant seed banks exhibit unique characteristics with regard to the distribution of seed size and seed density. Seeds were recovered from the Upper Pennsylvanian Wise Formation in southwest Virginia. Structurally preserved seeds were also examined from coal balls of the Pennsylvanian Pottsville and Allegheny Groups, Ohio. The size distribution of the seeds from the Wise Formation is similar to that of structurally preserved seeds of the Upper Pennsylvanian Pottsville and Allegheny Group coal balls. In contrast, the seed size distributions in extant wetland, grassland, woodland and forest habitats are significantly narrower than that of seeds from the Pennsylvanian seed banks. Larger seeds are less dependent on light for germination, and aid in seedling establishment more than smaller seeds, especially in dense stable forests where disturbance events are rare. Large seed size may contribute to increased seed longevity, which reduces the effect of environmental variability on seed germination and development. The significantly larger size of the Palaeozoic seeds may have imparted an advantage for seedling establishment in the dense Palaeozoic forests. The preponderance of large seeds may be a result of the absence of large seed predators (e.g. herbivorous tetrapods), and may have been an evolutionary strategy to minimize damage to the embryo from a predator population dominated by small invertebrates with chewing or sucking mouthparts. The estimated seed density of 192 seeds/m2in the Palaeozoic seed bank falls within the range of modern seed banks, but at the lower end of modern seed bank densities in a variety of habitats.

The paradox of berry production in temperate species of Vaccinium

1994 ◽  
Vol 72 (1) ◽  
pp. 52-58 ◽  
Author(s):  
S. P. Vander Kloet ◽  
N. M. Hill
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Bank ◽  
Soil Column ◽  
Common Species ◽  
Seed Banks ◽  
Soil Cores ◽  
Vegetative Cover ◽  
Buried Seeds ◽  
Avalon Peninsula

Vegetative cover, fruiting phenology, and seed production was estimated from six Vaccinia heathlands on the Avalon Peninsula of Newfoundland so that the efficacy of the Vaccinium seed bank could be ascertained. Out of the six species of Vaccinium present in this vegetation, only V. angustifolium and V. boreale were recovered from 120 soil cores taken; V. uliginosum and V. vitis-idaea, two of the most common species on these heaths, were not represented in the seed bank at all, yet experimentally buried seeds from both these taxa will successfully germinate when exhumed after 6 years of burial. Indeed, 81% of the germinants were from taxa with dry fruits such as Kalmia, Luzula, Juncus, and Agrostis. Paucity of Vaccinium seed in the soil column may be due in part to fungal rot and avian predation. Key words: Vaccinium, seed production, seed banks, heaths.

Post-dispersal losses to seed predators: an experimental comparison of native and exotic old field plants

2001 ◽  
Vol 79 (3) ◽  
pp. 284-292 ◽  
Author(s):  
C S Blaney ◽  
P M Kotanen
Keyword(s):  
Seed Predation ◽  
Seed Mass ◽  
Interspecific Variation ◽  
Experimental Comparison ◽  
Old Fields ◽  
Old Field ◽  
Seed Predators ◽  
Predator Exclusion ◽  
Reduced Rate ◽  
Insect Exclusion

Invasions by exotic plants may be more likely if exotics have low rates of attack by natural enemies, including post-dispersal seed predators (granivores). We investigated this idea with a field experiment conducted near Newmarket, Ontario, in which we experimentally excluded vertebrate and terrestrial insect seed predators from seeds of 43 native and exotic old-field plants. Protection from vertebrates significantly increased recovery of seeds; vertebrate exclusion produced higher recovery than controls for 30 of the experimental species, increasing overall seed recovery from 38.2 to 45.6%. Losses to vertebrates varied among species, significantly increasing with seed mass. In contrast, insect exclusion did not significantly improve seed recovery. There was no evidence that aliens benefitted from a reduced rate of post-dispersal seed predation. The impacts of seed predators did not differ significantly between natives and exotics, which instead showed very similar responses to predator exclusion treatments. These results indicate that while vertebrate granivores had important impacts, especially on large-seeded species, exotics did not generally benefit from reduced rates of seed predation. Instead, differences between natives and exotics were small compared with interspecific variation within these groups.Key words: aliens, exotics, granivores, invaders, old fields, seed predators.

Local seed rain and seed bank in a species-rich grassland: effects of plant abundance and seed size

2006 ◽  
Vol 84 (12) ◽  
pp. 1870-1881 ◽  
Author(s):  
Anna Jakobsson ◽  
Ove Eriksson ◽  
Hans Henrik Bruun
Keyword(s):  
Seed Size ◽  
Seed Bank ◽  
Negative Relationship ◽  
Seed Rain ◽  
Positive Relationships ◽  
Plant Abundance ◽  
M 10 ◽  
Seed Trap ◽  
Perennial Grassland ◽  
The Relationship

In this study, we examined the relationship between seed size, seed rain, and seed bank in a species-rich perennial grassland in Sweden. The seed rain was monitored by 100 seed traps placed in a 10 m × 10 m area for 1 year. The seed bank was sampled by taking 100 soil samples, each in close vicinity to a seed trap. Abundance of reproductive ramets in the area was estimated, since this is likely to affect the proportion of hit seed traps and seed bank samples. When abundance of reproductive ramets was accounted for, we found a negative relationship between seed size and proportion of hit seed bank samples, but we found no relationship between seed size and proportion of hit seed traps. We found strong positive relationships between the abundance of reproductive ramets and proportion of hit seed traps and seed bank samples. We also found strong positive relationships between abundance of reproductive ramets and abundance of seeds in the seed rain and the seed bank, but no relationship between seed size and abundance of seeds in the seed rain or the seed bank. We discuss these results in the context of theory suggesting that large-seeded and small-seeded species may coexist because of a trade-off between colonization and competitive abilities, where smaller-seeded species are able to reach more sites than seeds of larger-seeded species, because they are more numerous and (or) better dispersed.

Seed-coat thickness data clarify seed size–seed-bank persistence trade-offs inAbutilon theophrasti(Malvaceae)

2014 ◽  
Vol 24 (2) ◽  
pp. 119-131 ◽  
Author(s):  
Brian J. Schutte ◽  
Adam S. Davis ◽  
Stephen A. Peinado ◽  
Jamshid Ashigh
Keyword(s):  
Seed Size ◽  
Seed Coat ◽  
Seed Bank ◽  
Explanatory Power ◽  
Seed Mass ◽  
Trade Offs ◽  
Selection For ◽  
Viable Seeds ◽  
Seed Coats ◽  
Size Data

AbstractTheoretical models predict that seed size and seed-bank persistence evolve interdependently, such that strong selection for one trait corresponds with weak selection for the other. This framework has been supported and rejected by empirical data, and thus, conclusive evidence is lacking. We expanded the seed size–persistence framework to include seed-coat thickness, a defence trait previously correlated with seed survival in soil. To do this, we usedAbutilon theophrastiaccessions with varied evolutionary histories and we quantified associations among seed traits including morphology, size, coat thickness, dormancy (percentage of viable seeds that fail to germinate under optimum conditions) and seed-bank persistence (percentage of viable seeds remaining after 1 year of burial). Statistical models were developed to test the hypothesis that combined measurements of seed-coat thickness and seed size better explain variability in seed-bank persistence than seed-size data alone. Results indicated that measurements of seed size (length, width, mass) were negatively correlated with coat:width ratio (coat thickness relative to seed width) and coat:mass ratio (coat thickness relative to seed mass). Accessions characterized by smaller seeds with proportionally thicker seed coats were more dormant and more persistent in soil than accessions characterized by larger seeds with proportionally thinner seed coats. Seed-coat thickness data improved the explanatory power of logistic regression models for seed-size effects on both seed-bank persistence and dormancy. These results indicate that supplementing seed-size data with seed-defence data may clarify previously reported contradictory results regarding trade-offs between seed size and seed-bank persistence.

Seed size and shape are good predictors of seed persistence in soil in temperate mountain grasslands of Argentina

1999 ◽  
Vol 9 (4) ◽  
pp. 341-345 ◽  
Author(s):  
Guillermo Funes ◽  
Sandra Basconcelo ◽  
Sandra Díaz ◽  
Marcelo Cabido
Keyword(s):  
Seed Size ◽  
Previous Experiment ◽  
Seed Mass ◽  
Seed Banks ◽  
Herbaceous Species ◽  
Seed Persistence ◽  
Tagetes Minuta ◽  
Mountain Grasslands ◽  
Germinable Seed ◽  
Montane Grasslands

AbstractWe tested whether seed mass and shape are good predictors of seed persistence in the soil of subhumid temperate montane grasslands of central Argentina. We plotted seed mass against variance of seed dimensions of 71 herbaceous species and obtained information on their persistence in the soil from a previous experiment on germinable seed banks. We identified a certain seed mass/shape combination beyond which no seed was persistent in the soil, with the exception of the annual Tagetes minuta. Our results confirmed the patterns previously reported for British species: small and compact seeds tend to persist in the soil for a longer time than big and elongated or flattened seeds. We suggest that the value of seed mass and shape as predictors of persistence in the soil can be extended beyond the British flora to herbaceous floras from other humid temperate regions.

scholarly journals Seed bank formation and removal of Pinus hartwegii (Pinaceae) seeds along an altitudinal gradient in the Cofre de Perote National Park, Veracruz, Mexico

2019 ◽  
Vol 97 (4) ◽  
pp. 623-629
Author(s):  
Victor Manuel Tejeda Landero ◽  
Lázaro Rafael Sánchez-Velásquez ◽  
Héctor Viveros-Viveros ◽  
Armando Aparicio-Rentería ◽  
Rafael Flores-Peredo
Keyword(s):  
Seed Bank ◽  
National Park ◽  
Altitudinal Gradient ◽  
Seed Banks ◽  
Study Data ◽  
Seed Removal ◽  
Data Description ◽  
Pinus Hartwegii ◽  
Different Seasons ◽  
One Year

Background: Seed banks, an important element in the natural regeneration of plant communities, are regulated mostly by granivores along an altitudinal gradient. Question/Hypothesis: Pinus hartwegii forms transient and probably persistent seed banks along an altitudinal gradient. Seed removal will vary according to the removing agents, the altitude and the season. Species under study/Data description/Mathematical model: The formation of seed banks and the removal of Pinus hartwegii (Pinaceae) seeds along an altitudinal gradient were evaluated in different seasons using a linear model with two factorial variance analyses.  Site and years of study: The study was conducted at the Cofre de Perote National Park, Veracruz, Mexico, over an altitudinal gradient (at 3,400, 3,600, 3,800 and 4,000 m a.s.l.) in July-September 2015 (rainy season), and January-March 2016 (dry season).  Methods: In order to understand seed bank formation and identify the removal agents along an altitudinal gradient, two experiments were conducted with seeds from 10 trees at each altitudinal tier. Results: The results of the first experiment, after one year, demonstrated the formation of transient and probably persistent seed banks along an altitudinal gradient (P < 0.0001). The results of the second experiment showed significant variations in seed removal according to the removal agents and the seasons (P < 0.0001). Conclusions: Pinus hartwegii forms transient and probably persistent seed banks along an altitudinal gradient. Seed removal varies according to altitude and season.

Testing seed-size predictions in Mediterranean annual grasslands

2010 ◽  
Vol 20 (3) ◽  
pp. 179-188 ◽  
Author(s):  
Francisco M. Azcárate ◽  
Pablo Manzano ◽  
Begoña Peco
Keyword(s):  
Seed Size ◽  
Seed Predation ◽  
Seed Mass ◽  
Grazing Pressure ◽  
Community Level ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Summer Drought ◽  
Mediterranean Grasslands ◽  
Species Frequencies

AbstractOn the basis of previous research, we predict that Mediterranean grasslands should show larger-seeded annuals in: (1) more-arid grasslands; (2) more-fertile soils; (3) less-grazed grasslands; and (4) grasslands with lower intensities of seed predation by ants. To test these predictions, we set 29 sampling units of 50 m × 50 m in a 1000 km2 grassland area in Central Spain, and characterized them according to the former factors. We then recorded annual vegetation using ten quadrats of 20 cm × 20 cm in each sampling unit. Seed size at the community level was described using six variables: (1) mean seed mass; (2) standard deviation of seed mass; (3) weighted mean seed mass (by species frequencies); (4) proportion of small-seeded annuals; (5) proportion of medium-seeded annuals; and (6) proportion of large-seeded annuals. Most climate variables (mean annual temperature, length of the summer drought, water balance and mean annual precipitation) correlated with seed-size descriptors, showing that large-seeded annuals increase in warmer and more-arid communities. Mean seed size was modelled as a function of mean annual temperature and grazing pressure. According to this model, warmer and less-grazed communities tend to show a smaller mean seed size. These results confirm the importance of seed-size descriptors at the community level in Mediterranean grasslands, and the role of climate and grazing as major drivers in these communities. Conversely, hypotheses about soil fertility and seed predation by ants were not supported by our results.

Effect of different treatments on the seed bank of grazed and ungrazed Baltic seashore meadows

1998 ◽  
Vol 76 (7) ◽  
pp. 1188-1197 ◽  
Author(s):  
Heli M. Jutila b. Erkkilä
Keyword(s):  
Seed Bank ◽  
Brackish Water ◽  
Salt Water ◽  
Tap Water ◽  
Cold Treatment ◽  
Abundant Species ◽  
Seed Banks ◽  
The West ◽  
Pesticide Treatment ◽  
Juncus Gerardii

Seed banks of two seashore meadows were studied on the west coast of Finland (latitude 61°30'-61°33'N, longitude 21°28'-21°41'E). Samples were taken in June to a depth of 10 cm in the geolittoral zone of the grazed and ungrazed transects. The grazed samples were halved lengthwise: one half was grown immediately, the other after cold treatment. One third of the all samples was treated as controls, one third was watered with brackish water, and one third was given a pesticide treatment. Altogether, 13 926 seedlings germinated and 25 species were identified (three annuals, two biennials, and the rest perennials). Most seedlings were perennial monocots, with Juncus gerardii Loisel. the most abundant species. The seed bank was significantly larger and richer in the ungrazed site than in the grazed site. Cold treatment reduced the number of germinating species and seedlings. In the grazed and non-cold-treated samples, the numbers of species and seedlings were highest in the pesticide treatment. In ungrazed samples there were no significant differences among treatments. After the cold treatment, the least number of species and seedlings was produced by the salt-water treatment. Changing brackish water to tap water led to a burst of germination, especially of J. gerardii. The seed bank of the upper geolittoral zone was richer than that of the middle geolittoral. The multivariate classification and ordination groupings are based on the abundances of J. gerardii and Glaux maritima L.; different treatments were not distinguishable. There was a low resemblance between the seed bank and the aboveground vegetation.Key words: seed bank, salinity, pesticide, seashore meadow, cold treatment, vegetation.

Seed production and seedling emergence of Giant Parramatta grass on the north coast of New South Wales

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
New South ◽  
New South Wales ◽  
Seed Banks ◽  
North Coast ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
The Impact

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.

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