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.

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.

The role of seedbanks in invasions by Hyparrhenia hirta (L.) Stapf in Australia

2019 ◽  
Vol 41 (5) ◽  
pp. 383 ◽  
Author(s):  
Vinod K. Chejara ◽  
Paul Kristiansen ◽  
R. D. B. (Wal) Whalley ◽  
Brian M. Sindel ◽  
Christopher Nadolny
Keyword(s):  
South African ◽  
Seed Production ◽  
Seed Dormancy ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Perennial Grass ◽  
Seed Banks ◽  
Invasive Weed ◽  
South Wales ◽  
Poor Seed

Hyparrhenia hirta (L.) Stapf (also known as Coolatai grass, South African bluestem or thatching grass) has become a serious invasive weed in Australia. Within its native range, it is generally regarded as a useful grass particularly for thatching, and seed production is low with a low soil seed bank of from 2 to 200seedsm–2. Several hundred accessions of H. hirta were deliberately introduced into Australia up until the 1980s and nearly all were discarded because of poor seed production. However, at least one introduction in the 1890s in northern New South Wales (NSW), Australia, has possibly contributed to the present serious weed problem. Annual seed production from roadside stands in northern NSW ranged from 7000 to 92000seedsm–2 in 2015. The soil seed bank under dense H. hirta infestations in the same region in 2006 and 2007, was found to be ~30000seedsm–2 mostly confined to the top 2cm, with few dormant seeds and a large reduction of these numbers over the next 12 months when further seed input was prevented. Similar studies of other perennial grass weeds have found seed banks of similar sizes, but dormancy mechanisms ensure that their seed banks last for at least 10 years without further seed input. These results suggest that the present weedy populations of H. hirta have dramatically increased fecundity enabling a large seed bank to develop beneath dense stands. The development of seed dormancy and consequently a long-lived seed bank would make this weed even more difficult to control. Until seed dormancy develops, control of H. hirta in northern NSW can be effective provided further input into the seed bank can be prevented.

Buried propagule bank of a high subalpine site: microsite variation and comparisons with aboveground vegetation

1993 ◽  
Vol 71 (5) ◽  
pp. 712-717 ◽  
Author(s):  
Cheryl A. Ingersoll ◽  
Mark V. Wilson
Keyword(s):  
Spatial Pattern ◽  
Key Words ◽  
Seed Bank ◽  
Vegetation Cover ◽  
Bare Soil ◽  
Soil Cores ◽  
Cascade Mountains ◽  
Greenhouse Soil ◽  
Propagule Bank ◽  
Bare Soils

We assessed the composition and spatial pattern of the persistent buried propagule bank (seeds and vegetative structures) of a treeline site in the Oregon Cascade Mountains. We monitored emergence from soil cores removed from four microsite types and recorded vegetation cover and seedling abundance on the site. Over 3100 seedlings/m2 emerged from the greenhouse soil cores; the seed bank was dominated by Juncus species. Few vegetative sprouts emerged. Vegetated microsites produced significantly more emergents than did bare soils, but even bare soils contained abundant seeds. Overall site cover was low and few seedlings occurred on the site. Discrepancies between aboveground and belowground abundance were common. Phyllodoce empetriformis and Luetkea pectinata were abundant in the vegetation and produced many seeds but were poorly represented in the seed bank and as seedlings on the site. Other species were abundant in the seed bank, but rare in the vegetation. Our results indicate that despite the abundance of seeds in bare soil, colonization is likely to be extremely slow. Key words: seed bank, subalpine, seedlings, microsite, spatial pattern.

Effect of a Living Mulch on Weed Seed Banks in Tomato

2011 ◽  
Vol 25 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Kevin D. Gibson ◽  
John Mcmillan ◽  
Stephen G. Hallett ◽  
Thomas Jordan ◽  
Stephen C. Weller
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
Critical Period ◽  
Field Studies ◽  
Seed Banks ◽  
Weed Suppression ◽  
Weed Seed ◽  
Fresh Market ◽  
Living Mulch ◽  
Seed Rate

Weeds that emerge between rows in fresh market tomatoes after the critical period of competition are not suppressed by the crop and can produce large quantities of seed. A living mulch planted between rows might limit weed seed production. Buckwheat was seeded between tomato rows after the critical period in 2007 and 2008 in field studies near Lafayette, IN. Weeds were allowed to emerge after the critical period (CP), controlled throughout the growing season (no seed threshold [NST]), or mowed to limit seed production (MOW). Buckwheat and MOW plots were mowed twice after the critical period in 2007 and once in 2008. Seed banks were sampled after the critical period and in the following spring. Tomato yields were not reduced by growing buckwheat between rows. Seed bank densities for common purslane and carpetweed, which escaped mowing due to their prostrate habits, increased in all treatments. Germinable seed bank densities were 306 seeds m−2or less in the NST and buckwheat treatments but 755 seeds m−2or more in the CP treatments for species with erect habits in both years. Seed bank densities were lower in the MOW treatment than in the CP treatments in 2007 but not in 2008. In a parallel experiment conducted in adjacent plots, buckwheat was seeded at five rates (0, 56, 112, 168, and 224 kg seed ha−1). Plots were mowed and emergent weeds sampled as described for the intercrop experiment. Weed densities before mowing decreased linearly with buckwheat seed rate. After mowing, no relationship was detected between seed rate and weed densities. This study supports the hypothesis that a living mulch planted after the critical period can be used to limit seed bank growth without reducing tomato yields, but additional research is needed to better understand the effect of mowing on living mulch growth and weed suppression.

Seed bank size and composition of Betula nana, Vaccinium uliginosum, and Campanula rotundifolia habitats in Svalbard and northern Norway

2003 ◽  
Vol 81 (3) ◽  
pp. 220-231 ◽  
Author(s):  
Inger Greve Alsos ◽  
Sigmund Spjelkavik ◽  
Torstein Engelskjøn
Keyword(s):  
Seed Bank ◽  
Seed Banks ◽  
Climatic Conditions ◽  
The Arctic ◽  
Soil Cores ◽  
Betula Nana ◽  
Northern Norway ◽  
Vaccinium Uliginosum ◽  
Campanula Rotundifolia ◽  
Alpine Habitats

The rare thermophilous species in the arctic archipelago of Svalbard are probably relicts from previous warmer periods and may be unable to reproduce sexually under the present climatic conditions. Germination of seeds, seed banks, and vegetative sprouts were studied in one Betula nana L., one Vaccinium uliginosum L., and two Campanula rotundifolia L. habitats in Svalbard. For comparison, one islet and three alpine habitats in northern Norway were studied. In each habitat, 50 soil cores (9.6 cm2) were collected and placed in a phytotron for germination tests. In Svalbard, no germinable seeds or seed bank of the three species were observed, whereas vegetative sprout densities were 83, 1060, and 21–1060/m2 for B. nana, V. uliginosum, and C. rotundifolia, respectively. In northern Norway, germination percentages of the collected seeds were 59, 10–27, and 15–40%, seed bank densities of seedlings 21–2765, 21–187, and 21–374/m2, and vegetative sprouts densities 94–206, 56–674, and 94–711/m2 for B. nana, V. uliginosum, and C. rotundifolia, respectively. Less thermophilous plant species produced germinable seeds in Svalbard, as 1247–5405 seedlings/m2 of 26 species germinated from the soil cores. In comparison, 5322–9626 seedlings/m2 of 43 species germinated in soil cores from the alpine habitats and 3534 seedlings/m2 of 26 species from the islet habitat. The results suggest that the most thermophilous species in Svalbard rarely produce germinable seeds under the present climatic conditions.Key words: arctic–alpine, Betula nana, Campanula rotundifolia, seed bank, sexual reproduction, thermophily, Vaccinium uliginosum.

scholarly journals Edaphic and Seasonal Heterogeneity of Seed Banks in Agricultural Fields of a Tropical Dry Forest Region in Southern Mexico

2012 ◽  
Vol 90 (3) ◽  
pp. 287 ◽  
Author(s):  
Jorge A. Meave ◽  
Claudia Flores-Rodríguez ◽  
Eduardo A. Pérez-García ◽  
Marco Antonio Romero-Romero
Keyword(s):  
Seed Bank ◽  
Tropical Dry Forest ◽  
Abundant Species ◽  
Black Soil ◽  
Seed Banks ◽  
Dry Forest ◽  
Agricultural Fields ◽  
Tropical Region ◽  
Soil Cores ◽  
Southern Mexico

<p class="p1"><span class="s1">The slash-and-burn agriculture practiced across tropical dry regions results in the elimination of native vegetation. Upon field abandonment, the seed bank becomes a potentially important mechanism of natural regeneration at early successional stages. Soil properties and climate seasonality may affect seed bank characteristics, thus we analyzed the effects of these two factors on seed bank density and composition in agricultural fields of a seasonally dry tropical region of southern Mexico. Soil cores were collected for the rainy and the dry seasons in order to assess changes occurring in the seed bank from the time of harvest to the moment when succession could potentially start (the next rainy season). The 12 studied fields comprised three different soil types recognized by local inhabitants: sandy and stony, silty, and clayey soils, locally known as cascajo, black soil, and red soil, respectively. At each fi eld 20 soil cores (8 cm diameter, 4.5 cm depth) were collected and mixed to form four pooled samples, which were placed in a greenhouse to induce germination. A total of 4,422 seedlings (2,291 seeds m<sup>-2</sup>) representing 40 species were recorded. The most abundant species were, in decreasing order, <em>Melanthera nivea</em>, <em>Rhynchelytrum repens</em>, <em>Waltheria indica</em>, <em>Amaranthus scariosus</em>, <em>Digitaria bicornis</em>, and <em>Cenchrus pilosus</em>. Herbs were the prevailing growth form (&gt; 80% of total richness). No clear pattern was observed in the seed bank related to soil type; however, seed bank characteristics tended to be associated with the time of use of the agricultural fields, a variable that was not controlled in the study. Seed bank species richness was significantly larger in the dry season, and although seed density showed a similar trend, it was not significant. The studied seed banks contain no elements of the regional primary tropical dry forest, which suggests that seed banks in deforested areas cannot guarantee their maintenance beyond forested areas.</span></p>

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 Soil Seed Bank and Aboveground Vegetation in Grazing Lands of Southern Marmara, Turkey

2011 ◽  
Vol 39 (1) ◽  
pp. 96 ◽  
Author(s):  
Altıngül ÖZASLAN PARLAK ◽  
Ahmet GÖKKUŞ ◽  
Hasan Can DEMİRAY
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Common Species ◽  
Seed Banks ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Vegetation Survey ◽  
Soil Seed Banks ◽  
Grazing Lands

The composition and conservation of plant communities is greatly influenced by the soil seed bank. Information on the soil seed banks and the remaining vegetation in these ecosystems is crucial for guiding the restoration efforts. This study examines the size, species richness, diversity, uniformity, and similarity of soil seed banks and aboveground vegetation in 6 different grazing lands including coastal pasture, reseeded pasture, artificial pasture, lowland shrubland, ungrazed pasture, and hillside shrubland. Forty-eight soil samples were taken by cores with a diameter and depth of 10 cm from each of grazing lands in August of 2007. A vegetation survey was conducted using a 0.5 x 0.5-m quadrant in both the spring and fall. Eighty species were observed in soil seed banks and aboveground vegetation. The largest seed bank was observed in reseeded pasture (7,715 seed/m2), while the smallest seed bank was found in coastal pasture (2,755 seed/m2). Coastal pasture also possessed the least amount of aboveground vegetation (131 plants/m2). The most aboveground vegetation was found in ungrazed pasture (155 plants/m2). The most common species in seed banks were annual and perennial grasses in reseeded pasture, annual forbs in artificial pasture and hillside shrubland, and perennial forbs in low shrubland and ungrazed pasture. Species richness, diversity, and uniformity in seed banks were highest in lowland shrubland and lowest in artificial pasture. The seed bank and aboveground vegetation were similar in ungrazed pasture, coastal pasture, reseeded pasture, low shrubland, hillside shrubland and artificial pasture. Shrublands play an important role in species richness and the number of germinated seeds from seed banks of grazing lands in southern Marmara. The results showed that reseeding or a decrease in grazing pressure may improve the condition of grazing lands.

scholarly journals Effects of population- and seed bank noise on neutral evolution and efficacy of natural selection

2017 ◽  
Author(s):  
Lukas Heinrich ◽  
Johannes Müller ◽  
Aurélien Tellier ◽  
Daniel Živković
Keyword(s):  
Seed Production ◽  
Genetic Drift ◽  
Seed Bank ◽  
Death Rate ◽  
Seed Banks ◽  
Neutral Evolution ◽  
Plant Fitness ◽  
Below Ground ◽  
Ground Noise ◽  
The Impact

AbstractPopulation genetics models typically consider a fixed population size and a unique selection coefficient. However, population dynamics inherently generate noise in numbers of individuals and selection acts on various components of the individuals’ fitness. In plant species with seed banks, the size of both the above- and below-ground compartments present noise depending on seed production and the state of the seed bank. We investigate if this noise has consequences on 1) the rate of genetic drift, and 2) the efficacy of selection. We consider four variants of two-allele Moran-type models defined by combinations of presence and absence of noise in above-ground and seed bank compartments. Time scale analysis and dimension reduction methods allow us to reduce the corresponding Fokker-Planck equation to a one-dimensional diffusive Moran model. We first show that if the above-ground noise classically affects the rate of genetic drift, below-ground noise reduces the diversity storage effect of the seed bank. Second, we consider that selection can act on four different components of the plant fitness: plant or seed death rate, seed production or seed germination. Our striking result is that the efficacy of selection for seed death rate or germination rate is reduced by seed bank noise, whereas selection occurring on plant death rate or seed production is not affected. We derive the expected site-frequency spectrum reflecting this heterogeneity in selection efficacy between genes underpinning different plant fitness components. Our results highlight the importance to consider the effect of ecological noise to predict the impact of seed banks on neutral and selective evolution.

Teaching Seed Bank Ecology in an Undergraduate Laboratory Exercise

1995 ◽  
Vol 9 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Emilie E. Regnier
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Species Abundance ◽  
Conventional Tillage ◽  
Seed Banks ◽  
Soil Disturbance ◽  
Life Cycles ◽  
Weed Seed ◽  
Laboratory Exercise

The study of weed life cycles, reproductive strategies, and the soil seed bank is emphasized in the undergraduate weed science course at Ohio State University as central to an understanding of the survival of weeds in the environment. A laboratory exercise was conducted every spring and fall academic quarter from 1991 to 1993 to demonstrate the effects of long-term cropping and soil disturbance histories on weed seed banks and aboveground weed communities. Five sites with diverse histories of culture were sampled; these included a field cultivated in vegetables under continuous conventional tillage for 59 yr, a field cultivated in field corn under continuous no-tillage for 11 yr, a 24 yr-old turfgrass research farm, a 70 yr-old forest, and a section of the forest border. Students conducted a survey of the weeds growing at the sites and separated and identified seeds from soil samples over a 3-wk period in weekly 2-h laboratory periods. Students wrote reports interpreting the data based on their knowledge of the site histories, weed life cycles, and weed seed production and longevity characteristics. The data were consistent over academic quarters as well as with published research, indicating that the survey and soil sampling techniques provided a reasonably accurate representation of the weed flora and soil seed populations. Weeds found growing at the sites were primarily summer annuals at the vegetable site, and a mix of summer and winter annuals, biennials, and perennials at the remaining sites. Annual weeds dominated the seed banks of all sites with common lambsquarters, pigweed spp., and common purslane being the most commonly found seeds. The presence of most seeds in the soil could be explained by a combination of species seed production and seed longevity characteristics and species abundance in the standing community. Interpretation of the data required students to integrate and apply lecture material and provided an excellent thinking exercise.

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